文件的上传下载

一、servlet基本方式（servlet3.0以上）

 下面是工程的大致目录结构

upload.jsp

<%-- start --%>

<%@ 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>Insert title here</title>
</head>
<body>
<form action="test.do" enctype="multipart/form-data" method="post">
<input type="file" name="file"> <br>

<input type="submit" name="提交"> 
</form>
</body>
</html>



<%-- end --%>

Download.java

package com.upload;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;

//location表示文件缓存的位置
@MultipartConfig(location="D:/temp")
//定义servlet访问方式，对应web.xml
@WebServlet(loadOnStartup = 1, initParams = { @WebInitParam(name = "test", value = "test") }, urlPatterns = "/test.do")
public class Upload extends HttpServlet {

    private static final long serialVersionUID = 1L;
    
    private String test = "";

    @Override
    public void init(ServletConfig config) throws ServletException {
        test = config.getInitParameter("test");
        System.out.println(test);
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Part part = req.getPart("file");
        String info = part.getHeader("Content-Disposition");
        String fileName = info.substring(info.indexOf("filename="") + 10, info.lastIndexOf("""));
        //System.out.println(fileName);
        //part.write(fileName);
        resp.setContentType("application/x-msdownload");
        resp.addHeader("Content-Disposition", "attachment; filename="" + fileName + """);
        InputStream inputStream = part.getInputStream();
        byte[] buff = new byte[1024];
        OutputStream outputStream = resp.getOutputStream();
        while((inputStream.read(buff)) != -1) {
            outputStream.write(buff);
        }
        
    }

}

Upload.java

package com.upload;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;

//loaction定义要保存文件的路径
@MultipartConfig(location="D:/temp")
@WebServlet(loadOnStartup = 1, initParams = { @WebInitParam(name = "test", value = "test") }, urlPatterns = "/download.do")
public class Download extends HttpServlet {

    private static final long serialVersionUID = 1L;
    
    private String test = "";

    @Override
    public void init(ServletConfig config) throws ServletException {
        test = config.getInitParameter("test");
        System.out.println(test);
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Part part = req.getPart("file");
        String info = part.getHeader("Content-Disposition");
        String fileName = info.substring(info.indexOf("filename="") + 10, info.lastIndexOf("""));
        System.out.println(fileName);
        part.write(fileName);
        
    }

}

由于使用的是注释的方式注册servlet，所以web.xml没有注册信息

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>uploadAndDownload</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
</web-app>

启动tomcat，输入网址localhost:8080/uploadAndDownload/upload.jsp进行测试。

二、smartupload

需要下载smartupload的jar包


jsp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>Insert title here</title>
</head>
<body>
<form action="SUpload" method="post" enctype="multipart/form-data">
    <input type="file" name="file1"><br>
    <input type="file" name="file2"><br>
    <input type="file" name="file3"><br>
    
    <input type="submit" value="submit">
</form>
</body>
</html>

SUpload.java

package youth.hong;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.jspsmart.upload.Files;
import com.jspsmart.upload.SmartUpload;

@SuppressWarnings("serial")
public class SUpload extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        SmartUpload smartUpload = new SmartUpload();
        smartUpload.initialize(this.getServletConfig() , req, resp);
        String filePath = "D:/temp";
        smartUpload.setMaxFileSize(1024*1024*10);
        smartUpload.setTotalMaxFileSize(1024*1024*30);
        smartUpload.setAllowedFilesList("txt,jpg,jpeg,gif");
        try {
            //smartUpload.setDeniedFilesList("exe");
            //准备上传
            smartUpload.upload();
            //上传并返回上传成功的个数
            smartUpload.save(filePath);
        } catch (Exception e) {
            e.printStackTrace();
        }
        
