4.1 环境搭建
创建名为spring_mvc_demo2的新module,过程参考3.1节
4.1.1、创建请求控制器
package org.rain.controller;
import org.springframework.stereotype.Controller;
/**
* @author liaojy
* @date 2023/10/9 - 8:32
*/
@Controller
public class TestParamController {
}
package org.rain.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
/**
* @author liaojy
* @date 2023/10/9 - 8:49
*/
@Controller
public class PortalController {
@RequestMapping("/")
public String portal(){
return "index";
}
}
4.1.2、创建静态资源目录及页面
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>首页</title>
</head>
<body>
</body>
</html>
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>成功</title>
</head>
<body>
<h1>success.html</h1>
</body>
</html>
4.1.3、配置tomcat
4.2、通过ServletAPI获取请求参数
4.2.1、控制器方法示例
如果控制器方法有HttpServletRequest类型的形参,DispatcherServlet就会将封装了当前请求的对象传给控制器方法
@RequestMapping("/param/servletAPI")
public String getParamByServletAPI(HttpServletRequest request){
String username = request.getParameter("username");
String password = request.getParameter("password");
System.out.println("username:"+username);
System.out.println("password:"+password);
return "success";
}
4.2.2、页面请求示例
<form th:action="@{/param/servletAPI}" method="post">
用户名:<input type="text" name="username">
密码:<input type="password" name="password">
<input type="submit" value="登录">
</form>
4.2.3、测试效果
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4.3、通过控制器方法的形参获取请求参数
4.3.1、控制器方法示例
如果在控制器方法存在和请求参数同名的形参,DispatcherServlet就会将请求参数赋值给控制器方法中对应的形参
@RequestMapping("/param")
public String getParam(String username,String password){
System.out.println("username:"+username);
System.out.println("password:"+password);
return "success";
}
4.3.2、页面请求示例
<form th:action="@{/param}" method="post">
用户名:<input type="text" name="username">
密码:<input type="password" name="password">
<input type="submit" value="登录">
</form>
4.3.3、测试效果
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4.4、@RequestParam注解
@RequestParam注解用于将请求参数和控制器方法的形参建立映射关系,其有三个属性:
-
value:指定要为形参赋值的请求参数的参数名。
-
required:设置是否必须传输此请求参数,默认值为true;
若设置为true时,则当前请求必须传输value所指定的请求参数,
若没有传输该请求参数,且没有设置defaultValue属性,则页面报错400:Required String parameter 'xxx' is not present;
若设置为false时,则当前请求不是必须传输value所指定的请求参数,
若没有传输该请求参数,则注解所标识的形参的值为null。 -
defaultValue:设置形参的默认值;
不管required属性值为true或false,当value所指定的请求参数没有传输或传输的值为""时,则使用默认值为形参赋值。
4.4.1、控制器方法示例
@RequestMapping("/param")
public String getParam(@RequestParam(value = "name",required = true,defaultValue = "everyone") String username, String password){
System.out.println("username:"+username);
System.out.println("password:"+password);
return "success";
}
4.4.2、页面请求示例
<form th:action="@{/param}" method="post">
用户名:<input type="text" name="name">
密码:<input type="password" name="password">
<input type="submit" value="登录">
</form>
4.4.3、有传参的测试效果
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4.4.4、无传参的测试效果
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4.5、@RequestHeader和@CookieValue
-
@RequestHeader 注解用于将请求头信息和控制器方法的形参建立映射关系,其三个属性的用法和@RequestParam的相同
-
@CookieValue 注解用于将Cookie数据和控制器方法的形参建立映射关系,其三个属性的用法和@RequestParam的相同
4.5.1、控制器方法示例
@RequestMapping("/param")
public String getParam(
@RequestParam(value = "name",required = true,defaultValue = "everyone") String username,
String password,
@RequestHeader("referer") String referer,
@CookieValue(value = "JSESSIONID",required = false) String jsessionId
) {
System.out.println("username:"+username);
System.out.println("password:"+password);
System.out.println("referer:"+referer);
System.out.println("jsessionId:"+jsessionId);
return "success";
}
4.5.2、测试效果
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4.6、通过实体类形参获取请求参数(常用)
4.6.1、实体类示例
注意:要保证实体类的属性名和请求参数名一致
package org.rain.pojo;
/**
* @author liaojy
* @date 2023/10/10 - 8:45
*/
public class User {
private Integer id;
private String username;
private String password;
public User() {
}
public User(Integer id, String username, String password) {
this.id = id;
this.username = username;
this.password = password;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
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;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", username='" + username + '\'' +
", password='" + password + '\'' +
'}';
}
}
4.6.2、控制器方法示例
@RequestMapping("/param/pojo")
public String getParamByPojo(User user){
System.out.println(user);
return "success";
}
4.6.3、页面请求示例
<form th:action="@{/param/pojo}" method="post">
用户名:<input type="text" name="username">
密码:<input type="password" name="password">
<input type="submit" value="登录">
</form>
4.6.4、测试效果
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4.7、解决获取请求参数的乱码问题
4.7.1、post请求的乱码解决方式
注意:SpringMVC中处理编码的过滤器一定要配置到其他过滤器之前,否则无效;过滤器的顺序根据filter-mapping标签的排序决定。
<!--配置springMVC的编码过滤器-->
<filter>
<filter-name>CharacterEncodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<!--该初始化参数用于设置请求参数的编码方式-->
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
<init-param>
<!--该初始化参数用于设置响应参数也使用同样的编码方式-->
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>CharacterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
4.7.2、get请求的乱码解决方式
从tomcat8及以后的版本,get请求的乱码问题默认已被官方解决;本例展示tomcat7的解决方式。
-
找到并打开编辑该文件:tomcat安装目录\conf\server.xml
-
在第一个 Connector 标签中,添加对应的 UTF 编码
URIEncoding="UTF-8"
标签:username,请求,SpringMVC,参数,+++++++++++++++++++++++++,password,public,String
From: https://www.cnblogs.com/Javaer1995/p/17750684.html