使用ConfigurationFactory以编程方式配置log4j2

Question

我正在尝试通过使用ConfigurationFactory和这个参考来配置和设置Log4j2。我使用的代码如下：

public class LoggingConfiguration {

    public static final String PATTERN_LAYOUT = "[%d] [%t] [%-5level] - %msg (%logger{1}:%L) %n%throwable";
    public static final String LOG_FILE_NAME = "app.log";
    public static final String LOG_FILE_NAME_PATTERN = LOG_FILE_NAME + "-yyyy.MM.dd";

    static {
        ConfigurationFactory.setConfigurationFactory(new Log4j2ConfigurationFactory());
    }

    /**
     * Just to make JVM visit this class to initialize the static parts.
     */
    public static void configure() {
    }

    @Plugin(category = "ConfigurationFactory", name = "Log4j2ConfigurationFactory")
    @Order(0)
    public static class Log4j2ConfigurationFactory extends ConfigurationFactory {

        @Override
        protected String[] getSupportedTypes() {
            return null;
        }

        @Override
        public Configuration getConfiguration(ConfigurationSource source) {
            return new Log4j2Configuration();
        }

        @Override
        public Configuration getConfiguration(String name, URI configLocation) {
            return new Log4j2Configuration();
        }

    }

    private static class Log4j2Configuration extends DefaultConfiguration {

        public Log4j2Configuration() {
            setName("app-log4j2");
            String root = System.getProperty("APP_ROOT", "/tmp");
            if (!root.endsWith("/")) {
                root += "/";
            }
                            // MARKER
            Layout<? extends Serializable> layout = PatternLayout.createLayout(PATTERN_LAYOUT, null, null, null, null);

            String oneDay = TimeUnit.DAYS.toMillis(1) + "";
            String oneMB = (1024 * 1024) + "";
            final TimeBasedTriggeringPolicy timeBasedTriggeringPolicy = TimeBasedTriggeringPolicy.createPolicy(oneDay,
                    "true");
            final SizeBasedTriggeringPolicy sizeBasedTriggeringPolicy = SizeBasedTriggeringPolicy.createPolicy(oneMB);
            final CompositeTriggeringPolicy policy = CompositeTriggeringPolicy.createPolicy(timeBasedTriggeringPolicy,
                    sizeBasedTriggeringPolicy);
            final DefaultRolloverStrategy strategy = DefaultRolloverStrategy.createStrategy("7", "1", null,
                    Deflater.DEFAULT_COMPRESSION + "", this);
            Appender appender = RollingFileAppender.createAppender(root + LOG_FILE_NAME, LOG_FILE_NAME_PATTERN, "true",
                    "app-log-file-appender", "true", "true", policy, strategy, layout, null, null, null, null, null);
            addAppender(appender);
            getRootLogger().addAppender(appender, Level.INFO, null);
        }
    }

}

请注意：

• 它扩展了默认配置控制台的BaseConfiguration
• 它尝试向根记录器添加一个滚动文件附加程序

我得到了以下异常：

Exception in thread "main" java.lang.IllegalStateException: Pattern does not contain a date
    at org.apache.logging.log4j.core.appender.rolling.PatternProcessor.getNextTime(PatternProcessor.java:91)
    at org.apache.logging.log4j.core.appender.rolling.TimeBasedTriggeringPolicy.initialize(TimeBasedTriggeringPolicy.java:49)
    at org.apache.logging.log4j.core.appender.rolling.CompositeTriggeringPolicy.initialize(CompositeTriggeringPolicy.java:43)
    at org.apache.logging.log4j.core.appender.rolling.RollingFileManager.<init>(RollingFileManager.java:58)
    at org.apache.logging.log4j.core.appender.rolling.RollingFileManager$RollingFileManagerFactory.createManager(RollingFileManager.java:297)
    at org.apache.logging.log4j.core.appender.rolling.RollingFileManager$RollingFileManagerFactory.createManager(RollingFileManager.java:267)
    at org.apache.logging.log4j.core.appender.AbstractManager.getManager(AbstractManager.java:71)
    at org.apache.logging.log4j.core.appender.OutputStreamManager.getManager(OutputStreamManager.java:65)
    at org.apache.logging.log4j.core.appender.rolling.RollingFileManager.getFileManager(RollingFileManager.java:78)
    at org.apache.logging.log4j.core.appender.RollingFileAppender.createAppender(RollingFileAppender.java:175)
    at com.narmnevis.papyrus.LoggingConfiguration$Log4j2Configuration.<init>(LoggingConfiguration.java:79)
    at com.narmnevis.papyrus.LoggingConfiguration$Log4j2ConfigurationFactory.getConfiguration(LoggingConfiguration.java:55)
    at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:377)
    at org.apache.logging.log4j.core.LoggerContext.start(LoggerContext.java:149)
    at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:85)
    at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:34)
    at org.apache.logging.log4j.LogManager.getContext(LogManager.java:200)
    at org.slf4j.helpers.Log4jLoggerFactory$PrivateManager.getContext(Log4jLoggerFactory.java:104)
    at org.slf4j.helpers.Log4jLoggerFactory.getContext(Log4jLoggerFactory.java:90)
    at org.slf4j.helpers.Log4jLoggerFactory.getLogger(Log4jLoggerFactory.java:46)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:270)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:281)
    at com.narmnevis.papyrus.Main.<init>(Main.java:12)
    at com.narmnevis.papyrus.Main.main(Main.java:21)

如果我将上面代码中MARKER后的代码注释掉，它能正常工作，但似乎我错过了一些配置滚动文件附加器的内容。我该怎么办才能解决这个问题？

- nobeh

---

你是如何初始化这个log4j2实例的？我的意思是在主类还是其他地方？你能展示一下你所采取的方法吗？ - user2846382

Answer 1

在log4j 2.x中，您需要按照以下方式指定日期格式。

public static final String LOG_FILE_NAME_PATTERN = LOG_FILE_NAME + "-%d{dd-MM-yyy}";

• % 标记格式的开始
• d 表示日期格式（也可以使用 date）
• 在花括号 {} 中定义格式化程序选项。在这种情况下是日期格式。您可以使用SimpleDateFormat 接受的任何内容。

此外，您还可以使用：

• %d{ABSOLUTE} -> HH:mm:ss,SSS
• %d{COMPACT} -> yyyyMMddHHmmssSSS
• %d{DATE} -> dd MMM yyyy HH:mm:ss,SSS
• %d{ISO8601_BASIC} -> yyyyMMdd HHmmss,SSS
• %d{ISO8601} -> yyyy-MM-dd HH:mm:ss,SSS

注意：此信息基于log4j 2.0-beta9（当前版本）。由于它是一个beta版本，可能会稍微更改。

- René Link