Struts2(十五)实现文件上传

一、导入包

需要将commons-fileupload和commons-io包和struts包一起导入

实现步骤：

在Jsp页面实现客户端选择上传文件
配置Struts.xml，拦截器会自动接收上传的文件
在Action中实现代码上传文件存入服务器中
跳转至新页面展示上传的文件

二、单个文件上传

上传页面

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>单个文件上传</title>
</head>
<body>
<form action="doUpload.action" method="post" enctype="multipart/form-data">
<input type="file" name="upload"/>
<input type="submit" value="上传">
</form>
</body>
</html>

上传成功页面

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
 <%@ taglib prefix="s" uri="/struts-tags" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>文件上传成功</title>
</head>
<body>
<h1>上传的文件</h1>
<img alt="图片" src="<s:property value='savePath'/>" />

</body>
</html>

UploadAction

package com.pb.web.action;

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

import org.apache.commons.io.IOUtils;
import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class UploadAction extends ActionSupport {

    //上传文件全路径、类型、文件名
    private File upload;
    private String uploadContentType;
    private String uploadFileName;
    //新文件保存路径和名称
    private String savePah;

    public String doUpload() throws IOException{
        System.out.println(upload);
        System.out.println(uploadContentType);
        System.out.println(uploadFileName);
        String newFileName=System.currentTimeMillis()+uploadFileName.substring(uploadFileName.lastIndexOf("."));
        System.out.println("新的文件名:"+newFileName);
        //获取上传路径
        savePah=ServletActionContext.getServletContext().getRealPath("/upload/"+newFileName);
        System.out.println("上传保存的路径和名称:"+savePah);
        //使用文件输入、输出流写入文件
        FileInputStream fis=new FileInputStream(upload);
        FileOutputStream fos=new FileOutputStream(savePah);
        //设置缓冲区大小
        /*byte[] bytes=new byte[1024];
        //读取文件
        int length=fis.read(bytes);
        while(length>0){
            //写入文件
            fos.write(bytes);
            length=fis.read(bytes);
        }*/
        //复制文件
        IOUtils.copy(fis, fos);
        fos.flush();
        fos.close();
        fis.close();
        
        return SUCCESS;
    }


    public File getUpload() {
        return upload;
    }


    public void setUpload(File upload) {
        this.upload = upload;
    }


    public String getUploadContentType() {
        return uploadContentType;
    }


    public void setUploadContentType(String uploadContentType) {
        this.uploadContentType = uploadContentType;
    }


    public String getUploadFileName() {
        return uploadFileName;
    }


    public void setUploadFileName(String uploadFileName) {
        this.uploadFileName = uploadFileName;
    }


    public String getSavePah() {
        return savePah;
    }


    public void setSavePah(String savePah) {
        this.savePah = savePah;
    }
    
    
    
}

struts.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
    "http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>

    <constant name="struts.enable.DynamicMethodInvocation" value="false" />
    <constant name="struts.devMode" value="true" />
   <package name="default" namespace="/" extends="struts-default">
    <action name="doUpload" class="com.pb.web.action.UploadAction" method="doUpload">
    <result name="success">
    /singleUploadSuccess.jsp
    </result>
    <result name="error">
    /error.jsp
    </result>
    <result name="input">
    /singleUpload.jsp
    </result>
    </action>
    </package>
</struts>

三、限制文件大小

在struts.xml中配置常量

<constant name="struts.multipart.maxSize" value="5000000"/>
5M大小

在action下配置拦截器

<interceptor-ref name="fileUpload">
    <param name="maximumSize">5000000</param>    
    </interceptor-ref>
    <interceptor-ref name="defaultStack"></interceptor-ref>

五、限制文件类型

<interceptor-ref name="fileUpload">
    <param name="allowedTypes">image/pjpeg,image/jpeg,image/gif,image/png</param>
    <param name="maximumSize">5000000</param>    
    </interceptor-ref>
    <interceptor-ref name="defaultStack"></interceptor-ref>

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
    "http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>

    <constant name="struts.enable.DynamicMethodInvocation" value="false" />
    <constant name="struts.devMode" value="true" />
    <constant name="struts.multipart.maxSize" value="1000000" />
    <constant name="struts.multipart.saveDir" value="/tmp"/>
    <package name="default" namespace="/" extends="struts-default">
    <action name="doupload" class="com.pb.web.action.UploadAction" method="upload">
    <interceptor-ref name="fileUpload">
            <param name="maximumSize">40000</param>
             <param name="allowedTypes">image/jpeg,image/pjpeg,image/gif,image/png</param>
        </interceptor-ref> 
        <interceptor-ref name="defaultStack"></interceptor-ref>
    <result name="success">
    /oneUploadSuccess.jsp
    </result>
    <result name="input">
    /error.jsp
    </result>
    </action>
    </package>
</struts>

