Tomcat 7 NoSuchMethodError：java.util.concurrent.ConcurrentHashMap.keySet（）

Question

我在tomcat 7上部署Web應用程序時遇到問題。使用JDK 7編譯應用程序，因此我通過在/etc/default/tomcat7中設置JAVA_HOME=/usr/lib/jvm/jdk1.7.0_80/來配置tomcat以使用JDK 7 。當我運行top我可以證實，Tomcat是使用Java 7。但是，當我嘗試瀏覽應用程序，我得到下面的異常

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) 

據我瞭解這種方法在JDK 7和JDK 8和不同的返回類型tomcat出於某種原因尋找JDK 8版本，即使它被配置爲在JDK 7中運行。這是什麼原因？我必須配置其他任何東西才能使tomcat使用JDK 7嗎？

Answer 1

我認爲問題在於您使用的Tomcat實際上沒有用Java 7編譯。It looks like there are some Tomcat 7 builds floating around that were compiled with Java 8。

你應該使用Java 8.即使Tomcat的與Java 7的編譯，它應該在的Java運行8