SpringMVC實現文件下載功能。本站提示廣大學習愛好者：（SpringMVC實現文件下載功能）文章只能為提供參考，不一定能成為您想要的結果。以下是SpringMVC實現文件下載功能正文
本文實例為大家分享了SpringMVC文件下載的具體代碼，供大家參考，具體內容如下
兩個案例
1.為登錄用戶提供下載服務。
2.阻止僅通過輸入網址即可獲取下載。
文件下載概覽
為了將文件發送給浏覽器，我們需要在控制器中完成以下操作：
對請求處理方法使用void返回類型，並且在方法中添加HttpServletResponse參數。 將響應的內容類型設為文件的內容類型。Content-Type標題在某個實體的body中定義數據的類型，並包含媒體類型和子類型標識符。如果不清楚內容類型，並且希望浏覽器失始終顯示保存對話框，則將它設為APPLICATION/OCTET-STREAM。這個值時不區分大小寫的。 添加一個名為Content-Disposition的HTTP響應標題，並賦值attachment;filename=fileName，這裡的fileName是默認的文件名。案例1：為登錄用戶提供下載服務
Domain類
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;
}
}
編寫視圖
Main.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>DownPage</title> </head> <body> <h4>點擊鏈接下載文件</h4> <p> <a href="resource_download" rel="external nofollow" >Down</a> </p> </body> </html>
LoginForm.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>登錄頁面</title> </head> <body> <form:form commandName="login" action="login" method="post"> 賬號: <br> <form:input path="username" cssErrorClass="error" id="username"/> <br> 密碼： <br> <form:input path="password" cssErrorClass="error" id="password"/> <br> <input type="submit" value="提交"> </form:form> </body> </html>
案例2：阻止僅通過輸入網址即可獲取下載
@RequestMapping(value = "/resource_download")
public String downloadResource(HttpSession session, HttpServletRequest request, HttpServletResponse response,@RequestHeader String refuer
){
if(refer==null) //通過判斷refer來浏覽器輸入網址就能下載圖片的情況
{
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內容，希望對大家的學習有所幫助，也希望大家多多支持。
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