如何使用 logback 以文本和 json 格式打印 Spring Boot 日志？

Question

我们使用 Logback 进行日志记录。目前我们正在使用 Splunk 来查看 Spring Boot 日志。根据项目要求，我们需要转向 Kibana。首先，我们应该以 JSON 格式登录，以便 Kibana 可以轻松处理它。目前我们没有用 Kibana 替换 Splunk，但是当与 Kibana 成功集成后，我们可以逐步在所有项目中替换 Splunk。

因此，根据要求，我们需要现有日志，即文本日志，但出于研发目的，我们还需要 JSON 日志。

Answer 1

这很简单。您只需要在pom.xml 文件中添加logstash-logback-encoder 依赖项并在您的logback.xml 文件中写入一些配置。请按照以下步骤来满足您的要求。

第一步：在pom.xml中添加logstash-logback-encoder依赖。

<dependency>
    <groupId>net.logstash.logback</groupId>
    <artifactId>logstash-logback-encoder</artifactId>
    <version>6.4</version>
</dependency>

第二步：在src/main/resources/内创建logback.xml文件，复制粘贴以下内容。

<?xml version="1.0" encoding="UTF-8"?>
<configuration debug="false">
  <include resource="org/springframework/boot/logging/logback/defaults.xml" />
  <include resource="org/springframework/boot/logging/logback/console-appender.xml" />
  <property name="LOG_PATH" value="logs" />
  <property name="CONSOLE_LOG_PATTERN" value="[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %X{id} %c{1} - %msg%n" />
  <property name="FILE_LOG_PATTERN" value="[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %X{id} %c{1} - %msg%n" />

  <appender name="CONSOLE_APPENDER" class="ch.qos.logback.core.ConsoleAppender">
    <encoder>
      <pattern>${CONSOLE_LOG_PATTERN}</pattern>
      <charset>utf8</charset>
    </encoder>
  </appender>

  <appender name="ROLLING_TEXT_FILE_APPENDER" class="ch.qos.logback.core.rolling.RollingFileAppender">
    <file>${LOG_PATH}/application-text.log</file>
    <encoder>
      <Pattern>${FILE_LOG_PATTERN}</Pattern>
    </encoder>
    <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
      <fileNamePattern>${LOG_PATH}/application-text.%d{yyyy-MM-dd}.%i.gz
      </fileNamePattern>
      <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
        <maxFileSize>100MB</maxFileSize>
      </timeBasedFileNamingAndTriggeringPolicy>
      <maxHistory>10</maxHistory>
    </rollingPolicy>
  </appender>
  
  <appender name="ROLLING_JSON_FILE_APPENDER" class="ch.qos.logback.core.rolling.RollingFileAppender">
    <file>${LOG_PATH}/application-json.log</file>
    <encoder class="net.logstash.logback.encoder.LogstashEncoder" />
    <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
      <fileNamePattern>${LOG_PATH}/application-json.%d{yyyy-MM-dd}.%i.gz
      </fileNamePattern>
      <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
        <maxFileSize>100MB</maxFileSize>
      </timeBasedFileNamingAndTriggeringPolicy>
      <maxHistory>10</maxHistory>
    </rollingPolicy>
  </appender>

  <root level="INFO">
    <appender-ref ref="CONSOLE_APPENDER" />
    <appender-ref ref="ROLLING_TEXT_FILE_APPENDER" />
    <appender-ref ref="ROLLING_JSON_FILE_APPENDER" />
  </root>
</configuration>

第 3 步： 现在您可以在类中的任何位置使用 log 语句。假设您在 Spring Boot 的主类中使用。

import org.slf4j.MDC;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import com.altafjava.constant.AppConstant;
import lombok.extern.slf4j.Slf4j;

@Slf4j
@SpringBootApplication
public class JsonLogApplication {

    public static void main(String[] args) {
        SpringApplication.run(JsonLogApplication.class, args);
        MDC.put("id", AppConstant.PROJECT_NAME_PREFIX + "_" + AppConstant.MARKET_CODE + "_" + AppConstant.PARAM_TYPE);
        log.info("---------- Spring Application started successfully ----------");
        log.debug("This is a debug message.");
        log.info("This is an info message.");
        log.warn("This is a warn message.");
        log.error("This is an error message.");
        log.info("---------- