如何使用java以表单形式提交文件?

如何使用java以表单形式提交文件?,java,file,Java,File,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"); conne

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。文件输入名称为:file,我的文件位于:d:/images/test.gif 请帮我也提交图片。
查询是一个字符串:name=username&title=title

HttpUrlConnection
创建一个
DataOutputStream
,然后写入要上载到服务器的任何字节:

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

您可以在答案底部附近找到一个示例: