Refinements to RestApiCall plugin

Changes includes:
1) Check for null in JsonParser.convertToProperties() which can otherwise result in null pointer exception
2) Use logger built-in string formatting rather then string concatenation
3) Use StringBuilder for multiple string concatenations
4) Making utility classes final and defines private constructor for them
5) Added testcases/testpoints
https://sonar.onap.org/component_issues/index?id=org.onap.ccsdk.sli.plugins%3Accsdk-sli-plugins#resolved=false|severities=CRITICAL

Change-Id: Ic047b6d0369827a38a98c52e8365f1fe7266840f
Issue-Id: CCSDK-67
Signed-off-by: Gaurav Agrawal <gaurav.agrawal@huawei.com>

3 files changed, 21 insertions, 14 deletions

diff --git a/restapi-call-node/provider/src/test/java/jtest/org/onap/ccsdk/sli/plugins/restapicall/TestJsonParser.java b/restapi-call-node/provider/src/test/java/jtest/org/onap/ccsdk/sli/plugins/restapicall/TestJsonParser.java
index dbca5ad7b..5526be81f 100644
--- a/restapi-call-node/provider/src/test/java/jtest/org/onap/ccsdk/sli/plugins/restapicall/TestJsonParser.java
+++ b/restapi-call-node/provider/src/test/java/jtest/org/onap/ccsdk/sli/plugins/restapicall/TestJsonParser.java
@@ -22,6 +22,7 @@
 package jtest.org.onap.ccsdk.sli.plugins.restapicall;
 
 import java.io.BufferedReader;
+import java.io.IOException;
 import java.io.InputStreamReader;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -29,6 +30,7 @@ import java.util.List;
 import java.util.Map;
 
 import org.junit.Test;
+import org.onap.ccsdk.sli.core.sli.SvcLogicException;
 import org.onap.ccsdk.sli.plugins.restapicall.JsonParser;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -38,30 +40,34 @@ public class TestJsonParser {
     private static final Logger log = LoggerFactory.getLogger(TestJsonParser.class);
 
     @Test
-    public void test() throws Exception {
+    public void test() throws SvcLogicException, IOException {
         BufferedReader in = new BufferedReader(
                 new InputStreamReader(ClassLoader.getSystemResourceAsStream("test.json"))
         );
-        String ss = "";
-        String line = null;
+        StringBuilder b = new StringBuilder();
+        String line;
         while ((line = in.readLine()) != null)
-            ss += line + '\n';
+            b.append(line).append('\n');
 
-        Map<String, String> mm = JsonParser.convertToProperties(ss);
+        Map<String, String> mm = JsonParser.convertToProperties(b.toString());
 
         logProperties(mm);
 
         in.close();
     }
 
+    @Test(expected = NullPointerException.class)
+    public void testNullString() throws SvcLogicException {
+        JsonParser.convertToProperties(null);
+    }
+
     private void logProperties(Map<String, String> mm) {
         List<String> ll = new ArrayList<>();
         for (Object o : mm.keySet())
             ll.add((String) o);
         Collections.sort(ll);
-
         log.info("Properties:");
         for (String name : ll)
-            log.info("--- " + name + ": " + mm.get(name));
+            log.info("--- {}: {}", name, mm.get(name));
     }
 }
diff --git a/restapi-call-node/provider/src/test/java/jtest/org/onap/ccsdk/sli/plugins/restapicall/TestXmlParser.java b/restapi-call-node/provider/src/test/java/jtest/org/onap/ccsdk/sli/plugins/restapicall/TestXmlParser.java
index 544d259e0..e8567d591 100644
--- a/restapi-call-node/provider/src/test/java/jtest/org/onap/ccsdk/sli/plugins/restapicall/TestXmlParser.java
+++ b/restapi-call-node/provider/src/test/java/jtest/org/onap/ccsdk/sli/plugins/restapicall/TestXmlParser.java
@@ -44,10 +44,10 @@ public class TestXmlParser {
         BufferedReader in = new BufferedReader(
                 new InputStreamReader(ClassLoader.getSystemResourceAsStream("test3.xml"))
         );
-        String ss = "";
-        String line = null;
+        StringBuilder b = new StringBuilder();
+        String line;
         while ((line = in.readLine()) != null)
-            ss += line + '\n';
+            b.append(line).append('\n');
 
         Set<String> listNameList = new HashSet<String>();
         listNameList.add("project.dependencies.dependency");
@@ -57,10 +57,8 @@ public class TestXmlParser {
         listNameList.add("project.build.pluginManagement." +
                         "plugins.plugin.configuration.lifecycleMappingMetadata.pluginExecutions.pluginExecution");
 
-        Map<String, String> mm = XmlParser.convertToProperties(ss, listNameList);
-
+        Map<String, String> mm = XmlParser.convertToProperties(b.toString(), listNameList);
         logProperties(mm);
-
         in.close();
     }
 
diff --git a/restapi-call-node/provider/src/test/resources/test.json b/restapi-call-node/provider/src/test/resources/test.json
index a34f7e2a0..b48eb6b43 100644
--- a/restapi-call-node/provider/src/test/resources/test.json
+++ b/restapi-call-node/provider/src/test/resources/test.json
@@ -27,7 +27,10 @@
             "number-primary-servers": "2",
             "equipment-id": "Server1",
             "server-model": "Unknown",
-            "server-id": "Server1"
+            "server-id": "Server1",
+            "test-node" : {
+                "test-inner-node" : "Test-Value"
+            }
         }
     ],
     "resource-state": {