modify yang-comparator, such as yang compiler plugin, and some java doc. modify some functions of yang-compiler.

Issue-ID: MODELING-680
Change-Id: I37784c6a3511cfffafe0e19bd4ebdb4ba9d9b958
Signed-off-by: frank feng <frank.fengchong@huawei.com>

32 files changed, 203 insertions, 314 deletions

diff --git a/pom.xml b/pom.xml
index 6f2aae0..0ecc534 100644
--- a/pom.xml
+++ b/pom.xml
@@ -13,6 +13,7 @@
     <version>1.0.0-SNAPSHOT</version>
     <modules>
         <module>yang-compiler</module>
+        <module>yang-comparator</module>
     </modules>
     <packaging>pom</packaging>
     <name>yangkit</name>
diff --git a/yang-comparator/pom.xml b/yang-comparator/pom.xml
index 094b6ea..cac954e 100644
--- a/yang-comparator/pom.xml
+++ b/yang-comparator/pom.xml
@@ -63,9 +63,9 @@
             <version>1.3.5</version>
         </dependency>
         <dependency>
-            <groupId>io.github.yang-central.yangkit</groupId>
+            <groupId>org.onap.modeling.yangkit</groupId>
             <artifactId>yang-compiler</artifactId>
-            <version>1.3.1</version>
+            <version>1.0.0-SNAPSHOT</version>
         </dependency>
         <dependency>
             <groupId>org.dom4j</groupId>
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/AugmentComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/AugmentComparator.java
index 44fd21b..1870586 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/AugmentComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/AugmentComparator.java
@@ -24,10 +24,10 @@ import org.yangcentral.yangkit.model.api.stmt.Augment;
 public class AugmentComparator extends SchemaNodeComparator<Augment> {
 
     /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @return
+     * compare the left and right statement.
+     * @param left  left statement
+     * @param right right statement
+     * @return list of compare result
      */
     @Override
     public List<YangCompareResult> compare(Augment left, Augment right) {
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/BaseComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/BaseComparator.java
index d362fdd..bbb6fd7 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/BaseComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/BaseComparator.java
@@ -24,11 +24,11 @@ import org.yangcentral.yangkit.model.api.stmt.Type;
 public class BaseComparator extends CommonYangStatementComparator<Base> {
 
     /**
-     *
+     * get the default compatibility from left and right base statements.
      * @param left       left statement
      * @param right      right statement
-     * @param changeInfo
-     * @return
+     * @param changeInfo the change information
+     * @return default compatibility information
      */
     @Override
     protected CompatibilityInfo defaultCompatibility(Base left, Base right,
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ChangeType.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ChangeType.java
index 6f7f818..cc04039 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ChangeType.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ChangeType.java
@@ -25,16 +25,16 @@ public enum ChangeType {
     private String description;
 
     /**
-     *
-     * @param description
+     * the constructor (private).
+     * @param description description
      */
     private ChangeType(String description) {
         this.description = description;
     }
 
     /**
-     *
-     * @return
+     * get the name.
+     * @return the name
      */
     public String getName() {
         return this.description;
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/CommonYangStatementComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/CommonYangStatementComparator.java
index 8be269e..77be97b 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/CommonYangStatementComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/CommonYangStatementComparator.java
@@ -36,10 +36,10 @@ public class CommonYangStatementComparator<T extends YangStatement> extends Abst
     public static final int OPTION_ALL = 3;
 
     /**
-     *
+     * get then change information between left and right statements.
      * @param left       left statement
      * @param right      right statement
-     * @return
+     * @return the change information
      */
     @Override
     protected List<CompatibilityRule.ChangeInfo> getChangeInfo(T left, T right) {
@@ -65,11 +65,7 @@ public class CommonYangStatementComparator<T extends YangStatement> extends Abst
         return changeInfos;
     }
 
-    /**
-     *
-     * @param stmt
-     * @return
-     */
+
     private int getIndex(T stmt) {
         YangStatement parentStmt = stmt.getParentStatement();
         if (null == parentStmt) {
@@ -89,9 +85,9 @@ public class CommonYangStatementComparator<T extends YangStatement> extends Abst
     }
 
     /**
-     *
-     * @param changeInfo
-     * @return
+     * get the change type from change information.
+     * @param changeInfo change information
+     * @return change type
      */
     protected ChangeType getChangeType(CompatibilityRule.ChangeInfo changeInfo) {
         switch (changeInfo) {
@@ -110,11 +106,11 @@ public class CommonYangStatementComparator<T extends YangStatement> extends Abst
 
 
     /**
-     *
+     * get the default compatibility.
      * @param left       left statement
      * @param right      right statement
-     * @param changeInfo
-     * @return
+     * @param changeInfo change information
+     * @return default compatibility
      */
     @Override
     protected CompatibilityInfo defaultCompatibility(T left, T right, CompatibilityRule.ChangeInfo changeInfo) {
@@ -147,10 +143,10 @@ public class CommonYangStatementComparator<T extends YangStatement> extends Abst
     }
 
