OkHttpUtils

public class OkHttpUtils {
    /**
     * 懒汉 安全 加同步
     * 1.私有的静态成员变量 只声明不创建
     * 2.私有的构造方法
     * 3.提供返回实例的静态方法
     */
    private static OkHttpClient okHttpClient = null;

    private OkHttpUtils() {
    }

    public static OkHttpClient getInstance() {
        if (okHttpClient == null) { //加同步安全
            synchronized (OkHttpUtils.class) {
                if (okHttpClient == null) { //okhttp可以缓存数据....指定缓存路径
                    okHttpClient = new OkHttpClient.Builder()//构建器
                            .proxy(Proxy.NO_PROXY) //来屏蔽系统代理
                            .connectTimeout(10, TimeUnit.SECONDS)//连接超时
                            .writeTimeout(10, TimeUnit.SECONDS)//写入超时
                            .readTimeout(10, TimeUnit.SECONDS)//读取超时
                            .addInterceptor(new CommonParamsInterceptor())//添加应用拦截器的方法
                            .build();
                }
            }
        }
        return okHttpClient;
    }

    /**
     * post请求上传文件....包括图片....流的形式传任意文件...
     * 参数1 url
     * file表示上传的文件
     * fileName....文件的名字,,例如aaa.jpg
     * params ....传递除了file文件 其他的参数放到map集合
     */
    public static void uploadFile(String url, File file, String fileName, Map params, Callback callback) { //创建OkHttpClient请求对象
        OkHttpClient okHttpClient = getInstance(); //MultipartBody多功能的请求实体对象,,,formBody只能传表单形式的数据
        MultipartBody.Builder builder = new MultipartBody.Builder();
        builder.setType(MultipartBody.FORM); //参数
        if (params != null) {
            for (String key : params.keySet()) {
                builder.addFormDataPart(key, params.get(key));
            }
        } //文件...参数name指的是请求路径中所接受的参数...如果路径接收参数键值是fileeeee,此处应该改变
        builder.addFormDataPart("file", fileName, RequestBody.create(MediaType.parse("application/octet-stream"), file)); //构建
        MultipartBody multipartBody = builder.build(); //创建Request
        Request request = new Request.Builder().url(url).post(multipartBody).build(); //得到Call
        Call call = okHttpClient.newCall(request); //执行请求
        call.enqueue(callback);
    }

    /**
     * Post请求发送JSON数据....{"name":"zhangsan","pwd":"123456"}
     * 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er：请求Url
     * saveDir：保存文件的文件夹....download
     */
    public static void download(final String url, final String saveDir, OnDownloadListener downloadListener) { //get请求
        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) {

            }

            @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 {
                    //response.body().string()...json限制是1M大小...byteStream()流的方式
                    is = response.body().byteStream();//以字节流的形式拿回响应实体内容
                    AppLog.e(getClass(), "read file length--->" + is.available());
                    long total = response.body().contentLength();
                    //保存路径
                    final String fileDir = isExistDir(saveDir);
                    File file = new File(fileDir, getNameFromUrl(url));
                    fos = new FileOutputStream(file);
                    long sum = 0;
                    while ((len = is.read(buf)) != -1) {
                        fos.write(buf, 0, len);
                        sum += len;
                        int progress = (int) (sum * 1.0f / total * 100);
                        downloadListener.onDownloading(progress);
                    }
                    fos.flush();
                    AppLog.e(getClass(), "down load over");
                    downloadListener.onDownloadSuccess(fileDir + "/" + getNameFromUrl(url));
                } catch (IOException e) {
                    downloadListener.onDownloadFailed();
                    e.printStackTrace();
                } finally {
                    if (is != null) is.close();
                    if (fos != null) fos.close();
                }
            }
        });
    }

    /**
     * 判断下载目录是否存在......并返回绝对路径
     *
     * @param saveDir
     * @return
     * @throws IOException
     */
    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();
            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);
    }

    /**
     * 封装公共参数的拦截器
     */
    private static class CommonParamsInterceptor implements Interceptor { //intercept方法就是拦截的意思....拦截的是一个请求,,,一旦拦截之后可以对请求的参数进行处理
        //Chain chain 链条的意思
        @Override
        public Response intercept(Chain chain) throws IOException {
            Log.e("----", "拦截器------"); //调用request()方法得到拦截的请求
            Request request = chain.request(); //获取请求的方式
            String method = request.method();//GET POST
            //拦截的请求的路径
            String oldUrl = request.url().toString(); //要添加的公共参数...map
            Map map = new HashMap<>();
            map.put("source", "android");
            if ("GET".equals(method)) {
                StringBuilder stringBuilder = new StringBuilder();//创建一个stringBuilder...字符串缓冲区
                stringBuilder.append(oldUrl);
                if (oldUrl.contains("?")) { //?在最后面....2类型
                    if (oldUrl.indexOf("?") == oldUrl.length() - 1) {
                    } else { //3类型...拼接上&
                        stringBuilder.append("&");
                    }
                } else { //不包含? 属于1类型,,,先拼接上?号
                    stringBuilder.append("?");
                } //添加公共参数....source=android&appVersion=100&
                for (Map.Entry entry : map.entrySet()) { //拼接
                    stringBuilder.append(entry.getKey()).append("=").append(entry.getValue()).append("&");
                } //删掉最后一个&符号
                if (stringBuilder.indexOf("&") != -1) {
                    stringBuilder.deleteCharAt(stringBuilder.lastIndexOf("&"));
                } //得到含有公共参数的新路径.....使用新路径去请求
                String newUrl = stringBuilder.toString(); //新的路径构建一个新的请求
                request = request.newBuilder().url(newUrl).build();
            } else if ("POST".equals(method)) {
                Log.e("--oldUrl--", oldUrl); //参数在请求的实体内容上....拿到以前的参数,把以前的参数和公共参数全都添加到请求实体上
                RequestBody requestBody = request.body();
                if (requestBody instanceof FormBody) {//前边是不是后边的子类/实例对象
                    FormBody oldBody = (FormBody) requestBody;//keywords...page
                    FormBody.Builder builder = new FormBody.Builder(); //先添加之前的参数
                    for (int i = 0; i < oldBody.size(); i++) { //键值对的形式添加
                        builder.add(oldBody.name(i), oldBody.value(i));
                    } //添加公共参数
                    for (Map.Entry entry : map.entrySet()) {
                        builder.add(entry.getKey(), entry.getValue());
                    } //构建一个新的请求
                    request = request.newBuilder().url(oldUrl).post(builder.build()).build();
                }
            } //执行请求 获取到响应
            Response response = chain.proceed(request);
            return response;
        }
    }

}