有点难理解。
修饰方法是表示在该控制器的所有目标方法执行前都执行该modelattribute注解的方法。
修饰参数是表示什么？修饰参数时@modelattributes(value="xxxx") User user 中的value值需要和@modelattribute修改的方法加入的键的值一致。
Controller Code:
package com.tiekui.springmvc.handlers;
import java.util.Map;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import com.tiekui.springmvc.pojo.Address;
import com.tiekui.springmvc.pojo.User;
import com.tiekui.springmvc.pojo.UserNew;
@Controller
public class ModelAttributes {
@RequestMapping("testModelAttribute")
public String targetMethod(UserNew user){
System.out.println("Target method" + user);
return "afterModelAttributes";
}
@ModelAttribute
public void getuser(@RequestParam(value="id") String id,Map<String, UserNew> map) {
if ((id != null)) {
UserNew user = new UserNew("tiekui","1234","zhoutiekui@huawei.com",30,1, new Address("guangzhou", "zhenzhen"));
System.out.println("Get an object" + user);
map.put("userNew", user);
}
}
}
Response View:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
userAge: ${requestScope.userNew.age}
</body>
</html>
View:
<form action="testModelAttribute">
<br>
password : <input type="text" name="username" value="tiekui">
<br>
password : <input type="password" name="password" value="1234">
<br>
email : <input type="text" name="email" value="zhoutiekui@huawei.com">
<br>
age : <input type="text" name="age" value="18">
<br>
<input type="hidden" name="id" value="1">
<br>
Address Province: <input type="text" name="address.province" value="guangzhou">
<br>
Address City: <input type="text" name="address.city" value="shenzhen">
<br>
<input type="submit" value="Test ModelAttributes">
</form>
POJO userNew:
View CodePOJO Address:
package com.tiekui.springmvc.pojo;
public class Address {
private String province;
private String city;
public Address() {
super();
}
public Address(String province, String city) {
super();
this.province = province;
this.city = city;
}
@Override
public String toString() {
return "Address [province=" + province + ", city=" + city + "]";
}
public String getProvince() {
return province;
}
public void setProvince(String province) {
this.province = province;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
}