Spring Framework_学习记录_02

爱被打了一巴掌 2022-03-07 10:18 154阅读 0赞

### 1. 使用spring bean Factory 写代码。 ###

*  DrawingApp.java

package org.zcs.spring;
    
    import org.springframework.beans.factory.BeanFactory;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    import org.springframework.context.support.FileSystemXmlApplicationContext;
     
    
    public class DrawingApp { 
    
    	public static void main(String[] args) { 
    		// TODO Auto-generated method stub
    		BeanFactory factory = new  FileSystemXmlApplicationContext("src/spring.xml");
    		Triangle triangle = (Triangle)factory.getBean("triangle");
    		triangle.draw();
    	}
    }

*  Triangle.java

package org.zcs.spring;
    
    public class Triangle { 
    
    	private String type;
    	private int height;
    	
    	public int getHeight() { 
    		return height;
    	}
    	public void setHeight(int height) { 
    		this.height = height;
    	}
    	public String getType() { 
    		return type;
    	}
    	public void setType(String type) { 
    		this.type = type;
    	}
    	public void draw() { 
    		System.out.println(getType()+ " : There is a triangle. "  );
    	}
    }

*  spring.xml

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
       
       	<bean id = "triangle" class= "org.zcs.spring.Triangle" >
       	 	<property name="type" value = "this si my first say"></property>
       	</bean>
      </beans>

### 2.笔记： ###

*  学习了如何使用spring中xml的bean管理类中的值。然后再调用此xml来调用bean factory中的对象。
 *  学习了bean使用如何使用的。
 *  Applicationcontext 的使用和Property的初始化。

### 3.问题记录： ###

##### 3.1 XmlBeanFactory过期问题： #####

三月 16, 2019 10:26:51 上午 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
    信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@e2144e4: startup date [Sat Mar 16 10:26:51 CST 2019]; root of context hierarchy
    三月 16, 2019 10:26:51 上午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
    信息: Loading XML bean definitions from class path resource [src/spring.xml]
    Exception in thread "main" org.springframework.beans.factory.BeanDefinitionStoreException: IOException parsing XML document from class path resource [src/spring.xml]; nested exception is java.io.FileNotFoundException: class path resource [src/spring.xml] cannot be opened because it does not exist
    	at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:343)
    	at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:303)
    	at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:180)
    	at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:216)
    	at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:187)
    	at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:251)
    	at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:127)
    	at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:93)
    	at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:129)
    	at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:540)
    	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:454)
    	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
    	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
    	at org.zcs.spring.DrawingApp.main(DrawingApp.java:11)
    Caused by: java.io.FileNotFoundException: class path resource [src/spring.xml] cannot be opened because it does not exist
    	at org.springframework.core.io.ClassPathResource.getInputStream(ClassPathResource.java:158)
    	at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:329)
    ... 13 more

*  解决办法：

// 过时处理逻辑,XmlBeanFactory在3.1以后已经被废弃，不再推荐使用
            BeanFactory beanFactory = new XmlBeanFactory(new ClassPathResource("beanFactoryTest.xml"));
    
            // 当前方案一：BeanFactory在启动的时候不会创建bean实例,而是在getBean()的时候,才会创建bean的实例
            Resource resource = new ClassPathResource("applicationContext.xml");
            beanFactory = new DefaultListableBeanFactory();
            BeanDefinitionReader beanDefinitionReader = new XmlBeanDefinitionReader((BeanDefinitionRegistry) beanFactory);
            beanDefinitionReader.loadBeanDefinitions(resource);
    
            // 当前方案二：使用ApplicationContext
            // (ApplicationContext在读取配置文件的时候,配置文件中的bena就会被初始化(不考虑bean的作用域))
            ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

##### 3.2 ClassPathXmlApplicationContext找不到资源文件： #####

*  解决办法：

如果是用ApplicationContext ctx=new ClassPathXmlApplicationContext()也是这样是从当前路径寻找，xml文件应在当前目录下。

但是如果用FileSystemXmlApplicationContext呢，它是根据指定的路径来进行寻找，所以要把路径写完整。现在xml路径在src文件夹下。那就要写：ApplicationContext ctx=new FileSystemXmlApplicationContext(“src/applicationContext.xml”);

不过我发现这个可以把xml文件放到src目录下，就可了。ApplicationContext context = new ClassPathXmlApplicationContext(“spring.xml”);

##### 3.2 xml 上的官方库文件引入模板 #####

这个可以在官网的文档中找到。

### 4. 参考博客 ###

*  [https://blog.csdn.net/u013412772/article/details/79956346][https_blog.csdn.net_u013412772_article_details_79956346]
 *  [https://blog.csdn.net/tiananma0607/article/details/76595187][https_blog.csdn.net_tiananma0607_article_details_76595187]

[https_blog.csdn.net_u013412772_article_details_79956346]: https://blog.csdn.net/u013412772/article/details/79956346
[https_blog.csdn.net_tiananma0607_article_details_76595187]: https://blog.csdn.net/tiananma0607/article/details/76595187