SpringBoot日志打印实践

背景

在项目当中，我们经常需要打印一些日志埋点信息，这些日志埋点信息，在后续软件的运维、稳定性建设中发挥了巨大的作用：

  • 问题追踪：通过埋点日志中的关键信息，帮助定位系统异常原因
  • 系统监控：通过日志，监控系统的运行情况，包括性能指标、访问频率、错误等
  • 数据分析：分析用户行为、系统性能和业务趋势等
  • 调试：通过查看日志，帮助开发人员了解程序在执行过程中的状态和行为

SpringBoot整合Logback实现日志打印

SpringBoot默认使用Slf4j作为日志门面，并集成Logback作为日志实现。要在springboot中实现日志打印，只需要引入下列依赖：

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

然后在配置文件中，配置对应的日志级别：

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logging:
  level:
    root: INFO

对某些特定的包，需要指定日志级别，则配置如下：

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logging:
    level:
        com.example.demo: DEBUG

最后，我们创建logback-spring.xml，来自定义日志的配置信息，包括日志输出文件、日志格式等

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<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <property name="LOG_PATH" value="logs"/>
    <property name="LOG_FILE" value="${LOG_PATH}/spring-boot-logger.log"/>

    <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <pattern>%d{yyyy-MM-dd HH:mm:ss} - %msg%n</pattern>
        </encoder>
    </appender>

    <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>common.log</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>${LOG_PATH}/spring-boot-logger.%d{yyyy-MM-dd}.log</fileNamePattern>
            <maxHistory>30</maxHistory>
        </rollingPolicy>
        <encoder>
            <pattern>%d{yyyy-MM-dd HH:mm:ss} - %msg%n</pattern>
        </encoder>
    </appender>

    <root level="INFO">
        <appender-ref ref="CONSOLE"/>
        <appender-ref ref="FILE"/>
    </root>
</configuration>

然后，我们在需要打印日志的类，加上Slf4j注解，然后使用log来打印日志信息即可，如下代码所示：

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package com.yang.web.controller;

import com.yang.api.common.ResultT;
import com.yang.api.common.command.RegisterCommand;
import com.yang.api.common.dto.UserDTO;
import com.yang.api.common.facade.UserFacade;
import com.yang.web.request.RegisterRequest;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping(value = "/user")
@Slf4j
public class UserController {
    @Autowired
    private UserFacade userFacade;

    @GetMapping(value = "/{id}")
    public ResultT<UserDTO> queryById(@PathVariable("id") Integer id) {
        log.info("queryById===========");
        return userFacade.getById(id);
    }

    @PostMapping(value = "/register")
    public ResultT<String> register(@RequestBody RegisterRequest registerRequest) {
        RegisterCommand registerCommand = convert2RegisterCommand(registerRequest);
        return userFacade.register2(registerCommand);
    }

    private RegisterCommand convert2RegisterCommand(RegisterRequest registerRequest) {
        RegisterCommand registerCommand = new RegisterCommand();
        registerCommand.setLoginId(registerRequest.getLoginId());
        registerCommand.setEmail(registerRequest.getEmail());
        registerCommand.setPassword(registerRequest.getPassword());
        registerCommand.setExtendMaps(registerRequest.getExtendMaps());
        return registerCommand;
    }
}

然后访问queryById，打印结果如下：

日志打印工具类

在logback-spring.xml中，我们虽然能配置日志打印的格式，但是不够灵活，因此，我们可以添加一个日志打印工具类，通过该工具类，来自定义项目中的日志打印格式，以方便后续更好地通过日志排查、定位问题。

