Idea中tocmat启动源码调试，如何进入到tomcat内部进行调试_Java

使用idea开发工具调试代码的时候，如果是java的web项目，使用的是tomcat作为web容器，打断点debug调试跟踪，当跟踪到org.apache.catalina包下的时候，则无法进入，这是因为idea运行的tomcat是通过插件的方式集成的，tomcat里面的lib包不再项目的依赖路径中，所以不能跟踪进去

首先在自己项目中被tomcat回调的接口实现类中，标记一个断点信息，通过idea启动web项目，当出现如图所示的断点信息的时候，因为断点位置标记的是tomcat回调的接口类，所以按照调用堆栈网上则是tomcat内部代码，但此时双击org.apache.catalina包下面的类名，是没有任何反应的，因为我们还没有将tomcat对应的依赖文件添加到classpath下面

添加依赖

<dependency> <groupId>org.apache.tomcat</groupId> <artifactId>tomcat-catalina</artifactId> <version>8.5.55</version> <scope>provided</scope> </dependency>

因为运行时使用的是tomcat的lib目录下面的jar文件，所以此处的scope使用provided方式

下面就可以进入到tomcat源码调试了

tomcat启动日志是怎么执行打出来的？

03-Jun-2020 10:31:30.929 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Server.服务器版本: Apache Tomcat/8.5.55 03-Jun-2020 10:31:30.938 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 服务器构建: May 5 2020 22:10:54 UTC 03-Jun-2020 10:31:30.938 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 服务器版本号(: 8.5.55.0 03-Jun-2020 10:31:30.938 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 操作系统名称: Windows 10 03-Jun-2020 10:31:30.938 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log OS.版本: 10.0 03-Jun-2020 10:31:30.938 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 架构: amd64 03-Jun-2020 10:31:30.939 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Java 环境变量: C:\Program Files\Java\jdk1.8.0_212\jre 03-Jun-2020 10:31:30.939 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Java虚拟机版本: 1.8.0_212-b10 03-Jun-2020 10:31:30.939 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log JVM.供应商: Oracle Corporation 03-Jun-2020 10:31:30.939 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log CATALINA_BASE: C:\Users\Administrator\.IntelliJIdea2018.3\system\tomcat\Unnamed_spring-shiro-training 03-Jun-2020 10:31:30.939 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log CATALINA_HOME: D:\tomcat8.5.55\apache-tomcat-8.5.55

通过定位到 VersionLoggerListener 日志可以查看到

private void log() { log.info(sm.getString("versionLoggerListener.serverInfo.server.version", ServerInfo.getServerInfo())); log.info(sm.getString("versionLoggerListener.serverInfo.server.built", ServerInfo.getServerBuilt())); log.info(sm.getString("versionLoggerListener.serverInfo.server.number", ServerInfo.getServerNumber())); log.info(sm.getString("versionLoggerListener.os.name", System.getProperty("os.name"))); log.info(sm.getString("versionLoggerListener.os.version", System.getProperty("os.version"))); log.info(sm.getString("versionLoggerListener.os.arch", System.getProperty("os.arch"))); log.info(sm.getString("versionLoggerListener.java.home", System.getProperty("java.home"))); log.info(sm.getString("versionLoggerListener.vm.version", System.getProperty("java.runtime.version"))); log.info(sm.getString("versionLoggerListener.vm.vendor", System.getProperty("java.vm.vendor"))); log.info(sm.getString("versionLoggerListener.catalina.base", System.getProperty("catalina.base"))); log.info(sm.getString("versionLoggerListener.catalina.home", System.getProperty("catalina.home"))); if (logArgs) { List<String> args = ManagementFactory.getRuntimeMXBean().getInputArguments(); for (String arg : args) { log.info(sm.getString("versionLoggerListener.arg", arg)); } } if (logEnv) { SortedMap<String, String> sortedMap = new TreeMap<>(System.getenv()); for (Map.Entry<String, String> e : sortedMap.entrySet()) { log.info(sm.getString("versionLoggerListener.env", e.getKey(), e.getValue())); } } if (logProps) { SortedMap<String, String> sortedMap = new TreeMap<>(); for (Map.Entry<Object, Object> e : System.getProperties().entrySet()) { sortedMap.put(String.valueOf(e.getKey()), String.valueOf(e.getValue())); } for (Map.Entry<String, String> e : sortedMap.entrySet()) { log.info(sm.getString("versionLoggerListener.prop", e.getKey(), e.getValue())); } } }