     /**
-     *
+     * compare the children of left and right statements.
      * @param left       left statement
      * @param right      right statement
-     * @return
+     * @return list of compare result
      */
     protected List<YangCompareResult> compareChildren(T left, T right) {
         List<YangCompareResult> compareResults =
@@ -160,10 +156,10 @@ public class CommonYangStatementComparator<T extends YangStatement> extends Abst
     }
 
     /**
-     *
+     * compare the left and right statements.
      * @param left       left statement
      * @param right      right statement
-     * @return
+     * @return list compare result
      */
     @Override
     public List<YangCompareResult> compare(T left, T right) {
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/CompatibilityRules.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/CompatibilityRules.java
index cbab987..c7b3d6f 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/CompatibilityRules.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/CompatibilityRules.java
@@ -91,12 +91,7 @@ public class CompatibilityRules {
         }
     }
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @return
-     */
+
     private boolean matchCondition(CompatibilityRule left, CompatibilityRule.ChangeInfo right) {
         if (left.getCondition() == CompatibilityRule.ChangeInfo.ANY) {
             return true;
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ConfigComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ConfigComparator.java
index a0018d7..496978e 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ConfigComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ConfigComparator.java
@@ -26,10 +26,10 @@ import org.yangcentral.yangkit.model.api.stmt.SchemaNode;
 
 public class ConfigComparator extends CommonYangStatementComparator<Config> {
     /**
-     *
+     * get the change information.
      * @param left       left statement
      * @param right      right statement
-     * @return
+     * @return list of change information
      */
     @Override
     protected List<CompatibilityRule.ChangeInfo> getChangeInfo(Config left, Config right) {
@@ -60,11 +60,11 @@ public class ConfigComparator extends CommonYangStatementComparator<Config> {
     }
 
     /**
-     *
+     * get the default compatibility.
      * @param left       left statement
      * @param right      right statement
-     * @param changeInfo
-     * @return
+     * @param changeInfo change information
+     * @return  default compatibility
      */
     @Override
     protected CompatibilityInfo defaultCompatibility(Config left, Config right,
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/DefaultComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/DefaultComparator.java
index f7b1c13..f47ac5c 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/DefaultComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/DefaultComparator.java
@@ -22,11 +22,11 @@ import org.yangcentral.yangkit.model.api.stmt.Default;
 public class DefaultComparator extends CommonYangStatementComparator<Default> {
 
     /**
-     *
+     * get default compatibility.
      * @param left       left statement
      * @param right      right statement
-     * @param changeInfo
-     * @return
+     * @param changeInfo change information.
+     * @return default compatibility
      */
     @Override
     protected CompatibilityInfo defaultCompatibility(Default left, Default right,
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/DescriptionComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/DescriptionComparator.java
index 2b5db1c..ea7b7a3 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/DescriptionComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/DescriptionComparator.java
@@ -22,11 +22,11 @@ import org.yangcentral.yangkit.model.api.stmt.Description;
 public class DescriptionComparator extends CommonYangStatementComparator<Description> {
 
     /**
-     *
+     * get default compatibility.
      * @param left       left statement
      * @param right      right statement
-     * @param changeInfo
-     * @return
+     * @param changeInfo change information.
+     * @return default compatibility
      */
     @Override
     protected CompatibilityInfo defaultCompatibility(Description left, Description right,
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/EnumBitComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/EnumBitComparator.java
index e0fb3ef..30792b4 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/EnumBitComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/EnumBitComparator.java
@@ -22,11 +22,11 @@ import org.yangcentral.yangkit.model.api.stmt.YangStatement;
 public class EnumBitComparator extends CommonYangStatementComparator {
 
     /**
-     *
+     * get default compatibility.
      * @param left       left statement
      * @param right      right statement
-     * @param changeInfo
-     * @return
+     * @param changeInfo change information.
+     * @return default compatibility
      */
     @Override
     protected CompatibilityInfo defaultCompatibility(YangStatement left, YangStatement right,
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/IdentifierComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/IdentifierComparator.java
index 3eff979..6a6aa4e 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/IdentifierComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/IdentifierComparator.java
@@ -22,11 +22,11 @@ import org.yangcentral.yangkit.model.api.stmt.YangStatement;
 public class IdentifierComparator extends CommonYangStatementComparator {
 
