Tomcat源码 - 2. IDEA 调试 Tomcat 8 - 在码圈-专注编程技术分享-代码改变未来，努力coding

1. 首先下载源码和Tomcat

官网：https://tomcat.apache.org

下载source源码，zip包

2. 编辑pom文件

解压后在根目录新建一个 pom.xml 文件

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.apache</groupId>
  <artifactId>tomcatcode</artifactId>
  <version>1.0-SNAPSHOT</version>

  <!-- 远程仓库 -->
  <repositories>
    <repository>
      <id>aliyun</id>
      <name>aliyun Repository</name>
      <url>http://maven.aliyun.com/nexus/content/groups/public</url>
      <snapshots>
        <enabled>false</enabled>
      </snapshots>
    </repository>
    <repository>
      <id>ibiblio</id>
      <name>ibiblio Repository</name>
      <url>http://mirrors.ibiblio.org/pub/mirrors/maven2</url>
      <snapshots>
        <enabled>false</enabled>
      </snapshots>
    </repository>
  </repositories>

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>2.3</version>
        <configuration>
          <encoding>UTF-8</encoding>
          <source>1.8</source>
          <target>1.8</target>
        </configuration>
      </plugin>
    </plugins>
  </build>

  <dependencies>
    <dependency>
      <groupId>org.easymock</groupId>
      <artifactId>easymock</artifactId>
      <version>3.4</version>
    </dependency>
    <dependency>
      <groupId>ant</groupId>
      <artifactId>ant</artifactId>
      <version>1.7.0</version>
    </dependency>
    <dependency>
      <groupId>wsdl4j</groupId>
      <artifactId>wsdl4j</artifactId>
      <version>1.6.2</version>
    </dependency>
    <dependency>
      <groupId>javax.xml</groupId>
      <artifactId>jaxrpc</artifactId>
      <version>1.1</version>
    </dependency>
    <dependency>
      <groupId>org.eclipse.jdt.core.compiler</groupId>
      <artifactId>ecj</artifactId>
      <version>4.5.1</version>
    </dependency>
    <!-- junit -->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.13</version>
      <scope>test</scope>
    </dependency>

  </dependencies>

</project>

3. IDEA 打开 tomcat

4. 设置 Sources 目录 (否则启动无法找到Java主文件)

5. 修改`ContextConfig.java`文件

路径 org.apache.catalina.startup.ContextConfig
configureStart 方法里添加

// 解决启动为空的问题
context.addServletContainerInitializer(new JasperInitializer(), null);

否则便是这样的结果
千辛万苦把Tomcat配置的启动起来了，却发现默认的页面无法打开：

经过重重排查，原因竟然是jsp的编译器没有初始化，我们只需要在apache-tomcat-8.5.76-src\java\org\apache\catalina\startup\ContextConfig.java类中只需添加一句代码即可手动初始化

6. 配置IDEA启动项

QQ图片20220315193928.png

参数

org.apache.catalina.startup.Bootstrap