发现是通过键值对的方式获取的，再通过字符串全局搜索发现
在这里插入图片描述
但是匹配的是英文，那么中文是怎么打出来的呢？

最后通过调试发现找的是这个
在这里插入图片描述
类似上面的东西,调试的时候发现tocmat的东西启动还是相当多的
且看下面这个

idea tomcat启动后的数据

03-Jun-2020 10:31:30.939 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 命令行参数：-Djava.util.logging.config.file=C:\Users\Administrator\.IntelliJIdea2018.3\system\tomcat\Unnamed_spring-shiro-training\conf\logging.properties 03-Jun-2020 10:31:30.940 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 命令行参数：-Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager 03-Jun-2020 10:31:30.940 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 命令行参数：-agentlib:jdwp=transport=dt_socket,address=127.0.0.1:52290,suspend=y,server=n 03-Jun-2020 10:31:30.940 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 命令行参数：-javaagent:C:\Users\Administrator\.IntelliJIdea2018.3\system\captureAgent\debugger-agent.jar 03-Jun-2020 10:31:30.940 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 命令行参数：-Dfile.encoding=UTF-8 03-Jun-2020 10:31:30.940 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 命令行参数：-Dcom.sun.management.jmxremote= 03-Jun-2020 10:31:30.940 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 命令行参数：-Dcom.sun.management.jmxremote.port=1099 03-Jun-2020 10:31:30.940 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 命令行参数：-Dcom.sun.management.jmxremote.ssl=false 03-Jun-2020 10:31:30.940 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 命令行参数：-Dcom.sun.management.jmxremote.password.file=C:\Users\Administrator\.IntelliJIdea2018.3\system\tomcat\Unnamed_spring-shiro-training\jmxremote.password 03-Jun-2020 10:31:30.940 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 命令行参数：-Dcom.sun.management.jmxremote.access.file=C:\Users\Administrator\.IntelliJIdea2018.3\system\tomcat\Unnamed_spring-shiro-training\jmxremote.access 03-Jun-2020 10:31:30.940 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 命令行参数：-Djava.rmi.server.hostname=127.0.0.1 03-Jun-2020 10:31:30.940 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 命令行参数：-Djdk.tls.ephemeralDHKeySize=2048 03-Jun-2020 10:31:30.940 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 命令行参数：-Djava.protocol.handler.pkgs=org.apache.catalina.webresources 03-Jun-2020 10:31:30.941 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 命令行参数：-Dignore.endorsed.dirs= 03-Jun-2020 10:31:30.941 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 命令行参数：-Dcatalina.base=C:\Users\Administrator\.IntelliJIdea2018.3\system\tomcat\Unnamed_spring-shiro-training 03-Jun-2020 10:31:30.941 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 命令行参数：-Dcatalina.home=D:\tomcat8.5.55\apache-tomcat-8.5.55 03-Jun-2020 10:31:30.941 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log 命令行参数：-Djava.io.tmpdir=D:\tomcat8.5.55\apache-tomcat-8.5.55\temp

