Issue running Spring tests/applications from STS with Gradle support

[balteo]

There seems to be an issue with STS/Gradle support when running/testing Spring projects.

I have installed the STS 3.6.2 together with Gradle support and the exception below was raised when I ran Spring tests. My app uses logback and it appears Gradle support added a logback jar on the test classpath causing the exception below:

java.lang.IllegalStateException: Failed to load ApplicationContext
    at org.springframework.test.context.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:91)
    at org.springframework.test.context.DefaultTestContext.getApplicationContext(DefaultTestContext.java:74)
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:116)
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:82)
    at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:212)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:199)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:251)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:253)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:216)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:82)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:60)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:67)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:162)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
Caused by: java.lang.IllegalArgumentException: LoggerFactory is not a Logback LoggerContext but Logback is on the classpath. Either remove Logback or the competing implementation (class org.slf4j.impl.SimpleLoggerFactory loaded from file:/home/julien/system/spring-tool-suite-3.6.2.RELEASE-e4.4-linux-gtk-x86_64/sts-3.6.2.RELEASE/plugins/org.springsource.ide.eclipse.gradle.toolingapi_3.6.2.201410090835-RELEASE/lib/slf4j-simple-1.7.5.jar). Object of class [org.slf4j.impl.SimpleLoggerFactory] must be an instance of class ch.qos.logback.classic.LoggerContext
    at org.springframework.util.Assert.isInstanceOf(Assert.java:339)
    at org.springframework.boot.logging.logback.LogbackLoggingSystem.initialize(LogbackLoggingSystem.java:71)
    at org.springframework.boot.logging.AbstractLoggingSystem.initializeWithSensibleDefaults(AbstractLoggingSystem.java:62)
    at org.springframework.boot.logging.AbstractLoggingSystem.beforeInitialize(AbstractLoggingSystem.java:45)
    at org.springframework.boot.logging.Slf4JLoggingSystem.beforeInitialize(Slf4JLoggingSystem.java:36)
    at org.springframework.boot.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:136)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:151)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:128)
    at org.springframework.boot.context.event.EventPublishingRunListener.publishEvent(EventPublishingRunListener.java:100)
    at org.springframework.boot.context.event.EventPublishingRunListener.started(EventPublishingRunListener.java:54)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:278)
    at org.springframework.boot.test.SpringApplicationContextLoader.loadContext(SpringApplicationContextLoader.java:105)
    at org.springframework.test.context.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:63)
    at org.springframework.test.context.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:83)
    ... 25 more