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;
@@ -24,6 +25,7 @@
 import com.ibm.wala.core.util.ref.CacheReference;
 import com.ibm.wala.core.util.ref.ReferenceCleanser;
 import com.ibm.wala.core.util.strings.Atom;
+import com.ibm.wala.core.util.strings.StringStuff;
 import com.ibm.wala.core.util.warnings.Warning;
 import com.ibm.wala.core.util.warnings.Warnings;
 import com.ibm.wala.ipa.callgraph.AnalysisScope;
@@ -706,6 +708,56 @@ private void recursiveStringify(Node n, StringBuilder buffer) {
     }
   }
 
+  /**
+   * Converts ClassHierarchy to a JSON String, mapping each class name to a list of subclass names
+   */
+  public String toJson() {
+    // Initialize the map to store the <class, subclass> pairs
+    HashMap<String, Set<String>> classNameToSubclassNames = new HashMap<>();
+
+    // Start the recursive function from the root node
+    helperToJson(root, classNameToSubclassNames);
+
+    // Use Gson to convert the map to a JSON string
+    Gson gson = new Gson();
+    return gson.toJson(classNameToSubclassNames);
+  }
+
+  /** helper function to toJson that performs recursion to go through all of the DAG */
+  private void helperToJson(Node n, HashMap<String, Set<String>> hash) {
+    String key = nodeToString(n);
+
+    // If the node is already processed, return to avoid infinite recursion
+    if (hash.containsKey(key)) {
+      return;
+    }
+
+    // Initialize a set to store the names of the subclasses
+    Set<String> subclassNames = new HashSet<>();
+
+    // Process all children of the current node
+    if (n.children.size() > 0) {
+      Iterator<Node> children = n.getChildren();
+      while (children.hasNext()) {
+        Node temp = children.next();
+        helperToJson(temp, hash);
+
+        String childKey = nodeToString(temp);
+        subclassNames.add(childKey);
+      }
+    }
+
+    // Put the current node and its subclasses in the map
+    hash.put(key, subclassNames);
+  }
+
+  /**
+   * Removed unnecessary part of Node by turning it into a String (Made for toJson and helperToJson)
+   */
+  private String nodeToString(Node n) {
+    return StringStuff.jvmToBinaryName(n.getJavaClass().getName().toString());
+  }
+
   /**
    * 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

@@ -14,8 +14,12 @@
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import com.google.gson.Gson;
+import com.google.gson.reflect.TypeToken;
+import com.ibm.wala.classLoader.IClass;
 import com.ibm.wala.core.tests.util.TestConstants;
 import com.ibm.wala.core.tests.util.WalaTestCase;
+import com.ibm.wala.core.util.strings.StringStuff;
 import com.ibm.wala.ipa.callgraph.AnalysisCacheImpl;
 import com.ibm.wala.ipa.callgraph.AnalysisOptions;
 import com.ibm.wala.ipa.callgraph.AnalysisScope;
@@ -31,6 +35,10 @@
 import com.ibm.wala.types.TypeReference;
 import com.ibm.wala.util.CancelException;
 import java.io.IOException;
+import java.lang.reflect.Type;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
 import java.util.Set;
 import org.junit.jupiter.api.Test;
 
@@ -79,4 +87,30 @@ 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);
+    Gson gson = new Gson();
+    Type type = new TypeToken<HashMap<String, Set<String>>>() {}.getType();
+    String json = cha.toJson();
+    System.err.println(json);
+    HashMap<String, Set<String>> list = gson.fromJson(json, type);
+    assertTrue(list.containsKey(nodeToString(cha.getRootClass())));
+
+    Set<String> subclassNames = new HashSet<>();
+    Iterator<IClass> children = cha.computeSubClasses(cha.getRootClass().getReference()).iterator();
+    while (children.hasNext()) {
+      String temp = nodeToString(children.next());
+      subclassNames.add(temp);
+    }
+    assertTrue(subclassNames.containsAll(list.get(nodeToString(cha.getRootClass()))));
+  }
+
+  private String nodeToString(IClass klass) {
+    return StringStuff.jvmToBinaryName(klass.getName().toString());
+  }
 }