dubbox部署到jdk1.7环境，启动：java.lang.NoSuchMethodError: java.util.concurrent.ConcurrentHashMap.keySet()

　　本地用jdk1.8编译的服务提供端war包，部署到环境报错了：

INFO: Initializing Spring root WebApplicationContext
[16/08/17 05:14:54:054 CST] localhost-startStop-1  INFO context.ContextLoader: Root WebApplicationContext: initialization started
[16/08/17 05:14:54:054 CST] localhost-startStop-1  INFO support.XmlWebApplicationContext: Refreshing Root WebApplicationContext: startup date [Wed Aug 16 17:14:54 CST 2017]; root of context hierarchy
[16/08/17 05:14:55:055 CST] localhost-startStop-1  INFO xml.XmlBeanDefinitionReader: Loading XML bean definitions from class path resource [META-INF/spring/provider.xml]
[16/08/17 05:14:56:056 CST] localhost-startStop-1  INFO logger.LoggerFactory: using logger: com.alibaba.dubbo.common.logger.log4j.Log4jLoggerAdapter
[16/08/17 05:14:57:057 CST] localhost-startStop-1  INFO support.PropertySourcesPlaceholderConfigurer: Loading properties file from class path resource [global.properties]
[16/08/17 05:14:58:058 CST] localhost-startStop-1  INFO util.PropertiesUtil: Loading properties file from class path resource [plugins-zoneResource.properties]
...
Caused by: java.lang.ExceptionInInitializerError
    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:525)
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:148)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:87)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1030)
    ... 23 more
Caused by: java.lang.IllegalStateException: fail to create adaptive instance: java.lang.IllegalStateException: Can not create adaptive extenstion interface com.alibaba.dubbo.rpc.Protocol, 
cause: fail to create adaptive instance: java.lang.NoSuchMethodError: java.util.concurrent.ConcurrentHashMap.keySet()Ljava/util/concurrent/ConcurrentHashMap$KeySetView;
    at com.alibaba.dubbo.common.extension.ExtensionLoader.getAdaptiveExtension(ExtensionLoader.java:459)
    at com.alibaba.dubbo.config.ServiceConfig.<clinit>(ServiceConfig.java:62)
    ... 30 more
Caused by: java.lang.IllegalStateException: Can not create adaptive extenstion interface com.alibaba.dubbo.rpc.Protocol, cause: fail to create adaptive instance: 
java.lang.NoSuchMethodError: java.util.concurrent.ConcurrentHashMap.keySet()Ljava/util/concurrent/ConcurrentHashMap$KeySetView;
    at com.alibaba.dubbo.common.extension.ExtensionLoader.createAdaptiveExtension(ExtensionLoader.java:723)
    at com.alibaba.dubbo.common.extension.ExtensionLoader.getAdaptiveExtension(ExtensionLoader.java:455)
    ... 31 more
Caused by: java.lang.IllegalStateException: fail to create adaptive instance: java.lang.NoSuchMethodError: java.util.concurrent.ConcurrentHashMap.keySet()Ljava/util/concurrent/ConcurrentHashMap$KeySetView;
    at com.alibaba.dubbo.common.extension.ExtensionLoader.getAdaptiveExtension(ExtensionLoader.java:459)
    at com.alibaba.dubbo.common.extension.ExtensionLoader.createAdaptiveExtensionClass(ExtensionLoader.java:738)
    at com.alibaba.dubbo.common.extension.ExtensionLoader.getAdaptiveExtensionClass(ExtensionLoader.java:732)
    at com.alibaba.dubbo.common.extension.ExtensionLoader.createAdaptiveExtension(ExtensionLoader.java:721)
    ... 32 more
Caused by: java.lang.NoSuchMethodError: java.util.concurrent.ConcurrentHashMap.keySet()Ljava/util/concurrent/ConcurrentHashMap$KeySetView;
    at com.alibaba.dubbo.common.utils.ConcurrentHashSet.iterator(ConcurrentHashSet.java:48)
    at com.alibaba.dubbo.config.spring.extension.SpringExtensionFactory.getExtension(SpringExtensionFactory.java:44)
    at com.alibaba.dubbo.common.extension.factory.AdaptiveExtensionFactory.getExtension(AdaptiveExtensionFactory.java:47)
    at com.alibaba.dubbo.common.extension.ExtensionLoader.injectExtension(ExtensionLoader.java:533)
    at com.alibaba.dubbo.common.extension.ExtensionLoader.createAdaptiveExtension(ExtensionLoader.java:721)
    at com.alibaba.dubbo.common.extension.ExtensionLoader.getAdaptiveExtension(ExtensionLoader.java:455)
    ... 35 more

 

　　发现失败原因是环境用的jdk版本是1.7的，而1.7的jdk根本就没有下面这个对象和方法

private transient KeySetView<K,V> keySet;

　　解决办法自然是升级环境jdk版本到1.8，否则本地改为1.7。