OKHttp的使用

OKHttp是什么？

OKHttp是一个网络请求开源项目，Android网络请求轻量级框架,支持文件上传与下载，支持https。

OKHttp的优点

• 支持HTTP/2, HTTP/2通过使用多路复用技术在一个单独的TCP连接上支持并发, 通过在一个连接上 一次性发送多个请求来发送或接收数据
• 如果HTTP/2不可用, 连接池复用技术也可以极大减少延时
• 支持GZIP, 可以压缩下载体积
• 响应缓存可以直接避免重复请求
• 会从很多常用的连接问题中自动恢复
• 如果您的服务器配置了多个IP地址, 当第一个IP连接失败的时候, OKHttp会自动尝试下一个IP
• OKHttp还处理了代理服务器问题和SSL握手失败问题

OKHttp的基本使用

1. Get请求(同步和异步)
2. POST请求表单(key-value)
3. POST请求提交(JSON/String/文件等)
4. 文件下载
5. 请求超时设置

首先使用OKHttp之前要加入项目依赖

implementation("com.squareup.okhttp3:okhttp:4.10.0")

OKHttp的GET请求

 GET请求分为同步GET和异步GET

同步GET请求的使用   //OKHttp默认使用GET请求

private void getImg() {
        String url="https://api.vvhan.com/api/view?type=json";
        new Thread(new Runnable() {
            @Override
            public void run() {
                while (true){
                    OkHttpClient client=new OkHttpClient();
                    Request request=new Request.Builder().url(url).build();
                    try (Response response=client.newCall(request).execute()){
                        newsImg=response.body().string();
                        handler.sendEmptyMessage(0x112);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                    try {
                        Thread.sleep(15*1000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        }).start();

异步GET请求的使用

private void getRv() {
        String url="https://api.vvhan.com/api/hotlist?type=baiduRD";

        OkHttpClient client=new OkHttpClient();
        Request request=new Request.Builder().url(url).build();
        client.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(@NonNull Call call, @NonNull IOException e) {

            }

            @Override
            public void onResponse(@NonNull Call call, @NonNull Response response) throws IOException {
                news=response.body().string();
                handler.sendEmptyMessage(0x113);
            }
        });

这是在Handler里面的解析 

private Handler handler=new Handler(Looper.getMainLooper()){
        @Override
        public void handleMessage(@NonNull Message msg) {
            super.handleMessage(msg);
            
            if (msg.what==0x112){
                try {
                    JSONObject object=new JSONObject(newsImg);
                    String imgurl=object.getString("imgurl");
                    Glide.with(MainActivity.this).load(imgurl).into(iv_img);
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
            if (msg.what==0x113){
                try {
                    JSONObject jsonObject=new JSONObject(news);
                    JSONArray array=jsonObject.getJSONArray("data");
                    for (int i=0;i<array.length();i++){
                        JSONObject object=array.getJSONObject(i);
                        String pic=object.getString("pic");
                        String title=object.getString("title");
                        String desc=object.getString("desc");
                        String hot=object.getString("hot");

                        News news=new News(pic,title,desc,hot);
                        newsList.add(news);
                    }

                    NewsAdapter adapter=new NewsAdapter(newsList);
                    LinearLayoutManager layoutManager=new LinearLayoutManager(MainActivity.this);
                    rv_news.setAdapter(adapter);
                    rv_news.setLayoutManager(layoutManager);

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

OKHttp的POST请求

        同步POST

private void initSync(String pram) {
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        OkHttpClient client=new OkHttpClient();
                        MediaType type=MediaType.parse("application/json;charset=utf-8");
                        RequestBody body=RequestBody.Companion.create(pram,type);
                        Request request=new Request.Builder()
                                .url(url)
                                .post(body)
                                .build();

                        try (Response response=client.newCall(request).execute()){
                            result=response.body().string();
                            handler.sendEmptyMessage(0x111);
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }).start();
            }
        });

        异步 POST

private void initNoSync(String pram) {
        OkHttpClient client=new OkHttpClient();

        MediaType type=MediaType.parse("application?json;charset=utf_8");
        RequestBody body=RequestBody.Companion.create(pram,type);

        Request request=new Request.Builder()
                .url(url)
                .post(body)
                .build();
        client.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(@NonNull Call call, @NonNull IOException e) {
                Log.i("onFailure", "fos");
            }

            @Override
            public void onResponse(@NonNull Call call, @NonNull Response response) throws IOException {
                result=response.body().string();
                handler.sendEmptyMessage(0x111);
            }
        });
    }

Handler

private Handler handler=new Handler(Looper.getMainLooper()){
        @Override
        public void handleMessage(@NonNull Message msg) {
            super.handleMessage(msg);
            if (msg.what==0x111){
                Toast.makeText(MainActivity2.this, result, Toast.LENGTH_SHORT).show();
            }
        }
    };