用httpclient4.3 post方式推送文件到服务端  
准备：httpclient-4.3.3.jar；httpcore-4.3.2.jar；httpmime-4.3.3.jar
/** * 上传文件 * @throws  ParseException * @throws  IOException */   publicstaticvoidpostFile()throwsParseException, IOException{    CloseableHttpClient httpClient = HttpClients.createDefault();    try{        // 要上传的文件的路径        String filePath =newString("F:/pic/001.jpg");        // 把一个普通参数和文件上传给下面这个地址 是一个servlet        HttpPost httpPost =newHttpPost(                "http://localhost:8080/xxx/xxx.action");        // 把文件转换成流对象FileBody        File file =newFile(filePath);        FileBody bin =newFileBody(file);         StringBody uploadFileName =newStringBody(                "把我修改成文件名称", ContentType.create(                        "text/plain", Consts.UTF_8));        //以浏览器兼容模式运行，防止文件名乱码。            HttpEntity reqEntity = MultipartEntityBuilder.create().setMode(HttpMultipartMode.BROWSER_COMPATIBLE)                .addPart("uploadFile", bin)//uploadFile对应服务端类的同名属性<File类型>                .addPart("uploadFileName", uploadFileName)//uploadFileName对应服务端类的同名属性<String类型>                .setCharset(CharsetUtils.get("UTF-8")).build();         httpPost.setEntity(reqEntity);         System.out.println("发起请求的页面地址 "+ httpPost.getRequestLine());        // 发起请求 并返回请求的响应        CloseableHttpResponse response = httpClient.execute(httpPost);        try{            System.out.println("----------------------------------------");            // 打印响应状态            System.out.println(response.getStatusLine());            // 获取响应对象            HttpEntity resEntity = response.getEntity();            if(resEntity !=null) {                // 打印响应长度                System.out.println("Response content length: "                        + resEntity.getContentLength());                // 打印响应内容                System.out.println(EntityUtils.toString(resEntity,                        Charset.forName("UTF-8")));            }            // 销毁            EntityUtils.consume(resEntity);        }finally{            response.close();        }    }finally{        httpClient.close();    }}  /** * 下载文件 * @param  url * @param  destFileName   xxx.jpg/xxx.png/xxx.txt * @throws  ClientProtocolException * @throws IOException */publicstaticvoidgetFile(String url, String destFileName)        throwsClientProtocolException, IOException {    // 生成一个httpclient对象    CloseableHttpClient httpclient = HttpClients.createDefault();    HttpGet httpget =newHttpGet(url);    HttpResponse response = httpclient.execute(httpget);    HttpEntity entity = response.getEntity();    InputStream in = entity.getContent();    File file =newFile(destFileName);    try{        FileOutputStream fout =newFileOutputStream(file);        intl = -1;        byte[] tmp =newbyte[1024];        while((l = in.read(tmp)) != -1) {            fout.write(tmp,0, l);            // 注意这里如果用OutputStream.write(buff)的话，图片会失真，大家可以试试        }        fout.flush();        fout.close();    }finally{        // 关闭低层流。        in.close();    }    httpclient.close();}