Spring MVC Simple控制器示例

Question

Can you please help me figure out how to invoke the login page by using my controller?

Here is my code:

package com.mvc.demo;

public class Emp {
     private String name;
     private String password;

     public String getName() {
         return name;
     }

     public void setName(String name) {
         this.name = name;
     }

     public String getPassword() {
         return password;
     }

     public void setPassword(String password) {
         this.password = password;
     }

} 

MvcDemo.java (it's my controller; just for invoking login page)

package com.mvc.demo;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

public class MvcDemo {

     @RequestMapping(value="/login", method = RequestMethod.GET)
     public String showForm(Emp em) {
          return "login";
     } 
}

dispatcher-servlet.xml

<context:component-scan base-package="com.mvc.demo" />
<mvc:annotation-driven />
<beans>
<bean id="viewResolver"
    class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="prefix" value="/jsp/" />
    <property name="suffix" value=".jsp" />
</bean>
</beans>

web.xml

<servlet>
    <servlet-name>dispatcher</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
    <servlet-name>dispatcher</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>

<welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
</welcome-file-list>

login.jsp

 <form:form action="#" method = "post" modelAttribute="emp">
        <form:label path="username">Enter your user-name</form:label>
        <form:input id="username" name="username" path="name" /><br>
        <form:label path="username">Please enter your password</form:label>

        <form:password id="password" name="password" path="password" /><br>

        <input type="submit" value="Submit" />
 </form:form>

project Structure:

   MvcDemo
     JavaResources
      src
       com.mvc.demo
    WebContent
      jsp
        login.jsp
    WEB-INF
     lib
     web.xml
     dispatcher-servlet.xml
   index.jsp  

Answer 1

You are missing @Controller annotation on your controller class. Spring does not create a handler for url unless you instantiate a controller by using annotation.

Answer 2

It does the same as in your code,when you hit url with localhost:8080/Mvc_Demo/login it must show your login.jsp, hope this solves your problem.

package com.mvc.demo;

    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;

    import org.springframework.web.servlet.ModelAndView;

    public class MvcDemo {
    @RequestMapping(value="/login", method = RequestMethod.GET)

     public String showForm( )
     {
       ModelAndView mv = new ModelAndView("login");
       return mv;


       } 
     }

Answer 3

Try this code:

package com.mvc.demo;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class MvcDemo {

    // To call the view for login
    @RequestMapping(value = "/login", method = RequestMethod.GET)
    public ModelAndView login() {
         return new ModelAndView("login","newEmp", new Emp());
    }

    // To call the validate login after submit
    @RequestMapping(value = "/user-login", method = RequestMethod.POST)
    @ResponseBody
    public ModelAndView userLogin(Emp emp) {
         //TODO check 'emp' object to validate user
         return new ModelAndView("home");
    }


}