需求背景

SpringBoot用法：动态修改日志输出级别

问题痛点

SpringBoot在 spring-boot-starter-actuator 模块中提供了日志相关的EndPoint，通过该EndPoint可以在项目运行时不需要重启服务就可以修改日志的打印级别，解决了以前修改日志打印级别必须要重启服务的烦恼。

技术点

1. 集成actuator依赖组件

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

2. 配置EndPoint

# log
management:
   endpoints:
      web:
         exposure:
            include: loggers

代码演示

1. 项目目录结构

2. pom.xml依赖组件

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<parent>
		<groupId>com.md</groupId>
		<artifactId>spring-boot2-parent</artifactId>
		<version>0.0.1-SNAPSHOT</version>
		<relativePath>../pom.xml</relativePath>
	</parent>

	<artifactId>spring-boot2-log-level</artifactId>
	<packaging>jar</packaging>

	<name>spring-boot2-log-level</name>
	<description>Spring Boot, MVC, Rest API for App</description>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter</artifactId>
		</dependency>
		<!-- 构建成可运行的Web项目 -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
		<dependency>
			<groupId>net.sf.json-lib</groupId>
			<artifactId>json-lib-ext-spring</artifactId>
		</dependency>
		<!-- swagger集成 -->
		<dependency>
			<groupId>io.springfox</groupId>
			<artifactId>springfox-swagger2</artifactId>
		</dependency>
		<!-- 默认swagger-ui -->
		<dependency>
			<groupId>io.springfox</groupId>
			<artifactId>springfox-swagger-ui</artifactId>
		</dependency>
		<!-- 更易用第三方swagger-ui组件 -->
		<dependency>
			<groupId>com.github.xiaoymin</groupId>
			<artifactId>swagger-bootstrap-ui</artifactId>
		</dependency>
		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
		</dependency>
		<dependency>
			<groupId>com.alibaba</groupId>
			<artifactId>fastjson</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-actuator</artifactId>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

3. application.yml配置

server:
   port: 9090
# log
management:
   endpoints:
      web:
         exposure:
            include: loggers

4. LogController设置类

我把接口做成了通过接口代码访问。当然，你也可以通过直接请求接口

LogController：

package com.md.demo.rest;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.env.Environment;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.md.demo.util.HttpRequestUtil;
import com.md.demo.util.JsonResult;

import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import lombok.extern.slf4j.Slf4j;

/**
 * @author Minbo
 */
@RestController
@RequestMapping("/log")
@Api(tags = { "接口-演示" })
@Slf4j
public class LogController {

	@Autowired
	private Environment environment;

	/**
	 * http://localhost:9090/testLog
	 * 
	 * @return
	 */
	@GetMapping("/testLog")
	public String testLog() {
		log.debug("this is debug log");
		log.info("this is info log");
		return "Hello greetings from spring-boot2-log-level";
	}

	/**
	 * http://localhost:9090/getLogger
	 * 
	 * @return
	 */
	@ApiOperation(value = "获得当前项目：日志输出级别", httpMethod = "GET")
	@GetMapping("/getLogger")
	public JsonResult getLogger() {
		String port = this.environment.getProperty("local.server.port");
		String url = "http://localhost:" + port + "/actuator/loggers/com.md";
		String result = HttpRequestUtil.sendGet(url);
		log.info("当前项目：日志输出级别，url={}，result={}", url, result);
		return JsonResult.ok(result);
	}

	/**
	 * http://localhost:9090/setLogger
	 * 
	 * @return
	 */
	@ApiOperation(value = "设置当前项目：日志输出级别（INFO/DEBUG）", httpMethod = "POST")
	@PostMapping("/setLogger")
	public JsonResult setLogger(@RequestHeader String logLevel) {
		String port = this.environment.getProperty("local.server.port");
		String url = "http://localhost:" + port + "/actuator/loggers/com.md";
		String param = "{\"configuredLevel\":\"" + logLevel + "\"}";
		String result = HttpRequestUtil.sendJsonPost(url, param);
		log.info("设置当前项目：日志输出级别，url={}，param={}，result={}", url, param, result);
		return JsonResult.ok();
	}
}

5. 启动类

Application：

package com.md.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
import org.springframework.web.filter.CorsFilter;

import com.github.xiaoymin.swaggerbootstrapui.annotations.EnableSwaggerBootstrapUI;

/**
 * 程序主入口
 * 
 * @author Minbo
 *
 */
@SpringBootApplication
@EnableSwaggerBootstrapUI
public class Application {

	public static void main(String[] args) {
		SpringApplication.run(Application.class, args);
	}

	/**
	 * 开启过滤器功能
	 * 
	 * @return
	 */
	private CorsConfiguration buildConfig() {
		CorsConfiguration corsConfiguration = new CorsConfiguration();
		corsConfiguration.addAllowedOrigin("*");
		corsConfiguration.addAllowedHeader("*");
		corsConfiguration.addAllowedMethod("*");
		return corsConfiguration;
	}

	/**
	 * 跨域过滤器
	 * 
	 * @return
	 */
	@Bean
	public CorsFilter corsFilter() {
		UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
		source.registerCorsConfiguration("/**", buildConfig());
		return new CorsFilter(source);
	}
}

接口测试

1. 启动后，访问地址：http://localhost:9090/doc.html （已集成了swagger2框架，Swagger集成用法教程）

2. 获得当前项目：日志输出级别

3. 设置当前项目：日志输出级别（INFO/DEBUG）

设置成INFO级别：

查看最新日志级别：

4. 接口日志输出测试

@GetMapping("/testLog")
public String testLog() {
    log.debug("this is debug log");
    log.info("this is info log");
    return "Hello greetings from spring-boot2-log-level";
}

控制台输出：