        Files files = smartUpload.getFiles();
        
        for(int i = 0; i < files.getCount(); i++) {
            System.out.println("-------------------------");
            System.out.println("表单中的字段名：" + files.getFile(i).getFieldName());
            System.out.println("文件名：" + files.getFile(i).getFileName());
            System.out.println("文件路径名：" + files.getFile(i).getFilePathName());
            System.out.println("文件的大小：" + files.getFile(i).getSize());
            System.out.println("-------------------------");
        }
    
        
    }

    
    
}

 下载

Download.java

package youth.hong;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@SuppressWarnings("serial")
public class Download extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String fileName = req.getParameter("fileName");
        String path = "D:/" + fileName;
        File file = new File(path);
        InputStream inputStream = new FileInputStream(file);
        byte[] buff = new byte[inputStream.available()];
        OutputStream outputStream = resp.getOutputStream();
        resp.setContentType("application/x-msdownload");
        resp.addHeader("Content-Disposition", "attachment; filename="" + fileName + """);
        inputStream.read(buff);
        outputStream.write(buff);
        inputStream.close();
        outputStream.close();
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
    
    
    
}

批量下载

BatchDownload.java

package youth.hong;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@SuppressWarnings("serial")
public class BatchDownload extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        
        String[] fileNames = req.getParameterValues("fileName");
        
        String filePath = "D:/temp/";
        
        
        
        resp.setContentType("application/x-msdownload");
        resp.addHeader("Content-Disposition", "attachment; filename="hello.zip"");
        
        ZipOutputStream zip = new ZipOutputStream(resp.getOutputStream());
        
        for (String fileName : fileNames) {
            File file = new File(filePath + fileName);
            //用于区分单个文件
            ZipEntry zipEntry = new ZipEntry(fileName);
            zip.putNextEntry(zipEntry);
            
            FileInputStream read = new FileInputStream(file);
            byte[] buff = new byte[1024];
            
            while((read.read(buff)) != -1) {
                zip.write(buff);
            }
            
            zip.flush();
            zip.setComment("下载的项目：" + fileName +"
" );
            read.close();
        }
        
        
        zip.closeEntry();
        zip.close();
        
        
    }

    
    
}

 web.xml配置

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>scxz</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  
  <servlet>
      <servlet-name>upload</servlet-name>
      <servlet-class>youth.hong.Upload</servlet-class>
  </servlet>
  
  <servlet-mapping>
      <servlet-name>upload</servlet-name>
      <url-pattern>/upload</url-pattern>
  </servlet-mapping>
  
   <servlet>
      <servlet-name>download</servlet-name>
      <servlet-class>youth.hong.Download</servlet-class>
  </servlet>
  
  <servlet-mapping>
      <servlet-name>download</servlet-name>
      <url-pattern>/download</url-pattern>
  </servlet-mapping>
  
   <servlet>
      <servlet-name>SUpload</servlet-name>
      <servlet-class>youth.hong.SUpload</servlet-class>
  </servlet>
  
  <servlet-mapping>
      <servlet-name>SUpload</servlet-name>
      <url-pattern>/SUpload</url-pattern>
  </servlet-mapping>
  
  <servlet>
      <servlet-name>BatchDownload</servlet-name>
      <servlet-class>youth.hong.BatchDownload</servlet-class>
  </servlet>
  
  <servlet-mapping>
      <servlet-name>BatchDownload</servlet-name>
      <url-pattern>/BatchDownload</url-pattern>
  </servlet-mapping>
</web-app>

使用富文本上传文件

到http://kindeditor.codeplex.com/下载

jsp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>
<title>MultiImageDialog Examples</title>
<link rel="stylesheet" href="css/themes/default/default.css" />
<script src="js/kindeditor.js"></script>
<script src="js/lang/zh_CN.js"></script>
<script>
    var editor;
    KindEditor.ready(function(K) {
        editor = K.create('textarea[name="content"]', {
            allowFileManager : true,
　　　　　　　//设置上传文件的路径
            uploadJson : '/KindEditorSCXZ/uploadImg'
        });