     /**
-     *
+     * get default compatibility.
      * @param left       left statement
      * @param right      right statement
-     * @param changeInfo
-     * @return
+     * @param changeInfo change information.
+     * @return default compatibility
      */
     @Override
     protected CompatibilityInfo defaultCompatibility(YangStatement left, YangStatement right,
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/IfFeatureComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/IfFeatureComparator.java
index dfa0199..b4e770f 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/IfFeatureComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/IfFeatureComparator.java
@@ -21,11 +21,11 @@ import org.yangcentral.yangkit.model.api.stmt.IfFeature;
 
 public class IfFeatureComparator extends CommonYangStatementComparator<IfFeature> {
     /**
-     *
+     * get default compatibility.
      * @param left       left statement
      * @param right      right statement
-     * @param changeInfo
-     * @return
+     * @param changeInfo change information.
+     * @return default compatibility
      */
     @Override
     protected CompatibilityInfo defaultCompatibility(IfFeature left, IfFeature right,
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/MandatoryComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/MandatoryComparator.java
index 375d69b..6e5cb43 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/MandatoryComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/MandatoryComparator.java
@@ -24,10 +24,10 @@ import org.yangcentral.yangkit.model.api.stmt.Mandatory;
 public class MandatoryComparator extends CommonYangStatementComparator<Mandatory> {
 
     /**
-     *
+     * get the change information.
      * @param left       left statement
      * @param right      right statement
-     * @return
+     * @return list of change information
      */
     @Override
     protected List<CompatibilityRule.ChangeInfo> getChangeInfo(Mandatory left, Mandatory right) {
@@ -45,11 +45,11 @@ public class MandatoryComparator extends CommonYangStatementComparator<Mandatory
     }
 
     /**
-     *
+     * get default compatibility.
      * @param left       left statement
      * @param right      right statement
-     * @param changeInfo
-     * @return
+     * @param changeInfo change information.
+     * @return default compatibility
      */
     @Override
     protected CompatibilityInfo defaultCompatibility(Mandatory left, Mandatory right,
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/MaxElementsComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/MaxElementsComparator.java
index 1361ef2..e71b3f5 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/MaxElementsComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/MaxElementsComparator.java
@@ -25,10 +25,10 @@ import org.yangcentral.yangkit.model.api.stmt.MaxElements;
 public class MaxElementsComparator extends CommonYangStatementComparator<MaxElements> {
 
     /**
-     *
+     * get the change information.
      * @param left       left statement
      * @param right      right statement
-     * @return
+     * @return list of change information
      */
     @Override
     protected List<CompatibilityRule.ChangeInfo> getChangeInfo(MaxElements left, MaxElements right) {
@@ -51,11 +51,11 @@ public class MaxElementsComparator extends CommonYangStatementComparator<MaxElem
     }
 
     /**
-     *
+     * get default compatibility.
      * @param left       left statement
      * @param right      right statement
-     * @param changeInfo
-     * @return
+     * @param changeInfo change information.
+     * @return default compatibility
      */
     @Override
     protected CompatibilityInfo defaultCompatibility(MaxElements left, MaxElements right,
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/MinElementsComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/MinElementsComparator.java
index f97e313..4e8c133 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/MinElementsComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/MinElementsComparator.java
@@ -24,12 +24,7 @@ import org.yangcentral.yangkit.model.api.stmt.MinElements;
 
 public class MinElementsComparator extends CommonYangStatementComparator<MinElements> {
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @return
-     */
+
     @Override
     protected List<CompatibilityRule.ChangeInfo> getChangeInfo(MinElements left, MinElements right) {
         List<CompatibilityRule.ChangeInfo> changeInfos = new ArrayList<>();
@@ -44,13 +39,7 @@ public class MinElementsComparator extends CommonYangStatementComparator<MinElem
         return changeInfos;
     }
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @param changeInfo
-     * @return
-     */
+
     @Override
     protected CompatibilityInfo defaultCompatibility(MinElements left, MinElements right,
                                                      CompatibilityRule.ChangeInfo changeInfo) {
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ModuleComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ModuleComparator.java
index 9c9bb7f..574dff7 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ModuleComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ModuleComparator.java
@@ -25,24 +25,13 @@ import org.yangcentral.yangkit.model.api.stmt.Module;
 
 public class ModuleComparator extends CommonYangStatementComparator<Module> {
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @return
-     */
+
     @Override
     protected List<CompatibilityRule.ChangeInfo> getChangeInfo(Module left, Module right) {
         return super.getChangeInfo(left, right);
     }
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @param changeInfo
-     * @return
-     */
+
     @Override
     protected CompatibilityInfo defaultCompatibility(Module left, Module right,
                                                      CompatibilityRule.ChangeInfo changeInfo) {
@@ -54,12 +43,7 @@ public class ModuleComparator extends CommonYangStatementComparator<Module> {
         return super.defaultCompatibility(left, right, changeInfo);
     }
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @return
-     */
+
     @Override
     protected List<YangCompareResult> compareChildren(Module left, Module right) {
         List<YangCompareResult> results = new ArrayList<>();
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/NamespaceComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/NamespaceComparator.java
index 8ea9953..565cf6d 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/NamespaceComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/NamespaceComparator.java
@@ -21,13 +21,7 @@ import org.yangcentral.yangkit.model.api.stmt.Namespace;
 
