在struts2中使用MultipartEntityBuilder 在 addPart("file",new FileBody(file))出错

最近做一个类似于文件中专的功能，前端生成pdf文件，传到后台，再用httpclient访问接口发送到别人的服务器，具体代码如下

HttpClient httpClient = new DefaultHttpClient(); 
HttpPost post = new HttpPost(url); 
httpClient.getParams().setParameter(CoreConnectionPNames.CONNECTION_TIMEOUT, 4000);
httpClient.getParams().setParameter(CoreConnectionPNames.SO_TIMEOUT, 4000);
//设置不使用长连接

post = new HttpPost(url);
// 构造消息头
post.addHeader("Content-Type", "multipart/form-data; boundary="+boundary); // 添加请求头

post.setHeader("Connection", "keep-alive");

//    post.setHeader("Accept-Language","zh-CN,zh;q=0.9"); 
//    post.setHeader("Accept-Encoding","gzip, deflate");
post.setHeader("x-tif-paasid", passid);
post.setHeader("x-tif-uuid",uuid);

String result="";
MultipartEntityBuilder builder = MultipartEntityBuilder.create();

//模拟浏览器
builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
builder.setBoundary(boundary);
builder.addPart("file",new FileBody(file));
HttpEntity entity = builder.build();
try {
post.setEntity(entity);
HttpResponse response =null;
response = httpClient.execute(post);
// 检验返回码
int statusCode = response.getStatusLine().getStatusCode();
if(statusCode != HttpStatus.SC_OK){
System.out.println("请求出错："+statusCode);
}else{
HttpEntity ent = response.getEntity();
result = entityToString(ent);
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
if(post != null){
try {
post.releaseConnection();
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
return result;

 

在main方法调用时访问通畅，但是在ssh的struts2的应用中，运行到 builder.addPart("file",new FileBody(file));这里卡住了，断点调试的时候进入一个OgnlRuntime.class，不知道是啥意思，不知道有没有碰到过这个问题的小伙伴