Return type of Spring MVC

Return type of Spring MVC

 

In fact, Spring's return type can support a variety of

     

      1. ModelAndView

      2. String

      3. void

      4. Map

      5. Model

 

      6. object (this is often used in app back-end development)

 

 

code show as below

package com.wangbiao.springMVC;  
  
import java.util.HashMap;  
import java.util.Map;  
  
import javax.servlet.ServletContext;  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
  
import org.springframework.context.ApplicationContext;  
import org.springframework.stereotype.Controller;  
import org.springframework.ui.Model;  
import org.springframework.web.bind.annotation.RequestMapping;  
import org.springframework.web.bind.annotation.RequestMethod;  
import org.springframework.web.servlet.ModelAndView;  
import org.springframework.web.servlet.View;  
import org.springframework.web.servlet.mvc.multiaction.MultiActionController;  
@Controller  
@RequestMapping("/return")  
public class HelloWorld extends  MultiActionController{  
  
    /*
     * The return value is of type ModelAndView
     */  
    public ModelAndView sayHelloWorld(HttpServletRequest request, HttpServletResponse response) {  
        String param = request.getParameter("param");  
        System.out.println("springMVC测试：helloWorld;"+param);  
        ModelAndView mv = new ModelAndView();  
        User user = (User) this.getApplicationContext().getBean("user");  
        mv.addObject("content", "springMVC HelloWorld:"+param);  
        mv.setViewName("springMVC/helloWorld");  
        ServletContext ctx = this.getServletContext();    
        return mv;  
    }  
    /*
     * The return value is of type String, and the view name is the return value
     */  
    @RequestMapping(value="/returnString",method=RequestMethod.GET)  
    public String returnString(Model model) {  
        model.addAttribute("test", "return string!!!");  
        System.out.println("springMVC测试：helloWorld;");  
        return "return/returnString";  
    }  
      
    /*
     * The return value is of type void, since there is no return value
     * Its default display view name is the same as a segment in the url, namely returnVoid.jsp
     */  
    @RequestMapping("/returnVoid")  
    public void returnVoid(Model model){  
        model.addAttribute("test", "return void!!!");  
    }  
      
    /*
     * The return value is of type void, since the view name is not specified
     * Its default display view name is the same as a segment in the url, namely returnVoid.jsp
     */  
    @RequestMapping("/returnModel")  
    public Model returnModel(Model model){  
        model.addAttribute("test", "return Model!!!");  
        return model;  
    }  
      
    /*
     * The return value is of type void, since the view name is not specified
     * Its default display view name is the same as a segment in the url, namely returnVoid.jsp
     */  
    @RequestMapping("/returnMap")  
    public Map returnMap(Model model){  
        Map map = new HashMap<String,String>();  
        map.put("test", "return map!!!");  
        return map;  
    }  
      
  
}

 

If it is to return Object, you can use @ResponseBody like this

@Controller
public class LoginController {

    @Autowired
    private CmsUserSessionService cmsUserSessionService;

    @ResponseBody
    @RequestMapping(value = "/login", method = RequestMethod.POST)
    public ResultVO loginUser(final HttpServletRequest request, final UserLoginParam param) throws Exception {
	    AssertUtil.notBlank(param.getUserName(), "userName is required");
	    AssertUtil.notBlank(param.getPassword(), "password is required");

	    final String userAgent = request.getHeader("User-Agent");
        final String ip = RequestUtil.getRealIp(request);
        final ResultVO result = new ResultVO();

        result.setData(cmsUserSessionService.login(param, userAgent, ip));
        result.setMessage("Login success");
        return result;
	}
}

 

Or use @RestController, no need for @ResponseBody

@RestController
public class UserSessionController extends BaseController {

    @Autowired
    private UserSessionService userSessionService;

    @Autowired
    private UserDao userDao;

    @RequestMapping(value = "/user/session", method = RequestMethod.POST)
    public ResultVO logoutUser(final Long userId, final Long logoutUserId) {
        final UserInfoDTO userInfo = userDao.findUserInfoByUserId(logoutUserId);
        Constants.sActivitiesLogger.info(" Action:[" + Constants.LOG_USER_LOGOUT + "] Payme ID:["+userInfo.getMemberId()+"]");
        userSessionService.logoutAllSessions(logoutUserId, LogoutSessionRemark.CS_CASE.toValue());
        return new SuccessVO();
    }
}