 public class NamespaceComparator extends CommonYangStatementComparator<Namespace> {
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @param changeInfo
-     * @return
-     */
+
     @Override
     protected CompatibilityInfo defaultCompatibility(Namespace left, Namespace right,
                                                      CompatibilityRule.ChangeInfo changeInfo) {
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/OperationComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/OperationComparator.java
index 58cde02..6ae9aee 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/OperationComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/OperationComparator.java
@@ -28,11 +28,6 @@ import org.yangcentral.yangkit.model.api.stmt.YangStatement;
 
 public class OperationComparator extends SchemaNodeComparator<Operation> {
 
-    /**
-     *
-     * @param schemaNodeContainer
-     * @return
-     */
     private boolean hasActiveSchemaChildren(SchemaNodeContainer schemaNodeContainer) {
         for (SchemaNode schemaNode : schemaNodeContainer.getSchemaNodeChildren()) {
             if (schemaNode.isActive()) {
@@ -42,12 +37,7 @@ public class OperationComparator extends SchemaNodeComparator<Operation> {
         return false;
     }
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @return
-     */
+
     @Override
     protected List<YangCompareResult> compareChildren(Operation left, Operation right) {
         List<YangCompareResult> compareResults = new ArrayList<>();
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/PatternComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/PatternComparator.java
index 83f3f9b..f373a09 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/PatternComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/PatternComparator.java
@@ -21,13 +21,7 @@ import org.yangcentral.yangkit.model.api.stmt.type.Pattern;
 
 public class PatternComparator extends CommonYangStatementComparator<Pattern> {
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @param changeInfo
-     * @return
-     */
+
     @Override
     protected CompatibilityInfo defaultCompatibility(Pattern left, Pattern right,
                                                      CompatibilityRule.ChangeInfo changeInfo) {
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/RangeLengthComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/RangeLengthComparator.java
index 076b7bf..ea4ef6c 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/RangeLengthComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/RangeLengthComparator.java
@@ -24,12 +24,7 @@ import org.yangcentral.yangkit.model.api.stmt.type.SectionExpression;
 
 public class RangeLengthComparator extends CommonYangStatementComparator<SectionExpression> {
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @return
-     */
+
     @Override
     protected List<CompatibilityRule.ChangeInfo> getChangeInfo(SectionExpression left, SectionExpression right) {
         List<CompatibilityRule.ChangeInfo> changeInfos = new ArrayList<>();
@@ -48,13 +43,7 @@ public class RangeLengthComparator extends CommonYangStatementComparator<Section
         return changeInfos;
     }
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @param changeInfo
-     * @return
-     */
+
     @Override
     protected CompatibilityInfo defaultCompatibility(SectionExpression left, SectionExpression right,
                                                      CompatibilityRule.ChangeInfo changeInfo) {
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ReferenceComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ReferenceComparator.java
index be50fa1..59026c0 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ReferenceComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ReferenceComparator.java
@@ -21,13 +21,6 @@ import org.yangcentral.yangkit.model.api.stmt.Reference;
 
 public class ReferenceComparator extends CommonYangStatementComparator<Reference> {
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @param changeInfo
-     * @return
-     */
     @Override
     protected CompatibilityInfo defaultCompatibility(Reference left, Reference right,
                                                      CompatibilityRule.ChangeInfo changeInfo) {
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/SchemaNodeComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/SchemaNodeComparator.java
index ff6de53..3439b7f 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/SchemaNodeComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/SchemaNodeComparator.java
@@ -25,12 +25,7 @@ import org.yangcentral.yangkit.model.api.stmt.SchemaNodeContainer;
 
 
 public class SchemaNodeComparator<T extends SchemaNode> extends CommonYangStatementComparator<T> {
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @return
-     */
+
     @Override
     protected List<CompatibilityRule.ChangeInfo> getChangeInfo(T left, T right) {
         List<CompatibilityRule.ChangeInfo> changeInfos = new ArrayList<>();
@@ -48,13 +43,6 @@ public class SchemaNodeComparator<T extends SchemaNode> extends CommonYangStatem
         return changeInfos;
     }
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @param changeInfo
-     * @return
-     */
     @Override
     protected CompatibilityInfo defaultCompatibility(T left, T right,
                                                      CompatibilityRule.ChangeInfo changeInfo) {
@@ -66,12 +54,7 @@ public class SchemaNodeComparator<T extends SchemaNode> extends CommonYangStatem
     }
 
