IDEA 导入 Tomcat9 源码

源码下载（Source Code Distributions）地址：https://tomcat.apache.org/download-90.cgi

tomcat 和 servlet 以及 jdk 版本的对应关系：http://tomcat.apache.org/whichversion.html

附上搭建好的环境：https://gitee.com/jhxxb/MyTomcat

Maven方式

一、解压源码

在源码根目录新建 home 文件夹，把 conf 文件夹和 webapps 文件夹移动到 home 文件夹里，然后在源码根目录新建 pom.xml 文件（原来为 Ant 工程，这里把它改为 Maven 工程）

pom.xml

<?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>org.apache.tomcat</groupId>
    <artifactId>tomcat</artifactId>
    <name>tomcat</name>
    <version>9.0.19</version>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.ant</groupId>
            <artifactId>ant</artifactId>
            <version>1.10.5</version>
        </dependency>
        <dependency>
            <groupId>wsdl4j</groupId>
            <artifactId>wsdl4j</artifactId>
            <version>1.6.3</version>
        </dependency>

        <!--<dependency>-->
            <!--<groupId>javax.xml</groupId>-->
            <!--<artifactId>jaxrpc</artifactId>-->
            <!--<version>1.1</version>-->
        <!--</dependency>-->
        <dependency>
            <groupId>org.apache.geronimo.specs</groupId>
            <artifactId>geronimo-jaxrpc_1.1_spec</artifactId>
            <version>2.1</version>
        </dependency>

<!--        <dependency>-->
<!--            <groupId>org.eclipse.jdt.core.compiler</groupId>-->
<!--            <artifactId>ecj</artifactId>-->
<!--            <version>4.5</version>-->
<!--        </dependency>-->
        <dependency>
            <groupId>org.eclipse.jdt</groupId>
            <artifactId>ecj</artifactId>
            <version>3.17.0</version>
        </dependency>

        <dependency>
            <groupId>org.easymock</groupId>
            <artifactId>easymock</artifactId>
            <version>4.0.2</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

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

二、用 IDEA 直接打开

这里删除了一些无用的文件

1.打开项目属性（F4）

把 java 文件夹标记为 Sources，test 文件夹标记为 Tests

2.运行

找到 org.apache.catalina.startup.Bootstrap 运行 main 方法

2.1、ResponseTrailers 找不到，把 home\webapps\examples\WEB-INF\classes\trailers 目录拷贝到 test 目录下

ResponseTrailers.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package trailers;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Map;
import java.util.function.Supplier;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * This example writes some trailer fields to the HTTP response.
 */
public class ResponseTrailers extends HttpServlet {

    private static final long serialVersionUID = 1L;
    private static final Supplier<Map<String,String>> TRAILER_FIELD_SUPPLIER =
            new TrailerFieldSupplier();

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {

        resp.setTrailerFields(TRAILER_FIELD_SUPPLIER);
        resp.setContentType("text/plain");
        resp.setCharacterEncoding("UTF-8");

        PrintWriter pw  = resp.getWriter();

        pw.print("This response should include trailer fields.");
    }

    private static class TrailerFieldSupplier implements Supplier<Map<String,String>> {

        private static final Map<String,String> trailerFields = new HashMap<>();

        static {
            trailerFields.put("x-trailer-1", "Trailer value one");
            trailerFields.put("x-trailer-2", "Trailer value two");
        }

        @Override
        public Map<String, String> get() {
            return trailerFields;
        }
    }
}

2.2、CookieFilter 找不到，把 home\webapps\examples\WEB-INF\classes\util\CookieFilter.java 文件拷贝到 test\util 目录下

CookieFilter.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package util;

import java.util.Locale;
import java.util.StringTokenizer;

/**
 * Processes a cookie header and attempts to obfuscate any cookie values that
 * represent session IDs from other web applications. Since session cookie names
 * are configurable, as are session ID lengths, this filter is not expected to
 * be 100% effective.
 *
 * It is required that the examples web application is removed in security
 * conscious environments as documented in the Security How-To. This filter is
 * intended to reduce the impact of failing to follow that advice. A failure by
 * this filter to obfuscate a session ID or similar value is not a security
 * vulnerability. In such instances the vulnerability is the failure to remove
 * the examples web application.
 */
public class CookieFilter {

    private static final String OBFUSCATED = "[obfuscated]";

    private CookieFilter() {
        // Hide default constructor
    }

    public static String filter(String cookieHeader, String sessionId) {

        StringBuilder sb = new StringBuilder(cookieHeader.length());

        // Cookie name value pairs are ';' separated.
        // Session IDs don't use ; in the value so don't worry about quoted
        // values that contain ;
        StringTokenizer st = new StringTokenizer(cookieHeader, ";");

        boolean first = true;
        while (st.hasMoreTokens()) {
            if (first) {
                first = false;
            } else {
                sb.append(';');
            }
            sb.append(filterNameValuePair(st.nextToken(), sessionId));
        }

        return sb.toString();
    }

    private static String filterNameValuePair(String input, String sessionId) {
        int i = input.indexOf('=');
        if (i == -1) {
            return input;
        }
        String name = input.substring(0, i);
        String value = input.substring(i + 1, input.length());

        return name + "=" + filter(name, value, sessionId);
    }

    public static String filter(String cookieName, String cookieValue, String sessionId) {
        if (cookieName.toLowerCase(Locale.ENGLISH).contains("jsessionid") &&
                (sessionId == null || !cookieValue.contains(sessionId))) {
            cookieValue = OBFUSCATED;
        }

        return cookieValue;
    }
}

2.3、conf\server.xml 找不到，设置下 jvm 参数（就是指定之前创建的 home 目录）

-Dcatalina.home=D:\CodeLib\tomcat9\home

2.4、控制台报错：Error configuring application listener of class [listeners.ContextListener]

没找到具体原因，删掉 webapps 下的 examples 文件夹即可

2.5、控制台或网页报错：Servlet.service() for servlet [jsp] in context with path [] threw exception [org.apache.jasper.JasperException: Unable to compile class for JSP] with root cause

编辑 org.apache.catalina.startup.ContextConfig 文件的 configureStart() 方法，添加初始化 JSP 解析器的代码

context.addServletContainerInitializer(new JasperInitializer(), null);

最后访问 http://127.0.0.1:8080/ 就可以看到欢迎页了

Ant方式

解压 tomcat 源码，编辑 build.properties.default 文件，修改 base.path 路径

# ----- Default Base Path for Dependent Packages -----
# Please note this path must be absolute, not relative,
# as it is referenced with different working directory
# contexts by the various build scripts.
base.path=D:/CodeLib/apache-tomcat-9.0.19-src/tomcat-build-libs

下载 Ant，配置环境变量

https://ant.apache.org/bindownload.cgi

# 设置系统环境变量
setx /M ANT_HOME "D:\apache-ant-1.10.5"
setx /M Path "%Path%;%ANT_HOME%\bin"

编译 tomcat，生成 idea 项目

cd D:\CodeLib\apache-tomcat-9.0.19-src
ant
ant ide-intellij

用 idea 打开源码目录，会提示设置变量属性，按照自己设置的目录设置即可，后面运行和 Maven 方式类似

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https://gongxufan.github.io/2017/10/20/tomcat-source-debug/

https://emacsist.github.io/tags/tomcat%E6%BA%90%E7%A0%81/