1.导入okhttp的jar包

2.请求的方法
第一处写要发送的json数据,第二处写要请求的地址
该方法的完整代码:

    private void sendRequestWithOkHttp() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                JSONObject obj = new JSONObject();
                try {
                    obj.put("UserName","user1");
                    obj.put("UserPwd","123457");
                } catch (JSONException e) {
                    e.printStackTrace();
                }

                MediaType type = MediaType.parse("application/json;charset=utf-8");
                RequestBody RequestBody2 = RequestBody.create(type,""+obj.toString());
                try {
                    OkHttpClient client = new OkHttpClient();
                    Request request = new Request.Builder()
                            // 指定访问的服务器地址
                            .url("http://172.20.10.7:8080/transportservice/action/user_login.do").post(RequestBody2)
                            .build();
                    Response response = client.newCall(request).execute();
                    String responseData = response.body().string();
                    parseJSONWithJSONObject(responseData);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }

3.接收的方法
拿返回的key值接收即可

该方法的完整代码:

    private void parseJSONWithJSONObject(String jsonData) {
        try {
            JSONObject object=new JSONObject(jsonData);
            String name = object.getString("RESULT");
            //日志
            Log.d("name", "结果是："+name);

        } catch (JSONException e) {
            e.printStackTrace();
        }

Activity完整代码

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import okhttp3.MediaType;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
import org.json.JSONException;
import org.json.JSONObject;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button sendRequest = (Button) findViewById(R.id.send_request);
        sendRequest.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        if (v.getId() == R.id.send_request) {

            //sendRequestWithHttpURLConnection();
            sendRequestWithOkHttp();
        }
    }

    private void sendRequestWithOkHttp() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                JSONObject obj = new JSONObject();
                try {
                    obj.put("UserName","user1");
                    obj.put("UserPwd","123457");
                } catch (JSONException e) {
                    e.printStackTrace();
                }

                MediaType type = MediaType.parse("application/json;charset=utf-8");
                RequestBody RequestBody2 = RequestBody.create(type,""+obj.toString());
                try {
                    OkHttpClient client = new OkHttpClient();
                    Request request = new Request.Builder()
                            // 指定访问的服务器地址
                            .url("http://172.20.10.7:8080/transportservice/action/user_login.do").post(RequestBody2)
                            .build();
                    Response response = client.newCall(request).execute();
                    String responseData = response.body().string();
                    parseJSONWithJSONObject(responseData);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }

    private void parseJSONWithJSONObject(String jsonData) {
        try {
            JSONObject object=new JSONObject(jsonData);
            String name = object.getString("RESULT");
            //日志
            Log.d("name", "结果是："+name);

        } catch (JSONException e) {
            e.printStackTrace();
        }
    }


}