Tomcat 7 NoSuchMethodError: Tomcat

Question

我在Tomcat7上部署web应用程序时遇到了问题。该应用程序是使用JDK7编译的，所以我通过在/etc/default/tomcat7中设置JAVA_HOME=/usr/lib/jvm/jdk1.7.0_80/将tomcat配置为使用JDK7。当我运行top时，我可以确认tomcat使用的是Java7。

java.lang.NoSuchMethodError: java.util.concurrent.ConcurrentHashMap.keySet()Ljava/util/concurrent/ConcurrentHashMap$KeySetView;
    at org.apache.catalina.core.ApplicationContext.getInitParameterNames(ApplicationContext.java:368)
    at org.apache.catalina.core.ApplicationContextFacade.getInitParameterNames(ApplicationContextFacade.java:367)
    at com.intel.mtwilson.jpa.PersistenceManager.contextInitialized(PersistenceManager.java:143)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:5068)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5584)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:899)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:875)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)
    at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:1091)
    at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1980)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)

据我所知，这个方法在JDK 7和JDK 8中有不同的返回类型，而tomcat由于某种原因正在寻找JDK8版本，即使它被配置为在JDK7中运行，这是什么原因？要让tomcat使用JDK 7，我还需要配置其他东西吗？

Answer 1

我认为问题在于您正在使用的Tomcat实际上并不是用Java7.It looks like there are some Tomcat 7 builds floating around that were compiled with Java 8编译的。

你应该使用Java 8。即使Tomcat是用Java 7编译的，它也应该在Java 8上运行。