Okhttp3-基本用法

前言

Okhttp官网
Okhttp-Github

android网络框架之OKhttp一个处理网络请求的开源项目,是安卓端最火热的轻量级框架,由移动支付Square公司贡献(该公司还贡献了Picasso)

用于替代HttpUrlConnection和Apache HttpClient(android API23 6.0里已移除HttpClient)

官网的解释如下：

基本用法

1.集成

1.1.依赖

   implementation 'com.squareup.okhttp3:okhttp:3.11.0'

可以去Okhttp-Github 查看并依赖最新的版本。

1.2权限

添加网络权限

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

2.使用

2.1 同步GET请求

• 构建OkHttpClient对象
• 构建Request对象
• 构建Call对象并通过execute()方法来执行同步Get请求

 //同步请求
        OkHttpClient okHttpClient=new OkHttpClient();
        final Request request=new Request.Builder()
                .url("https://www.wanandroid.com/navi/json")
                .get()
                .build();
        final Call call = okHttpClient.newCall(request);
        try {
            Response response = call.execute();
            Log.e("同步结果----   ",response.body().string()+"");

        } catch (IOException e) {

            e.printStackTrace();

        }

运行后发现报错：

 android.os.NetworkOnMainThreadException

在Android4.0以后，会发现，只要是写在主线程（就是Activity）中的HTTP请求，运行时都会报错，这是因为Android在4.0以后为了防止应用的ANR（Aplication Not Response）异常。解决方法就是在子线程中运行：

        //同步请求
        OkHttpClient okHttpClient=new OkHttpClient();
        final Request request=new Request.Builder()
                .url("https://www.wanandroid.com/navi/json")
                .get()
                .build();
        final Call call = okHttpClient.newCall(request);

        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    Response response = call.execute();
                    Log.e("同步结果----   ",response.body().string()+"");

                } catch (IOException e) {

                    e.printStackTrace();

                }
            }
        }).start();

2.2 异步GET请求

   //异步请求
        OkHttpClient okHttpClient=new OkHttpClient();
        final Request request=new Request.Builder()
                .url("https://www.wanandroid.com/navi/json")
                .get()
                .build();
        final Call call = okHttpClient.newCall(request);
        call.enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                Log.d("okhttp_error",e.getMessage());
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                Gson gson=new Gson();

                Log.d("okhttp_success",response.body().string());
            }
        });

2.3 POST请求

POST请求支持提交文件，流，string，表单等等 。这里拿POST表单请求作为请求示例：

        OkHttpClient okHttpClient = new OkHttpClient();
        RequestBody requestBody = new FormBody.Builder()
                .add("username", "qinzishuai")
                .add("password", "111111")
                .build();
        Request request = new Request.Builder()
                .url("https://www.wanandroid.com/user/login")
                .post(requestBody)
                .build();   

        okHttpClient.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                Log.d("okhttp", "onFailure: " + e.getMessage());
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {

                Log.d("okhttp", "onResponse: " + response.body().string());
            }
        });