六、多个文件上传

和单个文件上传一个只是接收参数变为数组

mulUpload.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>多个 文件上传</title>
<script type="text/javascript" src="js/jquery-1.11.2.min.js"></script>
<script type="text/javascript">
function addFile(){
    /*  获取父元素*/
    var parent=$("#add").parent();
    /*创建新的节点  */
    var file=$("<input type='file' name='upload' /><br/>");
    /* 添中节点 */
    parent.append(file);
    
}
</script>
</head>
<body>
<form action="doupload.action" method="post" enctype="multipart/form-data">
<input type="file" name="upload" />
<input type="button" value="继续添加"  onclick="addFile();" id="add"/>
<input type="submit" value="上传" /><br/>
</form>
</body>
</html>

error.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>上传失败</title>
</head>
<body>
上传失败<a href="mulUpload.jsp">返回</a>
<s:debug/>
</body>
</html>

mulUploadSuccess.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>上传成功</title>
</head>
<body>
<!--显示上传的图片  -->
<s:iterator value="savePath" var="i">
<img alt="图片" src="<s:property value='#i'/>">
</s:iterator>
<s:debug/>
</body>
</html>

UploadAction.java

package com.pb.web.action;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.io.IOUtils;
import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class UploadAction extends ActionSupport {
    // 文件上传路径、类型、名称
    private List<File> upload;
    private List<String> uploadFileName;
    private List<String> uploadContentType;
    // 新的文件名称
    private List<String> savePath=new ArrayList<String>();

    public String upload() throws IOException {
        for (int i = 0; i < upload.size(); i++) {
            //重命名 用长时间+原来的文件名
            String newFileName = System.currentTimeMillis()+""+uploadFileName.get(i);
            System.out.println("新的文件名:"+newFileName);
        //获取上传路径
            //将新的路径和名称添加入集合
            savePath.add(ServletActionContext.getServletContext().getRealPath("/upload/"+newFileName));
            System.out.println(savePath.get(i));
            //读取文件
            FileInputStream fis=new FileInputStream(upload.get(i));
            //写入文件
            FileOutputStream fos=new FileOutputStream(savePath.get(i));
            //将文件从输入流，复制到输出流中
            IOUtils.copy(fis, fos);
            //强制刷新输出流，清空缓冲区
            fos.flush();
            fos.close();
            fis.close();
        }

        return SUCCESS;
    }

    public List<File> getUpload() {
        return upload;
    }

    public void setUpload(List<File> upload) {
        this.upload = upload;
    }

    public List<String> getUploadFileName() {
        return uploadFileName;
    }

    public void setUploadFileName(List<String> uploadFileName) {
        this.uploadFileName = uploadFileName;
    }

    public List<String> getUploadContentType() {
        return uploadContentType;
    }

    public void setUploadContentType(List<String> uploadContentType) {
        this.uploadContentType = uploadContentType;
    }

    public List<String> getSavePath() {
        return savePath;
    }

    public void setSavePath(List<String> savePath) {
        this.savePath = savePath;
    }


}

struts.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
    "http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>

    <constant name="struts.enable.DynamicMethodInvocation" value="false" />
    <constant name="struts.devMode" value="true" />
    <!--设置文件大小拦截器  -->
    <constant name="struts.multipart.maxSize" value="10000000"></constant>
    
    <constant name="struts.multipart.saveDir" value="/tmp"/>
    <package name="default" namespace="/" extends="struts-default">
    <action name="doupload" class="com.pb.web.action.UploadAction" method="upload">
    
    <interceptor-ref name="fileUpload">
    <!--设置文件类型拦截器  -->
    <param name="allowedTypes">image/jpeg,image/pjpeg,image/png</param>
    <!--设置文件大小拦截器  -->
    <param name="maximumSize">5000000</param>
    </interceptor-ref>
    <!-- struts默认的拦截器 -->
    <interceptor-ref name="defaultStack" />
    
    <result name="success">
    /mulUploadSuccess.jsp
    </result>
    <result name="input">
    /error.jsp
    </result>
    </action>
    </package>
</struts>

更详细的请参考：struts下载包中的帮助文档：

file://stuts2/struts2-2.3.4.1-all/struts-2.3.4.1/docs/WW/file-upload.html

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原文地址：https://www.cnblogs.com/liunanjava/p/4389661.html