content: package com.test.TestCompiler;
  /*
   * Copyright (C) 2008 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  import java.lang.ref.*;
  
  public class InternedString {
      public static final String CONST = "Class InternedString";
  
      public static void run() {
          System.out.println("InternedString.run");
          testImmortalInternedString();
          testDeadInternedString();
      }
  
      private static WeakReference<String> makeWeakString() {
          String s = "blah";
          s = s + s;
          WeakReference<String> strRef = new WeakReference<String>(s.intern());
          return strRef;
      }
  
      private static void testDeadInternedString() {
          WeakReference<String> strRef = makeWeakString();
          Runtime.getRuntime().gc();
          // "blahblah" should disappear from the intern list
          Main.assertTrue(strRef.get() == null);
      }
  
      private static void testImmortalInternedString() {
          WeakReference strRef = new WeakReference<String>(CONST.intern());
          Runtime.getRuntime().gc();
          // Class constant string should be entered to the interned table when
          // loaded
          Main.assertTrue(CONST == CONST.intern());
          // and it should survive the gc
          Main.assertTrue(strRef.get() != null);
  
          String s = CONST;
          // "Class InternedString" should remain on the intern list
          strRef = new WeakReference<String>(s.intern());
          // Kill s, otherwise the string object is still accessible from root set
          s = "";
          Runtime.getRuntime().gc();
          Main.assertTrue(strRef.get() == CONST);
      }
  }
  