log4j日志的使用

1:导入log4j架包,比如log4j-1.2.17.jar

2:在配置文件夹中新建文件log4j.properties

写入如下内容:

### 设置###

log4j.rootLogger = debug,stdout,D,E


### 输出信息到控制抬 ###
#log4j.appender.stdout = org.apache.log4j.ConsoleAppender
#log4j.appender.stdout.Target = System.out
#log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
#log4j.appender.stdout.layout.ConversionPattern = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n


### 输出DEBUG 级别以上的日志到=E://logs/error.log ###
log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
log4j.appender.D.File = E://logs/log.log
log4j.appender.D.Append = true
log4j.appender.D.Threshold = DEBUG
log4j.appender.D.layout = org.apache.log4j.PatternLayout
log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n


### 输出ERROR 级别以上的日志到=E://logs/error.log ###
log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
log4j.appender.E.File =E://logs/error.log
log4j.appender.E.Append = true
log4j.appender.E.Threshold = ERROR
log4j.appender.E.layout = org.apache.log4j.PatternLayout

log4j.appender.E.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n

3:测试代码

public class Test {
    private static Logger logger = Logger.getLogger(Test.class);
    public static void main(String[] args) {
         System.out.println("This is println message.");
        // 记录debug级别的信息
        logger.debug("This is debug message.");
        // 记录info级别的信息
        logger.info("This is info message.");
        // 记录error级别的信息
        logger.error("This is error message.");
    }

然后会在E://logs下生成相应的日志文件