Servlet文件下载

 

Servlet文件下载

中文文件下载与中文乱码方式：

package cn.csdn.web.servlet;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.UnsupportedEncodingException;

import java.net.URLEncoder;

import javax.servlet.ServletContext;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

publicclassDemo01Servletextends HttpServlet {

publicvoid doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

this.doPost(request, response);

}

publicvoid doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

/*文件下载*/

/*要知道你下载的资源*/

// test(response);

ServletContext context =this.getServletContext();

String path = context.getRealPath("/WEB-INF/classes/res/三.jpg");

/*构造文件*/

File file =new File(path);

/*构造文件的输入流*/

InputStream is =new FileInputStream(file);

/*写：输出流*/

/*文件的下载运用URLEncoder调用encode(String s,String enc)方法将字符串设置成指定的编码方式

*/

response.setHeader("Content-Disposition","attachment;filename="

+ URLEncoder.encode(file.getName(),"UTF-8"));

OutputStream os = response.getOutputStream();

byte n[] =newbyte[1024];

int len = 0;

while ((len = is.read(n)) != -1) {

os.write(n, 0, len);

}

os.close();

is.close();

}

// outputStream中文乱码问题

privatevoidtest(HttpServletResponse response) throws IOException,

UnsupportedEncodingException {

// response对象因为getbytes获取的是gb2312的数据，而浏览器默认以gb2312打开

// response.setHeader("Conten-Type","text/html;charset=UTF-8");

response.getOutputStream().write(

"<meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">"

.getBytes("UTF-8"));

response.getOutputStream().write("中国".getBytes("UTF-8"));

response.getOutputStream().write((98 +"").getBytes());

}

}

非中文文件下载方式：

package cn.csdn.web.servlet;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.UnsupportedEncodingException;

import java.net.URLEncoder;

import javax.servlet.ServletContext;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

publicclassDemo01Servletextends HttpServlet {

publicvoid doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

this.doPost(request, response);

}

publicvoid doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

/*文件下载*/

/*要知道你下载的资源*/

// test(response);

ServletContext context =this.getServletContext();

String path = context.getRealPath("/WEB-INF/classes/res/rigth.jpg");

/*构造文件*/

File file =new File(path);

/*构造文件的输入流*/

InputStream is =new FileInputStream(file);

/*写：输出流*/

/*文件的下载*/

response.setHeader("Content-Disposition","attachment;filename=file.getName()"

OutputStream os = response.getOutputStream();

byte n[] =newbyte[1024];

int len = 0;

while ((len = is.read(n)) != -1) {

os.write(n, 0, len);

}

os.close();

is.close();

}

}