@ModelAttribute注解在spring mvc中的使用方法

//ModelAttributeExampleController.javapackage javabeat.net;import org.springframework.beans.factory.annotation.Autowired;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;@Controllerpublic class ModelAttributeExampleController { @Autowired private UserDetails userDetails; @RequestMapping(value="/modelexample") public String getMethod(@ModelAttribute UserDetails userDetails){ System.out.println("User Name : " + userDetails.getUserName()); System.out.println("Email Id : " + userDetails.getEmailId()); return "example"; } //This method is invoked before the above method @ModelAttribute public UserDetails getAccount(@RequestParam String user, @RequestParam String emailId){ System.out.println("User Value from Request Parameter : " + user); userDetails.setUserName(user); userDetails.setEmailId(emailId); return userDetails; }}