一、Ajax使用：
1. index.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>首页</title>
<script src="${pageContext.request.contextPath}/statics/js/jquery-3.5.1.js"></script>
<script>
$(function () {
$("#btn").click(function () {
loadData();
})
});
function loadData(){
$.post({
url:"${pageContext.request.contextPath}/getData",
data:{"name":"无"},
success:function (data) {
var htmlStr="";
for (let i = 0; i <data.length ; i++) {
htmlStr += "<tr>" +
"<td>"+data[i].id +"</td>"+
"<td>"+data[i].name +"</td>"+
"<td>"+data[i].age +"</td>"+
"</tr>";
}
console.log(htmlStr);
$("#content").html(htmlStr);
},
});
}
</script>
</head>
<body>
<p>用户名：<input type="button" id="btn" value="加载数据"> </p>
<table>
<tr>
<td>编号</td>
<td>姓名</td>
<td>年龄</td>
</tr>
<tbody id="content"></tbody>
</table>
</body>
</html>
2. ajaxController.java
@RestController
public class AjaxController {
@RequestMapping("/getData")
public List<User> getData(String name){
System.out.println("name : "+name);
List<User> users = new ArrayList<User>();
users.add(new User(1,"战胜1",11));
users.add(new User(2,"战胜2",22));
users.add(new User(3,"战胜3",33));
System.out.println(users);
return users;
}
}
二、SpringMVC拦截器
① 拦截器是SpringMVC框架自己的，拦截器只会拦截访问控制层方法，如果访问的是
jsp/html/css/image/js
是不会拦截的；
② 拦截器是Aop思想的具体应用；
自定义拦截器：
① 新建一个moudule，添加web支持；
② 配置web.xml和applicationContext.xml文件；
③ 编写一个拦截器；
1. MyIntercepetor .java
public class MyIntercepetor implements HandlerInterceptor { @Override//返回ture时，执行下一个拦截器(放行) public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws ServletException, IOException { System.out.println("拦截前"); HttpSession session = request.getSession(); //1.放行 if(session.getAttribute("username")!=null){//已登录 System.out.println("已登录"); return true; } if(request.getRequestURI().contains("toLogin")){//将进入登录界面 System.out.println("进入登录界面"); return true; } if(request.getRequestURI().contains("login")){//将进入登录界面 System.out.println("正在提交登录数据"); return true; } //2.不放行 System.out.println("请先登录"); request.getRequestDispatcher("/WEB-INF/jsp/login.jsp").forward(request,response);//未登录->前往登录界面 return false; } @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) { // System.out.println("拦截后"); } @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) { // System.out.println("拦截清理"); } }
2. CommonController .java
@Controller @RequestMapping("/user") public class CommonController { @RequestMapping("/main") public String main(){ return "main"; } @RequestMapping("/toLogin") public String toLogin(){ return "login"; } @RequestMapping("/login") public String Login(HttpSession session, String username, String password, Model model){ System.out.println("username: "+username+" password: "+password); session.setAttribute("username",username); model.addAttribute("username",username); return "main"; } @RequestMapping("/goOut") public String goOut(HttpSession session,String username, String password){ session.removeAttribute("username"); return "login"; } }
3. applicationContext.xml
<!--拦截器配置--> <mvc:interceptors> <mvc:interceptor> <mvc:mapping path="/user/**"/> <bean class="com.nzs.config.MyIntercepetor"/> </mvc:interceptor> </mvc:interceptors>
4. login.jsp
<h1> ====登录界面==== </h1> <form action="${pageContext.request.contextPath}/user/login" method="post"> 用户名：<input type="text" name="username" value="admin"> 密码：<input type="text" name="password" value="123456"> <input type="submit" value="登录"> </form>
5. main.jsp
<h1>====欢迎进入主界面====</h1> ${username} <a href="${pageContext.request.contextPath}/user/goOut">退出登录</a>
6. index.jsp
<h1><a href="${pageContext.request.contextPath}/user/toLogin">前往登录</a></h1> <h1><a href="${pageContext.request.contextPath}/user/main">前往首页</a></h1>
三、文件上传和下载
文件上传：
① 在pom.xml中导入依赖；
servlet-api导入高版本的
；<!--文件上传--> <dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3.3</version> </dependency> <!--servlet-api导入高版本的--> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>4.0.1</version> </dependency>② applicationContext.xml
<!--文件上传配置 id="multipartResolver" 一定不能写错--> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <property name="defaultEncoding" value="utf-8"/> <!--单位字节：(10485760=10M)--> <property name="maxUploadSize" value="10485760"/> <property name="maxInMemorySize" value="40960"/> </bean>③ 上传表单
<form action="${pageContext.request.contextPath}/upload2" enctype="multipart/form-data" method="post"> <input type="file" name="file" value="选择文件"> <input type="submit" value="上传"> </form>④ 控制层FileController.java <
两种方式接收
>@RestController public class FileController { 方式一： @RequestMapping("/upload1") public String fileUploadWay1(@RequestParam("file")CommonsMultipartFile file, HttpServletRequest request) throws IOException { //1.获取文件名 String uploadFileName = file.getOriginalFilename(); //2.判断文件名是否为空 if("".equals(uploadFileName)){ return "redirect:/index.jsp"; } System.out.println("上传文件名："+uploadFileName); //3.上传保存路径设置 String path = request.getServletContext().getRealPath("/upload"); //4.如果路径不存在 则创建一个 File realPath = new File(path); if(!realPath.exists()){ realPath.mkdirs(); } System.out.println("上传文件保存路径："+realPath); //5.创建输入输出流 InputStream is = file.getInputStream(); FileOutputStream os = new FileOutputStream(new File(realPath, uploadFileName)); //6.读取写出 int len=0; byte[] buffer = new byte[1024]; while((len=is.read(buffer))!=-1){ os.write(buffer,0,len); os.flush(); } //7.结束 os.close(); is.close(); return "redirect:/index.jsp"; } 方式二： @RequestMapping("/upload2") public String fileUploadWay2(@RequestParam("file")CommonsMultipartFile file, >HttpServletRequest request) throws IOException { //1.上传路径保存设置 String path = request.getServletContext().getRealPath("/upload"); File realPath = new File(path); if(!realPath.exists()){ realPath.mkdirs(); } System.out.println("文件保存地址 ："+realPath); //2.上传文件 file.transferTo(new File(realPath+"/"+file.getOriginalFilename())); return "redirect:/index.jsp"; } }
文件下载：
① 设置response响应头；
② 读取文件：InputStream；
③ 写出文件：OutputStream；
④ 执行操作；
⑤ 关闭流；
@RequestMapping("/download")
public String downLoad(HttpServletResponse response,HttpServletRequest request) throws Exception{
//1.要下载文件的图片地址
String path = request.getServletContext().getRealPath("/upload");
String fileName = "1.png";//下载名可以改
//2.设置response响应头
response.reset();//设置页面不缓存，清空buffer
response.setCharacterEncoding("UTF-8");
response.setContentType("multipart/form-data");
response.setHeader("Content-Disposition",
"attachment;fileName="+ URLEncoder.encode(fileName,"UTF-8"));
System.out.println("8888888888888888888888888");
File file = new File(path,fileName);
//3.输入输出liu
FileInputStream input = new FileInputStream(file);
ServletOutputStream out = response.getOutputStream();
byte[] buff = new byte[1024];
int index = 0;
//4.执行写操作
while ((index=input.read(buff))!=-1){
out.write(buff,0,index);
out.flush();
}
out.close();
input.close();
System.out.println("OKOKOKOKOK");
return "OK";
}
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