javaweb 实现文件下载

不要再说用<a>标签下载了,这个会把文件打开而不是下载

例如：

<a href="E:MyDesktop37fecd65330184de67d419a8d02e7081.jpg">下载</a>

如果我这样写，浏览器就会把图片直接打开，除非是一个浏览器打不开的文件

所以我们还是要用到java本身的文件读写来进行文件的下载

<a href="downloadFile?filename=<s:property value='document_filename'/>">下载</a>

package com.cpsec.tang.chemical.action; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.List; import java.util.Random; import javax.annotation.Resource; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.struts2.ServletActionContext; import org.springframework.stereotype.Controller; import com.cpsec.tang.chemical.biz.DocumentBiz; import com.cpsec.tang.chemical.entity.Document; import com.cpsec.tang.chemical.util.Pager; import com.opensymphony.xwork2.ActionSupport; @Controller("documentAction") public class DocumentAction extends ActionSupport{private String filename; public String downloadFile(){ System.out.println(filename); try { HttpServletResponse response=ServletActionContext.getResponse(); //设置文件MIME类型 response.setContentType(ServletActionContext.getServletContext().getMimeType(filename)); //设置Content-Disposition response.setHeader("Content-Disposition", "attachment;filename="+filename); //获取目标文件的绝对路径 String fullFileName = ServletActionContext.getServletContext().getRealPath("/files/" + filename); //System.out.println(fullFileName); //读取文件 InputStream in = new FileInputStream(fullFileName); //读取目标文件，通过response将目标文件写到客户端 OutputStream out = response.getOutputStream(); //写文件 int b; while((b=in.read())!= -1) { out.write(b); } in.close(); out.close(); } catch (Exception e) { e.printStackTrace(); } return SUCCESS; } }

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