这几天在开发的过程，使用mvn tomcat7:redeploy命令打包部署到服务器上是，发现有报内存泄漏的日志。于是想在本地测试一下，看是哪里没有释放好内存。日志如下：
registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
21-Jul-2018 09:54:55.965 WARNING [http-nio-52000-exec-31] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [iicc_inf] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
java.lang.Object.wait(Native Method)
java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:143)
com.mysql.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:64)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
java.lang.Thread.run(Thread.java:748)
21-Jul-2018 09:54:55.966 WARNING [http-nio-52000-exec-31] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [iicc_inf] appears to have started a thread named [Thread-17] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
java.net.SocketInputStream.socketRead0(Native Method)
java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
java.net.SocketInputStream.read(SocketInputStream.java:171)
java.net.SocketInputStream.read(SocketInputStream.java:141)
java.io.BufferedInputStream.fill(BufferedInputStream.java:246)
java.io.BufferedInputStream.read1(BufferedInputStream.java:286)
java.io.BufferedInputStream.read(BufferedInputStream.java:345)
com.sun.jndi.ldap.Connection.run(Connection.java:860)
java.lang.Thread.run(Thread.java:748)
21-Jul-2018 09:54:56.015 INFO [http-nio-52000-exec-31] org.apache.catalina.startup.HostConfig.deployWAR Deploying web application archive 可能是因为是spring-boot项目的原因，所以我在tomcat中删除项目时，控制台上并没有打印日志。所以我想把manager加上，这样我可以在控制台上卸载项目，命令行一样卸载的目的。这就需要修改Server Locations了，以下说明Server Locations几项目设置。
Server Locations包括三个选项：
- Use workspace metadata(dose not modify Tomcat installation) 使用workspace的工作空间，不影响本地Tomcat安装配置
- Use Tomcat installation (takes control of Tomcat installation)
使用和控制本地安装的Tomcat - Use custom location (dose not modify Tomcat installation)
使用自定义的目录，不影响本地Tomcat安装配置
我们平时使用的配置都是第一项，tomcat启动的时候，war包和日志实际的路径可以在Open launch configuration这里找到：
我今天要使用的是第二项Use Tomcat installation，启动后，可以在tomcat的目录下看到wtpwebapps目录（其中wtpwebapps目录可以改为webapps，因不想影响里边的程序就没改），并且在logs目录下也能看到访问日志。
然后在%tomcat%/conf/tomcat-users.xml增加用户,再从http://localhost:8080/manager/html登录就可以部署和卸载war应用了。