    });
</script>
</head>
<body>
    <textarea name="content" style="800px;height:400px;visibility:hidden;">KindEditor</textarea>

</body>
</html>

upload.java

package com.upload;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;

@MultipartConfig(location = "D:\newworkspace20160818\KindEditorSCXZ\WebContent\images")
@WebServlet(urlPatterns = "/uploadImg")
public class Upload extends HttpServlet {

    private static final long serialVersionUID = 1L;

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    //    Collection<Part> parts = req.getParts();
        /**
         * 由于富文本是使用多次请求进行上传操作的，所以不存在一次请求有多个文件同时上传的问题
         */
        String filename = "";
        //富文本上传时的文件域名
        Part part = req.getPart("imgFile");
        String info = part.getHeader("Content-Disposition");
        System.out.println(info);
        filename = info.substring(info.indexOf("filename="") + 10, info.lastIndexOf("""));
        /*for (Part part : parts) {
            String info = part.getHeader("Content-Disposition");
            filename = info.substring(info.indexOf("filename="" + 10), info.lastIndexOf("""));
            part.write(filename);
        }*/
        part.write(filename);
        resp.setContentType("application/json;charset=utf-8");
        PrintWriter pw = resp.getWriter();
        pw.write("{"error":0, "url":"/KindEditorSCXZ/images/" + filename + ""}");
    }

}

 使用springMVC上传下载

UploadDownload.java

package youth.hong.annotation;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Date;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.UUID;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;
import org.springframework.web.multipart.commons.CommonsMultipartResolver;
import org.springframework.web.servlet.mvc.multiaction.MultiActionController;

@Controller
@RequestMapping("/upload")
public class UploadDownloadController extends MultiActionController {
    
    @RequestMapping("/file")
    public String uploadFile(@RequestParam("file") MultipartFile file, HttpServletRequest request, HttpServletResponse response){
        
        InputStream in = null;
                
        OutputStream out = null;
        
        System.out.println("文件名：" + file.getOriginalFilename() + "---------" + file.getContentType() + "----------" + file.getSize());
        
        long start = System.currentTimeMillis();
        
        if(!file.isEmpty()) {
            
            try {
                in = file.getInputStream();
                
                out = new FileOutputStream("D:/" + new Date().getTime() + file.getOriginalFilename());
                
                byte[] buff = new byte[1024];
                
                while((in.read(buff)) != -1) {
                    out.write(buff);
                    out.flush();
                }
                
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {
                    if(in != null) {
                        in.close();
                    }
                    if(out != null) {
                        out.close();
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
                
            }
        }
        
        long end = System.currentTimeMillis();
        
        System.out.println("传统java上传用时：" + (end - start));
        
        return "/fileupload";
    }
    
    
    
    @RequestMapping("/file2")
    public String uploadFile2(HttpServletRequest request, HttpServletResponse response){
        //拿到文件上传解析器
        CommonsMultipartResolver resolver = new CommonsMultipartResolver(request.getServletContext());
        //传统的java解析request是否为上传文件，这个与xml配置的解析器是一样的。
        if(resolver.isMultipart(request)) {
            
            MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest)request;
            //键值对的形式
            Map<String, MultipartFile> map = multipartRequest.getFileMap();
            
            Set<Map.Entry<String, MultipartFile>> set = map.entrySet();
            
            for (Entry<String, MultipartFile> entry : set) {
                
                MultipartFile file = entry.getValue();
                
                String fileName = "demo" + UUID.randomUUID() + "." + file.getOriginalFilename().split("\.")[1];
                
                File f = new File("D:/" + fileName);
                
                try {
                    long start = System.currentTimeMillis();
                    //将文件输出
                    file.transferTo(f);
                    long end = System.currentTimeMillis();
                    
                    System.out.println("springMVC 上传用时：" + (end - start));
                } catch (IllegalStateException | IOException e) {
                    e.printStackTrace();
                }
                
                System.out.println("ok!!");
            }
            
        }
        
        return "/fileupload";
    }
    
    @RequestMapping("/file3")
    public String uploadFile3(MultipartFile[] multipartFile) throws Exception {
        
        
        for (MultipartFile file : multipartFile) {
            //检查是否有文件输入框没有输入文件
            if(!file.isEmpty()) {
                file.transferTo(new File("D:/temp/", file.getOriginalFilename()));
            }
        }
        
        return "/fileupload";
    }
    
    @RequestMapping("/download")
    public void download(@RequestParam("fileName") String fileName, HttpServletRequest request, HttpServletResponse response) throws Exception {
        //得到当前上传缓存文件的位置
        String path = Thread.currentThread().getContextClassLoader().getResource("").getPath();
        
        System.out.println(path);
        
        response.setCharacterEncoding("utf-8");
        
        response.setContentType("multipart/form-data");
        
        File file = new File(path + "/" + fileName);
        
        InputStream in = new FileInputStream(file);
        
        OutputStream out = response.getOutputStream();
        
        byte[] buff = new byte[1024];
        
        int length = 0;
        
        while((length = in.read(buff)) != -1) {
            out.write(buff);
        }
                
        
    }
    
    
}

upload.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>Insert title here</title>
</head>
<body>
<form action="upload/file" method="post" enctype="multipart/form-data">
    　　
        file: <input type="file" name="file"><br>
        
        <input type="submit" value="submit">
    </form>
    
<form action="upload/file2" method="post" enctype="multipart/form-data">
    　　
        file: <input type="file" name="file"><br>
        
        <input type="submit" value="submit">
    </form>
    
    <form action="upload/file3" method="post" enctype="multipart/form-data">
    　　
        file: <input type="file" name="file"><br>
        file: <input type="file" name="file"><br>
        
        <input type="submit" value="submit">
    </form>
</body>
</html>

download.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>Insert title here</title>
</head>
<body>
<a href="upload/download?fileName=C语言游戏.doc">下载</a>
</body>
</html>

spring.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:p="http://www.springframework.org/schema/p"  
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop.xsd">
    <context:component-scan base-package="youth.hong.annotation"></context:component-scan>
　　

 　　<!-- 推荐使用这个标签定义注解的方式 -->
    <!-- <mvc:annotation-driven></mvc:annotation-driven> -->
    
　　<!-- 使用bean注入的方式配置注解解析，现在不推荐了，仅作了解使用 -->
    <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping"/>

    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"/>
    
　　<!-- 古老的xml配置方式，使用这些bean定义你访问的url是想要调用哪个方法，仅作了解，现在没人还用这个 -->
    <!-- <bean name="/youth/hong" class="youth.hong.HelloWorld"></bean>
    <bean name="/multiple" class="youth.hong.MultiController">
        <property name="methodNameResolver">
            <ref bean="paraMethodResolver"/>
        </property>
    </bean>
    
    <bean name="/img" class="youth.hong.StaticController">
        <property name="methodNameResolver">
            <ref bean="paraMethodResolver"/>
        </property>
    </bean>
    <bean id="paraMethodResolver"
        class="org.springframework.web.servlet.mvc.multiaction.ParameterMethodNameResolver">
        <property name="paramName">
            传参时的参数名http://localhost:8888/springMVC_003_multiple/multiple?action=update
            <value>action</value>
        </property>
        <property name="defaultMethodName">
            <value>img</value>
        </property>
    </bean> -->
    
    
    <!-- 告知静态文件不要拦截，直接访问 -->
    <mvc:resources location="/image/" mapping="/dog/image/**"></mvc:resources>

    <bean id="internalResourceViewResolver"
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>
    
