今天创建了一个新的 Tomcat，启动时，遇上这种报错：The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path，详细 catalina 日志如下：
七月 17, 2017 11:20:02 下午 org.apache.catalina.core.AprLifecycleListener init
信息: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: D:\Tomcat_8085\bin;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;C:\Program Files\Java\jdk1.7.0_67\bin;C:\Program Files\Java\jdk1.7.0_67\jre\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;D:\Program Files (x86)\Microsoft SQL Server\100\Tools\Binn\;D:\Program Files\Microsoft SQL Server\100\Tools\Binn\;D:\Program Files\Microsoft SQL Server\100\DTS\Binn\;D:\Program Files (x86)\Microsoft SQL Server\100\Tools\Binn\VSShell\Common7\IDE\;C:\Program Files (x86)\Microsoft Visual Studio 9.0\Common7\IDE\PrivateAssemblies\;D:\Program Files (x86)\Microsoft SQL Server\100\DTS\Binn\;.
七月 17, 2017 11:20:03 下午 org.apache.coyote.AbstractProtocol init
信息: Initializing ProtocolHandler ["http-bio-8085"]
七月 17, 2017 11:20:03 下午 org.apache.coyote.AbstractProtocol init
信息: Initializing ProtocolHandler ["ajp-bio-8009"]
七月 17, 2017 11:20:03 下午 org.apache.coyote.AbstractProtocol init
严重: Failed to initialize end point associated with ProtocolHandler ["ajp-bio-8009"]
java.net.BindException: Address already in use: JVM_Bind :8009
at org.apache.tomcat.util.net.JIoEndpoint.bind(JIoEndpoint.java:406)
at org.apache.tomcat.util.net.AbstractEndpoint.init(AbstractEndpoint.java:610)
at org.apache.coyote.AbstractProtocol.init(AbstractProtocol.java:429)
at org.apache.catalina.connector.Connector.initInternal(Connector.java:981)
at org.apache.catalina.util.LifecycleBase.init(LifecycleBase.java:102)
at org.apache.catalina.core.StandardService.initInternal(StandardService.java:559)
at org.apache.catalina.util.LifecycleBase.init(LifecycleBase.java:102)
at org.apache.catalina.core.StandardServer.initInternal(StandardServer.java:814)
at org.apache.catalina.util.LifecycleBase.init(LifecycleBase.java:102)
at org.apache.catalina.startup.Catalina.load(Catalina.java:640)
at org.apache.catalina.startup.Catalina.load(Catalina.java:665)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.catalina.startup.Bootstrap.load(Bootstrap.java:281)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:455)
Caused by: java.net.BindException: Address already in use: JVM_Bind
at java.net.DualStackPlainSocketImpl.bind0(Native Method)
at java.net.DualStackPlainSocketImpl.socketBind(DualStackPlainSocketImpl.java:106)
at java.net.AbstractPlainSocketImpl.bind(AbstractPlainSocketImpl.java:376)
at java.net.PlainSocketImpl.bind(PlainSocketImpl.java:190)
at java.net.ServerSocket.bind(ServerSocket.java:376)
at java.net.ServerSocket.(ServerSocket.java:237)
at java.net.ServerSocket.(ServerSocket.java:181)
at org.apache.tomcat.util.net.DefaultServerSocketFactory.createSocket(DefaultServerSocketFactory.java:49)
at org.apache.tomcat.util.net.JIoEndpoint.bind(JIoEndpoint.java:393)
... 16 more
七月 17, 2017 11:20:03 下午 org.apache.catalina.core.StandardService initInternal
严重: Failed to initialize connector [Connector[AJP/1.3-8009]]
org.apache.catalina.LifecycleException: Failed to initialize component [Connector[AJP/1.3-8009]]
at org.apache.catalina.util.LifecycleBase.init(LifecycleBase.java:106)
at org.apache.catalina.core.StandardService.initInternal(StandardService.java:559)
at org.apache.catalina.util.LifecycleBase.init(LifecycleBase.java:102)
at org.apache.catalina.core.StandardServer.initInternal(StandardServer.java:814)
at org.apache.catalina.util.LifecycleBase.init(LifecycleBase.java:102)
at org.apache.catalina.startup.Catalina.load(Catalina.java:640)
at org.apache.catalina.startup.Catalina.load(Catalina.java:665)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.catalina.startup.Bootstrap.load(Bootstrap.java:281)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:455)
Caused by: org.apache.catalina.LifecycleException: Protocol handler initialization failed
at org.apache.catalina.connector.Connector.initInternal(Connector.java:983)
at org.apache.catalina.util.LifecycleBase.init(LifecycleBase.java:102)
... 12 more
Caused by: java.net.BindException: Address already in use: JVM_Bind :8009
at org.apache.tomcat.util.net.JIoEndpoint.bind(JIoEndpoint.java:406)
at org.apache.tomcat.util.net.AbstractEndpoint.init(AbstractEndpoint.java:610)
