struts学习上传文件

1.新建fileUpload.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ taglib prefix="s" uri="/struts-tags"  %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>上传页面</title>
  </head>
  
  <body>
    <s:form namespace="/sys" action="FileUpload" enctype="multipart/form-data" method="post">
        <s:file name="upload"></s:file>
        <s:submit value="提交"></s:submit>
    </s:form>
  </body>
</html>

2.配置struts.xml
　　

<package name="sys" namespace="/sys" extends="default">
    <action name="*" class="web.{1}Action">
        <result>/success.jsp</result>
    </action>
</package>

3.新建class FileUploadAction.class

package web;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import javax.servlet.ServletContext;

import org.apache.struts2.util.ServletContextAware;

import com.opensymphony.xwork2.Action;

public class FileUploadAction implements ServletContextAware{
    private File upload;
    private String uploadFileName;
    private String uploadContentType;
    private ServletContext servletContext;
    
    public String execute() throws IOException {
        //输入流
        FileInputStream fis = null;
        //输出流
        FileOutputStream fos = null;
        //获得upload的绝对路径
        String path = servletContext.getRealPath("upload");
        //将图片名称带上当前时间,避免图片名称重复
        this.setUploadFileName(System.currentTimeMillis() + uploadFileName);
        //图片的绝对路径
        path = path + "/" + uploadFileName;
        try {
            fis = new FileInputStream(upload);
            fos = new FileOutputStream(path);
            byte[] bytes = new byte[1024];
            while ((fis.read(bytes)) != -1) {
                fos.write(bytes);
            }
        } finally {
            if (fos != null) 
                fos.close();
            
            if (fis != null)
                fis.close();
        }
        
        return Action.SUCCESS;
    }
    
    public File getUpload() {
        return upload;
    }
    public void setUpload(File upload) {
        this.upload = upload;
    }
    public String getUploadFileName() {
        return uploadFileName;
    }
    public void setUploadFileName(String uploadFileName) {
        this.uploadFileName = uploadFileName;
    }
    public String getUploadContentType() {
        return uploadContentType;
    }
    public void setUploadContentType(String uploadContentType) {
        this.uploadContentType = uploadContentType;
    }

    @Override
    public void setServletContext(ServletContext context) {
        // TODO Auto-generated method stub
        this.servletContext = context;
    }
}

4.新建成功页面 success.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'success.jsp' starting page</title>
  </head>
  
  <body>
      <img alt="" src="upload/<s:property value="uploadFileName"/>"/>
    <s:debug/>
    上传成功. <br>
  </body>
</html>

5.发布,启动tomcat,访问fileUpload.jsp,上传图片,成功后跳转至success.jsp,并显示刚刚上传的图片