OkHttp--post请求

1.依赖

implementation 'com.squareup.okhttp3:okhttp:3.11.0'
implementation 'com.squareup.okio:okio:1.11.0'
implementation 'com.squareup.okhttp3:logging-interceptor:3.11.0'

2.创建工具类

public class OkHttpUtils {
private static volatile OkHttpUtils mInstance;

private OkHttpClient mClient;

private Handler mHandler = new Handler(Looper.getMainLooper());
/**
     * 第一步，写一个单例，这里用的懒汉式，也可以使用饿汉
     * @return
     */
    public static OkHttpUtils getInstance() {
        if (mInstance == null) {
            synchronized (OkHttpUtils.class) {
                if (null == mInstance) {
                    mInstance = new OkHttpUtils();
                }
            }
        }
        return mInstance;
    }

/**
 * 完成构造方法，OkHttpClient
 */
private OkHttpUtils() {
    HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
    interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);

    /**
     * 使用构造者模式
     * 设置连接超时
     * 读取超时
     * 写超时
     * 添加拦截器
     */
    mClient = new OkHttpClient.Builder()
            .connectTimeout(10, TimeUnit.SECONDS)
            .readTimeout(10, TimeUnit.SECONDS)
            .writeTimeout(10, TimeUnit.SECONDS)
            .addInterceptor(interceptor)
            .build();
}
/**
 * 创建异步post方法
 * 创建表单FormBody
 * 把我们取出的key和value对应的放进去
 * 最后，build表单，生成RequestBody
 *
 * @param url 请求地址
 * @param params
 * @param clazz
 * @param callBack
 */
public void postEnqueue(final String url, Map<String, String> params, final Class clazz, final ICallBack callBack) {
    FormBody.Builder builder = new FormBody.Builder();

    for (Map.Entry<String, String> entry : params.entrySet()) {
        builder.add(entry.getKey(), entry.getValue());
    }

    RequestBody body = builder.build();
    Request request = new Request.Builder()
            .post(body)
            .url(url)
            .build();

    Call call = mClient.newCall(request);
    call.enqueue(new Callback() {
        @Override
        public void onFailure(Call call, final IOException e) {
            mHandler.post(new Runnable() {
                @Override
                public void run() {
                    callBack.failed(e);
                }
            });
        }

        @Override
        public void onResponse(Call call, Response response) throws IOException {
            String result = response.body().string();
            Gson gson = new Gson();
            final Object o = gson.fromJson(result, clazz);
            mHandler.post(new Runnable() {
                @Override
                public void run() {
                    callBack.success(o);
                }
            });
        }
    });
}