OkHttp3Utils

依赖：

compile 'com.squareup.okhttp3:okhttp:3.2.0'compile 'com.squareup.okio:okio:1.7.0'

public class OkHttp3Utils {

    /**

     * 懒汉 安全 加同步

     * 私有的静态成员变量 只声明不创建

     * 私有的构造方法

     * 提供返回实例的静态方法

     */

    private static OkHttpClient okHttpClient = null;

    private OkHttp3Utils() {

    }

    public static OkHttpClient getInstance() {

        if (okHttpClient == null) {

            //加同步安全

            synchronized (OkHttp3Utils.class) {

                if (okHttpClient == null) {

                    //判空 为空创建实例

                    // okHttpClient = new OkHttpClient();

/**

 * 和OkHttp2.x有区别的是不能通过OkHttpClient直接设置超时时间和缓存了，而是通过OkHttpClient.Builder来设置，

 * 通过builder配置好OkHttpClient后用builder.build()来返回OkHttpClient，

 * 所以我们通常不会调用new OkHttpClient()来得到OkHttpClient，而是通过builder.build()：

 */

                    //  File sdcache = getExternalCacheDir();

                    File sdcache = new File(Environment.getExternalStorageDirectory(), "cache");

                    int cacheSize = 10 * 1024 * 1024;

                    okHttpClient = new OkHttpClient.Builder().connectTimeout(15, TimeUnit.SECONDS)

                            .writeTimeout(20, TimeUnit.SECONDS).readTimeout(20, TimeUnit.SECONDS).cache(new Cache(sdcache.getAbsoluteFile(), cacheSize)).build();

                }

            }

        }

        return okHttpClient;

    }

    /**

     * get请求

     * 参数1 url

     * 参数2 回调Callback

     */

    public static void doGet(String url, Callback callback) {

        //创建OkHttpClient请求对象

        OkHttpClient okHttpClient = getInstance();

        //创建Request

        Request request = new Request.Builder().url(url).build();

        //得到Call对象

        Call call = okHttpClient.newCall(request);

        //执行异步请求

        call.enqueue(callback);

    }

    /**

     * post请求

     * 参数1 url

     * 参数2 回调Callback

     */

    public static void doPost(String url, Map<String, String> params, Callback callback) {

        //创建OkHttpClient请求对象

        OkHttpClient okHttpClient = getInstance();

        //3.x版本post请求换成FormBody 封装键值对参数

        FormBody.Builder builder = new FormBody.Builder();

        //遍历集合

        for (String key : params.keySet()) {

            builder.add(key, params.get(key));

        }

        //创建Request

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

       //得到Call对象       Call call = okHttpClient.newCall(request);       //执行异步请求       call.enqueue(callback);

    }

    /**

     * post请求上传文件

     * 参数1 url

     * 参数2 回调Callback

     */

    public static void uploadPic(String url, File file, String fileName) {

        //创建OkHttpClient请求对象

        OkHttpClient okHttpClient = getInstance();

        //创建RequestBody 封装file参数

        RequestBody fileBody = RequestBody.create(MediaType.parse("application/octet-stream"), file);

        //创建RequestBody 设置类型等

        RequestBody requestBody = new MultipartBody.Builder().setType(MultipartBody.FORM).addFormDataPart("file", fileName, fileBody).build();

        //创建Request

        Request request = new Request.Builder().url(url).post(requestBody).build();

        //得到Call

        Call call = okHttpClient.newCall(request);

        //执行请求

        call.enqueue(new Callback() {

            @Override

            public void onFailure(Call call, IOException e) {

            }

            @Override

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

                //上传成功回调 目前不需要处理

            }

        });

    }

    /**

     * Post请求发送JSON数据

     * 参数一：请求Url

     * 参数二：请求的JSON

     * 参数三：请求回调

     */

    public static void doPostJson(String url, String jsonParams, Callback callback) {

        RequestBody requestBody = RequestBody.create(MediaType.parse("application/json; charset=utf-8"), jsonParams);

        Request request = new Request.Builder().url(url).post(requestBody).build();

        Call call = getInstance().newCall(request);

        call.enqueue(callback);

    }

    /**

     * 下载文件 以流的形式把apk写入的指定文件 得到file后进行安装

     * 参数一：请求Url

     * 参数二：保存文件的路径名

     * 参数三：保存文件的文件名

     */

    public static void download(final MainActivity context, final String url, final String saveDir) {

        Request request = new Request.Builder().url(url).build();

        Call call = getInstance().newCall(request);

        call.enqueue(new Callback() {

            @Override

            public void onFailure(Call call, IOException e) {

                Log.i("xxx", e.toString());

            }

            @Override

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

                InputStream is = null;

                byte[] buf = new byte[2048];

                int len = 0;

                FileOutputStream fos = null;

                try {

                    is = response.body().byteStream();

                    //apk保存路径

                    final String fileDir = isExistDir(saveDir);

                    //文件

                    File file = new File(fileDir, getNameFromUrl(url));

                    context.runOnUiThread(new Runnable() {

                        @Override

                        public void run() {

                            Toast.makeText(context, "下载成功:" + fileDir + "," + getNameFromUrl(url), Toast.LENGTH_SHORT).show();

                        }

                    });

                    fos = new FileOutputStream(file);

                    while ((len = is.read(buf)) != -1) {

                        fos.write(buf, 0, len);

                    }

                    fos.flush();

                    //apk下载完成后 调用系统的安装方法

                    Intent intent = new Intent(Intent.ACTION_VIEW);

                    intent.setDataAndType(Uri.fromFile(file), "application/vnd.android.package-archive");

                    context.startActivity(intent);

                } catch (IOException e) {

                    e.printStackTrace();

                } finally {

                    if (is != null) is.close();

                    if (fos != null) fos.close();

                }

            }

        });

    }

    /**

     * @param saveDir

     * @return

     * @throws IOException 判断下载目录是否存在

     */

    public static String isExistDir(String saveDir) throws IOException {

        // 下载位置

        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {

            File downloadFile = new File(Environment.getExternalStorageDirectory(), saveDir);

            if (!downloadFile.mkdirs()) {

                downloadFile.createNewFile();

            }

            String savePath = downloadFile.getAbsolutePath();

            Log.e("savePath", savePath);

            return savePath;

        }

        return null;

    }

    /**

     * @param url

     * @return 从下载连接中解析出文件名

     */

    private static String getNameFromUrl(String url) {

        return url.substring(url.lastIndexOf("/") + 1);

    }

}