本文实例为大家分享了SpringMVC文件下载的具体代码，供大家参考，具体内容如下
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两个案例
1.为登录用户提供下载服务。
2.阻止仅通过输入网址即可获取下载。
文件下载概览
为了将文件发送给浏览器，我们需要在控制器中完成以下操作：
- 对请求处理方法使用void返回类型，并且在方法中添加HttpServletResponse参数。
- 将响应的内容类型设为文件的内容类型。Content-Type标题在某个实体的body中定义数据的类型，并包含媒体类型和子类型标识符。如果不清楚内容类型，并且希望浏览器失始终显示保存对话框，则将它设为APPLICATION/OCTET-STREAM。这个值时不区分大小写的。
- 添加一个名为Content-Disposition的HTTP响应标题，并赋值attachment;filename=fileName，这里的fileName是默认的文件名。
案例1：为登录用户提供下载服务
Domain类
package domain;
public class Login {
private String username;
private String password;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
Controller控制器
package controller;
import domain.Login;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.*;
@Controller
public class ResourceController {
private static final Log logger = LogFactory.getLog(ResourceController.class);
@RequestMapping(value = "/login")
public String login(@ModelAttribute Login login, HttpSession session, Model model)
{
model.addAttribute("login",new Login());
if("ms".equals(login.getUsername())&&"123".equals(login.getPassword()))
{
session.setAttribute("loggedIn",Boolean.TRUE);
return "Main";
}
else
{
return "LoginForm";
}
}
@RequestMapping(value = "/resource_download")
public String downloadResource(HttpSession session, HttpServletRequest request, HttpServletResponse response)
{
if(session==null||session.getAttribute("loggedIn")==null)
{
return "LoginForm";
}
String dataDirectory = request.getServletContext().getRealPath("/WEB-INF/data");
File file = new File(dataDirectory,"Blog.zip");
if(file.exists())
{
response.setContentType("application/octet-stream");
response.addHeader("Content-Disposition","attachment;filename=Blog.zip");
byte[] buffer = new byte[1024];
FileInputStream fis =null;
BufferedInputStream bis =null;
try {
fis = new FileInputStream(file);
bis = new BufferedInputStream(fis);
OutputStream os =response.getOutputStream();
int i =bis.read(buffer);
while (i!=-1) {
os.write(buffer, 0, i);
i=bis.read(buffer);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally {
try {
bis.close();
} catch (IOException e) {
e.printStackTrace();
}
try {
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return null;
}
}
编写视图
Main.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
DownPage
点击链接下载文件
Down
LoginForm.jsp
案例2：阻止仅通过输入网址即可获取下载
@RequestMapping(value = "/resource_download")
public String downloadResource(HttpSession session, HttpServletRequest request, HttpServletResponse response,@RequestHeader String refuer
){
if(refer==null) //通过判断refer来浏览器输入网址就能下载图片的情况
{
return "LoginForm";
}
String dataDirectory = request.getServletContext().getRealPath("/WEB-INF/data");
File file = new File(dataDirectory,"Blog.zip");
if(file.exists())
{
response.setContentType("application/octet-stream");
response.addHeader("Content-Disposition","attachment;filename=Blog.zip");
byte[] buffer = new byte[1024];
FileInputStream fis =null;
BufferedInputStream bis =null;
try {
fis = new FileInputStream(file);
bis = new BufferedInputStream(fis);
OutputStream os =response.getOutputStream();
int i =bis.read(buffer);
while (i!=-1) {
os.write(buffer, 0, i);
i=bis.read(buffer);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally {
try {
bis.close();
} catch (IOException e) {
e.printStackTrace();
}
try {
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return null;
}
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持创新互联。
网站标题：SpringMVC实现文件下载功能
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