首先创建一个日志打印抽象类，定义日志打印的格式：

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package com.yang.core.infrastructure.log;

import org.apache.commons.lang3.StringUtils;
import org.springframework.util.CollectionUtils;

import java.util.ArrayList;
import java.util.List;

public abstract class AbstractLogPrinter {
    protected String bizCode;
    
    protected List<String> params = new ArrayList<>();

    protected String msg;

    protected Throwable e;

    public AbstractLogPrinter addBizCode(String bizCode) {
        this.bizCode = bizCode;
        return this;
    }

    public AbstractLogPrinter addMsg(String msg) {
        this.msg = msg;
        return this;
    }

    public AbstractLogPrinter addParam(String key, String value) {
        this.params.add(key);
        this.params.add(value);
        return this;
    }

    public AbstractLogPrinter addThrowable(Throwable e) {
        this.e = e;
        return this;
    }

    public abstract void printBizLog();

    public abstract void printErrorLog();

    public abstract String getSeparator();

    public String commonContent() {
        StringBuilder stringBuilder = new StringBuilder();
        String separator = getSeparator();
        stringBuilder.append("bizCode").append(":")
                .append(this.bizCode).append(separator);
        if (!CollectionUtils.isEmpty(params)) {
            for (int i = 0; i < params.size(); i += 2) {
                stringBuilder.append(params.get(i))
                        .append(":")
                        .append(params.get(i + 1))
                        .append(separator);
            }
        }
        if (StringUtils.isNotEmpty(msg)) {
            stringBuilder.append("msg").append(":")
                    .append(msg).append(separator);
        }
        return stringBuilder.toString();
    }
}

然后创建日志打印实现类，在实现类中，定制实现日志打印的级别、分隔符等内容

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package com.yang.core.infrastructure.log;

import lombok.extern.slf4j.Slf4j;

@Slf4j
public class PlatformLogPrinter extends AbstractLogPrinter {

    public void printBizLog() {
        log.info(commonContent());
    }

    public void printErrorLog() {
        if (e != null) {
            log.error(commonContent(), e);
        } else {
            log.error(commonContent());
        }
    }

    @Override
    public String getSeparator() {
        return "<|>";
    }
}

同时，为了方便打印日志，创建一个日志打印创建者

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package com.yang.core.infrastructure.log;

public class PlatformLogger {

    public static AbstractLogPrinter build() {
        return new PlatformLogPrinter();
    }
}

上述内容准备完毕后，我们在controller中，使用PlatformLogger来打印日志，修改后的代码如下：

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package com.yang.web.controller;

import com.yang.api.common.ResultT;
import com.yang.api.common.command.RegisterCommand;
import com.yang.api.common.dto.UserDTO;
import com.yang.api.common.facade.UserFacade;
import com.yang.core.infrastructure.log.PlatformLogger;
import com.yang.web.request.RegisterRequest;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping(value = "/user")
public class UserController {
    @Autowired
    private UserFacade userFacade;

    @GetMapping(value = "/{id}")
    public ResultT<UserDTO> queryById(@PathVariable("id") Integer id) {
        PlatformLogger.build()
                .addBizCode("queryById")
                .addParam("id", id.toString())
                .addMsg("query by id")
                .printBizLog();
        return userFacade.getById(id);
    }
    
    @GetMapping(value = "/error/{id}")
    public ResultT testError(@PathVariable("id") Integer id) {
        try {
            int i = 1 / 0;
        } catch (Throwable t) {
            PlatformLogger.build()
                    .addBizCode("testError")
                    .addParam("id", id.toString())
                    .addMsg("test error print")
                    .addThrowable(t)
                    .printErrorLog();
        }
        return ResultT.fail();
    }

    @PostMapping(value = "/register")
    public ResultT<String> register(@RequestBody RegisterRequest registerRequest) {
        RegisterCommand registerCommand = convert2RegisterCommand(registerRequest);
        return userFacade.register2(registerCommand);
    }

    private RegisterCommand convert2RegisterCommand(RegisterRequest registerRequest) {
        RegisterCommand registerCommand = new RegisterCommand();
        registerCommand.setLoginId(registerRequest.getLoginId());
        registerCommand.setEmail(registerRequest.getEmail());
        registerCommand.setPassword(registerRequest.getPassword());
        registerCommand.setExtendMaps(registerRequest.getExtendMaps());
        return registerCommand;
    }
}

启动项目，分别访问queryById和testError，打印日志内容如下：

日志分文件打印

一般情况下，我们的项目会分为不同的模块，每一个模块承担不同的职责，比如bussiness模块，主要是负责业务逻辑代码的实现，业务逻辑编排等；web模块主要负责http请求的接收，参数的校验，入参转化为业务层入参等；而core模块主要负责基础能力实现，比如持久化数据库、领域服务实现等。

