Logback - 以编程方式设置日志文件名

Question

我正在使用logback,我试图在我的Java程序中以编程方式设置日志文件名(类似于以编程方式设置Logback Appender路径),我尝试按如下方式调整该解决方案:

在logback-test.xml中:

<appender name="FILE" class="ch.qos.logback.core.FileAppender">
  <file>log/${log_file_name}.log</file>
  ...

然后再在我的Java程序中:

String logFileName = "" + System.currentTimeMillis(); // just for example
System.setProperty("log_file_name", logFileName);

LoggerContext lc = (LoggerContext) LoggerFactory.getILoggerFactory();
ContextInitializer ci = new ContextInitializer(lc);
lc.reset();
try
{
    // I prefer autoConfig() over JoranConfigurator.doConfigure() so I
    // wouldn't need to find the file myself.
    ci.autoConfig();
}
catch (JoranException e)
{
    // StatusPrinter will try to log this
    e.printStackTrace();
}
StatusPrinter.printInCaseOfErrorsOrWarnings(lc);

然而,结果是两个日志,一个完整并按我想要的名称命名,例如"1319041145343.log",另一个是空的并命名为"log_file_name_IS_UNDEFINED.log".如何阻止创建其他空日志文件？

Answer 1

我相信以下内容更接近你想要的.

import ch.qos.logback.classic.Logger;
import ch.qos.logback.classic.encoder.PatternLayoutEncoder;
import ch.qos.logback.core.FileAppender;
import ch.qos.logback.core.util.StatusPrinter;
import org.slf4j.LoggerFactory;
import ch.qos.logback.classic.LoggerContext;

public class Main {
  public static void main(String[] args) {
    LoggerContext loggerContext = (LoggerContext) LoggerFactory.getILoggerFactory();

    FileAppender fileAppender = new FileAppender();
    fileAppender.setContext(loggerContext);
    fileAppender.setName("timestamp");
    // set the file name
    fileAppender.setFile("log/" + System.currentTimeMillis()+".log");

    PatternLayoutEncoder encoder = new PatternLayoutEncoder();
    encoder.setContext(loggerContext);
    encoder.setPattern("%r %thread %level - %msg%n");
    encoder.start();

    fileAppender.setEncoder(encoder);
    fileAppender.start();

    // attach the rolling file appender to the logger of your choice
    Logger logbackLogger = loggerContext.getLogger("Main");
    logbackLogger.addAppender(fileAppender);

    // OPTIONAL: print logback internal status messages
    StatusPrinter.print(loggerContext);

    // log something
    logbackLogger.debug("hello");
  }
}

如果您只需要添加日志文件名的时间戳,则logback已经支持timestamp元素.因此,您实际上根本不需要任何自定义代码.

Answer 2

要根据运行时属性将日志消息分离/筛选到不同的文件,您可能需要使用ch.qos.logback.classic.sift.SiftingAppender.

简而言之,这允许您根据MDC(映射诊断上下文)(例如,)设置替换位置的FileAppender(或任何其他appender ).请参阅完整示例的第一个链接.<file>${userid}.log</file>${userId}MDC.put("userid", "Alice");

Answer 3

您可以执行以下操作来忽略那些额外的文件创建.Below是配置文件

<configuration>
<appender name="FILE" class="ch.qos.logback.core.FileAppender">
<!-- "application-name" is a variable -->
<File>c:/logs/${application-name}.log</File>
<layout class="ch.qos.logback.classic.PatternLayout">
<Pattern>%d %p %t %c - %m%n</Pattern>
</layout>
</appender>
<root level="debug">
<appender-ref ref="FILE"/>
</root>
</configuration>  

这是java部分,

LoggerContext context = (LoggerContext) LoggerFactory.getILoggerFactory();
JoranConfigurator jc = new JoranConfigurator();
jc.setContext(context);
context.reset(); // override default configuration
// inject the name of the current application as "application-name"
// property of the LoggerContext
context.putProperty("application-name", NAME_OF_CURRENT_APPLICATION);
jc.doConfigure("/path/to/the/above/configuration/file.xml");

我从这里得到了这个http://logback.qos.ch/faq.html#sharedConfiguration

Answer 4

看起来记录器已初始化两次.第一次,可能是当应用程序加载并且它无法解决时${log_file_name}.如果您启动应用程序,则-Dlog_file_name=*something*可以验证此行为是否创建了具有该名称的另一个日志文件*something*