Java 日志打印

Java 日志

logback-classic 和 logback-core 的区别

logback-core：logback 框架基础
logback-classic：基于 logback-core，实现 sel4j 和其他高级功能

maven

<dependencies>
    <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-api</artifactId>
        <version>2.0.13</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-classic -->
    <dependency>
        <groupId>ch.qos.logback</groupId>
        <artifactId>logback-classic</artifactId>
        <version>1.3.14</version>
    </dependency>
</dependencies>

java

public class Application {  
    private static final org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(Application.class);  
    public static void main(String[] args) {  
        log.info("hello world");  
    }  
}

lombok

<!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->  
<dependency>  
    <groupId>org.projectlombok</groupId>  
    <artifactId>lombok</artifactId>  
    <version>1.18.32</version>  
</dependency>

@Slf4j  
public class Application {  
    public static void main(String[] args) {  
        log.info("hello world");  
    }  
}

Spring Boot 日志

格式

Date and Time: Millisecond precision and easily sortable.
Log Level: ERROR, WARN, INFO, DEBUG, or TRACE.
Process ID.
A --- separator to distinguish the start of actual log messages.
Application name: Enclosed in square brackets (logged by default only if spring.application.name is set)
Thread name: Enclosed in square brackets (may be truncated for console output).
Correlation ID: If tracing is enabled (not shown in the sample above)
Logger name: This is usually the source class name (often abbreviated).
The log message.

2024-05-23T12:38:13.986Z INFO 110098 --- [myapp] [ main] o.s.b.d.f.logexample.MyApplication : Starting MyApplication using Java 17.0.11 with PID 110098 (/opt/apps/myapp.jar started by myuser in /opt/apps/) 
2024-05-23T12:38:14.008Z INFO 110098 --- [myapp] [ main] o.s.b.d.f.logexample.MyApplication : No active profile set, falling back to 1 default profile: "default" 
2024-05-23T12:38:18.678Z INFO 110098 --- [myapp] [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port 8080 (http)

application.yaml

# 输出 debug 级别日志
debug: true

# 日志文件
## 绝对路径：输出到指定文件；相对路径：输出到当前目录指定文件
logging.file.name: my.log
## 文件名 spring.log；绝对路径：输出到指定目录；相对路径：输出到当前目录下的指定目录
logging.file.path: /var/log

## 日志切割，默认日志文件大小是 10MB
## logback 可以在 application.yaml 中配置，其他日志框架需要使用框架的配置文件
## 日志归档（切割的旧日志文件）名称格式，%i 是区分同日期的递增序号
logging.pattern.rolling-file-name: app-%d{yyyy-MM-dd}.%i.log
## 清除旧日志
logging.logback.rollingpolicy.clean-history-on-start: true
## 单日志文件大小
logging.logback.rollingpolicy.max-file-size: 10MB
## 所有日志文件大小
logging.logback.rollingpolicy.total-size-cap: 1G
## 保留文件数量
logging.logback.rollingpolicy.max-history: 7

## 日志级别
## 环境变量，只支持包级别，不支持类级别 LOGGING_LEVEL_ORG_SPRINGFRAMEWORK_WEB=DEBUG
logging.level.root: warn 
logging.level.org.springframework.web: debug 
logging.level.org.hibernate: error

## 日志分组，便于日志配置
logging.group.tomcat=org.apache.catalina,org.apache.coyote,org.apache.tomcat
logging.level.tomcat=trace

其他

参考：