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @return
-     */
+
     @Override
     protected List<YangCompareResult> compareChildren(T left, T right) {
         List<YangCompareResult> results = new ArrayList<>();
@@ -92,12 +75,7 @@ public class SchemaNodeComparator<T extends SchemaNode> extends CommonYangStatem
         return results;
     }
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @return
-     */
+
     @Override
     public List<YangCompareResult> compare(T left, T right) {
         List<YangCompareResult> compareResults = new ArrayList<>();
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/StatusComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/StatusComparator.java
index 8a6df4d..ff92321 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/StatusComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/StatusComparator.java
@@ -26,12 +26,6 @@ import org.yangcentral.yangkit.model.api.stmt.StatusStmt;
 
 public class StatusComparator extends CommonYangStatementComparator<StatusStmt> {
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @return
-     */
     @Override
     protected List<CompatibilityRule.ChangeInfo> getChangeInfo(StatusStmt left, StatusStmt right) {
         List<CompatibilityRule.ChangeInfo> changeInfos = new ArrayList<>();
@@ -52,13 +46,7 @@ public class StatusComparator extends CommonYangStatementComparator<StatusStmt>
     }
 
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @param changeInfo
-     * @return
-     */
+
     @Override
     protected CompatibilityInfo defaultCompatibility(StatusStmt left, StatusStmt right,
                                                      CompatibilityRule.ChangeInfo changeInfo) {
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/UniqueComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/UniqueComparator.java
index 1611818..be53a75 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/UniqueComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/UniqueComparator.java
@@ -25,12 +25,7 @@ import org.yangcentral.yangkit.model.api.stmt.YangStatement;
 
 public class UniqueComparator extends CommonYangStatementComparator<Unique> {
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @return
-     */
+
     @Override
     protected List<CompatibilityRule.ChangeInfo> getChangeInfo(Unique left, Unique right) {
         List<CompatibilityRule.ChangeInfo> changeInfos = new ArrayList<>();
@@ -85,13 +80,7 @@ public class UniqueComparator extends CommonYangStatementComparator<Unique> {
         return changeInfos;
     }
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @param changeInfo
-     * @return
-     */
+
     @Override
     protected CompatibilityInfo defaultCompatibility(Unique left, Unique right,
                                                      CompatibilityRule.ChangeInfo changeInfo) {
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/UnitsComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/UnitsComparator.java
index f484af2..a7f7045 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/UnitsComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/UnitsComparator.java
@@ -21,13 +21,7 @@ import org.yangcentral.yangkit.model.api.stmt.Units;
 
 public class UnitsComparator extends CommonYangStatementComparator<Units> {
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @param changeInfo
-     * @return
-     */
+
     @Override
     protected CompatibilityInfo defaultCompatibility(Units left, Units right,
                                                      CompatibilityRule.ChangeInfo changeInfo) {
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ValuePositionComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ValuePositionComparator.java
index c680dea..f27f5db 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ValuePositionComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/ValuePositionComparator.java
@@ -20,13 +20,7 @@ import org.yangcentral.yangkit.model.api.stmt.YangStatement;
 
 
 public class ValuePositionComparator extends CommonYangStatementComparator {
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @param changeInfo
-     * @return
-     */
+
     @Override
     protected CompatibilityInfo defaultCompatibility(YangStatement left, YangStatement right,
                                                      CompatibilityRule.ChangeInfo changeInfo) {
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/WhenMustComparator.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/WhenMustComparator.java
index 3825a74..a933ccc 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/WhenMustComparator.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/WhenMustComparator.java
@@ -20,13 +20,7 @@ import org.yangcentral.yangkit.model.api.stmt.YangStatement;
 
 public class WhenMustComparator extends CommonYangStatementComparator {
 
-    /**
-     *
-     * @param left       left statement
-     * @param right      right statement
-     * @param changeInfo
-     * @return
-     */
+
     @Override
     protected CompatibilityInfo defaultCompatibility(YangStatement left, YangStatement right,
                                                      CompatibilityRule.ChangeInfo changeInfo) {
diff --git a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/app/YangComparatorPlugin.java b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/app/YangComparatorPlugin.java
index 8b513cc..a46b97d 100644
--- a/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/app/YangComparatorPlugin.java
+++ b/yang-comparator/src/main/java/org/onap/modeling/yangkit/comparator/app/YangComparatorPlugin.java
@@ -16,26 +16,28 @@ limitations under the License.
 
 package org.onap.modeling.yangkit.comparator.app;
 
-import java.io.File;
+import com.google.gson.JsonElement;
+
 import java.io.IOException;
-import java.util.Iterator;
 import java.util.List;
-import java.util.Map;
-import java.util.Properties;
 
 import org.dom4j.Document;
 import org.dom4j.DocumentException;
 import org.onap.modeling.yangkit.comparator.CompareType;
 import org.onap.modeling.yangkit.comparator.YangComparator;
 import org.onap.modeling.yangkit.comparator.YangCompareResult;
+import org.onap.modeling.yangkit.compiler.BuildOption;
+import org.onap.modeling.yangkit.compiler.Settings;
+import org.onap.modeling.yangkit.compiler.Source;
+import org.onap.modeling.yangkit.compiler.YangCompiler;
+import org.onap.modeling.yangkit.compiler.YangCompilerException;
+import org.onap.modeling.yangkit.compiler.plugin.YangCompilerPlugin;
+import org.onap.modeling.yangkit.compiler.plugin.YangCompilerPluginParameter;
+import org.onap.modeling.yangkit.compiler.util.YangCompilerUtil;
 import org.yangcentral.yangkit.common.api.validate.ValidatorResult;
 
