日志工具 - log4j

步骤

:

1>新建文件 -> 注意:配置文件不是xml,而是properties（命名log4j.properties）。

2>依赖项

<!-- https://mvnrepository.com/artifact/log4j/log4j -->
		<dependency>
			<groupId>log4j</groupId>
			<artifactId>log4j</artifactId>
			<version>1.2.17</version>
		</dependency>

解析properties键值对

	//定义一个日志方案对象{appenderName} 确定日志的显示级别[level]  
	//DEBUG,INFO,WARN,ERROR注意：级别向上兼容
	log4j.rootLogger = [level],appenderName,appenderName2,... 
	
	//执行方式 参数设置
	log4j.appender.appenderName = fully.qualified.name.of.appender.class 
	log4j.appender.appenderName.optionN = valueN 
	
	//日志内容	格式设置 
	log4j.appender.appenderName.layout = fully.qualified.name.of.layout.class 
	log4j.appender.appenderName.layout.optionN = valueN

3>API

	Logger logger = Logger.getLogger(BookAdvice.class);
	logger.error(strb.toString());	//注意：向上兼容

代码实现

配置log4j.properties

log4j.rootLogger = [ERROR],mylog4j,mylogfile

log4j.appender.mylog4j = org.apache.log4j.ConsoleAppender
log4j.appender.mylog4j.Threshold = ERROR 
log4j.appender.mylog4j.ImmediateFlush = true 
log4j.appender.mylog4j.Target = System.err 

log4j.appender.mylog4j.layout = org.apache.log4j.PatternLayout
log4j.appender.mylog4j.layout.ConversionPattern = [%-10p]-%m:[%30d]

log4j.appender.mylogfile = org.apache.log4j.FileAppender
log4j.appender.mylogfile.Threshold = ERROR 
log4j.appender.mylogfile.ImmediateFlush = true 
log4j.appender.mylogfile.File = F:/tmp/log/book.log 
log4j.appender.mylogfile.Append = true

log4j.appender.mylogfile.layout = org.apache.log4j.PatternLayout
log4j.appender.mylogfile.layout.ConversionPattern = [%-5p][%-22d{yyyy/MM/dd HH:mm:ssS}][%l]%n%m%n 

面向切面代理类BookAdvice.java:通过代理完成日志信息填写，代理service层的所有类的所有方法

//<aop:aspect ref="bookAdvice">
@Aspect     //--->代理类
@Service("bookAdvice")
public class BookAdvice {
	
	private Logger logger;
	
	//<aop:pointcut expression="execution(* com.uplooking.service..*.*(..))" id="p1"/>
	@Pointcut("execution(* com.uplooking.service..*.*(..))")
	public void p1(){}
	
	
	//<aop:around method="invoke" pointcut-ref="p1"/>
	@Around("p1()")
	public Object invoke(ProceedingJoinPoint pjp) throws Throwable{
		StringBuilder strb = new StringBuilder();
		strb.append("****************业 务 日 志******************\r\n");
		strb.append("业务对象:"+pjp.getTarget()+"\r\n");
		strb.append("业务名称:"+pjp.getSignature().getName()+"\r\n");
		strb.append("业务参数:"+Arrays.toString(pjp.getArgs())+"\r\n");
		strb.append("执行时间:"+DateTimeUtils.getLocalDateTime()+"\r\n");
		strb.append("*****************************************\r\n\r\n");
		
		logger = Logger.getLogger(BookAdvice.class);
		logger.error(strb.toString());
		
		//是否回调原业务
		Object result = pjp.proceed();
		return result;
	}
	
	
	/*
	@Before("p1()")
	public void hello(){
		System.out.println("欢迎使用网上书籍管理APP");
	}
	
	@After("p1()")
	public void bye(){
		System.out.println("谢谢使用网上书籍管理APP");
	}
	
	@AfterReturning(pointcut="p1()",returning="result")
	public void result(Object result){
		System.out.println("###################################");
		System.out.println("业务结果:"+result);
		System.out.println("###################################");
	}
	
	@AfterThrowing(pointcut="p1()",throwing="error")
	public void error(Throwable error){
		System.out.println("###################################");
		System.out.println("发生异常:"+error);
		System.out.println("###################################");
	}
	*/
}

测试运行类：MyTest.java

public class MyTest {
	public void test1() {
		Logger logger = Logger.getLogger(MyTest.class);
		logger.error("Hello World");
	}
	
	@Test
	public void test() {
		String configLocation = "applicationContext.xml";
		ApplicationContext ctx = new ClassPathXmlApplicationContext(configLocation);
		BookService  bookService = (BookService) ctx.getBean("bookService");
		System.out.println(bookService.removeBook(1));
	}

}

运行结果

[ERROR     ]-****************业 务 日 志******************
业务对象:com.uplooking.service.impl.BookServiceImpl@3a52dba3
业务名称:removeBook
业务参数:[1]
执行时间:2021-05-09 16:09:19
*****************************************

:[       2021-05-09 16:09:19,810]业务>>>新书入库
书籍编号:1
持久化 DELETE ...
{code=200, messgae=书籍移除完成}

日志文件变化