    <!-- SpringMVC在超出上传文件限制时，会抛出org.springframework.web.multipart.MaxUploadSizeExceededException -->  
    <!-- 该异常是SpringMVC在检查上传的文件信息时抛出来的，而且此时还没有进入到Controller方法中 -->  
    <bean id="exceptionResolver" class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">  
        <property name="exceptionMappings">  
            <props>  
                <!-- 遇到MaxUploadSizeExceededException异常时，自动跳转到/WEB-INF/jsp/error_fileupload.jsp页面 -->  
                <prop key="org.springframework.web.multipart.MaxUploadSizeExceededException">error_fileupload</prop>  
            </props>  
        </property>  
    </bean>  
    
     <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver" p:defaultEncoding="UTF-8" />
</beans>

struts2框架上传下载

Action.java

package youth.hong;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.UUID;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

@SuppressWarnings("serial")
public class Action extends ActionSupport{
    private String title;
    private File[] upload;//private List<File> upload
    private String[] uploadContentType;//private List<String>
    private String[] uploadFileName;
    private String savePath;
    private String allowTypes;
    
    public String getAllowTypes() {
        return allowTypes;
    }
    public void setAllowTypes(String allowTypes) {
        this.allowTypes = allowTypes;
    }
    
    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 getSavePath() {
        return savePath;
    }
    public void setSavePath(String savePath) {
        this.savePath = savePath;
    }
    public String getTitle() {
        return title;
    }
    public void setTitle(String title) {
        this.title = title;
    }
    @Override
    public String execute() throws Exception {
        String[] types = this.getTypes();
        String check = this.fileFilter(types);
        System.out.println(check);
        if(check == null) {
            return INPUT;
        }
        String newName = null;
        FileInputStream fis = null;
        FileOutputStream fos = null;
        for(int i = 0; i < upload.length; i++) {
            
            newName = UUID.randomUUID() + uploadFileName[i].substring(uploadFileName[i].lastIndexOf('.'));
            uploadFileName[i] = newName;
            String path = ServletActionContext.getServletContext().getRealPath(savePath);
            System.out.println(path + "\" + newName);
            System.out.println(upload[i].getName());
            fis = new FileInputStream(upload[i]);
            fos = new FileOutputStream(path + "\" + newName);
            byte[] buff = new byte[1024];
            int len = 0;
            while((len=fis.read(buff)) > 0) {
                fos.write(buff, 0, len);
            }
        }
        this.setUploadFileName(uploadFileName);
        fis.close();
        fos.close();
        return SUCCESS;
    }
    /**
     * 还可以使用struts2自带的fileUpload拦截器来过滤
     * @param types
     * @return
     */
    
    public String fileFilter(String[] types) {
        boolean check;
        for(int i = 0; i < upload.length; i++) {
            
            check = false;
            
            for(String string : types) {
                if(uploadContentType[i].equals(string)) {
                    check = true;
                }
            }
            
            if(!check) {
                return null;
            }
        }
        return "continue";
    }
    
    public String[] getTypes() {
        String[] types = allowTypes.split(",");
        return types;
    }
    
}

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>

    <!-- 动态地调用方法打开 -->
    <constant name="struts.enable.DynamicMethodInvocation" value="true" />
    <constant name="struts.devMode" value="true" />
    <constant name="struts.i18n.encoding" value="utf-8"></constant>
    <constant name="struts.ognl.allowStaticMethodAccess" value="true"></constant>
    <constant name="struts.custom.i18n.resources" value="global"></constant>
    
   
 
     <package name="youth" namespace="/" extends="struts-default">
     
         
         <action name="test" class="youth.hong.Action">
             <interceptor-ref name="defaultStack"></interceptor-ref>
             <interceptor-ref name="fileUpload">
　　　　　　　　　　<!-- 使用拦截器进行文件上传操作的限制 -->
                 <param name="allowedTypes">image/jpeg,image/jpg,image/bmp,image/png</param>
                 <param name="maxSize">200000000000000</param><!-- 单位字节 -->
             </interceptor-ref>
             <param name="savePath">/upload</param>
　　　　　　　　<!-- 手工进行文件上传的限制 -->
             <param name="allowTypes">image/jpeg,image/jpg,image/bmp,image/png</param>
             <result name="success">/success.jsp</result>
             <result name="input">/test.jsp</result>

