安卓系统中如何使用网络请求库

56.04

注意事项

网络请求不能放到主线程中，要启动一个子线程运行

在清单文件中，赋予app网络权限

在包名下面加上这段内容

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

在module的gradle文件添加依赖

implementation 'com.squareup.okhttp3:okhttp:4.9.1'
implementation 'com.squareup.retrofit2:retrofit:2.9.0'
implementation 'com.squareup.retrofit2:converter-gson:2.9.0'
implementation 'com.squareup.retrofit2:adapter-rxjava2:2.9.0'
implementation 'io.reactivex.rxjava2:rxandroid:2.1.1'
implementation 'io.reactivex.rxjava2:rxjava:2.2.20'

操作方法如下图

GET 构建网络请求(同步写法)

private final OkHttpClient client = new OkHttpClient(); //新建一个okhttp的客户端

void OkHttpDemo(){
        Request request = new Request.Builder().url("https://reqres.in/api/users?page=2").build(); //构建一个request请求

        new Thread(new Runnable() { // 启动一个子线程
            @Override
            public void run() {
                try {
                    Response response = client.newCall(request).execute(); // 发送requet 请求
                    Log.d(TAG, "OkHttpDemo: "+ response.body().string()); // 得到响应信息

                }catch (Exception e){
                    e.printStackTrace();
                }
            }
        }).start();


    }

GET 构建网络请求(推荐异步写法)

private final OkHttpClient client = new OkHttpClient(); //新建一个okhttp的客户端
void OkHttpAsync(){
       Request request = new Request.Builder().url("https://reqres.in/api/users?page=2").build(); //构建一个request请求
       client.newCall(request).enqueue(new Callback() {
           @Override
           public void onFailure(@NotNull Call call, @NotNull IOException e) {
               // 请求失败走这里
               Log.d(TAG, "onFailure: 请求失败");
           }

           @Override
           public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
               // 请求成功走这里
               Log.d(TAG, "onResponse: "+ response.body().string());
           }
       });
   }

GET URL参数构建

void okHttpBuilder(){
        // 构建url
        HttpUrl.Builder builder = HttpUrl.parse("https://reqres.in/api/users").newBuilder();
        builder.addQueryParameter("page","2");
        String url = builder.build().toString();
        Log.d(TAG, "okHttpBuilder: " + url);
    }

POST 请求

请求目标示例

url :https://reqres.in/api/users
要发送的数据
{
"name": "morpheus",
"job": "leader"
}

构建请求demo

private final OkHttpClient client = new OkHttpClient(); //新建一个okhttp的客户端
void okHttpPost(){
        RequestBody body = new FormBody.Builder()
                .add("name","morpheus")
                .add("job","leader")
                .build();
        Request request = new Request.Builder().url("https://reqres.in/api/users").post(body).build();
        client.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(@NotNull Call call, @NotNull IOException e) {
                Log.d(TAG, "onFailure: 请求失败");
            }

            @Override
            public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
                Log.d(TAG, "onResponse: "+ response.body().string());

            }
        });
    }