JSP下载文档

1、设置doc格式的文件弹出对话框：

 

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
	<mime-mapping>
		<extension>doc</extension>
		<mime-type>application/vnd.ms-word</mime-type>
	</mime-mapping>

	<welcome-file-list>
		<welcome-file>DownloadFile.jsp</welcome-file>
	</welcome-file-list>
</web-app>

 

2、注意要主动释放out对象，否则会抛出错误：

<%@page language="java" contentType="application/x-msdownload"
	import="java.io.*,java.net.*" pageEncoding="gb2312"%>
<%
	response.reset();//可以加也可以不加
	//设置为下载application/x-download
	response.setContentType("application/x-download");
	// /../../退WEB-INF/classes两级到应用的根目录下去，
	//注意Tomcat与WebLogic下面这一句得到的路径不同，WebLogic中路径最后没有/
	System.out.println(this.getClass().getClassLoader()
			.getResource("/").getPath());
	String filenamedownload = this.getClass().getClassLoader()
			.getResource("/").getPath()
			+ "/../../系统解决方案.doc";
	String filenamedisplay = "系统解决方案.doc";//系统解决方案.txt
	filenamedisplay = URLEncoder.encode(filenamedisplay, "UTF-8");
	response.addHeader("Content-Disposition", "attachment;filename="
			+ filenamedisplay);

	OutputStream output = null;
	FileInputStream fis = null;
	try {
		output = response.getOutputStream();
		fis = new FileInputStream(filenamedownload);

		byte[] b = new byte[1024];
		int i = 0;

		while ((i = fis.read(b)) > 0) {
			output.write(b, 0, i);
		}
		output.flush();
	} catch (Exception e) {
		System.out.println("Error!");
		e.printStackTrace();
	} finally {
		if (fis != null) {
			fis.close();
			fis = null;
		}
		if (output != null) {
			output.close();
			output = null;
		}
		//主动释放在jsp中使用的对象
		out.clear();
		out = pageContext.pushBody();
	}
%>

 运行结果：

/D:/tomcat6_Green/webapps/DownloadFile/WEB-INF/classes/
/D:/tomcat6_Green/webapps/DownloadFile/WEB-INF/classes/

 

参考：

1、tomcat5下jsp出现getOutputStream() has already been called for this response异常的原因和解决方法

2、JSP文件下载及getOutputStream () has  already  been 的解决