Spring - Exception Handling Example

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The following example shows how to write a simple web-based application using Spring MVC Framework, which can handle one or more exceptions raised inside its controllers. To start with, let us have a working Eclipse IDE in place and take the following steps to develop a Dynamic Form-based Web Application using Spring Web Framework −

Following is the content of Student.java file

package com.tutorialspoint;

public class Student {
   private Integer age;
   private String name;
   private Integer id;

   public void setAge(Integer age) {
      this.age = age;
   }
   public Integer getAge() {
      return age;
   }
   public void setName(String name) {
      this.name = name;
   }
   public String getName() {
      return name;
   }
   public void setId(Integer id) {
      this.id = id;
   }
   public Integer getId() {
      return id;
   }
}

Following is the content of SpringException.java file

package com.tutorialspoint;

public class SpringException extends RuntimeException{
   private String exceptionMsg;
   
   public SpringException(String exceptionMsg) {
      this.exceptionMsg = exceptionMsg;
   }
   public String getExceptionMsg(){
      return this.exceptionMsg;
   }
   public void setExceptionMsg(String exceptionMsg) {
      this.exceptionMsg = exceptionMsg;
   }
}

Following is the content of StudentController.java file. Here, you need to annotate a service method using @ExceptionHandler where you can specify one or more exceptions to be handled. If you are specifying more than one exception then you can use comma separated values.

package com.tutorialspoint;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.ui.ModelMap;

@Controller
public class StudentController {
   @RequestMapping(value = "/student", method = RequestMethod.GET)
   public ModelAndView student() {
      return new ModelAndView("student", "command", new Student());
   }
   @RequestMapping(value = "/addStudent", method = RequestMethod.POST)
   @ExceptionHandler({SpringException.class})
   public String addStudent( @ModelAttribute("HelloWeb")Student student, 
      ModelMap model) {
      
      if(student.getName().length() < 5 ){
         throw new SpringException("Given name is too short");
      } else {
         model.addAttribute("name", student.getName());
      }
      
      if( student.getAge() < 10 ){
         throw new SpringException("Given age is too low");
      } else {
         model.addAttribute("age", student.getAge());
      }
      model.addAttribute("id", student.getId());
      return "result";
   }
}

Following is the content of Spring Web configuration file web.xml

<web-app id = "WebApp_ID" version = "2.4"
   xmlns = "http://java.sun.com/xml/ns/j2ee" 
   xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation = "http://java.sun.com/xml/ns/j2ee 
   http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
 
   <display-name>Spring Exception Handling</display-name>
 
   <servlet>
      <servlet-name>HelloWeb</servlet-name>
      <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
      <load-on-startup>1</load-on-startup>
   </servlet>
   
   <servlet-mapping>
      <servlet-name>HelloWeb</servlet-name>
      <url-pattern>/</url-pattern>
   </servlet-mapping>
  
</web-app>

Following is the content of another Spring Web configuration file HelloWeb-servlet.xml

<beans xmlns = "http://www.springframework.org/schema/beans"
   xmlns:context = "http://www.springframework.org/schema/context"
   axmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation = "http://www.springframework.org/schema/beans     
   http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
   http://www.springframework.org/schema/context 
   http://www.springframework.org/schema/context/spring-context-3.0.xsd">

   <context:component-scan base-package = "com.tutorialspoint" />

   <bean class = "org.springframework.web.servlet.view.InternalResourceViewResolver">
      <property name = "prefix" value = "/WEB-INF/jsp/" />
      <property name = "suffix" value = ".jsp" />
   </bean>

   <bean class = "org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
      <property name = "exceptionMappings">
         <props>
            <prop key = "com.tutorialspoint.SpringException">
               ExceptionPage
            </prop>
         </props>
      </property>
      <property name = "defaultErrorView" value = "error"/>
   </bean>

</beans>

Here you specified ExceptionPage as an exception view in case SpringException occurs, if there is any other type of exception then a generic view error will take place.

Following is the content of Spring view file student.jsp

<%@taglib uri = "http://www.springframework.org/tags/form" prefix = "form"%>
<html>
   <head>
      <title>Spring MVC Exception Handling</title>
   </head>

   <body>
      <h2>Student Information</h2>
      <form:form method = "POST" action = "/HelloWeb/addStudent">
         <table>
            <tr>
               <td><form:label path = "name">Name</form:label></td>
               <td><form:input path = "name" /></td>
            </tr>
            <tr>
               <td><form:label path = "age">Age</form:label></td>
               <td><form:input path = "age" /></td>
            </tr>
            <tr>
               <td><form:label path = "id">id</form:label></td>
               <td><form:input path = "id" /></td>
            </tr>
            <tr>
               <td colspan = "2"><input type = "submit" value = "Submit"/></td>
            </tr>
         </table>  
      </form:form>
   </body>
   
</html>

Following is the content of Spring view file error.jsp

<html>
   <head>
      <title>Spring Error Page</title>
   </head>

   <body>
      <p>An error occured, please contact webmaster.</p>
   </body>
</html>

Following is the content of Spring view file ExceptionPage.jsp. Here you will access the exception instance via ${exception}.

<%@taglib uri = "http://www.springframework.org/tags/form" prefix = "form"%>
<html>
   <head>
      <title>Spring MVC Exception Handling</title>
   </head>

   <body>
      <h2>Spring MVC Exception Handling</h2>
      <h3>${exception.exceptionMsg}</h3>
   </body>
</html>

Following is the content of Spring view file result.jsp

<%@taglib uri = "http://www.springframework.org/tags/form" prefix = "form"%>
<html>
   <head>
      <title>Spring MVC Form Handling</title>
   </head>

   <body>
      <h2>Submitted Student Information</h2>
      
      <table>
         <tr>
            <td>Name</td>
            <td>${name}</td>
         </tr>
         <tr>
            <td>Age</td>
            <td>${age}</td>
         </tr>
         <tr>
            <td>ID</td>
            <td>${id}</td>
         </tr>
      </table>  
   </body>
   
</html>

Finally, following is the list of Spring and other libraries to be included in your web application. You simply drag these files and drop them in WebContent/WEB-INF/lib folder.

• commons-logging-x.y.z.jar
• org.springframework.asm-x.y.z.jar
• org.springframework.beans-x.y.z.jar
• org.springframework.context-x.y.z.jar
• org.springframework.core-x.y.z.jar
• org.springframework.expression-x.y.z.jar
• org.springframework.web.servlet-x.y.z.jar
• org.springframework.web-x.y.z.jar
• spring-web.jar

Once you are done creating the source and configuration files, export your application. Right-click on your application and use the Export > WAR File option and save yourHelloWeb.war file in Tomcat's webapps folder.

Now start your Tomcat server and make sure you are able to access other web pages from webapps folder using a standard browser. Now try to access the URL http://localhost:8080/HelloWeb/student. If everything is fine with your Spring Web Applicationand, you should see the following result.

Enter the values as shown above and click the Submit buttom. If everything is fine with your Spring Web Application, you should see the following result.