public class StaticClassLoaderTest {
  protected static final ThreadLocal<Object> local = new ThreadLocal<Object>();
  //cusLoader加載器加載的對象
  private Test3 test3;

  public StaticClassLoaderTest() {
    try {
      test3 = (Test3) Class.forName("gittest.Test3", true, new cusLoader()).newInstance();
    }
    catch (Exception e) {
      e.printStackTrace();
    }
  }
  public Test3 getTest3() {
    return test3;
  }
  public static void main(String[] args) {
    try {
      //默認(rèn)類加載器加載StaticClassLoaderTest，并設(shè)置值
      StaticClassLoaderTest.local.set(new Object());
      new StaticClassLoaderTest().getTest3();
    }
    catch (Exception e) {
      e.printStackTrace();
    }
  }
  //自定義類加載器
  public static class cusLoader extends ClassLoader {
    @Override
    protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
      if (name.contains("StaticClassLoaderTest")) {
        InputStream is = Thread.currentThread().getContextClassLoader()
            .getResourceAsStream(name.replace(".", "/") + ".class");
        ByteArrayOutputStream output = new ByteArrayOutputStream();
        try {
          IOUtils.copy(is, output);
          return defineClass(output.toByteArray(), 0, output.toByteArray().length);
        }
        catch (IOException e) {
          e.printStackTrace();
        }
      }
      return super.loadClass(name, resolve);
    }
  }

}

public class Test3 {

  public void test() {
    //由cusLoader加載器加載StaticClassLoaderTest，并獲取值，由于StaticClassLoaderTest并不相同所以無法獲取到值
    System.out.println(StaticClassLoaderTest.local.get());
  }
}