对于不同的模块，我们希望将日志输出到不同的文件当中，从而协助我们后续定位问题以及建设不同模块下的监控，包括基础服务监控、业务成功率监控等。

因此，我们在不同的模块下，分别实现不同的日志打印工具类：

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package com.yang.web.log;

import com.yang.core.infrastructure.log.AbstractLogPrinter;

public class WebLogger {
    public static AbstractLogPrinter build() {
        return new WebLogPrinter();
    }
}


package com.yang.web.log;

import com.yang.core.infrastructure.log.AbstractLogPrinter;
import lombok.extern.slf4j.Slf4j;

@Slf4j
public class WebLogPrinter extends AbstractLogPrinter {
    @Override
    public void printBizLog() {
        log.info(commonContent());
    }

    @Override
    public void printErrorLog() {
        if (this.e != null) {
            log.error(commonContent(), e);
        } else {
            log.error(commonContent());
        }
    }

    @Override
    public String getSeparator() {
        return "<|>";
    }
}


package com.yang.business.log;

public class BusinessLogger {
    public static BusinessLogPrinter build() {
        return new BusinessLogPrinter();
    }
}


package com.yang.business.log;

import com.yang.core.infrastructure.log.AbstractLogPrinter;
import lombok.extern.slf4j.Slf4j;

@Slf4j
public class BusinessLogPrinter extends AbstractLogPrinter {
    @Override
    public void printBizLog() {
        log.info(commonContent());
    }

    @Override
    public void printErrorLog() {
        if (this.e != null) {
            log.error(commonContent(), e);
        } else {
            log.error(commonContent());
        }
    }

    @Override
    public String getSeparator() {
        return "<|>";
    }
}

然后我们修改logback-spring.xml文件，将不同的日志打印工具类，输出到不同的日志文件中

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<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <property name="LOG_PATH" value="logs"/>
    <property name="LOG_FILE" value="${LOG_PATH}/spring-boot-logger.log"/>

    <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <pattern>%d{yyyy-MM-dd HH:mm:ss} - %msg%n</pattern>
        </encoder>
    </appender>

    <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>common.log</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>${LOG_PATH}/spring-boot-logger.%d{yyyy-MM-dd}.log</fileNamePattern>
            <maxHistory>30</maxHistory>
        </rollingPolicy>
        <encoder>
            <pattern>%d{yyyy-MM-dd HH:mm:ss} - %msg%n</pattern>
        </encoder>
    </appender>

    <appender name="PLATFORM_FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>platform.log</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>${LOG_PATH}/platform-logger.%d{yyyy-MM-dd}.log</fileNamePattern>
            <maxHistory>30</maxHistory>
        </rollingPolicy>
        <encoder>
            <pattern>%d{yyyy-MM-dd HH:mm:ss} - %msg%n</pattern>
        </encoder>
    </appender>

    <appender name="BUSINESS_FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>business.log</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>${LOG_PATH}/business-logger.%d{yyyy-MM-dd}.log</fileNamePattern>
            <maxHistory>30</maxHistory>
        </rollingPolicy>
        <encoder>
            <pattern>%d{yyyy-MM-dd HH:mm:ss} - %msg%n</pattern>
        </encoder>
    </appender>

    <appender name="WEB_FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>web.log</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>${LOG_PATH}/web-logger.%d{yyyy-MM-dd}.log</fileNamePattern>
            <maxHistory>30</maxHistory>
        </rollingPolicy>
        <encoder>
            <pattern>%d{yyyy-MM-dd HH:mm:ss} - %msg%n</pattern>
        </encoder>
    </appender>

    <root level="INFO">
        <appender-ref ref="CONSOLE"/>
        <appender-ref ref="FILE"/>
    </root>

    <!-- 工具类PlatformLogPrinter的logger -->
    <logger name="com.yang.core.infrastructure.log.PlatformLogPrinter" level="INFO" additivity="false">
        <appender-ref ref="PLATFORM_FILE" />
    </logger>