at org.apache.coyote.AbstractProtocol.init(AbstractProtocol.java:429)
at org.apache.catalina.connector.Connector.initInternal(Connector.java:981)
... 13 more
Caused by: java.net.BindException: Address already in use: JVM_Bind
at java.net.DualStackPlainSocketImpl.bind0(Native Method)
at java.net.DualStackPlainSocketImpl.socketBind(DualStackPlainSocketImpl.java:106)
at java.net.AbstractPlainSocketImpl.bind(AbstractPlainSocketImpl.java:376)
at java.net.PlainSocketImpl.bind(PlainSocketImpl.java:190)
at java.net.ServerSocket.bind(ServerSocket.java:376)
at java.net.ServerSocket.(ServerSocket.java:237)
at java.net.ServerSocket.(ServerSocket.java:181)
at org.apache.tomcat.util.net.DefaultServerSocketFactory.createSocket(DefaultServerSocketFactory.java:49)
at org.apache.tomcat.util.net.JIoEndpoint.bind(JIoEndpoint.java:393)
... 16 more
七月 17, 2017 11:20:03 下午 org.apache.catalina.startup.Catalina load
信息: Initialization processed in 1065 ms
七月 17, 2017 11:20:03 下午 org.apache.catalina.core.StandardService startInternal
信息: Starting service Catalina
七月 17, 2017 11:20:03 下午 org.apache.catalina.core.StandardEngine startInternal
信息: Starting Servlet Engine: Apache Tomcat/7.0.42
七月 17, 2017 11:20:03 下午 org.apache.catalina.startup.HostConfig deployDirectory
信息: Deploying web application directory D:\Tomcat_8085\webapps\docs
七月 17, 2017 11:20:03 下午 org.apache.catalina.startup.HostConfig deployDirectory
信息: Deploying web application directory D:\Tomcat_8085\webapps\manager
七月 17, 2017 11:20:03 下午 org.apache.catalina.startup.HostConfig deployDirectory
信息: Deploying web application directory D:\Tomcat_8085\webapps\ROOT
七月 17, 2017 11:20:03 下午 org.apache.coyote.AbstractProtocol start
信息: Starting ProtocolHandler ["http-bio-8085"]
七月 17, 2017 11:20:03 下午 org.apache.catalina.startup.Catalina start
信息: Server startup in 676 ms
七月 17, 2017 11:20:03 下午 org.apache.catalina.core.StandardServer await
严重: StandardServer.await: create[localhost:8005]:
java.net.BindException: Address already in use: JVM_Bind
at java.net.DualStackPlainSocketImpl.bind0(Native Method)
at java.net.DualStackPlainSocketImpl.socketBind(DualStackPlainSocketImpl.java:106)
at java.net.AbstractPlainSocketImpl.bind(AbstractPlainSocketImpl.java:376)
at java.net.PlainSocketImpl.bind(PlainSocketImpl.java:190)
at java.net.ServerSocket.bind(ServerSocket.java:376)
at java.net.ServerSocket.(ServerSocket.java:237)
at org.apache.catalina.core.StandardServer.await(StandardServer.java:427)
at org.apache.catalina.startup.Catalina.await(Catalina.java:779)
at org.apache.catalina.startup.Catalina.start(Catalina.java:725)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:322)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:456)
七月 17, 2017 11:20:03 下午 org.apache.coyote.AbstractProtocol pause
信息: Pausing ProtocolHandler ["http-bio-8085"]
七月 17, 2017 11:20:03 下午 org.apache.coyote.AbstractProtocol pause
信息: Pausing ProtocolHandler ["ajp-bio-8009"]
七月 17, 2017 11:20:03 下午 org.apache.catalina.core.StandardService stopInternal
信息: Stopping service Catalina
七月 17, 2017 11:20:03 下午 org.apache.coyote.AbstractProtocol stop
信息: Stopping ProtocolHandler ["http-bio-8085"]
七月 17, 2017 11:20:03 下午 org.apache.coyote.AbstractProtocol destroy
信息: Destroying ProtocolHandler ["http-bio-8085"]
七月 17, 2017 11:20:03 下午 org.apache.coyote.AbstractProtocol stop
信息: Stopping ProtocolHandler ["ajp-bio-8009"]
七月 17, 2017 11:20:03 下午 org.apache.coyote.AbstractProtocol destroy
信息: Destroying ProtocolHandler ["ajp-bio-8009"]
看到与“APR”有关，我就搜索了 APR 相关的资料，比较好的资料有：StackOverFlow中的回答 和 博客园的方法。但是以上资料都表明，tcnative-1.dll 这个 APR 脚本工具是让 Tomcat 运行更流畅的而不是必需的。也就是说，如果缺少 tcnative-1.dll，就算有以上报错，Tomcat 仍然会启动。
但我的 Tomcat 根本就没有启动。
于是我从系统环境着手解决问题，因为前几天正好改动过系统环境，不知是否有关系。可是检查后发现，系统环境（主要是 Java 环境的配置）完好，应该是其他原因。
然后我就开始仔细分析 catalina 日志了。
我发现日志中有这样的信息：
Failed to initialize end point associated with ProtocolHandler ["ajp-bio-8009"]Address already in useStandardServer.await: create[localhost:8005]:Address already in use
OK，Address already in use，我突然想到，这个新建的 Tomcat 是我在这台计算机上建立的第二个 Tomcat 服务器，其默认的 Shutdown Port 8005 和默认的 AJP/1.3 Connector Port 8009 我都没有修改，只是重新设置了一个 HTTP Connector Port，关键是，另一个早就搭建的 Tomcat 正在运行中，二者 Shutdown Port 和 AJP/1.3 Connector Port 冲突了，所以日志中才会提示 Address already in use。
我迅速删掉这个 Tomcat，又重新搭建了一个，搭建的时候特意把默认端口全部改掉。搭建完成之后，启动，果然可以正常访问了。
因此，同一台计算机上的两个 Tomcat 服务必须保持每个端口的独立！