要自定义Log4j2的日志文件名，可以通过配置文件或者代码方式来实现。
通过配置文件方式：在log4j2的配置文件中，可以使用<RollingRandomAccessFile>或者<RollingFile>节点来定义日志文件的名称。例如：<RollingRandomAccessFile name="FileLogger" fileName="logs/mylog.log" filePattern="logs/mylog-%d{MM-dd-yyyy}.log.gz"> <PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" /> <Policies> <TimeBasedTriggeringPolicy /> </Policies></RollingRandomAccessFile>上述配置中，fileName指定了日志文件的初始名称，filePattern指定了滚动日志文件的命名规则。%d表示日期格式，%t表示线程名。
RollingRandomAccessFileAppender或者RollingFileAppender来定义日志文件的名称。例如：import org.apache.logging.log4j.LogManager;import org.apache.logging.log4j.Logger;import org.apache.logging.log4j.core.appender.RollingRandomAccessFileAppender;import org.apache.logging.log4j.core.config.Configuration;import org.apache.logging.log4j.core.config.ConfigurationFactory;import org.apache.logging.log4j.core.config.ConfigurationSource;import org.apache.logging.log4j.core.config.Configurator;import org.apache.logging.log4j.core.config.builder.api.*;import org.apache.logging.log4j.core.config.builder.impl.BuiltConfiguration;import java.io.File;import java.io.FileInputStream;import java.io.IOException;public class Log4j2CustomFileNameExample { public static void main(String[] args) { // 使用代码方式配置Log4j2 Configuration configuration = createLogConfiguration(); Configurator.initialize(configuration); // 获取Logger Logger logger = LogManager.getLogger(Log4j2CustomFileNameExample.class); logger.info("This is a custom log message"); } private static Configuration createLogConfiguration() { ConfigurationBuilder<BuiltConfiguration> builder = ConfigurationBuilderFactory.newConfigurationBuilder(); // 创建Appender AppenderComponentBuilder appenderBuilder = builder.newAppender("FileLogger", "RollingRandomAccessFile") .addAttribute("fileName", "logs/mylog.log") .addAttribute("filePattern", "logs/mylog-%d{MM-dd-yyyy}.log.gz"); // 创建Layout LayoutComponentBuilder layoutBuilder = builder.newLayout("PatternLayout") .addAttribute("pattern", "%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"); // 添加Appender和Layout到Root Logger builder.add(appenderBuilder) .add(builder.newRootLogger(Level.INFO).add(builder.newAppenderRef("FileLogger").addAttribute("level", Level.INFO))) .add(layoutBuilder); return builder.build(); }}上述代码中，fileName指定了日志文件的初始名称，filePattern指定了滚动日志文件的命名规则。%d表示日期格式，%t表示线程名。
