javax/servlet/ServletContext : Unsupported major.minor version 52.0 - spring

Question

I am trying to run simple app engine guestbook app modified for Spring
I am running od InteliJ IDEA
Since it is AppEngine, I need to run on JAVA 7
When I am compiling with Java 8 compiler, I have no problem. However when compiling with Java 7, I get this:
org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.test.context.web.WebDelegatingSmartContextLoader]: Constructor threw exception; nested exception is java.lang.UnsupportedClassVersionError: javax/servlet/ServletContext : Unsupported major.minor version 52.0
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:154)
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:102)
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:125)
at org.springframework.test.context.support.AbstractTestContextBootstrapper.resolveContextLoader(AbstractTestContextBootstrapper.java:474)
at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildMergedContextConfiguration(AbstractTestContextBootstrapper.java:359)
at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildMergedContextConfiguration(AbstractTestContextBootstrapper.java:305)
at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildTestContext(AbstractTestContextBootstrapper.java:112)
at org.springframework.test.context.TestContextManager.<init>(TestContextManager.java:120)
at org.springframework.test.context.TestContextManager.<init>(TestContextManager.java:105)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTestContextManager(SpringJUnit4ClassRunner.java:152)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.<init>(SpringJUnit4ClassRunner.java:143)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at org.junit.internal.builders.AnnotatedBuilder.buildRunner(AnnotatedBuilder.java:104)
at org.junit.internal.builders.AnnotatedBuilder.runnerForClass(AnnotatedBuilder.java:86)
at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:26)
at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:33)
at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:250)
at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:141)
at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:112)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:189)
at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:165)
at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:85)
at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:115)
at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:75)
Caused by: java.lang.UnsupportedClassVersionError: javax/servlet/ServletContext : Unsupported major.minor version 52.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at org.springframework.test.context.web.WebDelegatingSmartContextLoader.<init>(WebDelegatingSmartContextLoader.java:63)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:142)
... 32 more
Here is my Pom
<?xml version="1.0" encoding="UTF-8"?><project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<packaging>war</packaging>
<version>0.1-SNAPSHOT</version>
<groupId>XXXXX</groupId>
<artifactId>XXXXX</artifactId>
<properties>
<app.id>XXXXX</app.id>
<app.version>1</app.version>
<appengine.version>1.9.46</appengine.version>
<gcloud.plugin.version>2.0.9.74.v20150814</gcloud.plugin.version>
<objectify.version>5.1.13</objectify.version>
<guava.version>20.0</guava.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.showDeprecation>true</maven.compiler.showDeprecation>
<spring.framework.version> 4.3.4.RELEASE</spring.framework.version>
<jackson.version>2.8.5</jackson.version>
<javax.servlet.api.version>4.0.0-b01</javax.servlet.api.version>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
</properties>
<prerequisites>
<maven>3.1.0</maven>
</prerequisites>
<dependencies>
<!-- Compile/runtime dependencies -->
<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-api-1.0-sdk</artifactId>
<version>${appengine.version}</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>${javax.servlet.api.version}</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>jstl</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<!-- [START Spring Dependencies] -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.framework.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.framework.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.framework.version}</version>
</dependency>
<!-- [END Spring Dependencies] -->
<!-- [START Objectify_Dependencies] -->
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>${guava.version}</version>
</dependency>
<dependency>
<groupId>com.googlecode.objectify</groupId>
<artifactId>objectify</artifactId>
<version>${objectify.version}</version>
</dependency>
<!-- [END Objectify_Dependencies] -->
<!-- Test Dependencies -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.mockito</groupId>
<artifactId>mockito-all</artifactId>
<version>2.0.2-beta</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-testing</artifactId>
<version>${appengine.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-api-stubs</artifactId>
<version>${appengine.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${spring.framework.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>org.hamcrest</groupId>
<artifactId>hamcrest-all</artifactId>
<version>1.3</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<!-- for hot reload of the web application-->
<outputDirectory>${project.build.directory}/${project.build.finalName}/WEB-INF/classes</outputDirectory>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>versions-maven-plugin</artifactId>
<version>2.1</version>
<executions>
<execution>
<phase>compile</phase>
<goals>
<goal>display-dependency-updates</goal>
<goal>display-plugin-updates</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<version>3.6</version>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.7</source>
<target>1.7</target>
<compilerVersion>1.7</compilerVersion>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>3.0.0</version>
<configuration>
<archiveClasses>true</archiveClasses>
<webResources>
<!-- in order to interpolate version from pom into appengine-web.xml -->
<resource>
<directory>${basedir}/src/main/webapp/WEB-INF</directory>
<filtering>true</filtering>
<targetPath>WEB-INF</targetPath>
</resource>
</webResources>
</configuration>
</plugin>
<plugin>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-maven-plugin</artifactId>
<version>${appengine.version}</version>
<configuration>
<enableJarClasses>false</enableJarClasses>
<version>${app.version}</version>
<!-- Comment in the below snippet to bind to all IPs instead of just localhost -->
<!-- address>0.0.0.0</address>
<port>8080</port -->
<!-- Comment in the below snippet to enable local debugging with a remote debugger
like those included with Eclipse or IntelliJ -->
<!-- jvmFlags>
<jvmFlag>-agentlib:jdwp=transport=dt_socket,address=8000,server=y,suspend=n</jvmFlag>
</jvmFlags -->
</configuration>
</plugin>
<plugin>
<groupId>com.google.appengine</groupId>
<artifactId>gcloud-maven-plugin</artifactId>
<version>${gcloud.plugin.version}</version>
<configuration>
<set_default>true</set_default>
</configuration>
</plugin>
</plugins>
<testResources>
<testResource>
<directory>${basedir}/src/main/webapp</directory>
</testResource>
</testResources>
</build>
My JAVA_HOME is iset to Java7, inside project structure Project SDK is defined for Java7.
JDK for maven importer is Java77, JRE for maven runner is set to Project JDK
Can you please tell me how it is possible that I get this error, even if I have everything set to Java 7? And also how to fix it :)
Thanks

Answer 1

silly me...
solution was to use javax.servlet-api version 3.1.0