@Test
  public void test5() {
    List<LinkedList<SimpleObj>> list = new LinkedList<LinkedList<SimpleObj>>();

    LinkedList<SimpleObj> list1 = new LinkedList<SimpleObj>();
    for (int j = 0; j < 10; j++) {
      SimpleObj i = new SimpleObj();
      i.setAge(10);
      i.setId(33442 + j);
      i.setNumber(30);
      i.setName("PengtaoQiu\nAlvin");

      SimpleObj i2 = new SimpleObj();
      i2.setAge(20);
      i2.setId(12341);
      i2.setNumber(33);
      i2.setName("Tom");
      i.setContact1(i2);
      list1.add(i);
    }
    list.add(list1);

    list1 = new LinkedList<SimpleObj>();
    for (int j = 0; j < 10; j++) {
      SimpleObj i = new SimpleObj();
      i.setAge(10);
      i.setId(1000 + j);
      i.setNumber(30);
      i.setName("PengtaoQiu\nAlvin");

      SimpleObj i2 = new SimpleObj();
      i2.setAge(20);
      i2.setId(12341);
      i2.setNumber(33);
      i2.setName("Tom");
      i.setContact1(i2);
      list1.add(i);
    }
    list.add(list1);

    CollectionObj o = new CollectionObj();
    o.setList(list);
    String json = Json.toJson(o);

    CollectionObj o2 = Json.toObject(json, CollectionObj.class);
    Assert.assertThat(o2.getList().size(), is(2));
    Assert.assertThat(o2.getList().get(0).size(), is(10));
    Assert.assertThat(o2.getList().get(0).get(1).getId(), is(33443));
    Assert.assertThat(o2.getList().get(1).get(1).getId(), is(1001));
  }
  @Test
  public void test2() {
    SimpleObj i = new SimpleObj();
    i.setAge(10);
    i.setId(33442);
    i.setNumber(30);
    i.setName("PengtaoQiu\nAlvin");

    SimpleObj i2 = new SimpleObj();
    i2.setAge(20);
    i2.setId(12341);
    i2.setNumber(33);
    i2.setName("Tom");
    i.setContact1(i2);
    String jsonStr = Json.toJson(i);

    SimpleObj temp = Json.toObject(jsonStr, SimpleObj.class);
    Assert.assertThat(temp.getId(), is(33442));
    Assert.assertThat(temp.getContact1().getId(), is(12341));
    Assert.assertThat(temp.getContact1().getName(), is("Tom"));
    Assert.assertThat(temp.getContact1().getAge(), is(20));
    Assert.assertThat(temp.getContact2(), nullValue());
  }