有一台生产环境的CPU占用率达到了100%，想分析一下是什么问题，如果用传统的线程分析会比较繁琐，需要记录pid，再转16进制，用jstack进行分析，如果要一直监控，就要一直重复输入，非常累人，于是我在github上找到个好用的工具
show-busy-java-threads，下面介绍如何使用。
工具GitHub：点我访问
一、在服务器上下载工具
wget --no-check-certificate https://github.com/oldratlee/useful-scripts/archive/release-2.x.zip
unzip release-2.x.zip
解压出来后，先放置在那，先看看我们服务器上有没有配$JAVA_HOME环境变量。
二、配置JAVA_HOME环境变量
先确认你的JDK安装路径，比如我的路径是 /usr/java/jdk1.6.0_45/，记住该路径，接着
sudo vim /etc/profile
添加以下配置：
export JAVA_HOME=/usr/java/jdk1.6.0_45
export JRE_HOME=$JAVA_HOME/jre
export CLASSPATH=$JAVA_HOME/lib:$JRE_HOME/lib:$CLASSPATH
export PATH=$JAVA_HOME/bin:$JRE_HOME/bin:$PATH
ctrl+c后输入:wq保存，再输入
source /etc/profile使配置生效，这样就可以使用show-busy-java-threads工具了。进到刚才解压好的工具目录下，
cd /解压好的目录/bin
show-busy-java-threads
就会显示排行前5的占用CPU利用率的线程栈，从中可以看到哪块代码引起的CPU占用，如：
"[ACTIVE] ExecuteThread: '36' for queue: 'weblogic.kernel.Default (self-tuning)'" daemon prio=10 tid=0x00007f5adc02b800 nid=0x4494 runnable [0x00007f58ef1ee000]
java.lang.Thread.State: RUNNABLE
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:129)
at oracle.net.ns.Packet.receive(Packet.java:293)
at oracle.net.ns.DataPacket.receive(DataPacket.java:92)
at oracle.net.ns.NetInputStream.getNextPacket(NetInputStream.java:174)
at oracle.net.ns.NetInputStream.read(NetInputStream.java:119)
at oracle.net.ns.NetInputStream.read(NetInputStream.java:94)
at oracle.net.ns.NetInputStream.read(NetInputStream.java:79)
at oracle.jdbc.driver.T4CSocketInputStreamWrapper.readNextPacket(T4CSocketInputStreamWrapper.java:112)
at oracle.jdbc.driver.T4CSocketInputStreamWrapper.read(T4CSocketInputStreamWrapper.java:73)
at oracle.jdbc.driver.T4CMAREngine.unmarshalUB1(T4CMAREngine.java:1040)
at oracle.jdbc.driver.T4CMAREngine.unmarshalSB1(T4CMAREngine.java:1016)
at oracle.jdbc.driver.T4C8Oall.receive(T4C8Oall.java:588)
at oracle.jdbc.driver.T4CPreparedStatement.doOall8(T4CPreparedStatement.java:194)
at oracle.jdbc.driver.T4CPreparedStatement.executeForRows(T4CPreparedStatement.java:953)
at oracle.jdbc.driver.OraclePreparedStatement.executeForRowsWithTimeout(OraclePreparedStatement.java:9253)
at oracle.jdbc.driver.OraclePreparedStatement.executeBatch(OraclePreparedStatement.java:9353)
- locked <0x000000071aa6c400> (a oracle.jdbc.driver.T4CConnection)
at oracle.jdbc.driver.OracleStatementWrapper.executeBatch(OracleStatementWrapper.java:211)
at weblogic.jdbc.wrapper.PreparedStatement.executeBatch(PreparedStatement.java:191)
at com.primeton.ext.infra.connection.StatementWrapper.executeBatch(StatementWrapper.java:239)
at com.primeton.das.entity.impl.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:49)
at com.primeton.das.entity.impl.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:254)
at com.primeton.das.entity.impl.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:235)
at com.primeton.das.entity.impl.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:140)
at com.primeton.das.entity.impl.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:298)
at com.primeton.das.entity.impl.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
at com.primeton.das.entity.impl.hibernate.impl.SessionImpl.flush(SessionImpl.java:1021)
at com.primeton.das.entity.impl.DASSessionImpl.updateEntity(DASSessionImpl.java:650)
at com.eos.foundation.database.DatabaseUtil.updateEntity(DatabaseUtil.java:259)
at com.hymake.valentine.ep.housesale.contract.Contractbiz.
addContract
_biz.invokePojo14(addContract_biz.java:1560)
at com.hymake.valentine.ep.housesale.contract.Contractbiz.addContract_biz._invoke(addContract_biz.java:3361)
at com.hymake.valentine.ep.housesale.contract.Contractbiz.addContract_biz.invoke(addContract_biz.java:3927)
at com.primeton.engine.core.impl.process.BLProxy.invoke(BLProxy.java:364)
at com.primeton.engine.component.impl.OperationAccessor.invoke(OperationAccessor.java:237)
at com.primeton.engine.component.impl.OperationAccessor.invoke(OperationAccessor.java:213)
at com.primeton.ext.engine.component.Operation.invoke(Operation.java:185)
at com.primeton.engine.component.impl.LogicCompoment.invoke(LogicCompoment.java:287)
如以上代码就是在addContract这里引起的。
