Java Post 上传文件，返回结果为文件

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.3</version>

</dependency>
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpmime</artifactId>
    <version>4.3</version>
</dependency>

public static void main(String[] args) throws Exception {
        byte[] b = getImage("14598222157082.png");
        HttpClient httpClient = HttpClients.createDefault();
        HttpPost httppost = new HttpPost("http://localhost/test");
        MultipartEntityBuilder mEntityBuilder = MultipartEntityBuilder.create();
        mEntityBuilder.addBinaryBody("file",b,ContentType.MULTIPART_FORM_DATA,"14598222157082.png");
        httppost.setEntity(mEntityBuilder.build());
        HttpResponse response = httpClient.execute(httppost);
        Header[] hs= response.getAllHeaders();
        for(Header h:hs)System.out.println(h.getName()+":"+h.getValue());
        InputStream in=response.getEntity().getContent();
        save(in, "result.png");
    }
public static void  save(InputStream in,String path) throws IOException{
        OutputStream out =new FileOutputStream(path);
        int l;
        int n=0;
        //不要使用in.available()  容易丢失数据
         while ((l = in.read()) != -1) {
             n++;
             out.write(l);
                }  

        out.flush();
        out.close();
    }