Linux下tomcat启动报错：port already in use

小鱼儿 2022-08-26 11:25 217阅读 0赞

导致该问题的原因很多，标题说明不了具体问题。

在此仅说下我的操作，遇到的问题及其解决方法，希望能起到抛砖引玉的作用。

启动tomcat，报错如下：

Error: Exception thrown by the agent : java.rmi.server.ExportException: Port already in use: 7800; nested exception is:  
        java.net.BindException: Address already in use

检查了$\{TOMCAT\_HOME\}/conf/server.xml,context.xml,web.xml等配置文件，未发现配置7800端口的地方。

于是google搜索，一篇文章给了我提示：[https://bowerstudios.com/node/636][https_bowerstudios.com_node_636]

引用内容如下：

## Port already in use error when trying to shutdown Apache Tomcat with JMX monitoring enabled ##

So you tried to use JMX to monitor your Tomcat instance. You might have done so with the following lines in catalina.sh:

JAVA\_OPTS="$JAVA\_OPTS -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=8085"  
JAVA\_OPTS="$JAVA\_OPTS -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false"

Everything started up nicely, and you were able to monitor. YAY!

But when you ran the shutdown script:

user@host:/apache-tomcat-6.0.26$ bin/shutdown.sh  
Using CATALINA\_BASE: /apache-tomcat-6.0.26  
Using CATALINA\_HOME: /apache-tomcat-6.0.26  
Using CATALINA\_TMPDIR: /apache-tomcat-6.0.26/temp  
Using JRE\_HOME: /usr/lib/jvm/java-6-sun  
Using CLASSPATH: /apache-tomcat-6.0.26/bin/bootstrap.jar  
Error: Exception thrown by the agent : java.rmi.server.ExportException: Port already in use: 8085; nested exception is:  
java.net.BindException: Address already in use

Only a kill -9 would bring down tomcat. Uh oh!

Setting these properties in JAVA\_OPTS tries to start a jmx server when you start tomcat AND when you shutdown tomcat. Hence the port already in use exception. You need to set these properties for CATALINA\_OPTS instead of JAVA\_OPTS. This will only run when you start tomcat.

CATALINA\_OPTS="$CATALINA\_OPTS -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=8999"  
CATALINA\_OPTS="$CATALINA\_OPTS -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false"

于是从 $\{TOMCAT\_HOME\}/bin/catalina.sh 启动文件中找到了答案。

<span style="font-family:Courier New;font-size:14px;">JAVA_OPTS="-server -Xms2048m -Xmx2048m -XX:PermSize=512m -XX:MaxPermSize=512m -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.pwd.file=/opt/app/appcode/jmxremote.password -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.port=7803"</span>

分析了一下，因为tomcat不是由我配置，本人仅维护而已，从而不能全部掌握安装人员的配置精髓。

[https_bowerstudios.com_node_636]: https://bowerstudios.com/node/636