-import org.yangcentral.yangkit.compiler.Settings;
-import org.yangcentral.yangkit.compiler.YangCompiler;
-import org.yangcentral.yangkit.compiler.YangCompilerException;
+
 import org.yangcentral.yangkit.model.api.schema.YangSchemaContext;
-import org.yangcentral.yangkit.plugin.YangCompilerPlugin;
-import org.yangcentral.yangkit.plugin.YangCompilerPluginParameter;
 import org.yangcentral.yangkit.utils.file.FileUtil;
 import org.yangcentral.yangkit.utils.xml.XmlWriter;
 
@@ -45,65 +47,62 @@ import org.yangcentral.yangkit.utils.xml.XmlWriter;
  */
 public class YangComparatorPlugin implements YangCompilerPlugin {
     @Override
-    public YangCompilerPluginParameter getParameter(Properties properties, String name, String value)
+    public YangCompilerPluginParameter getParameter(String name, JsonElement value)
             throws YangCompilerException {
         if (!name.equals("old-yang") && !name.equals("settings")
                 && !name.equals("compare-type") && !name.equals("rule")
                 && !name.equals("result")) {
             throw new YangCompilerException("unrecognized parameter:" + name);
         }
-        YangCompilerPluginParameter yangCompilerPluginParameter = new YangCompilerPluginParameter() {
-            @Override
-            public String getName() {
-                return name;
-            }
+        if (name.equals("old-yang") || name.equals("compare-type")) {
+            YangCompilerPluginParameter yangCompilerPluginParameter = new YangCompilerPluginParameter() {
+                @Override
+                public String getName() {
+                    return name;
+                }
 
-            @Override
-            public Object getValue() throws YangCompilerException {
-                if (name.equals("old-yang") || name.equals("settings")
-                        || name.equals("rule") || name.equals("result")) {
-                    Iterator<Map.Entry<Object, Object>> it = properties.entrySet().iterator();
-                    String formatStr = value;
-                    while (it.hasNext()) {
-                        Map.Entry<Object, Object> entry = it.next();
-                        formatStr = formatStr.replaceAll("\\{" + entry.getKey() + "\\}", (String) entry.getValue());
+                @Override
+                public Object getValue() throws YangCompilerException {
+                    if (name.equals("old-yang")) {
+                        return BuildOption.parseSources(value);
                     }
-                    return formatStr;
-                }
 
-                if (name.equals("compare-type")) {
-                    if (value.equals("stmt")) {
-                        return CompareType.STMT;
-                    } else if (value.equals("tree")) {
-                        return CompareType.TREE;
-                    } else if (value.equals("compatible-check")) {
-                        return CompareType.COMPATIBLE_CHECK;
+                    if (name.equals("compare-type")) {
+                        if (value.equals("stmt")) {
+                            return CompareType.STMT;
+                        } else if (value.equals("tree")) {
+                            return CompareType.TREE;
+                        } else if (value.equals("compatible-check")) {
+                            return CompareType.COMPATIBLE_CHECK;
+                        }
+                        throw new YangCompilerException("unrecognized value:" + value);
                     }
-                    throw new YangCompilerException("unrecognized value:" + value);
+                    return null;
                 }
-                return null;
-            }
 
-        };
-        return yangCompilerPluginParameter;
+            };
+            return yangCompilerPluginParameter;
+        }
+        return YangCompilerPlugin.super.getParameter(name, value);
+
     }
 
     @Override
     public void run(YangSchemaContext yangSchemaContext, YangCompiler yangCompiler,
                     List<YangCompilerPluginParameter> list) throws YangCompilerException {
         CompareType compareType = null;
-        String oldYangPath = null;
+        List<Source> sources = null;
+        Settings settings = yangCompiler.getSettings();
         String rulePath = null;
         String resultPath = null;
         for (YangCompilerPluginParameter parameter : list) {
             //System.out.println("para name="+parameter.getName() + " para value="+parameter.getValue());
             if (parameter.getName().equals("old-yang")) {
-                oldYangPath = (String) parameter.getValue();
-                yangCompiler.setYang(new File(oldYangPath));
+                sources = (List<Source>) parameter.getValue();
             } else if (parameter.getName().equals("settings")) {
                 String settingsPath = (String) parameter.getValue();
                 try {
-                    yangCompiler.setSettings(Settings.parse(FileUtil.readFile2String(settingsPath)));
+                    settings = Settings.parse(FileUtil.readFile2String(settingsPath));
                 } catch (IOException e) {
                     throw new RuntimeException(e);
                 }
@@ -116,7 +115,7 @@ public class YangComparatorPlugin implements YangCompilerPlugin {
             }
 