         </action>
   
    </package>
    
    
    <!-- Add packages here -->

</struts>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>Struts2_001</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <filter>
    <filter-name>struts2</filter-name>
    <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>struts2</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping> 
</web-app>

upload.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib uri="/struts-tags" prefix="s" %>
<%=application.getRealPath("/upload") %>
<!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>Insert title here</title>
<script type="text/javascript">
/* function checkusername() {
    var username = document.getElementById("username");
    var request = new XMLHttpRequest();
    url = "path/index";
    request.open("POST", url, true);
    request.send(username.value);
} */
</script>
</head>
<body>
<s:fielderror></s:fielderror>
<s:head/>
<form method="post" action="test" enctype="multipart/form-data">
    <input type="file" name="upload" /><br>
    <br>
    <input type="file" name="upload" /><br>
    <br>
    <input type="file" name="upload" /><br>
    <br>
    <input type="text" name="title" /><br>
    <br>
    <input type="submit" value="submit" />

</form>

</body>
</html>

success.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib uri="/struts-tags" prefix="s"%>
<!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>Insert title here</title>
</head>
<body>
<img src="/upload/<s:property value='uploadFileName'  />"/>

</body>
</html>

Download

package youth.hong;

import java.io.InputStream;
import java.io.UnsupportedEncodingException;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

@SuppressWarnings("serial")
public class Action extends ActionSupport{
    private String inputName;
    private String contentType;
    private String fileName;
    
    public String getInputName() {
        return inputName;
    }
    public void setInputName(String inputName)  {
        this.getInputStream();
        System.out.println(inputName);
        try {
            inputName = new String(inputName.getBytes("ISO-8859-1"),"utf-8");
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        this.inputName = inputName;
    }
    public String getContentType() {
        return contentType;
    }
    public void setContentType(String contentType)  {
        try {
            contentType = new String(contentType.getBytes("ISO-8859-1"),"utf-8");
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        this.contentType = contentType;
    }
    public String getFileName() {
        return fileName;
    }
    public void setFileName(String fileName)  {
        try {
            fileName = new String(fileName.getBytes("ISO-8859-1"),"utf-8");
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        this.fileName = fileName;
    }
    
    public InputStream getInputStream() {
        InputStream is = ServletActionContext.getServletContext().getResourceAsStream("/upload/warArea.jsp");
        System.out.println(is);
        return is;
    }
    
}

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>

    <!-- 动态地调用方法打开 -->
    <constant name="struts.enable.DynamicMethodInvocation" value="true" />
    <constant name="struts.devMode" value="true" />
    <constant name="struts.i18n.encoding" value="utf-8"></constant>
    <constant name="struts.ognl.allowStaticMethodAccess" value="true"></constant>
    <constant name="struts.custom.i18n.resources" value="global"></constant>
    
   
 
     <package name="youth" namespace="/" extends="struts-default">
     
         
         <action name="download" class="youth.hong.Action">
             <result name="success" type="stream">
                 <param name="contentType">${contentType}</param>
                 <param name="inputName">${getInputStream}</param>
                 <param name="contentDisposition">filename="${fileName}"</param>
                 <param name="bufferSize">800000000000000</param>
             </result>
         </action>
   
    </package>
    
    
    <!-- Add packages here -->

</struts>

jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib uri="/struts-tags" prefix="s" %>
<!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>Insert title here</title>
<script type="text/javascript">
/* function checkusername() {
    var username = document.getElementById("username");
    var request = new XMLHttpRequest();
    url = "path/index";
    request.open("POST", url, true);
    request.send(username.value);
} */
</script>
</head>
<body>
<a href="download?inputName=/upload/warArea.jpg&contentType=image/jpg&fileName=warArea.jpg">download</a>

</body>
</html>
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原文地址：https://www.cnblogs.com/honger/p/5846810.html