以上还只是基本的环境配置等启动
然后是准备链接到tomcat服务

03-Jun-2020 10:31:30.941 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent 使用APR版本[1.7.0]加载了基于APR的Apache Tomcat本机库[1.2.24]。 03-Jun-2020 10:31:30.941 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent APR功能：IPv6[true]、sendfile[true]、accept filters[false]、random[true]。 03-Jun-2020 10:31:30.941 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent APR/OpenSSL配置：useAprConnector[false]，useOpenSSL[true] 03-Jun-2020 10:31:30.944 信息 [main] org.apache.catalina.core.AprLifecycleListener.initializeSSL OpenSSL成功初始化 [OpenSSL 1.1.1g 21 Apr 2020] 03-Jun-2020 10:31:31.032 信息 [main] org.apache.coyote.AbstractProtocol.init 初始化协议处理器 ["http-nio-8080"] 03-Jun-2020 10:31:31.046 信息 [main] org.apache.tomcat.util.net.NioSelectorPool.getSharedSelector Using a shared selector for servlet write/read 03-Jun-2020 10:31:31.055 信息 [main] org.apache.catalina.startup.Catalina.load Initialization processed in 175489 ms 03-Jun-2020 10:31:31.080 信息 [main] org.apache.catalina.core.StandardService.startInternal 正在启动服务[Catalina] 03-Jun-2020 10:31:31.080 信息 [main] org.apache.catalina.core.StandardEngine.startInternal Starting Servlet Engine: Apache Tomcat/8.5.55 03-Jun-2020 10:31:31.089 信息 [main] org.apache.coyote.AbstractProtocol.start 开始协议处理句柄["http-nio-8080"] 03-Jun-2020 10:31:31.102 信息 [main] org.apache.catalina.startup.Catalina.start Server startup in 47 ms

tomat启动主要是在Catalina中
在这里插入图片描述

然后是

启动

 /**
* Await and shutdown.
*/ public void await() { getServer().await(); }

其实tomcat启动本质上就是socket的服务器罢了

@Override public void await() { // Negative values - don't wait on port - tomcat is embedded or we just don't like ports if (port == -2) { // undocumented yet - for embedding apps that are around, alive. return; } if (port==-1) { try { awaitThread = Thread.currentThread(); while(!stopAwait) { try { Thread.sleep( 10000 ); } catch( InterruptedException ex ) { // continue and check the flag } } } finally { awaitThread = null; } return; } // Set up a server socket to wait on try { awaitSocket = new ServerSocket(port, 1, InetAddress.getByName(address)); } catch (IOException e) { log.error("StandardServer.await: create[" + address + ":" + port + "]: ", e); return; } try { awaitThread = Thread.currentThread(); // Loop waiting for a connection and a valid command while (!stopAwait) { ServerSocket serverSocket = awaitSocket; if (serverSocket == null) { break; } // Wait for the next connection Socket socket = null; StringBuilder command = new StringBuilder(); try { InputStream stream; long acceptStartTime = System.currentTimeMillis(); try { socket = serverSocket.accept(); //一旦accecpt后面就开始执行了 socket.setSoTimeout(10 * 1000); // Ten seconds stream = socket.getInputStream(); } catch (SocketTimeoutException ste) { // This should never happen but bug 56684 suggests that // it does. log.warn(sm.getString("standardServer.accept.timeout", Long.valueOf(System.currentTimeMillis() - acceptStartTime)), ste); continue; } catch (AccessControlException ace) { log.warn(sm.getString("standardServer.accept.security"), ace); continue; } catch (IOException e) { if (stopAwait) { // Wait was aborted with socket.close() break; } log.error(sm.getString("standardServer.accept.error"), e); break; } // Read a set of characters from the socket int expected = 1024; // Cut off to avoid DoS attack while (expected < shutdown.length()) { if (random == null) random = new Random(); expected += (random.nextInt() % 1024); } while (expected > 0) { int ch = -1; try { ch = stream.read(); } catch (IOException e) { log.warn(sm.getString("standardServer.accept.readError"), e); ch = -1; } // Control character or EOF (-1) terminates loop if (ch < 32 || ch == 127) { break; } command.append((char) ch); expected--; } } finally { // Close the socket now that we are done with it try { if (socket != null) { socket.close(); } } catch (IOException e) { // Ignore } } // Match against our command string boolean match = command.toString().equals(shutdown); if (match) { log.info(sm.getString("standardServer.shutdownViaPort")); break; } else log.warn(sm.getString("standardServer.invalidShutdownCommand", command.toString())); } } finally { ServerSocket serverSocket = awaitSocket; awaitThread = null; awaitSocket = null; // Close the server socket and return if (serverSocket != null) { try { serverSocket.close(); } catch (IOException e) { // Ignore } } } }