ClassHierarchy toJson Function

core/src/main/java/com/ibm/wala/ipa/cha/ClassHierarchy.java

@@ -10,6 +10,7 @@
  */
 package com.ibm.wala.ipa.cha;
 
+import com.google.gson.Gson;
 import com.ibm.wala.classLoader.ArrayClass;
 import com.ibm.wala.classLoader.BytecodeClass;
 import com.ibm.wala.classLoader.ClassLoaderFactory;
@@ -706,6 +707,86 @@ private void recursiveStringify(Node n, StringBuilder buffer) {
     }
   }
 
+  /*
+   * Puts ClassHierarchy into a JSON readable variable that maps the class to a list of its
+   * subclasses
+   */
+  public String toJson() {
+    // initialize variables (subclass and dag) to store important values like hashmap of each
+    // iteration and a list of all maps of class to subclasses
+    HashMap<String, Set<String>> subclass = new HashMap<>();
+    Iterator<Node> children = root.getChildren();
+    // Goes through all subclasses of the root class, and adds the subclass hashmap to the
+    // list of all subclass hashmaps
+    while (children.hasNext()) {
+      helperToJson(children.next(), subclass);
+    }
+    // Removes unnecesarry parts from name of the class
+    String key = nodeToString(root);
+    // inserting the root class to its subclasses into the main hashmap while removing
+    // unnecessary substrings from the class name
+    Iterator<Node> rootChildren = root.getChildren();
+    Set<String> finalRootChildren = new HashSet<>();
+    while (rootChildren.hasNext()) {
+      finalRootChildren.add(nodeToString(rootChildren.next()));
+    }
+    subclass.put(key, finalRootChildren);
+    Gson gson = new Gson();
+    return gson.toJson(subclass);
+  }
+
+  /*
+   * helper function to toJson that performs recursion to go through all of the DAG
+   */
+  private void helperToJson(Node n, HashMap<String, Set<String>> hash) {
+    if (n.children.size() > 0) {
+      // while loop: defines iterator to go through the class's subclasses
+      Iterator<Node> children = n.getChildren();
+      while (children.hasNext()) {
+        // puts subclass variable into temp, and start recursion from that subclass
+        // until base case reaches
+        Node temp = children.next();
+        helperToJson(temp, hash);
+        // remove unnecessary substrings from class name
+        String key = nodeToString(temp);
+        // if statement: only adds the map from class to subclass if class name does
+        // not exist in the overall hashmap
+        if (!hash.containsKey(key)) {
+          // Iterates through the subclass list and removes unnecessary substrings from
+          // class name --> adds that new value into varibale, root, containig all it's subclasses
+          Iterator<Node> val = temp.getChildren();
+          Set<String> root = new HashSet<>();
+          while (val.hasNext()) {
+            Node tempVal = val.next();
+            String newVal = nodeToString(tempVal);
+            root.add(newVal);
+          }
+          // insert into hashmap containing all class to subclass pairs
+          hash.put(key, root);
+        }
+      }
+    } else {
+      // remove unnecessary substring from class name and map that to an empty
+      // list to add into the hashmap
+      String key = nodeToString(n);
+      if (!hash.containsKey(key)) {
+        Set<String> root = new HashSet<>();
+        hash.put(key, root);
+      }
+    }
+  }
+
+  /*
+   * Removed unnecessary part of Node by turning it into a String (Made for toJson and helperToJson)
+   */
+  private String nodeToString(Node n) {
+    String key = n.getJavaClass().toString();
+    key = key.replace("<Primordial,", "");
+    key = key.replace("<Application,", "");
+    key = key.replace(">", "");
+    return key;
+  }
+
   /**
    * Number the class hierarchy tree to support efficient subclass tests. After numbering the tree,
    * n1 is a child of n2 iff n2.left &lt;= n1.left ^ n1.left &lt;= n2.right. Described as "relative

core/src/test/java/com/ibm/wala/core/tests/callGraph/ClassConstantTest.java

@@ -79,4 +79,14 @@ public void testClassConstants()
     // make sure call to hashCode from main
     assertTrue(cg.hasEdge(mainMethodNode, hashCodeNodes.iterator().next()));
   }
+
+  @Test
+  public void classHierarchyToJson() throws ClassHierarchyException, IOException {
+    AnalysisScope scope =
+        CallGraphTestUtil.makeJ2SEAnalysisScope(
+            TestConstants.WALA_TESTDATA, CallGraphTestUtil.REGRESSION_EXCLUSIONS);
+    ClassHierarchy cha = ClassHierarchyFactory.make(scope);
+    Object unused = cha.toJson();
+    // assertEquals("", json);
+  }
 }