SpringMVC学习笔记
SpringMVC快速入门
入门代码实现
导入SpringMVC坐标
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>5.3.17</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.3.17</version>
</dependency>
配置SpringMVC的前端控制器
<!-- 配置SpringMVC的前端控制器-->
<servlet>
<servlet-name>DispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring-mvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>DispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>mapping>
创建Controller类和视图界面,使用注解配置Controller类中业务方法的映射地址
@Controller
public class UserController {
@RequestMapping("/quick")
public String save(){
System.out.println("Controller save running....");
return "success.jsp";
}
}
<html>
<head>
<title>test</title>
</head>
<body>
<h1>success!!!</h1>
</body>
</html>
配置SpringMVC核心文件spring-mvc.xml
<!-- Controller的组件扫描-->
<context:component-scan base-package="com.example.controller"/>
运行测试
SpringMVC的数据响应方式
页面跳转
直接返回字符串
@RequestMapping(value = "/quick",method = RequestMethod.GET,params = {"username"})
public String save(){
System.out.println("Controller save running....");
// return "redirect:/success.jsp";//forward:转发（默认） redirect:重定向
return "success";
}
通过ModelAndView对象返回
@RequestMapping("/quick4")
public String save4(HttpServletRequest request){
request.setAttribute("username","王五");
return "success";
}
@RequestMapping("/quick3")
public String save3(ModelAndView modelAndView){
modelAndView.addObject("username","李四");
return "success";
}
@RequestMapping("/quick2")
public ModelAndView save2(){
// Model:模型 封装数据
// view:视图 展示数据
ModelAndView modelAndView = new ModelAndView();
//设置模型数据
modelAndView.addObject("username","张三");
modelAndView.setViewName("success");
return modelAndView;
}
回写数据
直接返回字符串
@RequestMapping("/quick8")
@ResponseBody //告知SpringMVC框架 不进行视图跳转 直接进行数据响应
public String save8() throws Exception{
User user = new User();
user.setUsername("lisi");
user.setAge(30);
//使用json的转换工具将对象转换成json格式字符串返回
ObjectMapper objectMapper = new ObjectMapper();
String json = objectMapper.writeValueAsString(user);
return json;
}
@RequestMapping("/quick7")
@ResponseBody //告知SpringMVC框架 不进行视图跳转 直接进行数据响应
public String save7() throws Exception{
return "{\"username\":\"zs\",\"age\":18}";
}
@RequestMapping("/quick6")
@ResponseBody //告知SpringMVC框架 不进行视图跳转 直接进行数据响应
public String save6() throws Exception{
return "zl";
}
@RequestMapping("/quick5")
public void save5(HttpServletResponse response) throws Exception{
response.getWriter().print("hello word!");
}
返回对象或集合
//<!-- MVC注解驱动-->
// <mvc:annotation-driven/>
@RequestMapping(value = "/quick9",produces = "application/json;charset=UTF-8")
@ResponseBody //告知SpringMVC框架 不进行视图跳转 直接进行数据响应
//期望SpringMVC自动将User转换成json格式的字符串
public User save9() throws Exception{
User user = new User();
user.setUsername("lisi");
user.setAge(30);
return user;
}
SpringMVC获得请求数据
SpringMVC可以获得如下类型参数：
-
基本类型参数
-
POJO类型参数
-
数组类型参数
-
集合类型参数
获得基本类型参数
@RequestMapping("/quick")
@ResponseBody //不进行页面跳转
public void save(String username,int age) throws Exception{
System.out.println(username);
System.out.println(age);
}
获取POJO类型参数
@RequestMapping("/quick1")
@ResponseBody //不进行页面跳转
public void save(User user) throws Exception{
System.out.println(user);
}
获取数组类型参数
@RequestMapping("/quick2")
@ResponseBody //不进行页面跳转
public void save2(String[] strs) throws Exception{
System.out.println(Arrays.asList(strs));
}
获取集合类型参数
<html>
<head>
<title>Title</title>
<script src="/js/jquery.min.js"/>
<script>
var userList = new Array();
userList.push({username:"zs",age:18});
userList.push({username:"lisi",age:20});
$.ajax({
type:"POST",
url:"/req/quick4",
data:JSON.stringify(userList),
contentType:"application/json;charset=UTF_8"
});
</script>
</head>
<body>
</body>
</html>
@RequestMapping("/quick4")
@ResponseBody //不进行页面跳转
public void save4(@RequestBody List<User> userList) throws Exception{
System.out.println(userList);
}
请求数据乱码解决
<!-- 配置全局过滤filter-->
<filter>
<filter-name>characterEncodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>characterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
参数绑定注解@requestParam
当请求的参数名称与Controller的业务方法参数名称不一致时使用
@RequestMapping("/quick5")
@ResponseBody //不进行页面跳转
public void save5(@RequestParam(value="name") String username) throws Exception{
//@RequestParam参数：value(请求参数名称)，required(此参数在请求中是否必须包括，默认为true)，defaultValue(当没有指定参数时使用默认值赋值)
System.out.println(username);
}
获取请求头
//获取请求头
@RequestMapping("/quick8")
@ResponseBody //不进行页面跳转
public void save8(@RequestHeader(value = "User-Agent",required = false) String header) throws Exception{
System.out.println(header);
}
//获取Cookie值
@RequestMapping("/quick9")
@ResponseBody //不进行页面跳转
public void save9(@CookieValue(value = "JSESSIONID",required = false) String cookie) throws Exception{
System.out.println(cookie);
}
文件上传
导入fileupload和io坐标
<!-- 文件上传坐标导入-->
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.4</version>
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.6</version>
</dependency>
配置文件上传解析器
<!-- 配置文件上传解析器-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- 上传文件总大小-->
<property name="maxUploadSize" value="5242800"/>
<!-- 上传单个文件大小-->
<property name="maxUploadSizePerFile" value="5242800"/>
<!-- 上传文件编码类型-->
<property name="defaultEncoding" value="UTF-8"/>
</bean>
编写文件上传代码(单文件)
<html>
<head>
<title>Title</title>
</head>
<body>
<form action="/req/quick10" method="post" enctype="multipart/form-data">
<input name="username" type="text"><br>
<input name="password" type="password"><br>
<input type="file" name="upload1">
<input type="submit" value="提交">
</form>
</body>
</html>
@RequestMapping("/quick10")
@ResponseBody //不进行页面跳转
public void save10(String name, MultipartFile upload1) throws Exception{
// 获得文件名称
String originalFilename1 = upload1.getOriginalFilename();
// 保存文件
upload1.transferTo(new File("E:\\Spring_Project\\"+originalFilename1));
}
编写文件上传代码(多文件)
<html>
<head>
<title>Title</title>
</head>
<body>
<form action="/req/quick11" method="post" enctype="multipart/form-data">
<input name="username" type="text"><br>
<input name="password" type="password"><br>
<input type="file" name="upload">
<input type="file" name="upload">
<input type="submit" value="提交">
</form>
</body>
</html>
@RequestMapping("/quick11")
@ResponseBody //不进行页面跳转
public void save11(String name, MultipartFile[] upload) throws Exception{
// 获得文件名称
for (MultipartFile multipartFile:upload) {
String originalFilename = multipartFile.getOriginalFilename();
// 保存文件
multipartFile.transferTo(new File("E:\\Spring_Project\\" + originalFilename));
}
}
