日志 Slf4j , Java 中使用

// 示例代码package biz.baijing.controller;import biz.baijing.pojo.Result;
import lombok.extern.slf4j.Slf4j;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;@RestController
public class DeptController {// slf4j Loggerprivate static final Logger logger = LoggerFactory.getLogger(DeptController.class);@RequestMapping("/depts")public Result list() {log.info("查询全部部门数据");return Result.success();}
}

Logger 选择

第一个。

网址 — SLF4J

The Simple Logging Facade for Java (SLF4J) serves as a simple facade or abstraction for various logging frameworks (e.g. java.util.logging, logback, log4j) allowing the end user to plug in the desired logging framework at deployment time.

当然可以注解掉 定义 logger 的语句。

直接引用 @Slf4j 

代码

package biz.baijing.controller;import biz.baijing.pojo.Result;
import lombok.extern.slf4j.Slf4j;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;@Slf4j             // 引入
@RestController
public class DeptController {// slf4j Logger// private static final Logger logger = LoggerFactory.getLogger(DeptController.class);@RequestMapping("/depts")public Result list() {logger.info("查询全部部门数据");return Result.success();}
}

logger 会报错。

@Slf4j  默认的 variable 是 log，改成 

正确代码

package biz.baijing.controller;import biz.baijing.pojo.Result;
import lombok.extern.slf4j.Slf4j;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;@Slf4j
@RestController
public class DeptController {// slf4j Logger// private static final Logger logger = LoggerFactory.getLogger(DeptController.class);@RequestMapping("/depts")public Result list() {log.info("查询全部部门数据");         // log 是 @Slf4j 默认的return Result.success();}
}

查看源代码

will generate:public class LogExample {private static final org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(LogExample.class);}

这里定义的就是 log 。