Add pretty() method to Coder

"Pretty" JSON is often needed, so added Coder.pretty() to facilitate
that.
Incorporated review comment(s):
- changed pretty() to encode(object, pretty)

Issue-ID: POLICY-1625
Signed-off-by: Jim Hahn <jrh3@att.com>
Change-Id: I180fa6de416836008bf1c410132ae30f4dde9271

4 files changed, 67 insertions, 8 deletions

diff --git a/utils/src/main/java/org/onap/policy/common/utils/coder/Coder.java b/utils/src/main/java/org/onap/policy/common/utils/coder/Coder.java
index bb51f2b9..ec0e5e42 100644
--- a/utils/src/main/java/org/onap/policy/common/utils/coder/Coder.java
+++ b/utils/src/main/java/org/onap/policy/common/utils/coder/Coder.java
@@ -1,8 +1,8 @@
 /*
  * ============LICENSE_START=======================================================
- * ONAP PAP
+ * ONAP
  * ================================================================================
- * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved.
+ * Copyright (C) 2019-2020 AT&T Intellectual Property. All rights reserved.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -41,6 +41,16 @@ public interface Coder {
     String encode(Object object) throws CoderException;
 
     /**
+     * Encodes an object into json, optionally making it "pretty".
+     *
+     * @param object object to be encoded
+     * @param pretty {@code true} if it should be encoded as "pretty" json, {@code false} otherwise
+     * @return a json string representing the object
+     * @throws CoderException if an error occurs
+     */
+    String encode(Object object, boolean pretty) throws CoderException;
+
+    /**
      * Encodes an object into json, writing to the given target.
      *
      * @param target target to which to write the encoded json
diff --git a/utils/src/main/java/org/onap/policy/common/utils/coder/StandardCoder.java b/utils/src/main/java/org/onap/policy/common/utils/coder/StandardCoder.java
index 6d0cbc9d..13973f1c 100644
--- a/utils/src/main/java/org/onap/policy/common/utils/coder/StandardCoder.java
+++ b/utils/src/main/java/org/onap/policy/common/utils/coder/StandardCoder.java
@@ -54,9 +54,21 @@ public class StandardCoder implements Coder {
      * Gson object used to encode and decode messages.
      */
     @Getter(AccessLevel.PROTECTED)
-    private static final Gson GSON = GsonMessageBodyHandler.configBuilder(
-                    new GsonBuilder().registerTypeAdapter(StandardCoderObject.class, new StandardTypeAdapter()))
-                    .create();
+    private static final Gson GSON;
+
+    /**
+     * Gson object used to encode messages in "pretty" format.
+     */
+    @Getter(AccessLevel.PROTECTED)
+    private static final Gson GSON_PRETTY;
+
+    static {
+        GsonBuilder builder = GsonMessageBodyHandler.configBuilder(
+                        new GsonBuilder().registerTypeAdapter(StandardCoderObject.class, new StandardTypeAdapter()));
+
+        GSON = builder.create();
+        GSON_PRETTY = builder.setPrettyPrinting().create();
+    }
 
     /**
      * Constructs the object.
@@ -67,8 +79,18 @@ public class StandardCoder implements Coder {
 
     @Override
     public String encode(Object object) throws CoderException {
+        return encode(object, false);
+    }
+
+    @Override
+    public String encode(Object object, boolean pretty) throws CoderException {
         try {
-            return toJson(object);
+            if (pretty) {
+                return toPrettyJson(object);
+
+            } else {
+                return toJson(object);
+            }
 
         } catch (RuntimeException e) {
             throw new CoderException(e);
@@ -151,6 +173,16 @@ public class StandardCoder implements Coder {
         }
     }
 
+    /**
+     * Encodes the object as "pretty" json.
+     *
+     * @param object object to be encoded
+     * @return the encoded object
+     */
+    protected String toPrettyJson(Object object) {
+        return GSON_PRETTY.toJson(object);
+    }
+
     @Override
     public StandardCoderObject toStandard(Object object) throws CoderException {
         try {
diff --git a/utils/src/main/java/org/onap/policy/common/utils/coder/StandardValCoder.java b/utils/src/main/java/org/onap/policy/common/utils/coder/StandardValCoder.java
index 378254b8..6e08e722 100644
--- a/utils/src/main/java/org/onap/policy/common/utils/coder/StandardValCoder.java
+++ b/utils/src/main/java/org/onap/policy/common/utils/coder/StandardValCoder.java
@@ -62,10 +62,21 @@ public class StandardValCoder extends StandardCoder {
     }
 
     @Override
+    protected String toPrettyJson(Object object) {
+        /*
+         * The validator strips off the "pretty" stuff (i.e., spaces), thus we have to validate
+         * and generate the pretty JSON in separate steps.
+         */
+        getGSON().toJson(object, object.getClass(), validatorApi.createJsonWriter(validator, new StringWriter()));
+
+        return super.toPrettyJson(object);
+    }
+
+    @Override
     protected String toJson(@NonNull Object object) {
         StringWriter output = new StringWriter();
         toJson(output, object);
-        return String.valueOf(output);
+        return output.toString();
     }
 
     @Override
diff --git a/utils/src/main/java/org/onap/policy/common/utils/coder/StandardYamlCoder.java b/utils/src/main/java/org/onap/policy/common/utils/coder/StandardYamlCoder.java
index 36f15b96..1bcf6ac0 100644
--- a/utils/src/main/java/org/onap/policy/common/utils/coder/StandardYamlCoder.java
+++ b/utils/src/main/java/org/onap/policy/common/utils/coder/StandardYamlCoder.java
@@ -2,7 +2,7 @@
  * ============LICENSE_START=======================================================
  * ONAP
  * ================================================================================
- * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved.
+ * Copyright (C) 2019-2020 AT&T Intellectual Property. All rights reserved.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -38,6 +38,12 @@ public class StandardYamlCoder extends StandardCoder {
     }
 
     @Override
+    protected String toPrettyJson(Object object) {
+        // YAML is already "pretty"
+        return toJson(object);
+    }
+
+    @Override
     protected String toJson(Object object) {
         return translator.toYaml(object);
     }