【SpringBoot】日志在项目中的应用

日志的目的：

为了方便日后的运维，快速定位BUG，错误信息等等

日志算是一个救命稻草

pom.xml需要的依赖：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.8</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.jmc</groupId>
    <artifactId>tco</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>tco</name>
    <description>tco project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.4</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.18</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.13</version>
        </dependency>

        <!-- mybatis-plus -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.2.0</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-logging</artifactId>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

application.yml的日志配置信息

logging:
  file:
    name: # 配置日志文件名称
      log-info.log
    path: # 配置日志文件所在路径
      ./logs
  level: # 设置日志输出级别
    root : info # 根类下 info输出级别
    # 指定项目路径下级别
    com.jmc.tco : debug
    org.springframework : warn
  logback:
    rollingpolicy:
      max-file-size: 50MB # 设置单个日志文件大小上限
      max-history: 30 # 设置日志保存时长 (天)

有Lombok支持，可以直接对类打这个【@Slf4j】注解即可

import lombok.extern.slf4j.Slf4j;

代替写入的方法：

private static final Logger logger = LoggerFactory.getLogger(需要日志输出的类.class);

关于输出问题，没有设置任何的路径，只有文件名称

用Jar包运行发现，日志文件会输出在jar包所在的目录下面，同理可以推算出目录也是同目录下创建