Java程序的classpath探索

Java 8

Spring Boot 2.5.2

Spring Cloud 2020.0.3

本文为搞清楚classpath而作。

参考文档里面的两篇文章讲的很到位，可以直接看它们。

不同项目可能略有不同。

Java文件首先“编译”成字节码文件——*.class，然后运行字节码文件——平台无关。

怎么运行？通过不同层级的ClassLoader——ClassLoader加载class文件到内存，然后从main函数开始运行。

classpath即指出不同的class文件的位置。来自博客园

在javac、java命令中有 -cp、-classpath 选项，可以指定类加载路径。

javac的：

java的：

三种获取classpath的方式：

// 方式1
ctx.getClassLoader().getResources("");

// 方式2
ClassLoader.getSystemResources("");
底层调用：
return getSystemClassLoader().getResources(name);

// 方式3
Thread.currentThread().getContextClassLoader().getResources("");

除了 getResources函数，还有 getResource 函数，前者返回 Enumeration<URL>，后者仅返回一个 URL。

疑问：

getResources函数的参数只能是 "" 吗？来自博客园

1、一个普通Java程序的类路径

2、一个Spring Boot项目的类路径

2.1、在Eclipse（Version: 2021-03 (4.19.0)）执行

2.2、在Windows 10上使用java命令执行

2.3、在Ubuntu 18.04上使用java命令执行

2.4、web-first-0.0.1-SNAPSHOT.jar包结构

参考文档

1、一个普通Java程序的类路径

程序如下：

import java.io.IOException;
import java.net.URL;
import java.util.Date;
import java.util.Enumeration;

public class MyClass{

	public static void main(String[] args) {
		System.out.println("hello world");
		
		ThisClass tc = new ThisClass();
		
		// 方式1
		try {
			System.out.println("class loader 1: " + tc.getClass().getClassLoader());
			Enumeration<URL> cpurl1 = tc.getClass().getClassLoader().getResources("");
			while (cpurl1.hasMoreElements()) {
				URL cp1 = cpurl1.nextElement();
				System.out.println("cp1=" + cp1);
			}
			System.out.println();
		} catch (IOException e) {
			e.printStackTrace();
		}
		
		// 方式2
		try {
			System.out.println("class loader 2: " + ClassLoader.getSystemClassLoader());
			Enumeration<URL> cpurl2 = ClassLoader.getSystemResources("");
			while (cpurl2.hasMoreElements()) {
				URL cp2 = cpurl2.nextElement();
				System.out.println("cp2=" + cp2);
			}
			System.out.println();
		} catch (IOException e) {
			e.printStackTrace();
		}
		
		// 方式3
		try {
			System.out.println("class loader 3: " + Thread.currentThread().getContextClassLoader());
			Enumeration<URL> cpurl3 = Thread.currentThread().getContextClassLoader().getResources("");
			while (cpurl3.hasMoreElements()) {
				URL cp3 = cpurl3.nextElement();
				System.out.println("cp3=" + cp3);
			}
			System.out.println();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
}

class ThisClass {
	
}

在Windows上执行结果：

hello world
class loader 1: sun.misc.Launcher$AppClassLoader@73d16e93
cp1=file:/D:/test/
cp1=file:/D:/Program%20Files/Java/jdk1.8.0_202/lib/

class loader 2: sun.misc.Launcher$AppClassLoader@73d16e93
cp2=file:/D:/test/
cp2=file:/D:/Program%20Files/Java/jdk1.8.0_202/lib/

class loader 3: sun.misc.Launcher$AppClassLoader@73d16e93
cp3=file:/D:/test/
cp3=file:/D:/Program%20Files/Java/jdk1.8.0_202/lib/

在Ubuntu上执行结果：来自博客园

ben@ben-VirtualBox:~/test$ java MyClass
hello world
class loader 1: sun.misc.Launcher$AppClassLoader@75b84c92
cp1=file:/home/ben/test/


class loader 2: sun.misc.Launcher$AppClassLoader@75b84c92
cp2=file:/home/ben/test/


class loader 3: sun.misc.Launcher$AppClassLoader@75b84c92
cp3=file:/home/ben/test/

三种方式执行的ClassLoader是同一个，获取的类路径相同。来自博客园

2、一个Spring Boot项目的类路径

项目名：web-first，一个Web项目，依赖了spring-boot-starter-web、spring-cloud-starter-netflix-eureka-client包。

程序如下：

@SpringBootApplication
public class WebFirstApplication {

	public static void main(String[] args) {
		ConfigurableApplicationContext ctx = SpringApplication.run(WebFirstApplication.class, args);
		// 方式1
		try {
			System.out.println("class loader 1: " + ctx.getClassLoader());
			Enumeration<URL> cpurl1 = ctx.getClassLoader().getResources("");
			while (cpurl1.hasMoreElements()) {
				URL cp1 = cpurl1.nextElement();
				System.out.println("cp1=" + cp1);
			}
			System.out.println();
		} catch (IOException e) {
			e.printStackTrace();
		}
		
		// 方式2
		try {
			System.out.println("class loader 2: " + ClassLoader.getSystemClassLoader());
			Enumeration<URL> cpurl2 = ClassLoader.getSystemResources("");
			while (cpurl2.hasMoreElements()) {
				URL cp2 = cpurl2.nextElement();
				System.out.println("cp2=" + cp2);
			}
			System.out.println();
		} catch (IOException e) {
			e.printStackTrace();
		}
		
		// 方式3
		try {
			System.out.println("class loader 3: " + Thread.currentThread().getContextClassLoader());
			Enumeration<URL> cpurl3 = Thread.currentThread().getContextClassLoader().getResources("");
			while (cpurl3.hasMoreElements()) {
				URL cp3 = cpurl3.nextElement();
				System.out.println("cp3=" + cp3);
			}
			System.out.println();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

}

2.1、在Eclipse（Version: 2021-03 (4.19.0)）执行

在Eclipse执行结果：

class loader 1: jdk.internal.loader.ClassLoaders$AppClassLoader@7382f612
cp1=file:/D:/spcloud/web-first/target/classes/
cp1=jar:file:/D:/work/mvnrepo/org/apache/logging/log4j/log4j-api/2.14.1/log4j-api-2.14.1.jar!/META-INF/versions/9/
cp1=jar:file:/D:/work/mvnrepo/org/bouncycastle/bcpkix-jdk15on/1.68/bcpkix-jdk15on-1.68.jar!/META-INF/versions/9/
cp1=jar:file:/D:/work/mvnrepo/org/bouncycastle/bcprov-jdk15on/1.68/bcprov-jdk15on-1.68.jar!/META-INF/versions/15/

class loader 2: jdk.internal.loader.ClassLoaders$AppClassLoader@7382f612
cp2=file:/D:/spcloud/web-first/target/classes/
cp2=jar:file:/D:/work/mvnrepo/org/apache/logging/log4j/log4j-api/2.14.1/log4j-api-2.14.1.jar!/META-INF/versions/9/
cp2=jar:file:/D:/work/mvnrepo/org/bouncycastle/bcpkix-jdk15on/1.68/bcpkix-jdk15on-1.68.jar!/META-INF/versions/9/
cp2=jar:file:/D:/work/mvnrepo/org/bouncycastle/bcprov-jdk15on/1.68/bcprov-jdk15on-1.68.jar!/META-INF/versions/15/

class loader 3: jdk.internal.loader.ClassLoaders$AppClassLoader@7382f612
cp3=file:/D:/spcloud/web-first/target/classes/
cp3=jar:file:/D:/work/mvnrepo/org/apache/logging/log4j/log4j-api/2.14.1/log4j-api-2.14.1.jar!/META-INF/versions/9/
cp3=jar:file:/D:/work/mvnrepo/org/bouncycastle/bcpkix-jdk15on/1.68/bcpkix-jdk15on-1.68.jar!/META-INF/versions/9/
cp3=jar:file:/D:/work/mvnrepo/org/bouncycastle/bcprov-jdk15on/1.68/bcprov-jdk15on-1.68.jar!/META-INF/versions/15/

三种方式的 ClassLoader对象是同一个，类路径也是同一个。

疑问：

作为一个Spring Boot的Web项目，类路径中怎么没有 spring相关的Jar包呢？

2.2、在Windows 10上使用java命令执行

首先打包web-first项目，得到：web-first-0.0.1-SNAPSHOT.jar；

执行：java -jar web-first-0.0.1-SNAPSHOT.jar

控制台输出：

点击查看代码

class loader 1: org.springframework.boot.loader.LaunchedURLClassLoader@2e5d6d97
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/classes!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-boot-2.5.2.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-boot-autoconfigure-2.5.2.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/logback-classic-1.2.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/logback-core-1.2.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/log4j-to-slf4j-2.14.1.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/log4j-api-2.14.1.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jul-to-slf4j-1.7.31.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jakarta.annotation-api-1.3.5.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/snakeyaml-1.28.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-databind-2.12.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-datatype-jdk8-2.12.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-datatype-jsr310-2.12.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-module-parameter-names-2.12.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/tomcat-embed-core-9.0.48.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/tomcat-embed-el-9.0.48.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/tomcat-embed-websocket-9.0.48.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-web-5.3.8.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-beans-5.3.8.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-webmvc-5.3.8.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-aop-5.3.8.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-context-5.3.8.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-expression-5.3.8.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-starter-netflix-eureka-client-3.0.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-starter-3.0.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-context-3.0.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-security-crypto-5.5.1.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-commons-3.0.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-security-rsa-1.0.10.RELEASE.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/bcpkix-jdk15on-1.68.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/bcprov-jdk15on-1.68.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-netflix-eureka-client-3.0.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/eureka-client-1.10.14.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/netflix-eventbus-0.3.0.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/netflix-infix-0.3.0.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-jxpath-1.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/joda-time-2.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/antlr-runtime-3.4.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/stringtemplate-3.2.1.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/antlr-2.7.7.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/gson-2.8.7.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-math-2.2.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/xstream-1.4.16.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/mxparser-1.2.1.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/xmlpull-1.1.3.1.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jsr311-api-1.1.1.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/servo-core-0.12.21.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/guava-19.0.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/httpclient-4.5.13.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/httpcore-4.4.14.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-codec-1.15.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-configuration-1.10.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-lang-2.6.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/guice-4.1.0.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/javax.inject-1.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/aopalliance-1.0.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-annotations-2.12.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-core-2.12.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jettison-1.4.0.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/eureka-core-1.10.14.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/woodstox-core-6.2.1.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/stax2-api-4.2.1.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-starter-loadbalancer-3.0.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-loadbalancer-3.0.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/hibernate-validator-6.2.0.Final.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jakarta.validation-api-2.0.2.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jboss-logging-3.4.2.Final.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/classmate-1.5.1.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/reactor-core-3.4.7.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/reactive-streams-1.0.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/reactor-extra-3.4.3.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-context-support-5.3.8.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/evictor-1.0.0.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/slf4j-api-1.7.31.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-core-5.3.8.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-jcl-5.3.8.jar!/
cp1=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-boot-jarmode-layertools-2.5.2.jar!/

class loader 2: sun.misc.Launcher$AppClassLoader@5c647e05

class loader 3: org.springframework.boot.loader.LaunchedURLClassLoader@2e5d6d97
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/classes!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-boot-2.5.2.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-boot-autoconfigure-2.5.2.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/logback-classic-1.2.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/logback-core-1.2.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/log4j-to-slf4j-2.14.1.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/log4j-api-2.14.1.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jul-to-slf4j-1.7.31.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jakarta.annotation-api-1.3.5.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/snakeyaml-1.28.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-databind-2.12.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-datatype-jdk8-2.12.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-datatype-jsr310-2.12.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-module-parameter-names-2.12.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/tomcat-embed-core-9.0.48.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/tomcat-embed-el-9.0.48.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/tomcat-embed-websocket-9.0.48.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-web-5.3.8.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-beans-5.3.8.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-webmvc-5.3.8.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-aop-5.3.8.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-context-5.3.8.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-expression-5.3.8.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-starter-netflix-eureka-client-3.0.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-starter-3.0.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-context-3.0.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-security-crypto-5.5.1.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-commons-3.0.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-security-rsa-1.0.10.RELEASE.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/bcpkix-jdk15on-1.68.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/bcprov-jdk15on-1.68.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-netflix-eureka-client-3.0.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/eureka-client-1.10.14.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/netflix-eventbus-0.3.0.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/netflix-infix-0.3.0.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-jxpath-1.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/joda-time-2.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/antlr-runtime-3.4.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/stringtemplate-3.2.1.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/antlr-2.7.7.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/gson-2.8.7.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-math-2.2.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/xstream-1.4.16.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/mxparser-1.2.1.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/xmlpull-1.1.3.1.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jsr311-api-1.1.1.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/servo-core-0.12.21.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/guava-19.0.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/httpclient-4.5.13.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/httpcore-4.4.14.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-codec-1.15.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-configuration-1.10.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-lang-2.6.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/guice-4.1.0.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/javax.inject-1.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/aopalliance-1.0.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-annotations-2.12.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-core-2.12.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jettison-1.4.0.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/eureka-core-1.10.14.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/woodstox-core-6.2.1.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/stax2-api-4.2.1.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-starter-loadbalancer-3.0.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-loadbalancer-3.0.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/hibernate-validator-6.2.0.Final.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jakarta.validation-api-2.0.2.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jboss-logging-3.4.2.Final.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/classmate-1.5.1.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/reactor-core-3.4.7.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/reactive-streams-1.0.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/reactor-extra-3.4.3.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-context-support-5.3.8.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/evictor-1.0.0.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/slf4j-api-1.7.31.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-core-5.3.8.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-jcl-5.3.8.jar!/
cp3=jar:file:/D:/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-boot-jarmode-layertools-2.5.2.jar!/

class loader 1、3相同，有配置classpath，而class locader 2存在，但classpath为空。

使用这种方式执行，可以看到程序依赖的Jar包了。

可以看出，打包得到的web-first-0.0.1-SNAPSHOT.jar已经包含了各个依赖包了。

2.3、在Ubuntu 18.04上使用java命令执行

同 2.2节的步骤，执行结果：

点击查看代码

class loader 1: org.springframework.boot.loader.LaunchedURLClassLoader@5a10411
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/classes!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-boot-2.5.2.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-boot-autoconfigure-2.5.2.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/logback-classic-1.2.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/logback-core-1.2.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/log4j-to-slf4j-2.14.1.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/log4j-api-2.14.1.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jul-to-slf4j-1.7.31.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jakarta.annotation-api-1.3.5.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/snakeyaml-1.28.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-databind-2.12.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-datatype-jdk8-2.12.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-datatype-jsr310-2.12.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-module-parameter-names-2.12.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/tomcat-embed-core-9.0.48.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/tomcat-embed-el-9.0.48.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/tomcat-embed-websocket-9.0.48.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-web-5.3.8.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-beans-5.3.8.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-webmvc-5.3.8.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-aop-5.3.8.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-context-5.3.8.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-expression-5.3.8.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-starter-netflix-eureka-client-3.0.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-starter-3.0.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-context-3.0.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-security-crypto-5.5.1.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-commons-3.0.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-security-rsa-1.0.10.RELEASE.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/bcpkix-jdk15on-1.68.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/bcprov-jdk15on-1.68.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-netflix-eureka-client-3.0.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/eureka-client-1.10.14.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/netflix-eventbus-0.3.0.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/netflix-infix-0.3.0.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-jxpath-1.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/joda-time-2.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/antlr-runtime-3.4.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/stringtemplate-3.2.1.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/antlr-2.7.7.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/gson-2.8.7.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-math-2.2.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/xstream-1.4.16.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/mxparser-1.2.1.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/xmlpull-1.1.3.1.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jsr311-api-1.1.1.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/servo-core-0.12.21.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/guava-19.0.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/httpclient-4.5.13.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/httpcore-4.4.14.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-codec-1.15.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-configuration-1.10.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-lang-2.6.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/guice-4.1.0.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/javax.inject-1.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/aopalliance-1.0.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-annotations-2.12.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-core-2.12.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jettison-1.4.0.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/eureka-core-1.10.14.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/woodstox-core-6.2.1.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/stax2-api-4.2.1.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-starter-loadbalancer-3.0.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-loadbalancer-3.0.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/hibernate-validator-6.2.0.Final.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jakarta.validation-api-2.0.2.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jboss-logging-3.4.2.Final.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/classmate-1.5.1.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/reactor-core-3.4.7.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/reactive-streams-1.0.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/reactor-extra-3.4.3.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-context-support-5.3.8.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/evictor-1.0.0.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/slf4j-api-1.7.31.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-core-5.3.8.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-jcl-5.3.8.jar!/
cp1=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-boot-jarmode-layertools-2.5.2.jar!/

class loader 2: sun.misc.Launcher$AppClassLoader@677327b6

class loader 3: org.springframework.boot.loader.LaunchedURLClassLoader@5a10411
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/classes!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-boot-2.5.2.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-boot-autoconfigure-2.5.2.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/logback-classic-1.2.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/logback-core-1.2.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/log4j-to-slf4j-2.14.1.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/log4j-api-2.14.1.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jul-to-slf4j-1.7.31.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jakarta.annotation-api-1.3.5.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/snakeyaml-1.28.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-databind-2.12.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-datatype-jdk8-2.12.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-datatype-jsr310-2.12.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-module-parameter-names-2.12.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/tomcat-embed-core-9.0.48.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/tomcat-embed-el-9.0.48.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/tomcat-embed-websocket-9.0.48.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-web-5.3.8.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-beans-5.3.8.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-webmvc-5.3.8.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-aop-5.3.8.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-context-5.3.8.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-expression-5.3.8.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-starter-netflix-eureka-client-3.0.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-starter-3.0.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-context-3.0.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-security-crypto-5.5.1.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-commons-3.0.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-security-rsa-1.0.10.RELEASE.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/bcpkix-jdk15on-1.68.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/bcprov-jdk15on-1.68.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-netflix-eureka-client-3.0.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/eureka-client-1.10.14.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/netflix-eventbus-0.3.0.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/netflix-infix-0.3.0.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-jxpath-1.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/joda-time-2.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/antlr-runtime-3.4.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/stringtemplate-3.2.1.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/antlr-2.7.7.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/gson-2.8.7.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-math-2.2.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/xstream-1.4.16.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/mxparser-1.2.1.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/xmlpull-1.1.3.1.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jsr311-api-1.1.1.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/servo-core-0.12.21.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/guava-19.0.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/httpclient-4.5.13.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/httpcore-4.4.14.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-codec-1.15.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-configuration-1.10.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/commons-lang-2.6.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/guice-4.1.0.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/javax.inject-1.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/aopalliance-1.0.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-annotations-2.12.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jackson-core-2.12.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jettison-1.4.0.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/eureka-core-1.10.14.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/woodstox-core-6.2.1.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/stax2-api-4.2.1.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-starter-loadbalancer-3.0.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-cloud-loadbalancer-3.0.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/hibernate-validator-6.2.0.Final.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jakarta.validation-api-2.0.2.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/jboss-logging-3.4.2.Final.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/classmate-1.5.1.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/reactor-core-3.4.7.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/reactive-streams-1.0.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/reactor-extra-3.4.3.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-context-support-5.3.8.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/evictor-1.0.0.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/slf4j-api-1.7.31.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-core-5.3.8.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-jcl-5.3.8.jar!/
cp3=jar:file:/home/ben/web-first-0.0.1-SNAPSHOT.jar!/BOOT-INF/lib/spring-boot-jarmode-layertools-2.5.2.jar!/

和 2.2节的结果对比，除了 class loader的地址不同、classpath的路径不同，其它完全相同。

2.4、web-first-0.0.1-SNAPSHOT.jar包结构

web-first-0.0.1-SNAPSHOT.jar包结构如下图：

jar包中部分文件的内容：来自博客园

想要了解spring boot程序是如何启动的，需要清楚这些文件在执行 java -jar 时是怎么用的，TODO

参考文档：

1、java打印出classpath_JAVA获取CLASSPATH路径

2、java项目中的classpath到底是什么

3、MANIFEST.MF文件详解

4、jvm系列(一):java类的加载机制

5、

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原文地址：https://www.cnblogs.com/luo630/p/15054847.html