Main Tutorials

Google App Engine + Spring 3 MVC REST example

In this tutorial, we will show you how to develop and deploy a Spring 3.0 MVC REST web application in Google App Engine (GAE) environment.

Tools and technologies used :

  1. Google App Engine Java SDK 1.6.3.1
  2. Spring 3.1.1
  3. JDK 1.6
  4. Eclipse 3.7 + Google Plugin for Eclipse
Note
This example is going to reuse this Spring 3 MVC REST example, modify it and integrate with Google App Engine, you may also interest to read this – GAE + Java + Eclipse example

1. New Web Application Project

In Eclipse, create a new Web Application project, named as “SpringMVCGoogleAppEngine“.

gae spring new web application

The “Google Plugin for Eclipse” will generate a sample of GAE project structure.

2. Spring 3.0 Dependencies

To use Spring MVC + REST in GAE, you need following jars

  1. aopalliance-1.0.jar
  2. commons-logging-1.1.1.jar
  3. spring-aop-3.1.1.RELEASE.jar
  4. spring-asm-3.1.1.RELEASE.jar
  5. spring-beans-3.1.1.RELEASE.jar
  6. spring-context-3.1.1.RELEASE.jar
  7. spring-context-support-3.1.1.RELEASE.jar
  8. spring-core-3.1.1.RELEASE.jar
  9. spring-expression-3.1.1.RELEASE.jar
  10. spring-web-3.1.1.RELEASE.jar
  11. spring-webmvc-3.1.1.RELEASE.jar

Copy and put it in “war/WEB-INF/lib” folder.

gae spring dependency library

Add it to your project’s build path as well – right click on project folder, select “Properties“. Select “Java Build Path” -> “Libraries” tab, click “Add Jars” button and select above jars.

gae spring java build path

3. Spring Controller

3.1 Delete auto generated SpringMVCGoogleAppEngineServlet.java, you don’t need this.

3.2 Create a bean, act as controller in REST structure. In addition, DI a message into the “message” property.

File : src/com/mkyong/MovieController.java


package com.mkyong.controller;

import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
@RequestMapping("/movie")
public class MovieController {

	//DI via Spring
	String message;
	
	@RequestMapping(value="/{name}", method = RequestMethod.GET)
	public String getMovie(@PathVariable String name, ModelMap model) {

		model.addAttribute("movie", name);
		model.addAttribute("message", this.message);
		
		//return to jsp page, configured in mvc-dispatcher-servlet.xml, view resolver
		return "list";

	}
	
	public void setMessage(String message) {
		this.message = message;
	}
	
}

4. JSP Pages

Create a list.jsp page, display the result.

File : war/list.jsp


<html>
<body>
	<h1>GAE + Spring 3 MVC REST example</h1>
	
	<h2>Movie : ${movie} , DI message : ${message}</h2>	
</body>
</html>

5. Spring Configuration

Create a Spring XML bean configuration file, define the beans and view resolver.

File : war/WEB-INF/mvc-dispatcher-servlet.xml


<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc" 
	xmlns: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
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

	<!-- 
		Need DI a message into controller, so auto component scan is disabled, 
		to avoid double create the movieController bean.
                Only controller need this hack.
	-->
	<context:component-scan base-package="com.mkyong.controller">
		<context:exclude-filter type="regex"
			expression="com.mkyong.controller.Movie.*" />
	</context:component-scan>

	<mvc:annotation-driven />

	<!-- Bean to show you Di in GAE, via Spring, also init the MovieController -->
	<bean class="com.mkyong.controller.MovieController">
		<property name="message">
			<value>Hello World</value>
		</property>
	</bean>

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

</beans>

6. web.xml

Update web.xml, integrate Spring framework.

File : war/WEB-INF/web.xml


<?xml version="1.0" encoding="utf-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
	
	<servlet>
		<servlet-name>mvc-dispatcher</servlet-name>
		<servlet-class>
                    org.springframework.web.servlet.DispatcherServlet
                </servlet-class>
		<load-on-startup>1</load-on-startup>
	</servlet>

	<servlet-mapping>
		<servlet-name>mvc-dispatcher</servlet-name>
		<url-pattern>/</url-pattern>
	</servlet-mapping>

	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>/WEB-INF/mvc-dispatcher-servlet.xml</param-value>
	</context-param>

	<listener>
		<listener-class>
                    org.springframework.web.context.ContextLoaderListener
                </listener-class>
	</listener>
	
	<welcome-file-list>
		<welcome-file>index.html</welcome-file>
	</welcome-file-list>
</web-app>

7. Directory Structure

Review the final directory structure.

gae spring final directory structure

8. Run on Local

Right click on the project, run as “Web Application“.

URL : http://localhost:8888/movie/Avengers

gae spring deploy on local development environemnt

9. Deploy on GAE

Update appengine-web.xml file, add your App Engine application ID.

