【SpringFramework】Spring初体验

<dependencies>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>5.3.31</version>
  </dependency>
</dependencies>

public class HelloWorld {
    public HelloWorld() {
        System.out.println("Construction Method Execute ...");
    }
    public String sayHello() {
        System.out.println("Hello World!");
        return "Hello World!";
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
    <!--配置HelloWorld对应的Bean，即将HelloWorld的对象交给Spring的IoC容器管理
        通过Bean标签配置
        属性：
            id：设置对象（bean）的唯一标识
            class：设置对象（bean）的全类名
    -->
    <bean id="helloWorld" class="com.sheeprunner.spring.b.one.HelloWorld" />
</beans>

<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.13.2</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-core</artifactId>
    <version>2.23.1</version>
</dependency>
<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-slf4j-impl</artifactId>
    <version>2.23.1</version>
</dependency>

public class TestHelloWorld {
    @Test
    public void testHelloWorld(){
        HelloWorld helloWorld = new HelloWorld();
        Assert.assertEquals("Hello World!", helloWorld.sayHello());
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        HelloWorld helloWorldBean = context.getBean(HelloWorld.class);
        Assert.assertEquals("Hello World!", helloWorldBean.sayHello());
    }
}

使用Spring容器，向容器索取对象：2024-11-09 15:11:24 978 [main] DEBUG org.springframework.context.support.ClassPathXmlApplicationContext - Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@6ab7a896
2024-11-09 15:11:25 063 [main] DEBUG org.springframework.beans.factory.xml.XmlBeanDefinitionReader - Loaded 1 bean definitions from class path resource [applicationContext.xml]
2024-11-09 15:11:25 084 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Creating shared instance of singleton bean 'helloWorld'
Construction Method Execute ...
Hello World!

2024-11-09 15:11:24 978 [main] DEBUG org.springframework.context.support.ClassPathXmlApplicationContext
 - Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@6ab7a896
2024-11-09 15:11:25 063 [main] DEBUG org.springframework.beans.factory.xml.XmlBeanDefinitionReader
 - Loaded 1 bean definitions from class path resource [applicationContext.xml]
2024-11-09 15:11:25 084 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory
 - Creating shared instance of singleton bean 'helloWorld'
Construction Method Execute ...
Hello World!

<!--log4j2的依赖-->
<dependency>
  <groupId>org.apache.logging.log4j</groupId>
  <artifactId>log4j-core</artifactId>
  <version>2.19.0</version>
</dependency>
<dependency>
  <groupId>org.apache.logging.log4j</groupId>
  <artifactId>log4j-slf4j2-impl</artifactId>
  <version>2.19.0</version>
</dependency>

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <loggers>
        <!--
            level指定日志级别，从低到高的优先级：
                TRACE < DEBUG < INFO < WARN < ERROR < FATAL
                trace：追踪，是最低的日志级别，相当于追踪程序的执行
                debug：调试，一般在开发中，都将其设置为最低的日志级别
                info：信息，输出重要的信息，使用较多
                warn：警告，输出警告的信息
                error：错误，输出错误信息
                fatal：严重错误
        -->
        <root level="DEBUG">
            <appender-ref ref="spring6log"/>
            <appender-ref ref="RollingFile"/>
            <appender-ref ref="log"/>
        </root>
    </loggers>
    <appenders>
        <!--输出日志信息到控制台-->
        <console name="spring6log" target="SYSTEM_OUT">
            <!--控制日志输出的格式-->
            <PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss SSS} [%t] %-3level %logger{1024} - %msg%n"/>
        </console>
        <!--文件会打印出所有信息，这个log每次运行程序会自动清空，由append属性决定，适合临时测试用-->
        <File name="log" fileName="d:/spring6_log/test.log" append="false">
            <PatternLayout pattern="%d{HH:mm:ss.SSS} %-5level %class{36} %L %M - %msg%xEx%n"/>
        </File>
        <!-- 这个会打印出所有的信息，
            每次大小超过size，
            则这size大小的日志会自动存入按年份-月份建立的文件夹下面并进行压缩，
            作为存档-->
        <RollingFile name="RollingFile" fileName="d:/spring6_log/app.log"
                     filePattern="log/$${date:yyyy-MM}/app-%d{MM-dd-yyyy}-%i.log.gz">
            <PatternLayout pattern="%d{yyyy-MM-dd 'at' HH:mm:ss z} %-5level %class{36} %L %M - %msg%xEx%n"/>
            <SizeBasedTriggeringPolicy size="50MB"/>
            <!-- DefaultRolloverStrategy属性如不设置，
            则默认为最多同一文件夹下7个文件，这里设置了20 -->
            <DefaultRolloverStrategy max="20"/>
        </RollingFile>
    </appenders>
</configuration>

private static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(HelloWorld.class);
public void method() {
    logger.info("第一个是new的对象：{}", "helloWorld1");
}