PropertiesFactoryBean和PropertyPlaceholderConfigurer管理属性文件

水深无声 2022-03-20 14:13 200阅读 0赞

org.springframework.beans.factory.config.PropertiesFactoryBean管理属性文件，通过@Value("\#\{settingBean\[‘properties\_key’\]\}")注解来获取相应的属性。

org.springframework.beans.factory.config.PropertyPlaceholderConfigurer也可以管理配置文件，通过@Value("$\{property\_key\}")注解来获取相应的属性。通过自己实现一个PropertyPlaceholderConfigure类来加载，当然也可以不用自己来实现，Spring会自己为我们加载property文件。

//JDBC.java
    package sping.analysis.properties.file;
    
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.stereotype.Component;
    
    /** * 通过PropertyPlaceholderConfigurer来加载 * * @author slHuang * @since 2019-02-10 */
    @Component("jdbcBean")
    public class JDBC { 
    
    	@Value("${jdbc.driverClassName}")
    	private String driver;
    	
    	@Value("${jdbc.url}")
    	private String url;
    	
    	@Value("${jdbc.username}")
    	private String username;
    	
    	@Value("${jdbc.password}")
    	private String password;
    
    	@Override
    	public String toString() { 
    		return "JDBC [driver=" + driver + ", url=" + url + ", username=" + username + ", password=" + password + "]";
    	}
    	
    }

//JDBC2.java
    package sping.analysis.properties.file;
    
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.stereotype.Component;
    
    /** * 通过PropertiesFactoryBean来加载 * * @author slHuang * @since 2019-02-10 */
    @Component("jdbc2Bean")
    public class JDBC2 { 
    
    	@Value("#{settingBean['jdbc.driverClassName']}")
    	private String driver;
    	
    	@Value("#{settingBean['jdbc.url']}")
    	private String url;
    	
    	@Value("#{settingBean['jdbc.username']}")
    	private String username;
    	
    	@Value("#{settingBean['jdbc.password']}")
    	private String password;
    
    	@Override
    	public String toString() { 
    		return "JDBC [driver=" + driver + ", url=" + url + ", username=" + username + ", password=" + password + "]";
    	}
    	
    }

//MyPropertiesFile.java
    package sping.analysis.properties.file;
    
    import java.util.HashMap;
    import java.util.Map;
    import java.util.Properties;
    
    import org.springframework.beans.BeansException;
    import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
    import org.springframework.beans.factory.config.PropertyPlaceholderConfigurer;
    
    /** * @component 默认是单例的 * * @author slHuang * @since 2019-02-10 */
    public class MyPropertiesFile extends PropertyPlaceholderConfigurer { 
    
    	private Map<String, Object> propMap;
    	
    	public MyPropertiesFile() { 
    		propMap = new HashMap<String, Object>();
    	}
    	
    	@Override
    	protected void processProperties(ConfigurableListableBeanFactory beanFactoryToProcess, Properties props)
    			throws BeansException { 
    		super.processProperties(beanFactoryToProcess, props);
    		for (Object key : props.keySet()) { 
    			String keyStr = key.toString();
    			System.out.println(keyStr + ":" + props.getProperty(keyStr));
    			propMap.put(keyStr, props.getProperty(keyStr));
    		}
    	}
    	
    	public void usePropertiesFile() { 
    		System.out.println(propMap);
    		System.out.println(propMap.get("jdbc.url"));
    	}
    	
    }

//TestApplication.java
    package sping.analysis.properties.file;
    
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    public class TestApplication { 
    
    	@SuppressWarnings("resource")
    	public static void main(String[] args) { 
    		System.out.println( "Hello World!" );
    		ApplicationContext context = new ClassPathXmlApplicationContext("application2.xml");
            
    		System.out.println();
            System.out.println("------------Load properties file-------------->");
            System.out.println("通过继承PropertyPlaceholderConfigurer的方式，获取并存储properties:");
            MyPropertiesFile myPropertiesFile = (MyPropertiesFile) context.getBean("settingBean2");
            myPropertiesFile.usePropertiesFile();
            
            System.out.println();
            System.out.println("通过PropertyPlaceholderConfigurer类加载property文件，并使用@value('property_id')注解来获取值:");
            JDBC jdbc = (JDBC) context.getBean("jdbcBean");
            System.out.println(jdbc);
            System.out.println("<------------Load properties file--------------");
            
    	}
    	
    }

//TestApplication2.java
    package sping.analysis.properties.file;
    
    import javax.annotation.Resource;
    
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.test.context.ContextConfiguration;
    import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
    
    /** * @Resource等同于@Autowired + @Qualifier * @Resource默认是根据名称来依赖注入的 * @Autowired默认是根据类型来依赖注入的 * * @author slHuang * @since 2019-02-10 */
    @RunWith(SpringJUnit4ClassRunner.class)
    @ContextConfiguration(locations="classpath:application2.xml")
    public class TestApplication2 { 
    	
    	@Resource(name="jdbc2Bean")
    	//@Autowired @Qualifier("jdbc2Bean")
    	private JDBC2 jdbc2Bean;
    	
    	@Test
    	public void test() { 
    		System.out.println(jdbc2Bean.toString());
    	}
    	
    }

//application2.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:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    
        
        <context:component-scan base-package="sping.analysis.properties.file"/>
        
        
        
         
    
        
        <bean id="settingBean2" class="sping.analysis.properties.file.MyPropertiesFile">
            <property name="locations" value="classpath:application.properties"/>
            <property name="fileEncoding" value="UTF-8"></property>
            <property name="ignoreUnresolvablePlaceholders" value="true" />
        </bean>
        
     
        <bean id="settingBean" class="org.springframework.beans.factory.config.PropertiesFactoryBean">
            <property name="locations" value="classpath:application.properties"/>
            <property name="fileEncoding" value="UTF-8"></property>
        </bean>
     
        
    
    </beans>