Java 为什么我会得到不受支持的major.minor 51.0版

我试图用Gradle 2.14.1编译Spring Boot 1.3.6.RELEASE应用程序的基本框架。我需要使用Java6。我无法升级到Java 7或8

为什么我的gradle构建失败了

Unsupported major.minor version 51.0

例外似乎指向了这条线

apply plugin: 'spring-boot'

My gradle.properties文件包含：

org.gradle.java.home=C:/Program Files/Java/jdk1.6.0_45

为了使用Tomcat7而不是Tomcat8，我尝试包括以下内容，但这没有帮助

configurations.all {
    resolutionStrategy {
        eachDependency {
            if (it.requested.group == 'org.apache.tomcat.embed') {
                it.useVersion '7.0.56'
            }
        }
    }
} 

我遵循了SpringBootReference指南中有关Java6IE的建议，使用Tomcat7而不是8。 我没有使用JTA

* Exception is:
org.gradle.api.GradleScriptException: A problem occurred evaluating root project 'myProject'.
        at org.gradle.groovy.scripts.internal.DefaultScriptRunnerFactory$ScriptRunnerImpl.run(DefaultScriptRunnerFactory
.java:93)
        at org.gradle.configuration.DefaultScriptPluginFactory$ScriptPluginImpl$2.run(DefaultScriptPluginFactory.java:17
7)
        at org.gradle.configuration.ProjectScriptTarget.addConfiguration(ProjectScriptTarget.java:77)
        at org.gradle.configuration.DefaultScriptPluginFactory$ScriptPluginImpl.apply(DefaultScriptPluginFactory.java:18
2)
        at org.gradle.configuration.project.BuildScriptProcessor.execute(BuildScriptProcessor.java:38)
        at org.gradle.configuration.project.BuildScriptProcessor.execute(BuildScriptProcessor.java:25)
        at org.gradle.configuration.project.ConfigureActionsProjectEvaluator.evaluate(ConfigureActionsProjectEvaluator.j
ava:34)
        at org.gradle.configuration.project.LifecycleProjectEvaluator.evaluate(LifecycleProjectEvaluator.java:55)
        at org.gradle.api.internal.project.AbstractProject.evaluate(AbstractProject.java:540)
        at org.gradle.api.internal.project.AbstractProject.evaluate(AbstractProject.java:93)
        at org.gradle.execution.TaskPathProjectEvaluator.configureHierarchy(TaskPathProjectEvaluator.java:42)
        at org.gradle.configuration.DefaultBuildConfigurer.configure(DefaultBuildConfigurer.java:35)
        at org.gradle.initialization.DefaultGradleLauncher$2.run(DefaultGradleLauncher.java:124)
        at org.gradle.internal.Factories$1.create(Factories.java:22)
        at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:91)
        at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:53)
        at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:121)
        at org.gradle.initialization.DefaultGradleLauncher.access$200(DefaultGradleLauncher.java:32)
        at org.gradle.initialization.DefaultGradleLauncher$1.create(DefaultGradleLauncher.java:98)
        at org.gradle.initialization.DefaultGradleLauncher$1.create(DefaultGradleLauncher.java:92)
        at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:91)
        at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:63)
        at org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradleLauncher.java:92)
        at org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLauncher.java:83)
        at org.gradle.launcher.exec.InProcessBuildActionExecuter$DefaultBuildController.run(InProcessBuildActionExecuter
.java:99)
        at org.gradle.tooling.internal.provider.ExecuteBuildActionRunner.run(ExecuteBuildActionRunner.java:28)
        at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35)
        at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:48)
        at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:30)
        at org.gradle.launcher.exec.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:81)
        at org.gradle.launcher.exec.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:46)
        at org.gradle.launcher.daemon.server.exec.ExecuteBuild.doBuild(ExecuteBuild.java:52)
        at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36)
        at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
        at org.gradle.launcher.daemon.server.exec.WatchForDisconnection.execute(WatchForDisconnection.java:37)
        at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
        at org.gradle.launcher.daemon.server.exec.ResetDeprecationLogger.execute(ResetDeprecationLogger.java:26)
        at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
        at org.gradle.launcher.daemon.server.exec.RequestStopIfSingleUsedDaemon.execute(RequestStopIfSingleUsedDaemon.ja
va:34)
        at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
        at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.call(ForwardClientInput.java:74)
        at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.call(ForwardClientInput.java:72)
        at org.gradle.util.Swapper.swap(Swapper.java:38)
        at org.gradle.launcher.daemon.server.exec.ForwardClientInput.execute(ForwardClientInput.java:72)
        at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
        at org.gradle.launcher.daemon.server.health.DaemonHealthTracker.execute(DaemonHealthTracker.java:40)
        at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
        at org.gradle.launcher.daemon.server.exec.LogToClient.doBuild(LogToClient.java:60)
        at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36)
        at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
        at org.gradle.launcher.daemon.server.exec.EstablishBuildEnvironment.doBuild(EstablishBuildEnvironment.java:72)
        at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36)
        at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
        at org.gradle.launcher.daemon.server.health.HintGCAfterBuild.execute(HintGCAfterBuild.java:41)
        at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
        at org.gradle.launcher.daemon.server.exec.StartBuildOrRespondWithBusy$1.run(StartBuildOrRespondWithBusy.java:50)

        at org.gradle.launcher.daemon.server.DaemonStateCoordinator$1.run(DaemonStateCoordinator.java:237)
        at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:54)
        at org.gradle.internal.concurrent.StoppableExecutorImpl$1.run(StoppableExecutorImpl.java:40)
Caused by: java.lang.UnsupportedClassVersionError: io/spring/gradle/dependencymanagement/exclusions/Exclusions : Unsuppo
rted major.minor version 51.0
        at io.spring.gradle.dependencymanagement.DependencyManagementPlugin.apply(DependencyManagementPlugin.groovy:58)
        at io.spring.gradle.dependencymanagement.DependencyManagementPlugin.apply(DependencyManagementPlugin.groovy)
        at org.gradle.api.internal.plugins.ImperativeOnlyPluginApplicator.applyImperative(ImperativeOnlyPluginApplicator
.java:35)
        at org.gradle.api.internal.plugins.RuleBasedPluginApplicator.applyImperative(RuleBasedPluginApplicator.java:43)
        at org.gradle.api.internal.plugins.DefaultPluginManager.doApply(DefaultPluginManager.java:137)
        at org.gradle.api.internal.plugins.DefaultPluginManager.addImperativePlugin(DefaultPluginManager.java:67)
        at org.gradle.api.internal.plugins.DefaultPluginManager.addImperativePlugin(DefaultPluginManager.java:73)
        at org.gradle.api.internal.plugins.DefaultPluginContainer.apply(DefaultPluginContainer.java:60)
        at org.springframework.boot.gradle.dependencymanagement.DependencyManagementPluginFeatures.apply(DependencyManag
ementPluginFeatures.java:44)
        at org.springframework.boot.gradle.SpringBootPlugin.apply(SpringBootPlugin.java:47)
        at org.springframework.boot.gradle.SpringBootPlugin.apply(SpringBootPlugin.java:38)
        at org.gradle.api.internal.plugins.ImperativeOnlyPluginApplicator.applyImperative(ImperativeOnlyPluginApplicator
.java:35)
        at org.gradle.api.internal.plugins.RuleBasedPluginApplicator.applyImperative(RuleBasedPluginApplicator.java:43)
        at org.gradle.api.internal.plugins.DefaultPluginManager.doApply(DefaultPluginManager.java:137)
        at org.gradle.api.internal.plugins.DefaultPluginManager.apply(DefaultPluginManager.java:112)
        at org.gradle.api.internal.plugins.DefaultObjectConfigurationAction.applyType(DefaultObjectConfigurationAction.j
ava:113)
        at org.gradle.api.internal.plugins.DefaultObjectConfigurationAction.access$200(DefaultObjectConfigurationAction.
java:36)
        at org.gradle.api.internal.plugins.DefaultObjectConfigurationAction$3.run(DefaultObjectConfigurationAction.java:
80)
        at org.gradle.api.internal.plugins.DefaultObjectConfigurationAction.execute(DefaultObjectConfigurationAction.jav
a:136)
        at org.gradle.api.internal.project.AbstractPluginAware.apply(AbstractPluginAware.java:46)
        at org.gradle.api.internal.project.ProjectScript.apply(ProjectScript.java:34)
        at org.gradle.api.Script$apply$0.callCurrent(Unknown Source)
        at build_eb0vk878b797zgtn3oumoubtl.run(C:\Users\...\myProject\build.gradle:25)
        at org.gradle.groovy.scripts.internal.DefaultScriptRunnerFactory$ScriptRunnerImpl.run(DefaultScriptRunnerFactory
.java:91)
        ... 58 more

---

Java6的使用正是导致这个问题的原因。似乎其中一个必需的库至少支持Java 7/8—没有解决方法，您可能必须迁移到较新的Java版本。

该错误是由使用Java 7编译的依赖项引起的，因此无法使用Java 6

话虽如此，从系统需求的角度来看，如果您执行一些额外的配置，Java 6似乎是受支持的

关于嵌入式servlet容器兼容性，在第节中，您应该使用Tomcat 7或Jetty 8，这是gradle配置：

您可以通过设置Tomcat.version来更改Tomcat版本 财产：

ext['tomcat.version'] = '7.0.59'
dependencies {
    compile 'org.springframework.boot:spring-boot-starter-web'
}

---

显然，如果可以，最好升级到较新的JVM版本。

Spring Boot的Gradle插件使用的依赖关系管理插件需要Java 7。这意味着您必须使用Java 7或更高版本构建应用程序，但仍然可以使用Java 6运行应用程序。

查看、查看和文档部分扫描您是否共享了所有错误消息？它应该能弄清楚哪个类的版本不受支持。我也尝试过，但得到了相同的异常结果。设置gradle.properties为：org.gradle.java.home=C:/Program Files x86/java/jdk1.7.079似乎在生成，但现在我得到了警告：warning:[选项]引导类路径未与-source 1.6 My gradle.build文件一起设置包含：sourceCompatibility=1.6 targetCompatibility=1.6