Log4j 的自定义 logger

https://www.bilibili.com/video/BV1iJ411H74S?p=17

log4j.properties

# 指定 RootLogger 顶级父元素默认配置信息
# 指定日志级别=trace，使用的 appender 为 console
log4j.rootLogger = trace,console

# 自定义 logger 对象设置
log4j.logger.io.github.jihch = info,file

# 指定控制台日志输出的 appender
log4j.appender.console = org.apache.log4j.ConsoleAppender
# 指定消息格式 layout
log4j.appender.console.layout = org.apache.log4j.PatternLayout
# 指定消息格式的内容
log4j.appender.console.layout.conversionPattern = [%-10p]%r %l %d{yyyy-MM-dd HH:mm:ss.SSS} %m%n

# 日志文件输出的 appender 对象
log4j.appender.file = org.apache.log4j.FileAppender
# 指定消息格式 layout
log4j.appender.file.layout = org.apache.log4j.PatternLayout
# 指定消息格式的内容
log4j.appender.file.layout.conversionPattern = [%-10p]%r %l %d{yyyy-MM-dd HH:mm:ss.SSS} %m%n
# 指定日志文件的保存路径
log4j.appender.file.file = /logs/log4j.log
# 指定日志文件的字符集
log4j.appender.file.encoding = UTF-8

Log4jTest.java

import org.apache.log4j.Logger;
import org.apache.log4j.helpers.LogLog;
import org.junit.Test;

public class Log4jTest {

    // 快速入门
    @Test
    public void testQuick() {

        // 开启 log4j 内置日志记录
        LogLog.setInternalDebugging(true);

        // 初始化配置信息，在入门案例中暂不使用配置文件
//        BasicConfigurator.configure();

        // 获取日志记录器对象
        Logger logger = Logger.getLogger(Log4jTest.class);

        // 日志记录输出
        logger.info("hello log4j");

        // 日志级别
        logger.fatal("fatal"); // 严重错误，一般会造成系统崩溃并终止运行

        logger.error("error"); // 错误信息，不会影响系统运行
        logger.warn("warn");   // 警告信息，可能会发生问题
        logger.info("info");   // 运行信息，数据连接、网络连接、IO 操作等等
        logger.debug("debug"); // 调试信息，一般在开发中使用，记录程序变量参数传递信息等等

        logger.debug("trace"); // 追踪信息，记录程序所有的流程信息

    }

}

控制台输出

log4j: Trying to find [log4j.xml] using context classloader sun.misc.Launcher$AppClassLoader@18b4aac2.
log4j: Trying to find [log4j.xml] using sun.misc.Launcher$AppClassLoader@18b4aac2 class loader.
log4j: Trying to find [log4j.xml] using ClassLoader.getSystemResource().
log4j: Trying to find [log4j.properties] using context classloader sun.misc.Launcher$AppClassLoader@18b4aac2.
log4j: Using URL [file:/E:/record/2023/2/19/log4j-demo/target/classes/log4j.properties] for automatic log4j configuration.
log4j: Reading configuration from URL file:/E:/record/2023/2/19/log4j-demo/target/classes/log4j.properties
log4j: Parsing for [root] with value=[trace,console].
log4j: Level token is [trace].
log4j: Category root set to TRACE
log4j: Parsing appender named "console".
log4j: Parsing layout options for "console".
log4j: Setting property [conversionPattern] to [[%-10p]%r %l %d{yyyy-MM-dd HH:mm:ss.SSS} %m%n].
log4j: End of parsing for "console".
log4j: Parsed "console" options.
log4j: Parsing for [io.github.jihch] with value=[info,file].
log4j: Level token is [info].
log4j: Category io.github.jihch set to INFO
log4j: Parsing appender named "file".
log4j: Parsing layout options for "file".
log4j: Setting property [conversionPattern] to [[%-10p]%r %l %d{yyyy-MM-dd HH:mm:ss.SSS} %m%n].
log4j: End of parsing for "file".
log4j: Setting property [file] to [/logs/log4j.log].
log4j: Setting property [encoding] to [UTF-8].
log4j: setFile called: /logs/log4j.log, true
log4j: setFile ended
log4j: Parsed "file" options.
log4j: Handling log4j.additivity.io.github.jihch=[null]
log4j: Finished configuring.
[INFO      ]0 io.github.jihch.Log4jTest.testQuick(Log4jTest.java:23) 2023-02-25 23:30:38.202 hello log4j
[FATAL     ]2 io.github.jihch.Log4jTest.testQuick(Log4jTest.java:27) 2023-02-25 23:30:38.204 fatal
[ERROR     ]2 io.github.jihch.Log4jTest.testQuick(Log4jTest.java:29) 2023-02-25 23:30:38.204 error
[WARN      ]2 io.github.jihch.Log4jTest.testQuick(Log4jTest.java:30) 2023-02-25 23:30:38.204 warn
[INFO      ]2 io.github.jihch.Log4jTest.testQuick(Log4jTest.java:31) 2023-02-25 23:30:38.204 info

Process finished with exit code 0

log4j.log

[INFO      ]0 io.github.jihch.Log4jTest.testQuick(Log4jTest.java:23) 2023-02-25 23:30:38.202 hello log4j
[FATAL     ]2 io.github.jihch.Log4jTest.testQuick(Log4jTest.java:27) 2023-02-25 23:30:38.204 fatal
[ERROR     ]2 io.github.jihch.Log4jTest.testQuick(Log4jTest.java:29) 2023-02-25 23:30:38.204 error
[WARN      ]2 io.github.jihch.Log4jTest.testQuick(Log4jTest.java:30) 2023-02-25 23:30:38.204 warn
[INFO      ]2 io.github.jihch.Log4jTest.testQuick(Log4jTest.java:31) 2023-02-25 23:30:38.204 info