public class MainActivity extends AppCompatActivity {

    private String TAG = "jsonTest";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        Map<String ,String > map = new HashMap<>();
        map.put("小明","男");

        List<Map> listMap = new ArrayList<>();
        listMap.add(map);
        listMap.add(map); // 这里直接添加一样的数据对象

        JSONArray jsonArray = new JSONArray();
        jsonArray.addAll(listMap);

        Log.i(TAG,jsonArray.toJSONString());
    }

}

public class MainActivity extends AppCompatActivity {

    private String TAG = "jsonTest";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        Map<String ,String > map = new HashMap<>();
        map.put("小明","男");

        List<Map> listMap = new ArrayList<>();
        listMap.add(map);
        listMap.add(map);

        // 单个关闭引用检测
        String listString  = JSON.toJSONString(listMap, SerializerFeature.DisableCircularReferenceDetect);
        JSONArray jsonList = (JSONArray) JSON.parse(listString);

        Log.i(TAG,jsonList.toJSONString());
    }

}