《Struts 的文件上传与下载》

傷城~ 2022-04-16 05:46 236阅读 0赞

(部分代码，内有注释)  
**1:Action**

package com.zy.interceptor;
    
    import java.io.BufferedInputStream;
    import java.io.BufferedOutputStream;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.IOException;
    
    import org.apache.commons.io.FileUtils;
    
    import com.zy.action.BaseAction;
    
    import jdk.nashorn.internal.objects.annotations.Where;
    /**
     * 图片上传的三种方式：
     * 1：上传的图片以二进制的形式保存到数据库（activtit,jbpm工作流框架，OA系统）
     * 2：将文件上传到服务器的硬盘（要求：CPU快，硬盘大）
     * 3：将文件上传到tomcat所在的服务器（对应的静态资源服务器--上线不重启）
     * 
     * 真实路径与虚拟路径的概念
     * 
     * @author 1
     *
     */
    public class FileAction extends BaseAction{
    //	命名：xxxx,xxxxFileName,xxxxContentType
    	private File file; //文件
    	private String fileFileName; //文件名
    	private String fileContentType; //文件类型
        //虚拟路径	
    	private String serverDir = "/upload";
    	
    	/**
    	 * 上传
    	 * @return
    	 */
    	public String upload() {
    		System.out.println("fileFileName 文件名 :"+fileFileName);
    		System.out.println("fileContentType 文件类型 :"+fileContentType);
    		
    		String realPath = getRealPath(serverDir + "/" + fileFileName);
    		try {
    			FileUtils.copyFile(file, new File(realPath)); //参数1：从哪里读取， 参数2：写到哪里去
    			System.out.println("serverDir 虚拟路径 :" + serverDir);
    			System.out.println("realPath 真实路径 :" + realPath);
    		} catch (IOException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    		return "demo2"; //返回结果码
    	}
    	
    	/**
    	 * 获取文件夹的真实路径
    	 * @param path
    	 * @return
    	 */
    	private String getRealPath(String path) {
    		return this.request.getServletContext().getRealPath(path);
    	}
    	
    	/**
    	 * 下载
    	 * @return
    	 */
    	public String saveAs() {
    //		从数据库获取fileName，fileType
    		String fileName = "25e58PIC8GS_1024.jpg";
    		String fileType = "image/jpeg";
    		response.setContentType(fileType);
    		response.setHeader("Content-Disposition","attachment;filename=" + fileName);
    //		从服务器获取图片到本地
    		String realPath = getRealPath(serverDir + "/" + fileName);
    		try {
    			FileUtils.copyFile(new File(realPath), response.getOutputStream());
    		} catch (IOException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    		return null;
    	}
    	
    	/**
    	 * 打开
    	 * @return
    	 */
    	public String openAs() {
    //		从数据库获取fileName，fileType
    		String fileName = "25e58PIC8GS_1024.jpg";
    		String fileType = "image/jpeg";
    		response.setContentType(fileType);
    		response.setHeader("Content-Disposition","filename=" + fileName);
    		//从服务器获取图片到本地
    		String realPath = getRealPath(serverDir + "/" + fileName);
    		try {
    			//原方法
    			//FileUtils.copyFile(new File(realPath), response.getOutputStream());
    			
    			//自定义方法--copy二进制文件方法
    			BufferedInputStream in = new BufferedInputStream(new FileInputStream(new File(realPath))); //获取读取流
    			BufferedOutputStream out = new BufferedOutputStream(response.getOutputStream()); //获取输出流
    			copyBufStream(in, out); //调用copy二进制文件方法
    			
    		} catch (IOException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    		return null;
    	}
    	
    	/**
    	 * copy二进制文件方法
    	 * 
    	 * @param in 从哪里读取
    	 * @param out 写到哪里去
    	 * @throws IOException 
    	 */
    	private void copyBufStream(BufferedInputStream in,BufferedOutputStream out) throws IOException {
    		byte[] buff = new byte[1024*1024]; //每次读取1M（自定义）
    		int len = 0;
    		while((len = in.read(buff)) != -1){
    			out.write(buff, 0, len);
    		}
    		in.close();
    		out.close();
    	} 
    	
    	
    	//set,get方法
    	public File getFile() {
    		return file;
    	}
    	public void setFile(File file) {
    		this.file = file;
    	}
    	public String getFileFileName() {
    		return fileFileName;
    	}
    	public void setFileFileName(String fileFileName) {
    		this.fileFileName = fileFileName;
    	}
    	public String getFileContentType() {
    		return fileContentType;
    	}
    	public void setFileContentType(String fileContentType) {
    		this.fileContentType = fileContentType;
    	}
    	
    	
    	//无参构造方法
    	public FileAction() {
    		super();
    	}
    
    	//有参构造方法
        public FileAction(File file, String fileFileName, String fileContentType) {
    		super();
    		this.file = file;
    		this.fileFileName = fileFileName;
    		this.fileContentType = fileContentType;
    	}
    	
    
        //toString方法
    	@Override
    	public String toString() {
    		return "FileAction [file=" + file + ", fileFileName=" + fileFileName + ", fileContentType=" + fileContentType + "]";
    	}
    	
    	
    
    }

**2:struts-sy.xml**

<action name="FileAction_*" class="com.zy.interceptor.FileAction" method="{1}">
       <result name="demo2">/Demo2.jsp</result>
      </action>

**3:jsp**

3.1:Demo1.jsp

<h1> struts的文件上传 </h1>
    <form action="${pageContext.request.contextPath}/sy/FileAction_upload.action" method="post" enctype="multipart/form-data">
     <input type="file" name="file"/>
     <input type="submit"/>
    </form>

3.2:Demo2.jsp