java 上传文件(简单例子)

jsp页面：

<%-- 有附件的话:要设置enctype属性;  --%>
<html:form action="submitPublishReply.do" method="POST" onsubmit="return check();"  enctype="multipart/form-data">

     附件：<input type="file" name="attach" />
    <input type="submit" value="回 复" />
  </ul>
</html:form>

 

 ActionForm:

private FormFile file;

 

Action：

import org.apache.commons.fileupload.*;
import org.apache.commons.fileupload.disk.*;
import org.apache.commons.fileupload.servlet.*;
import java.io.PrintWriter;
import java.io.File;
import org.apache.struts.upload.FormFile;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.FileOutputStream;
            //附件
            FormFile file = (FormFile) replyForm.getFile();
            if (file != null && file.getFileName().trim().length() > 0) {
                String fileName = file.getFileName();
                byte[] b = file.getFileData();
                String dir = request.getRealPath("/uploadfile"); //request.getRealPath获得web应用程序在服务器的绝对路径
                OutputStream streamOut = new FileOutputStream(dir + "/" +
                        fileName);
                streamOut.write(b, 0, b.length);
            }