一、環境說明

1、在gradle中引入依賴

    implementation 'com.squareup.okhttp3:okhttp:3.12.1'
    debugImplementation 'com.squareup.okhttp3:logging-interceptor:3.12.1'

2、AndroidManifest中開啟網路權限

<uses-permission android:name="android.permission.INTERNET"/>

注意:

在android9.0以后,Android默認禁止使用Http協議，必須使用Https協議，否則會報錯誤，

所以要使用Http協議的請求必須在AndroidManifest中添加屬性,android:usesCleartextTraffic=“true”

3、搭建測驗介面

package com.icodingzy.androidback.controller;

import com.icodingzy.androidback.pojo.User;
import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping("user")
public class UserController {
    /**
     * GET NoParameter
     * @return
     */
    @GetMapping("getUser")
    public Object getUser() {
        User user = new User();
        user.setId((int) (Math.random()*100));
        user.setName("熊順");
        user.setStudentId("201815110110" + (int) (Math.random()*100));
        user.setSex("男");
        user.setData("Not have Parameter!");
        return user;
    }

    /**
     * GET TakeParameter
     * @param id userId
     * @return
     */
    @GetMapping("getParamUser")
    public Object getParamUser(Integer id){
        User user = new User();
        user.setId(id);
        user.setName("熊順");
        user.setStudentId("201815110110" + (int) (Math.random()*100));
        user.setSex("男");
        user.setData("parameter is " + id);
        return user;
    }
    /**
     * Post NoParameter
     * @return
     */
    @PostMapping("postNoParamUser")
    public Object postNoParamUser(){
        User user = new User();
        user.setId((int) (Math.random()*100));
        user.setName("熊順");
        user.setStudentId("201815110110" + (int) (Math.random()*100));
        user.setSex("男");
        user.setData("Not have parameter");
        return user;
    }
    /**
     * Post TakeParameter
     * @param id userId
     * @return
     */
    @PostMapping("postParamUser")
    public Object postParamUser(Integer id){
        User user = new User();
        user.setId(id);
        user.setName("熊順");
        user.setStudentId("201815110110" + (int) (Math.random()*100));
        user.setSex("男");
        user.setData("parameter is " + id);
        return user;
    }
    /**
     * Post ObjectParameter
     * @return
     */
    @PostMapping("postObjectParamUser")
    public Object postObjectParamUser(@RequestBody User user){
        return user;
    }
}

介面檔案

4、撰寫OkHttp工具類

package com.zhuoyue.travelwh.OkHttpUtil;


import android.app.ProgressDialog;
import android.content.Context;
import android.util.Log;


import com.zhuoyue.travelwh.bean.MsgBean;

import org.greenrobot.eventbus.EventBus;

import java.io.IOException;

import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;

public class OkHttpUtil {
    public static ProgressDialog dialog;

    /**
     * 發送網路請求
     * @param url 請求Url
     * @param context 背景關系物件
     * @param body 請求體，如果有請求體則發送Post請求，反之發送Get請求
     */
    public static void getHttpRequset(String url, Context context, RequestBody body) {
        startDialog(context);
        OkHttpClient client = new OkHttpClient();

        Request request = null;
        
            //Post請求
        if (body != null) {
            request = new Request.Builder()
                    .url(url)
                    .post(body)
                    .build();
        } else {
        //Get請求
            request = new Request.Builder()
                    .url(url)
                    .get()
                    .build();
        }

        client.newCall(request).enqueue(new Callback() {
            /*請求失敗時的回呼*/
            @Override
            public void onFailure(Call call, IOException e) {
                stopDialog();
                Log.e("onFailure: ", e.getMessage());
            }
            /*請求成功時的回呼*/
            @Override
            public void onResponse(Call call, Response response) throws IOException {
                stopDialog();
                Log.e("ApiData:", response.body().string());
            }
        });
    }

    /**
     * 顯示等待框
     * @param context
     */
    public static void startDialog(Context context) {
        dialog = new ProgressDialog(context);
        dialog.setMessage("資料加載，，，");
        dialog.setTitle("請稍后");
        dialog.setCanceledOnTouchOutside(false);
        dialog.show();
    }

    /**
     * 關閉等待框
     */
    public static void stopDialog() {
        if (dialog != null) {

            dialog.dismiss();
        }
    }
}

二、發送請求

1.發送無參的Get請求

在自己的業務中使用工具類發送網路請求

	//無參介面
   private final String url = "http://xxxxxx/user/getParamUser";
      @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        OkHttpUtil.getHttpRequset(url,this,null);
    }

列印結果如下
E/ApiData:: {“id”:82,“name”:“熊順”,“studentId”:“20181511011066”,“sex”:“男”,“data”:“Not have Parameter!”}

2.發送有參的Get請求

OkHttp發送Get請求時，請求引數全部放在url中

//有參Get介面
   private final String url = "http://xxxxxx/user/getParamUser";
      @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        OkHttpUtil.getHttpRequset(url + "?id=9999",this,null);
    }

3.發送無參Post請求

發送Post請求時必需要帶上請求體

//無參Post介面
   private final String url = "http://xxxxxx/user/postNoParamUser";
      @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        RequestBody body = new FormBody.Builder()
                        .build();
                OkHttpUtil.getHttpRequset(url, this, body);
    }

4.發送有參Pos請求

add中固定為String型別

//有參Post介面
   private final String url = "http://xxxxxx/user/postParamUser";
      @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        RequestBody body = new FormBody.Builder()
                        .add("id","8888")
                        .build();
                OkHttpUtil.getHttpRequset(url, this, body);
    }

5.發送Post 的Json資料

發送Json資料需要借助JSONObject，把資料轉換成Json格式

//Json化引數Post介面
   private final String url = "http://xxxxxx/user/postObjectParamUser";
      @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        JSONObject jsonObject = new JSONObject();
                try {
                    jsonObject.put("id",1111111);
                    jsonObject.put("name","順");
                    jsonObject.put("studentId","123123");
                    jsonObject.put("sex","小萌新");
                    jsonObject.put("data","I have pan");
                } catch (JSONException e) {
                    e.printStackTrace();
                }
                RequestBody body = FormBody.create(MediaType.parse("application/json;charset=utf-8"), jsonObject.toString());

                OkHttpUtil.getHttpRequset(url, this, body);
    }