OKHTTP3的簡單使用，表單提交，json傳遞

OKHTTP3的簡單使用

使用okhttp3需引入以下依賴

 compile 'com.squareup.okio:okio:1.13.0'
 compile 'com.squareup.okhttp3:okhttp:3.9.0'

1.okhttp GET方式請求

            //創建OkHttpClient對象
            OkHttpClient okHttpClient  = new OkHttpClient.Builder()
                    .connectTimeout(10, TimeUnit.SECONDS)
                    .writeTimeout(10,TimeUnit.SECONDS)
                    .readTimeout(20, TimeUnit.SECONDS)
                    .build();

            final Request request = new Request.Builder()
                    .url("http://172.20.192.168:8080/getbookByFrom?name=android基礎&price=50")//請求的url
                    .get()//設置請求方式，get()/post()  查看Builder()方法知，在構建時默認設置請求方式爲GET
                    .build(); //構建一個請求Request對象

            //創建/Call
            Call call = okHttpClient.newCall(request);
            //加入隊列 異步操作
            call.enqueue(new Callback() {
                //請求錯誤回調方法
                @Override
                public void onFailure(Call call, IOException e) {
                    System.out.println("連接失敗");
                }
                //異步請求(非主線程)
                @Override
                public void onResponse(Call call, Response response) throws IOException {
                    if(response.code()==200) {
                        System.out.println(response.body().string());
                    }             
            });

注：在okhttp3中 如果想設置超時時間直接通過OkHttpClient 對象來設置

     okHttpClient .setConnectTimeout(10, TimeUnit.SECONDS);  
     okHttpClient .setWriteTimeout(10, TimeUnit.SECONDS);  
     okHttpClient .setReadTimeout(20, TimeUnit.SECONDS); 

但okhttp3OkHttpClient 對象沒有這個方法，需要藉助new OkHttpClient.Builder()按照上面的方法設置超時時間。

2.okhttp POST方式請求（提交表單方式）

OkHttpClient okHttpClient  = new OkHttpClient.Builder()
                .connectTimeout(10, TimeUnit.SECONDS)
                .writeTimeout(10,TimeUnit.SECONDS)
                .readTimeout(20, TimeUnit.SECONDS)
                .build();

        //post方式提交的數據
        FormBody formBody = new FormBody.Builder()
                .add("name", "android基礎")
                .add("price", "50")
                .build();

        final Request request = new Request.Builder()
                .url("http://172.20.192.168:8080/getbookByFrom")//請求的url
                .post(formBody)
                .build();


        //創建/Call
        Call call = okHttpClient.newCall(request);
        //加入隊列 異步操作
        call.enqueue(new Callback() {
            //請求錯誤回調方法
            @Override
            public void onFailure(Call call, IOException e) {
                System.out.println("連接失敗");
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                if(response.code()==200) {
                    System.out.println(response.body().string());
                }
            }
        });

3.okhttp POST方式請求（提交json方式）

 OkHttpClient okHttpClient  = new OkHttpClient.Builder()
                .connectTimeout(10, TimeUnit.SECONDS)
                .writeTimeout(10,TimeUnit.SECONDS)
                .readTimeout(20, TimeUnit.SECONDS)
                .build();

        Book book = new Book();
        book.setName("android基礎");
        book.setPrice(59);
        //使用Gson 添加 依賴 compile 'com.google.code.gson:gson:2.8.1'
        Gson gson = new Gson();
        //使用Gson將對象轉換爲json字符串
        String json = gson.toJson(book);

        //MediaType  設置Content-Type 標頭中包含的媒體類型值
        RequestBody requestBody = FormBody.create(MediaType.parse("application/json; charset=utf-8")
        , json);

         Request request = new Request.Builder()
                .url("http://172.20.192.168:8080/getbookByJson")//請求的url
                .post(requestBody)
                .build();

        //創建/Call
        Call call = okHttpClient.newCall(request);
        //加入隊列 異步操作
        call.enqueue(new Callback() {
            //請求錯誤回調方法
            @Override
            public void onFailure(Call call, IOException e) {
                System.out.println("連接失敗");
            }
            @Override
            public void onResponse(Call call, Response response) throws IOException {
                System.out.println(response.body().string());
            }
        });