File : war/WEB-INF/appengine-web.xml


<?xml version="1.0" encoding="utf-8"?>
<appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
  <application>mkyong-springmvc</application>
  <version>1</version>
 
  <system-properties>
    <property name="java.util.logging.config.file" 
          value="WEB-INF/logging.properties"/>
  </system-properties>
  
</appengine-web-app>

Select project, click on Google icon, “Deploy to App Engine“.

URL : http://mkyong-springmvc.appspot.com/movie/forrest%20gump

gae spring deploy on production environment

Download Source Code

Due to large file size, all Spring and GAE jars are excluded.

Download – SpringMVC-GoogleAppEngine.zip (12 KB)

References

  1. Spring 3.0 beans reference
  2. REST explains Wikipedia
  3. Google App Engine + Java + Google Plugin for eclipse example
  4. Spring 3 MVC hello world example
  5. Spring 3 REST hello world example
  6. Google Add Engine Java doc

About Author

author image
Founder of Mkyong.com, love Java and open source stuff. Follow him on Twitter. If you like my tutorials, consider make a donation to these charities.

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Pradeep Sharma
7 years ago

I have created an app-engine app where in I am loading properties files using Spring based configuration and using it in as “${app.id}”. When I run my app, all properties are getting loaded properly and my program works like charm but when I deploy the same application in Google App-Engine, I noticed that properties are not getting loaded and am getting null pointer exception. Does anyone has any pointer for this issue. I have googled a lot but not getting any correct solutions. Thanks !!
http://stackoverflow.com/a/37826145/3724864

Stanley Izturriaga
8 years ago

Hello one question, GAE supports web applications with hibernate?. Thank You

Eduardo Eduardo
9 years ago

I am unable to access the Servlet from the AppEngine, I request help …

———————————————————————————
Error: Server Error
The server encountered an error and could not complete your request.
Please try again in 30 seconds.
———————————————————————————

Prashant Rana
9 years ago

Did you get any solution for issue? I am getting same.

Error: Server Error
The server encountered an error and could not complete your request.
Please try again in 30 seconds.

Logs:-

org.springframework.web.context.ContextLoader initWebApplicationContext: Context initialization failed
org.springframework.beans.factory.BeanDefinitionStoreException: Failed to read candidate component class: file [/base/data/home/apps/s~indifantasycricket/2.382191145722035040/WEB-INF/classes/com/gyan/spot/controller/FantasyCricHomeCntrl.class]; nested exception is java.lang.IllegalArgumentException
at org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider.findCandidateComponents(ClassPathScanningCandidateComponentProvider.java:281)
at org.springframework.context.annotation.ClassPathBeanDefinitionScanner.doScan(ClassPathBeanDefinitionScanner.java:242)
at org.springframework.context.annotation.ComponentScanBeanDefinitionParser.parse(ComponentScanBeanDefinitionParser.java:84)
at org.springframework.beans.factory.xml.NamespaceHandlerSupport.parse(NamespaceHandlerSupport.java:73)
at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseCustomElement(BeanDefinitionParserDelegate.java:1435)
at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseCustomElement(BeanDefinitionParserDelegate.java:1425)
at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.parseBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:184)
at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.doRegisterBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:140)
at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.registerBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:111)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.registerBeanDefinitions(XmlBeanDefinitionReader.java:493)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:390)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:334)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:302)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:174)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:209)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:180)
at org.springframework.web.context.support.XmlWebApplicationContext.loadBeanDefinitions(XmlWebApplicationContext.java:125)
at org.springframework.web.context.support.XmlWebApplicationContext.loadBeanDefinitions(XmlWebApplicationContext.java:94)
at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:131)
at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:537)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:451)
at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:383)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:283)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:112)
at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.java:548)
at org.mortbay.jetty.servlet.Context.startContext(Context.java:136)
at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250)
at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517)
at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.createHandler(AppVersionHandlerMap.java:199)
at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.getHandler(AppVersionHandlerMap.java:174)
at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:134)
at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:484)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:438)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:445)
at com.google.tracing.CurrentContext.runInContext(CurrentContext.java:220)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:309)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:301)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:442)
at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:251)
at java.lang.Thread.run(Thread.java:724)
Caused by: java.lang.IllegalArgumentException
at org.springframework.asm.ClassReader.(Unknown Source)
at org.springframework.asm.ClassReader.(Unknown Source)
at org.springframework.asm.ClassReader.(Unknown Source)
at org.springframework.core.type.classreading.SimpleMetadataReader.(SimpleMetadataReader.java:52)
at org.springframework.core.type.classreading.SimpleMetadataReaderFactory.getMetadataReader(SimpleMetadataReaderFactory.java:80)
at org.springframework.core.type.classreading.CachingMetadataReaderFactory.getMetadataReader(CachingMetadataReaderFactory.java:101)
at org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider.findCandidateComponents(ClassPathScanningCandidateComponentProvider.java:257)
… 41 more

Sibi
9 years ago

I cannot run the project. The war folder shows an error.
Exception
com.google.apphosting.utils.config.AppEngineConfigException: appengine-web.xml does not contain a element.

lynas
9 years ago

for the maven build of this https://www.youtube.com/watch?v=JA_KxvCFhBg

suresh
9 years ago

why context component scan is not working

Raj
10 years ago

Hi,

Can you pls write a tutorial on how to consume external JSON REST service from your app deployed in Google App Engine. Say, you have a Spring web app which displays weather information based on the city name by calling the openweathermap.org/API JSON services.

