OKHttp

导依赖：

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

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();
}

/**
 * 网络同步方法
 * 创建一个get请求
 * 设置一个路径
 *
 * 通过mClient.newCall建一个Call对象
 * 调用同步请求方法
 *
 * @param url
 * @param callBack
 * @param clazz
 * @return
 * @throws IOException
 */
public String getExecute(String url, final ICallBack callBack, final Class clazz) throws IOException {
    Request request = new Request.Builder()
            .get()
            .url(url)
            .build();

    Call call = mClient.newCall(request);
    Response response = call.execute();
    return byte2String(response.body().bytes());
}

/**
 * 异步的get方法
 * 创建一个请求
 * 创建一个call
 * 调用异步请求
 *
 * @param url
 * @param callBack
 * @param clazz
 */
public void getEnqueue(final String url, final ICallBack callBack, final Class clazz) {
    Request request = new Request.Builder()
            .get()
            .url(url)
            .build();

    Call call = mClient.newCall(request);
    call.enqueue(new Callback() {
        //网络请求连接失败
        @Override
        public void onFailure(Call call, final IOException e) {
            mHandler.post(new Runnable() {
                @Override
                public void run() {
                    callBack.failed(e);
                }
            });
        }

        //网络请求连接成功
        @Override
        public void onResponse(Call call, Response response) throws IOException {
            String result = response.body().string();
            Log.i("dj", "----------------------------");
            Log.i("dj", "url is " + url);
            Log.i("dj", "result is " + result);
            Log.i("dj", "----------------------------");
            Gson gson = new Gson();
            final Object o = gson.fromJson(result, clazz);
            mHandler.post(new Runnable() {
                @Override
                public void run() {
                    callBack.success(o);
                }
            });
        }
    });
}

/**
 * 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 params, final Class clazz, final ICallBack callBack) {
    FormBody.Builder builder = new FormBody.Builder();

    for (Map.Entry 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);

            Log.i("dj", "----------------------------");
            Log.i("dj", "url is " + url);
            Log.i("dj", "result is " + result);
            Log.i("dj", "----------------------------");

            mHandler.post(new Runnable() {
                @Override
                public void run() {
                    callBack.success(o);
                }
            });
        }
    });
}

/**
 * 上传图片
 * 创建MultipartBody.Builder，类型为Form
 * 如果上传的是图片
 * 通过File找到图片
 * 给我们 MultipartBody.Builder添加一个表单数据
 * 第二个参数filename为上传之后，服务器保存的名称
 * 第三个参数创建requestBody,类型为表单数据
 * 第四个参数，文件
 *
 * 如果遍历发现不是文件，则保存普通键值对
 *
 * @param url
 * @param params
 * @param clazz
 * @param callBack
 */
public void uploadImage(String url, Map params, final Class clazz, final ICallBack callBack) {
    OkHttpClient okHttpClient = new OkHttpClient();
    MultipartBody.Builder builder = new MultipartBody.Builder()
            .setType(MultipartBody.FORM);

    for (Map.Entry entry : params.entrySet()) {
        if (entry.getKey().equals(Constants.MAP_KEY_UP_LOAD_IMG)) {
            File file = new File(entry.getValue());
            builder.addFormDataPart(entry.getKey(), "图片1.png",
                    RequestBody.create(MediaType.parse("multipart/form-data"), file));
        }else{
            builder.addFormDataPart(entry.getKey(), entry.getValue());
        }
    }

    RequestBody requestBody = builder.build();

    final Request request = new Request.Builder()
            .url(url)
            .post(requestBody)
            .build();
    Call call = okHttpClient.newCall(request);
    call.enqueue(new Callback() {
        @Override
        public void onFailure(Call call, IOException e) {
            e.printStackTrace();
        }

        @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);
                }
            });
        }
    });
}

/**
 * 把流转成字符串 666版
 */
private static String byte2String(byte[] bytes) {
    return new String(bytes);
}

}