         }
-        if (oldYangPath == null) {
+        if (sources == null) {
             throw new YangCompilerException("missing mandatory parameter:old-yang");
         }
         if (compareType == null) {
@@ -125,11 +124,10 @@ public class YangComparatorPlugin implements YangCompilerPlugin {
         if (resultPath == null) {
             throw new YangCompilerException("missing mandatory parameter:result");
         }
-        YangSchemaContext oldSchemaContext = yangCompiler.buildSchemaContext();
+        YangSchemaContext oldSchemaContext = YangCompilerUtil.buildSchemaContext(sources, settings);
         ValidatorResult oldResult = oldSchemaContext.validate();
         if (!oldResult.isOk()) {
-            throw new YangCompilerException("fail to validate the schema context of "
-                    + oldYangPath
+            throw new YangCompilerException("fail to validate the schema context"
                     + ".\n"
                     + oldResult);
         }
diff --git a/yang-compiler/src/main/java/org/onap/modeling/yangkit/compiler/BuildOption.java b/yang-compiler/src/main/java/org/onap/modeling/yangkit/compiler/BuildOption.java
index 328d2a4..0c95e45 100644
--- a/yang-compiler/src/main/java/org/onap/modeling/yangkit/compiler/BuildOption.java
+++ b/yang-compiler/src/main/java/org/onap/modeling/yangkit/compiler/BuildOption.java
@@ -95,6 +95,65 @@ public class BuildOption {
     }
 
     /**
+     * parse the sources.
+     * @param yangElement yang element
+     * @return list of sources
+     */
+    public static List<Source> parseSources(JsonElement yangElement) {
+        List<Source> sources = new ArrayList<>();
+        JsonObject yang = yangElement.getAsJsonObject();
+        JsonElement dirElement = yang.get("dir");
+        if (dirElement != null) {
+            JsonArray dirArray = dirElement.getAsJsonArray();
+            List<JsonElement> dirElementList = dirArray.asList();
+            List<String> dirs = new ArrayList<>();
+            for (JsonElement dirElementItem : dirElementList) {
+                String yangDir = dirElementItem.getAsString();
+                dirs.add(yangDir);
+            }
+            DirectorySource directorySource = new DirectorySource(dirs);
+            sources.add(directorySource);
+        }
+        JsonElement filesElement = yang.get("file");
+        if (filesElement != null) {
+            JsonArray fileArray = filesElement.getAsJsonArray();
+            List<JsonElement> fileElementList = fileArray.asList();
+            List<String> files = new ArrayList<>();
+            for (JsonElement fileElementItem : fileElementList) {
+                String yangFile = fileElementItem.getAsString();
+                files.add(yangFile);
+            }
+            FileSource fileSource = new FileSource(files);
+            sources.add(fileSource);
+        }
+        JsonElement modulesElement = yang.get("module");
+        if (modulesElement != null) {
+            JsonArray moduleArray = modulesElement.getAsJsonArray();
+            List<JsonElement> moduleList = moduleArray.asList();
+            List<ModuleInfo> moduleInfos = new ArrayList<>();
+            for (JsonElement moduleElement : moduleList) {
+                JsonObject moduleObject = moduleElement.getAsJsonObject();
+                String name = moduleObject.get("name").getAsString();
+                String revision = moduleObject.get("revision").getAsString();
+                String organization = null;
+                if (moduleObject.get("organization") != null) {
+                    organization = moduleObject.get("organization").getAsString();
+                }
+                URI schema = null;
+                if (moduleObject.get("schema") != null) {
+                    schema = URI.create(moduleObject.get("schema").getAsString());
+                }
+                ModuleInfo moduleInfo = new ModuleInfo(name, revision, organization);
+                moduleInfo.setSchema(schema);
+                moduleInfos.add(moduleInfo);
+            }
+            ModuleSource moduleSource = new ModuleSource(moduleInfos);
+            sources.add(moduleSource);
+        }
+        return sources;
+    }
+
+    /**
      * parse the build.json.
      *
      * @param jsonElement json element
@@ -106,55 +165,7 @@ public class BuildOption {
 
