ClassPathXmlApplicationContext源码分析

ClassPathXmlApplicationContext源码解读

入口函数

通过ClassPathXmlApplicationContext类构造方法启动父类AbstractApplicationContext的函数refresh方法

ClassPathXmlApplicationContext源码：

package org.springframework.context.support;?import org.springframework.beans.BeansException;import org.springframework.context.ApplicationContext;import org.springframework.core.io.ClassPathResource;import org.springframework.core.io.Resource;import org.springframework.lang.Nullable;import org.springframework.util.Assert;?public class ClassPathXmlApplicationContext extends AbstractXmlApplicationContext {    @Nullable    private Resource[] configResources;?    public ClassPathXmlApplicationContext() {    }?    public ClassPathXmlApplicationContext(ApplicationContext parent) {        super(parent);    }?    public ClassPathXmlApplicationContext(String configLocation) throws BeansException {        this(new String[]{configLocation}, true, (ApplicationContext)null);    }?    public ClassPathXmlApplicationContext(String... configLocations) throws BeansException {        this(configLocations, true, (ApplicationContext)null);    }?    public ClassPathXmlApplicationContext(String[] configLocations, @Nullable ApplicationContext parent) throws BeansException {        this(configLocations, true, parent);    }?    public ClassPathXmlApplicationContext(String[] configLocations, boolean refresh) throws BeansException {        this(configLocations, refresh, (ApplicationContext)null);    }?    public ClassPathXmlApplicationContext(String[] configLocations, boolean refresh, @Nullable ApplicationContext parent) throws BeansException {        super(parent);        this.setConfigLocations(configLocations);        if (refresh) {            this.refresh();        }?    }?    public ClassPathXmlApplicationContext(String path, Class<?> clazz) throws BeansException {        this(new String[]{path}, clazz);    }?    public ClassPathXmlApplicationContext(String[] paths, Class<?> clazz) throws BeansException {        this(paths, clazz, (ApplicationContext)null);    }?    public ClassPathXmlApplicationContext(String[] paths, Class<?> clazz, @Nullable ApplicationContext parent) throws BeansException {        super(parent);        Assert.notNull(paths, "Path array must not be null");        Assert.notNull(clazz, "Class argument must not be null");        this.configResources = new Resource[paths.length];?        for(int i = 0; i < paths.length; ++i) {            this.configResources[i] = new ClassPathResource(paths[i], clazz);        }?        this.refresh();    }?    @Nullable    protected Resource[] getConfigResources() {        return this.configResources;    }}?

ClassPathXmlApplicationContext(String configLocation) 一般使用这个方法，传入一个string类型的xml文件名，通过xml配置文件指定特定的组件，实例化到bean工厂里，即DefaultSingletonBeanRegistry 下的Map集合里

ClassPathXmlApplicationContext(String... configLocations)：可传入多个xml，装配到spring，bean工厂

public ClassPathXmlApplicationContext(String[] configLocations, boolean refresh) :传入String数组

@Test    public void TestXmlBean(){        ClassPathXmlApplicationContext context =new ClassPathXmlApplicationContext("classpath:xmlRegBean.xml");        Animal cat =context.getBean("cat", Cat.class);        cat.getName();    }?    @Test    public void TestMultiXml(){            ClassPathXmlApplicationContext context =new ClassPathXmlApplicationContext("classpath:xmlRegBean.xml","classpath:xmlRegBean2.xml");            Animal cat =context.getBean("cat", Cat.class);            cat.getName();            System.out.println(cat);            Animal cat2 =context.getBean("cat2", Cat.class);            cat2.getName();            System.out.println(cat2);    }     @Test    public void TestArrayXml(){        String[] arrXml = {"classpath:xmlRegBean.xml","classpath:xmlRegBean2.xml"};        ClassPathXmlApplicationContext context =new ClassPathXmlApplicationContext(arrXml,true);        Animal cat =context.getBean("cat", Cat.class);        cat.getName();        System.out.println(cat);        Animal cat2 =context.getBean("cat2", Cat.class);        cat2.getName();        System.out.println(cat2);    }