如何使用java提交表单中的文件？

Question

我使用以下代码提交表单：

URL url = new URL(submit_url);
HttpURLConnection connection = (HttpURLConnection)url.openConnection();

connection.setDoInput(true);
connection.setDoOutput(true);
connection.setUseCaches(false);
connection.setRequestMethod("POST");
connection.setRequestProperty("Connection", "Keep-Alive");
connection.setRequestProperty("Content-Type", "multipart/form-data;boundary=*****");
connection.setRequestProperty("Cookie", cookie);            

BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(connection.getOutputStream()));
bw.write(query);
bw.write("\r\n");
bw.flush();
bw.close();

但我也需要提交一份文件。文件输入名称是：file，我的文件位于：d：/images/test.gif 请帮我提交图片。 查询是一个字符串：name = username＆amp; title = title

Answer 1

从DataOutputStream创建HttpUrlConnection，然后将要上传的字节写入服务器：

DataOutputStream dataOutputStream = 
        new DataOutputStream(connection.getOutputStream());
dataOutputStream.writeBytes(bytes);
dataOutputStream.close();