//文件上传  
   String baseUrl = "http://localhost:9000/file";
        File file = new File("E:/girl.jpg");
        OkHttpClient okHttpClient = new OkHttpClient();
        RequestBody fileBody = RequestBody.create(MediaType.parse("application/octet-stream"), file);
        MultipartBody body = new MultipartBody.Builder().setType(MediaType.parse("multipart/form-data"))
                .addFormDataPart("file", file.getName(), fileBody).build();
        Request request = new Request.Builder().post(body).url(baseUrl).build();
        long start = new Date().getTime();
        okHttpClient.newCall(request).execute().body().string();
        long end = new Date().getTime();
        System.out.println("use "+(end-start));
 
 
//下载文件
OkHttpClient okHttpClient = new OkHttpClient();
        Request.Builder builder=new Request.Builder().url(url);
        okHttpClient.newCall(builder.build()).enqueue(new Callback() {
            
            public void onResponse(Call arg0, Response arg1) throws IOException {
                // TODO Auto-generated method stub
                System.out.println("onResponse");
                InputStream is = arg1.body().byteStream();
                File file=new File("e:/down.png");
                int len=-1;
                byte[] buffer=new byte[1024];
                FileOutputStream fileOutputStream=new FileOutputStream(file);
                while((len=is.read(buffer))>0) {
                    fileOutputStream.write(buffer, 0, len);
                }
            }
            
            public void onFailure(Call arg0, IOException arg1) {
                // TODO Auto-generated method stub
                System.out.println("onFailure");
            }
        });
 
 
//post json ,header添加参数
OkHttpClient okHttpClient =new OkHttpClient();
        Request.Builder requetBuilder=new Request.Builder();
        requetBuilder.addHeader("token", "33344");
        RequestBody requestBody=RequestBody.create("{\"name\":\"rrrrxxxng\",\"sex\":30,\"id\":2}",MediaType.parse("application/json"));
       
        try {
            Response result = okHttpClient.newCall( requetBuilder.url(baseUrl).post(requestBody).build()).execute();
            System.out.println(result.body().string());
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }