JVM启动过程 类加载器 【待删除】

下图来自：http://blog.csdn.net/jiangwei0910410003/article/details/17733153

package com.test.jvm.common;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * 自定义的类加载器
 */
public class MyClassLoader extends ClassLoader {
    private String name; //加载器的名字
//    private String className; //被加载类的全名
    private String path = "D:/workspace/eclipse-workspace64bit17-forPersonalProject/openbank-parent/openbank-test/src/test/java/"; //加载类的路径
    private final String fileType = ".class"; //class文件的扩展名
    
    public MyClassLoader(String name) {
        super(); //让系统类加载器成为该类加载器的父类
        this.name = name;
    }
    public MyClassLoader(ClassLoader parent,String name) {
        super(parent); //显示指定该类加载器的的父加载器
        this.name = name;
    }
    @Override
    public String toString() {
        // TODO Auto-generated method stub
        return this.name;
    }
    
    // TODO Auto-generated method stub
    private byte[] loadClassData(String className) {
        InputStream inputStream = null;
        byte[] data = null;
        ByteArrayOutputStream byteArrayOutputStream  = null;
        try {
            className = className.replace('.', '/');
            inputStream = new FileInputStream(new File(path+className+fileType));
            byteArrayOutputStream = new ByteArrayOutputStream();
            int ch = 0;
            while(-1 != (ch = inputStream.read())) {
                byteArrayOutputStream.write(ch);
            }
            data = byteArrayOutputStream.toByteArray();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                inputStream.close();
                byteArrayOutputStream.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        return data;
    }
    @Override
    protected Class<?> findClass(String className) throws ClassNotFoundException {
        byte[] data =this.loadClassData(className);
        //将字节数组转换成Class对象
        return this.defineClass(className, data, 0, data.length);
    }
    public String getPath() {
        return path;
    }
    public void setPath(String path) {
        this.path = path;
    }
    public static void main(String[] args) throws ClassNotFoundException, InstantiationException, IllegalAccessException {
        System.out.println(System.getProperty("java.class.path"));
        System.out.println("------------------");
        MyClassLoader loader1 = new MyClassLoader("loader1");
//        loader1.setPath("D:/temp/serverlib");
        MyClassLoader loader2 = new MyClassLoader(loader1,"loader2"); //将loader1作为loader2的父加载器
//        loader2.setPath("D:/temp/clientlib");
        MyClassLoader loader3 = new MyClassLoader(null,"loader3"); //将第一个参数设为空表示父加载器为根加载器
//        loader3.setPath("d:/temp/systemlib");
        test(loader2);
        System.out.println("-----------------");
        test(loader3);
    }
    public static void test(ClassLoader loader) throws ClassNotFoundException, InstantiationException, IllegalAccessException {
        Class clazz = loader.loadClass("com.test.jvm.common.Sample");
        Object object = clazz.newInstance();
    }
}

public class Sample {
    public int v1 = 1;
    public Sample() {
        System.out.println("Sample is loaded by: "+this.getClass().getClassLoader());
        new Dog();
    }
}

public class Dog {
    public Dog() {
        System.out.println("Dog is loaded by: "+this.getClass().getClassLoader());
    }
}