Thanks in advance.

-Raj

Surya Dhyani
8 years ago
Reply to  Raj

I tried this. But on my eclipse it is not showing the archtypes for google app engine

Steve
10 years ago

Hi mkyong,

Could you please explain a little more what the following lines in mvc-dispatcher-servlet.xml are doing? You mentioned it stopping a double creation of the movieController bean but I didn’t quite understand why it would be created twice.

Thanks,

Steve

Steve
10 years ago
Reply to  Steve

Ah my code paste was removed. I’m referring to the context:component-scan and mvc:annotation-driven tags. Thanks.

Mani
10 years ago

Hi,

I tried your tutorial but this is not working. I got the below error.

HTTP ERROR: 503
Problem accessing /movie/Avengers. Reason:
SERVICE_UNAVAILABLE

Can you please help me to solve this issue

Thanks.

Ahmad Hariyanto
8 years ago
Reply to  Mani

Are you use port 8888? If yes, try change it to port 88. It works fine for me

jaw crusher price
11 years ago

the only way to get rid of temptation is to yield to it… i can resist everything but temptation. jaw crusher price http://jawcrushers.yolasite.com/

sachin
11 years ago

Hi,

Thanks for good tutorial.
I want to know GAE is support for Hibernate or not.
Thank you.

Rajesh Murli Mirchandani
11 years ago
Reply to  sachin

It is not supported.
Have a look to code.google.com/p/googleappengine/wiki/WillItPlayInJava

Bahador
11 years ago

Perfect, clean, and robust tutorial. Thanks for sharing.

Nick Kaye
11 years ago

My IDE is JetBrains IntelliJ IDEA and I’m trying to deploy to the local App Engine development server from the SDK. I was receiving a “could not locate artifacts/…/appengine-web.xml” error on run. The fix is based on http://erikeldridge.wordpress.com/tag/appengine/

In IntelliJ IDEA, Ctrl+Shift+Alt+S and look in the “Facets” project settings on the left. You will have already setup a “web:war exploded” Facet and simply need to add appengine-web.xml and web.xml to the list of files in the Output Layout.

Sudha
11 years ago

Hi Mkyong,

I need your help. I have a requirement in that I have to use AOP framework on both a client and server side. Here the client is android cellphone and server is GAE. What I want to do is need to offload a part of the android module to cloud for computation which consumes lots of battery, power and memory or else it will be run in android cellphone itself. please give some suggestions how to go about it. Thank you.

w
11 years ago

works on local, but doesn’t work when deployed to GAE!

w
11 years ago
Reply to  w

sorry, used to wrong spring jars. changed to correct ones as mentioned by Mr Yong, now its working, thanks!

Miguel
11 years ago

Here are the Jars, just downloaded from Maven repositories.

https://docs.google.com/open?id=0B3yWZxAiFGhzbjVOcEhLMDU4c0k

Jeremiah Miller
11 years ago

Thanks for this tutorial. It’s exactly what I needed and worked as described. As a side note, for Step 2 (Spring 3.0 Dependencies), I found the necessary jars on maven.
jm

bar
11 years ago

hey ,
im looking for this jars .
can u please send me link or tell me how to get them .
thank
bar

Jeremiah Miller
11 years ago
Reply to  bar

The jars themselves are hosted on maven.org but sites like mvnrepository.com and grepcode.com provide links and background info for these files. Just google the name of one of the jars and you’ll see these third-party sites that link to the downloads from maven.org. Hope this helps.

Thakur Parveen
11 years ago

I am a Java Er. and I want to read more on web services please suggest me….

tony
11 years ago
Reply to  Thakur Parveen

REST web services or soap ?
if restful like this great example (Thanks!), a more fully featured example is here:
http://www.ibm.com/developerworks/webservices/library/wa-restful/index.html

tony
11 years ago

Thanks for your example, look forward to using it…but was wondering if based on your experience, is there a best rest framework to rely upon ? i.e. spring mvc rest vs. spring rest templates vs. gae spring server…and nice to have would be control over format of serialized objects….
Thanks again.
-tony

tony
11 years ago
Reply to  tony

i meant gae rest server not spring server

Dana
11 years ago
Reply to  tony

spring rest will be portable across platforms, in case you decide to scrap GAE, anyway.