Java现场技巧汇总

1. 现场linux环境下，编译项目的java文件

   编译后台文件：
   jarpath=/opt/kangaroo-module-center/kangaroo-earlywarn-process/lib/
   CP="" ; for jar in `find ${jarpath} -name '*.jar'`; do CP="$jar:$CP" ; done
   javac -cp $CP KangarooFlowModuleBase.java
   javac -cp $CP SourceObjectMapManage.java

2. 现场排查jar包冲突问题

   Exception in thread "main" java.lang.NoSuchMethodError: com.google.common.util.concurrent.MoreExecutors.sameThreadExecutor()Lcom/google/common/util/concurrent/ListeningExecutorService;
   
   
   for i in `ls`;do unzip -l $i | grep com/google/common/util/concurrent/ListeningExecutorService;done
   
   hive-exec-2.0.0.jar
        1386  02-09-2016 18:36   com/google/common/util/concurrent/ListeningExecutorService.class
   guava-23.0.jar
        2071  08-04-2017 17:23   com/google/common/util/concurrent/ListeningExecutorService.class

处理jar冲突，两种方式：

1. 显示的在classpath中指定jar –优先选择显示指定
2. 删除冲突jar