我将编译后的Sample.class和Dog.class放在他们源代码所在的包里

运行结果：

D:workspaceeclipse-workspace64bit17-forPersonalProjectopenbank-parentopenbank-test	arget	est-classes;D:workspaceeclipse-workspace64bit17-forPersonalProjectopenbank-parentopenbank-test	argetclasses;D:IDEeclipsepluginsorg.testng.eclipse_6.9.13.201609291640lib	estng.jar;D:IDEeclipsepluginsorg.testng.eclipse_6.9.13.201609291640libjcommander.jar;D:IDEeclipsepluginsorg.testng.eclipse_6.9.13.201609291640libsh-2.0b4.jar;D:IDEeclipsepluginsorg.testng.eclipse_6.9.13.201609291640libsnakeyaml.jar;D:workspaceeclipse-workspace64bit17-forPersonalProjectopenbank-parentopenbank-batch	argetclasses;C:UsersAsh.m2
epositoryorgspringframeworkatchspring-batch-core3.0.6.RELEASEspring-batch-core-3.0.6.RELEASE.jar;C:UsersAsh.m2
epositorycomibmjbatchcom.ibm.jbatch-tck-spi1.0com.ibm.jbatch-tck-spi-1.0.jar;C:UsersAsh.m2
epositoryjavaxatchjavax.batch-api1.0javax.batch-api-1.0.jar;C:UsersAsh.m2
epositorycom	houghtworksxstreamxstream1.4.7xstream-1.4.7.jar;C:UsersAsh.m2
epositoryxmlpullxmlpull1.1.3.1xmlpull-1.1.3.1.jar;C:UsersAsh.m2
epositoryxpp3xpp3_min1.1.4cxpp3_min-1.1.4c.jar;C:UsersAsh.m2
epositoryorgcodehausjettisonjettison1.2jettison-1.2.jar;C:UsersAsh.m2
epositoryorgspringframeworkatchspring-batch-infrastructure3.0.6.RELEASEspring-batch-infrastructure-3.0.6.RELEASE.jar;C:UsersAsh.m2
epositoryorgspringframework
etryspring-retry1.1.0.RELEASEspring-retry-1.1.0.RELEASE.jar;C:UsersAsh.m2
epositoryorgspringframeworkspring-beans4.1.9.RELEASEspring-beans-4.1.9.RELEASE.jar;C:UsersAsh.m2
epositoryorgspringframeworkspring-context4.1.9.RELEASEspring-context-4.1.9.RELEASE.jar;D:workspaceeclipse-workspace64bit17-forPersonalProjectopenbank-parentopenbank-base	argetclasses;C:UsersAsh.m2
epositorycommons-dbcpcommons-dbcp1.4commons-dbcp-1.4.jar;C:UsersAsh.m2
epositorycommons-poolcommons-pool1.6commons-pool-1.6.jar;C:UsersAsh.m2
epositorycomoracleojdbc611.2.0.4ojdbc6-11.2.0.4.jar;C:UsersAsh.m2
epositoryjunitjunit3.8.1junit-3.8.1.jar;C:UsersAsh.m2
epositoryorgspringframeworkootspring-boot-starter-web1.2.8.RELEASEspring-boot-starter-web-1.2.8.RELEASE.jar;C:UsersAsh.m2
epositoryorgspringframeworkootspring-boot-starter1.2.8.RELEASEspring-boot-starter-1.2.8.RELEASE.jar;C:UsersAsh.m2
epositoryorgspringframeworkootspring-boot1.2.8.RELEASEspring-boot-1.2.8.RELEASE.jar;C:UsersAsh.m2
epositoryorgspringframeworkootspring-boot-autoconfigure1.2.8.RELEASEspring-boot-autoconfigure-1.2.8.RELEASE.jar;C:UsersAsh.m2
epositoryorgspringframeworkootspring-boot-starter-logging1.2.8.RELEASEspring-boot-starter-logging-1.2.8.RELEASE.jar;C:UsersAsh.m2
epositoryorgslf4jjul-to-slf4j1.7.13jul-to-slf4j-1.7.13.jar;C:UsersAsh.m2
epositoryorgslf4jlog4j-over-slf4j1.7.13log4j-over-slf4j-1.7.13.jar;C:UsersAsh.m2
epositorychqoslogbacklogback-classic1.1.3logback-classic-1.1.3.jar;C:UsersAsh.m2
epositorychqoslogbacklogback-core1.1.3logback-core-1.1.3.jar;C:UsersAsh.m2
epositoryorgyamlsnakeyaml1.14snakeyaml-1.14.jar;C:UsersAsh.m2
epositorycomfasterxmljacksoncorejackson-databind2.4.6jackson-databind-2.4.6.jar;C:UsersAsh.m2
epositorycomfasterxmljacksoncorejackson-annotations2.4.6jackson-annotations-2.4.6.jar;C:UsersAsh.m2
epositorycomfasterxmljacksoncorejackson-core2.4.6jackson-core-2.4.6.jar;C:UsersAsh.m2
epositoryorghibernatehibernate-validator5.1.3.Finalhibernate-validator-5.1.3.Final.jar;C:UsersAsh.m2
epositoryjavaxvalidationvalidation-api1.1.0.Finalvalidation-api-1.1.0.Final.jar;C:UsersAsh.m2
epositoryorgjbossloggingjboss-logging3.1.3.GAjboss-logging-3.1.3.GA.jar;C:UsersAsh.m2
epositorycomfasterxmlclassmate1.0.0classmate-1.0.0.jar;C:UsersAsh.m2
epositoryorgspringframeworkspring-core4.1.9.RELEASEspring-core-4.1.9.RELEASE.jar;C:UsersAsh.m2
epositoryorgspringframeworkspring-web4.1.9.RELEASEspring-web-4.1.9.RELEASE.jar;C:UsersAsh.m2
epositoryorgspringframeworkspring-webmvc4.1.9.RELEASEspring-webmvc-4.1.9.RELEASE.jar;C:UsersAsh.m2
epositoryorgspringframeworkspring-expression4.1.9.RELEASEspring-expression-4.1.9.RELEASE.jar;C:UsersAsh.m2
epositoryorgspringframeworkootspring-boot-starter-batch1.2.8.RELEASEspring-boot-starter-batch-1.2.8.RELEASE.jar;C:UsersAsh.m2
epositoryorghsqldbhsqldb2.3.3hsqldb-2.3.3.jar;C:UsersAsh.m2
epositoryorgspringframeworkspring-jdbc4.1.9.RELEASEspring-jdbc-4.1.9.RELEASE.jar;C:UsersAsh.m2
epositoryorgspringframeworkootspring-boot-starter-jetty1.2.8.RELEASEspring-boot-starter-jetty-1.2.8.RELEASE.jar;C:UsersAsh.m2
epositoryorgeclipsejettyjetty-jsp9.2.14.v20151106jetty-jsp-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryorgeclipsejetty	oolchainjetty-schemas3.1.M0jetty-schemas-3.1.M0.jar;C:UsersAsh.m2
epositoryjavaxservletjavax.servlet-api3.1.0javax.servlet-api-3.1.0.jar;C:UsersAsh.m2
epositoryjavaxservletjspjavax.servlet.jsp-api2.3.1javax.servlet.jsp-api-2.3.1.jar;C:UsersAsh.m2
epositoryorgglassfishwebjavax.servlet.jsp2.3.2javax.servlet.jsp-2.3.2.jar;C:UsersAsh.m2
epositoryorgeclipsejettyorbitjavax.servlet.jsp.jstl1.2.0.v201105211821javax.servlet.jsp.jstl-1.2.0.v201105211821.jar;C:UsersAsh.m2
epositoryorgglassfishwebjavax.servlet.jsp.jstl1.2.2javax.servlet.jsp.jstl-1.2.2.jar;C:UsersAsh.m2
epositoryorgglassfishjavax.el3.0.0javax.el-3.0.0.jar;C:UsersAsh.m2
epositoryorgeclipsejettyorbitorg.eclipse.jdt.core3.8.2.v20130121org.eclipse.jdt.core-3.8.2.v20130121.jar;C:UsersAsh.m2
epositoryorgeclipsejettyjetty-webapp9.2.14.v20151106jetty-webapp-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryorgeclipsejettyjetty-xml9.2.14.v20151106jetty-xml-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryorgeclipsejettyjetty-util9.2.14.v20151106jetty-util-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryorgeclipsejettyjetty-servlet9.2.14.v20151106jetty-servlet-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryorgeclipsejettyjetty-security9.2.14.v20151106jetty-security-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryorgeclipsejettyjetty-server9.2.14.v20151106jetty-server-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryorgeclipsejettywebsocketwebsocket-server9.2.14.v20151106websocket-server-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryorgeclipsejettywebsocketwebsocket-common9.2.14.v20151106websocket-common-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryorgeclipsejettywebsocketwebsocket-api9.2.14.v20151106websocket-api-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryorgeclipsejettyjetty-io9.2.14.v20151106jetty-io-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryorgeclipsejettywebsocketwebsocket-client9.2.14.v20151106websocket-client-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryorgeclipsejettywebsocketwebsocket-servlet9.2.14.v20151106websocket-servlet-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryorgeclipsejettyjetty-http9.2.14.v20151106jetty-http-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryorgeclipsejettywebsocketjavax-websocket-server-impl9.2.14.v20151106javax-websocket-server-impl-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryorgeclipsejettyjetty-annotations9.2.14.v20151106jetty-annotations-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryorgeclipsejettyjetty-plus9.2.14.v20151106jetty-plus-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryorgeclipsejettyjetty-jndi9.2.14.v20151106jetty-jndi-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryjavaxannotationjavax.annotation-api1.2javax.annotation-api-1.2.jar;C:UsersAsh.m2
epositoryorgow2asmasm5.0.1asm-5.0.1.jar;C:UsersAsh.m2
epositoryorgow2asmasm-commons5.0.1asm-commons-5.0.1.jar;C:UsersAsh.m2
epositoryorgow2asmasm-tree5.0.1asm-tree-5.0.1.jar;C:UsersAsh.m2
epositoryorgeclipsejettywebsocketjavax-websocket-client-impl9.2.14.v20151106javax-websocket-client-impl-9.2.14.v20151106.jar;C:UsersAsh.m2
epositoryjavaxwebsocketjavax.websocket-api1.0javax.websocket-api-1.0.jar;C:UsersAsh.m2
epositoryorgspringframeworkdataspring-data-redis1.7.0.RELEASEspring-data-redis-1.7.0.RELEASE.jar;C:UsersAsh.m2
epositoryorgspringframeworkdataspring-data-keyvalue1.1.0.RELEASEspring-data-keyvalue-1.1.0.RELEASE.jar;C:UsersAsh.m2
epositoryorgspringframeworkdataspring-data-commons1.9.4.RELEASEspring-data-commons-1.9.4.RELEASE.jar;C:UsersAsh.m2
epositoryorgspringframeworkspring-tx4.1.9.RELEASEspring-tx-4.1.9.RELEASE.jar;C:UsersAsh.m2
epositoryorgspringframeworkspring-oxm4.1.9.RELEASEspring-oxm-4.1.9.RELEASE.jar;C:UsersAsh.m2
epositoryorgspringframeworkspring-aop4.1.9.RELEASEspring-aop-4.1.9.RELEASE.jar;C:UsersAsh.m2
epositoryaopallianceaopalliance1.0aopalliance-1.0.jar;C:UsersAsh.m2
epositoryorgspringframeworkspring-context-support4.1.9.RELEASEspring-context-support-4.1.9.RELEASE.jar;C:UsersAsh.m2
epositoryorgslf4jslf4j-api1.7.19slf4j-api-1.7.19.jar;C:UsersAsh.m2
epositoryorgslf4jjcl-over-slf4j1.7.13jcl-over-slf4j-1.7.13.jar;C:UsersAsh.m2
epository
edisclientsjedis2.8.0jedis-2.8.0.jar;C:UsersAsh.m2
epositoryorgapachecommonscommons-pool22.2commons-pool2-2.2.jar;C:UsersAsh.m2
epositoryorgspringframeworkootspring-boot-starter-test1.2.8.RELEASEspring-boot-starter-test-1.2.8.RELEASE.jar;C:UsersAsh.m2
epositoryorgmockitomockito-core1.10.19mockito-core-1.10.19.jar;C:UsersAsh.m2
epositoryorgobjenesisobjenesis2.1objenesis-2.1.jar;C:UsersAsh.m2
epositoryorghamcresthamcrest-core1.3hamcrest-core-1.3.jar;C:UsersAsh.m2
epositoryorghamcresthamcrest-library1.3hamcrest-library-1.3.jar;C:UsersAsh.m2
epositoryorgspringframeworkspring-test4.1.9.RELEASEspring-test-4.1.9.RELEASE.jar;C:UsersAsh.m2
epositoryorg	estng	estng6.9.10	estng-6.9.10.jar;C:UsersAsh.m2
epositorycomeustjcommander1.48jcommander-1.48.jar;C:UsersAsh.m2
epositoryorgeanshellsh2.0b4sh-2.0b4.jar
------------------
Sample is loaded by: sun.misc.Launcher$AppClassLoader@2d8eef25
Dog is loaded by: sun.misc.Launcher$AppClassLoader@2d8eef25
-----------------
Sample is loaded by: loader3
Dog is loaded by: loader3

如果我将Sample.class和Dog.class放在非System.getProperty("java.class.path")路径下，则AppClassLoader将无法找到这个类，则加载这个类的任务将落在自定义类加载器身上，那么上面的输出结果将会不同