初始Java中的日誌記錄工具slf4j

前言

至於slf4j和log4j還有其他日誌工具的關係這裏就不具體說明。
具體可參考如下：
https://www.techug.com/post/how-log4j-designed.html

初識slf4j

1. 創建Maven項目
   這裏使用IDEA工具：
   其他參數默認即可。。。
   
2. 添加依賴到pom.xml

    <dependencies>
        <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.25</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-log4j12 -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.25</version>
            <!--<scope>test</scope>-->
        </dependency>
    </dependencies>

2. 添加資源log4j.properties
   在 src/main/resources/ 下創建 log4j.properties，內容如下：
   注意修改輸出的路徑

### 設置###
log4j.rootLogger = debug,stdout,D,E,I

### 輸出信息到控制擡 ###
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

### 輸出DEBUG 級別以上的日誌到=E://project//LoggerTest//target//log//debug.log ###
log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
log4j.appender.D.File = E://project//LoggerTest//target//log//debug.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

### 輸出ERROR 級別以上的日誌到=E://project//LoggerTest//target//log//error.log ###
log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
log4j.appender.E.File = E://project//LoggerTest//target//log//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

### 輸出INFO 級別以上的日誌到=E://project//LoggerTest//target//log//info.log ###
log4j.appender.I = org.apache.log4j.DailyRollingFileAppender
log4j.appender.I.File = E://project//LoggerTest//target//log//info.log
log4j.appender.I.Append = true
log4j.appender.I.Threshold = INFO
log4j.appender.I.layout = org.apache.log4j.PatternLayout
log4j.appender.I.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n

3. 編寫測試代碼

package cn.com.gyt;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class LoggerTesting {
    public static void main(String[] args) {
        Logger logger = LoggerFactory.getLogger("SimpleLogger");

        logger.info("info messages!");

        logger.debug("debug messages!");

        logger.error("error messages!");
    }
}

項目結構：

4. 運行：
   
   
   參考：https://www.yiibai.com/slf4j/slf4j_firstapp.html#article-start

完！