         JsonElement yangElement = jsonObject.get("yang");
         if (yangElement != null) {
-            JsonObject yang = yangElement.getAsJsonObject();
-            JsonElement dirElement = yang.get("dir");
-            if (dirElement != null) {
-                JsonArray dirArray = dirElement.getAsJsonArray();
-                List<JsonElement> dirElementList = dirArray.asList();
-                List<String> dirs = new ArrayList<>();
-                for (JsonElement dirElementItem : dirElementList) {
-                    String yangDir = dirElementItem.getAsString();
-                    dirs.add(yangDir);
-                }
-                DirectorySource directorySource = new DirectorySource(dirs);
-                buildOption.addSource(directorySource);
-            }
-            JsonElement filesElement = yang.get("file");
-            if (filesElement != null) {
-                JsonArray fileArray = filesElement.getAsJsonArray();
-                List<JsonElement> fileElementList = fileArray.asList();
-                List<String> files = new ArrayList<>();
-                for (JsonElement fileElementItem : fileElementList) {
-                    String yangFile = fileElementItem.getAsString();
-                    files.add(yangFile);
-                }
-                FileSource fileSource = new FileSource(files);
-                buildOption.addSource(fileSource);
-            }
-            JsonElement modulesElement = yang.get("module");
-            if (modulesElement != null) {
-                JsonArray moduleArray = modulesElement.getAsJsonArray();
-                List<JsonElement> moduleList = moduleArray.asList();
-                List<ModuleInfo> moduleInfos = new ArrayList<>();
-                for (JsonElement moduleElement : moduleList) {
-                    JsonObject moduleObject = moduleElement.getAsJsonObject();
-                    String name = moduleObject.get("name").getAsString();
-                    String revision = moduleObject.get("revision").getAsString();
-                    String organization = null;
-                    if (moduleObject.get("organization") != null) {
-                        organization = moduleObject.get("organization").getAsString();
-                    }
-                    URI schema = null;
-                    if (moduleObject.get("schema") != null) {
-                        schema = URI.create(moduleObject.get("schema").getAsString());
-                    }
-                    ModuleInfo moduleInfo = new ModuleInfo(name, revision, organization);
-                    moduleInfo.setSchema(schema);
-                    moduleInfos.add(moduleInfo);
-                }
-                ModuleSource moduleSource = new ModuleSource(moduleInfos);
-                buildOption.addSource(moduleSource);
-            }
+            buildOption.sources = parseSources(yangElement);
         }
         JsonElement settingsElement = jsonObject.get("settings");
         if (settingsElement != null) {
diff --git a/yang-compiler/src/main/java/org/onap/modeling/yangkit/compiler/YangCompiler.java b/yang-compiler/src/main/java/org/onap/modeling/yangkit/compiler/YangCompiler.java
index 87a1c5e..ccbfcbc 100644
--- a/yang-compiler/src/main/java/org/onap/modeling/yangkit/compiler/YangCompiler.java
+++ b/yang-compiler/src/main/java/org/onap/modeling/yangkit/compiler/YangCompiler.java
@@ -126,10 +126,7 @@ public class YangCompiler {
     public YangSchemaContext buildSchemaContext() {

         YangSchemaContext schemaContext = null;

         try {

-            List<Source> sources = buildOption.getSources();

-            for (Source source : sources) {

-                schemaContext = source.buildSource(settings, schemaContext, true);

-            }

+            schemaContext = YangCompilerUtil.buildSchemaContext(buildOption.getSources(),getSettings());

 

             return schemaContext;

         } catch (YangCompilerException e) {

diff --git a/yang-compiler/src/main/java/org/onap/modeling/yangkit/compiler/util/YangCompilerUtil.java b/yang-compiler/src/main/java/org/onap/modeling/yangkit/compiler/util/YangCompilerUtil.java
index 19a63bd..0f9c99f 100644
--- a/yang-compiler/src/main/java/org/onap/modeling/yangkit/compiler/util/YangCompilerUtil.java
+++ b/yang-compiler/src/main/java/org/onap/modeling/yangkit/compiler/util/YangCompilerUtil.java
@@ -46,11 +46,14 @@ import javax.net.ssl.X509TrustManager;
 import org.onap.modeling.yangkit.catalog.ModuleInfo;
 import org.onap.modeling.yangkit.catalog.YangCatalog;
 import org.onap.modeling.yangkit.compiler.Settings;
+import org.onap.modeling.yangkit.compiler.Source;
+import org.onap.modeling.yangkit.compiler.YangCompilerException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.yangcentral.yangkit.base.YangBuiltinKeyword;
 
 
+import org.yangcentral.yangkit.model.api.schema.YangSchemaContext;
 import org.yangcentral.yangkit.model.api.stmt.Module;
 import org.yangcentral.yangkit.model.api.stmt.SubModule;
 import org.yangcentral.yangkit.model.api.stmt.YangStatement;
@@ -438,4 +441,22 @@ public class YangCompilerUtil {
         }
         return dependencies;
     }
+
+    /**
+     * build schema context from sources and settings.
+     * @param sources yang sources
+     * @param settings settings
+     * @return yang schema context
+     * @throws YangCompilerException yang compiler exception
+     */
+    public static YangSchemaContext buildSchemaContext(List<Source> sources, Settings settings)
+            throws YangCompilerException {
+        YangSchemaContext schemaContext = null;
+
+        for (Source source : sources) {
+            schemaContext = source.buildSource(settings, schemaContext, true);
+        }
+        return schemaContext;
+
+    }
 }