一 为何要替换成log4j2
1.1 log4j2的优点
log4j2使用了两种方式记录日志：AsyncAppender和AsyncLogger。
1.AsyncAppender使用队列异步记录日志，但是一旦队列已满，appender线程需要等待。
2.AsyncLogger是采用Disruptor，通过环形队列无阻塞队列作为缓冲，多生产者多线程的竞争是通过CAS实现，无锁化实现，可以降低极端大的日志量时候的延迟尖峰，Disruptor 可是号称一个线程里每秒处理600万订单的高性能队列。
注意的是: 使用AsyncLogger才会使用disruptor提高性能。如果使用的AsyncAppender，则使用的是类似logback一样的队列的方式做异步记录。
https://blog.csdn.net/m0_69057918/article/details/130972522
1.2 log4j2.xml如何读取application.yml中属性值
1.2.1 操作步骤
1.在application.properties 或者application.yml文件中配置
patcher.log=/data350/fengqxLogFile/patcher
2.编写监听器
@Component
public class LoggerListener implements ApplicationListener<ApplicationEvent>, Ordered {@Overridepublic void onApplicationEvent(ApplicationEvent applicationEvent) {if (applicationEvent instanceof ApplicationEnvironmentPreparedEvent) {ConfigurableEnvironment environment = ((ApplicationEnvironmentPreparedEvent) applicationEvent).getEnvironment();String filePath = environment.getProperty("patcher.log");if (StringUtils.isNotEmpty(filePath)) {System.err.println("=================" + filePath);System.setProperty("patcher.log", filePath);}}}@Overridepublic int getOrder() {// 当前监听器的启动顺序需要在日志配置监听器的前面，所以此处减 1return LoggingApplicationListener.DEFAULT_ORDER - 1;}3.在 /src/main/resources/META-INF/spring.factories进行加载监听器
org.springframework.context.ApplicationListener=com.longze.patcher.listener.MyLoggerListener
4.log4j2.xml进行使用配置是路径
springboot log4j2日志 配置路径_springboot指定log4j配置文件位置-CSDN博客
1.3 log4j&slf4j&log4j2需要的导入的包
Log4j实例:
import org.apache.log4j.Logger;
private static final Logger LOGGER = Logger.getLogger(X.class);
Slf4j实例:
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
private static final Logger logger = LoggerFactory.getLogger(X.class);
Log4j2的使用：
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
private static final Logger logger = LogManager.getLogger(X.class);
升级log4j 2.x版本 缓存异步化配置解读 - 欲上九天揽月 - ITeye博客
1.4 整合log4j2需要引入的依赖与排除依赖
1.引入依赖
<dependencies><!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-slf4j-impl --><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-slf4j-impl</artifactId><version>2.17.1</version><scope>test</scope></dependency><!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-api --><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-api</artifactId><version>2.17.1</version></dependency><!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core --><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-core</artifactId><version>2.17.1</version></dependency><dependency><groupId>com.Imax</groupId><artifactId>disruptor</artifactId><version>2.17.1</version></dependency>
</dependencies>排除jar包：
