本文實(shí)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(nèi)容如下
兩個案例
1.為登錄用戶提供下載服務(wù)。
2.阻止僅通過輸入網(wǎng)址即可獲取下載。
文件下載概覽
為了將文件發(fā)送給瀏覽器，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，并且在方法中添加HttpServletResponse參數(shù)。
- 將響應(yīng)的內(nèi)容類型設(shè)為文件的內(nèi)容類型。Content-Type標(biāo)題在某個實(shí)體的body中定義數(shù)據(jù)的類型，并包含媒體類型和子類型標(biāo)識符。如果不清楚內(nèi)容類型，并且希望瀏覽器失始終顯示保存對話框，則將它設(shè)為APPLICATION/OCTET-STREAM。這個值時不區(qū)分大小寫的。
- 添加一個名為Content-Disposition的HTTP響應(yīng)標(biāo)題，并賦值attachment;filename=fileName，這里的fileName是默認(rèn)的文件名。
案例1：為登錄用戶提供下載服務(wù)
Domain類
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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
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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.*;@Controllerpublic 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
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<%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head> <title>DownPage</title></head><body> <h4>點(diǎn)擊鏈接下載文件</h4> <p> <a href="resource_download" rel="external nofollow" >Down</a> </p></body></html> |
LoginForm.jsp
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<%@ 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(wǎng)址即可獲取下載
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@RequestMapping(value = "/resource_download") public String downloadResource(HttpSession session, HttpServletRequest request, HttpServletResponse response,@RequestHeader String refuer ){ if(refer==null) //通過判斷refer來瀏覽器輸入網(wǎng)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(nèi)容，希望對大家的學(xué)習(xí)有所幫助，也希望大家多多支持服務(wù)器之家。