    <!-- 工具类BusinessLogPrinter的logger -->
    <logger name="com.yang.business.log.BusinessLogPrinter" level="INFO" additivity="false">
        <appender-ref ref="BUSINESS_FILE" />
    </logger>

    <!-- 工具类WebLogPrinter的logger -->
    <logger name="com.yang.web.log.WebLogPrinter" level="INFO" additivity="false">
        <appender-ref ref="WEB_FILE" />
    </logger>
</configuration>

最后，分别在web模块、business模块和core模块下，添加埋点日志

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// WEB模块
@GetMapping(value = "/{id}")
    public ResultT<UserDTO> queryById(@PathVariable("id") Integer id) {
        WebLogger.build()
                .addBizCode("userController_queryById")
                .addParam("id", id.toString())
                .addMsg("query by id")
                .printBizLog();
        return userFacade.getById(id);
    }

// Business模块
@Override
    public ResultT<UserDTO> getById(Integer id) {
        UserQueryDomainRequest userQueryDomainRequest = new UserQueryDomainRequest.UserQueryDomainRequestBuilder()
                .queryMessage(id.toString())
                .userQueryType(UserQueryType.ID)
                .build();
        UserQueryDomainResponse userQueryDomainResponse = userDomainService.query(userQueryDomainRequest);
        List<UserAccount> userAccountList = userQueryDomainResponse.getUserAccountList();
        UserDTO userDTO = null;
        if (!CollectionUtils.isEmpty(userAccountList)) {
            UserAccount userAccount = userAccountList.get(0);
            userDTO = userDTOConvertor.convert2DTO(userAccount);
        }
        BusinessLogger.build()
                .addBizCode("userFacade_getById")
                .addParam("id", id.toString())
                .addParam("userDTO", JSONObject.toJSONString(userDTO))
                .addMsg("get by id")
                .printBizLog();
        return ResultT.success(userDTO);
    }


// core模块
public UserQueryDomainResponse query(UserQueryDomainRequest userQueryDomainRequest) {
        UserQueryType userQueryType = userQueryDomainRequest.getUserQueryType();
        UserDO userDO = null;
        switch (userQueryType) {
            case ID:
                userDO = queryById(Integer.valueOf(userQueryDomainRequest.getQueryMessage()));
                break;
            case EMAIL:
                userDO = queryByEmail(userQueryDomainRequest.getQueryMessage());
                break;
            case LOGIN_ID:
                userDO = queryByLoginId(userQueryDomainRequest.getQueryMessage());
                break;
        }
        if (userDO == null) {
            return new UserQueryDomainResponse();
        }
        UserAccount userAccount = new UserAccount();
        userAccount.setId(userDO.getId());
        userAccount.setLoginId(userDO.getLoginId());
        userAccount.setEmail(userDO.getEmail());
        userAccount.setFeatureMap(FeatureUtils.convert2FeatureMap(userDO.getFeatures()));
        userAccount.setCreateTime(userDO.getCreateTime());
        userAccount.setUpdateTime(userDO.getUpdateTime());
        UserQueryDomainResponse userQueryDomainResponse = new UserQueryDomainResponse();
        List<UserAccount> userAccounts = new ArrayList<>();
        userAccounts.add(userAccount);
        userQueryDomainResponse.setUserAccountList(userAccounts);

        PlatformLogger.build()
                .addBizCode("userDomainService_query")
                .addParam("queryMsg", userQueryDomainRequest.getQueryMessage())
                .addParam("queryType", userQueryDomainRequest.getUserQueryType().name())
                .printBizLog();
        return userQueryDomainResponse;
    }

启动项目，访问queryById接口，可以看到在web.log，business.log和platform.log下分别打印了不同的日志信息

参考文档

【Spring Boot】深入解密Spring Boot日志：最佳实践与策略解析-腾讯云开发者社区-腾讯云 (tencent.com)

#工作积累
SpringBoot日志打印实践
https://cxydhi.github.io/2024/10/04/SpringBoot日志打印实践/
作者
沉河不浮
发布于
2024年10月4日
许可协议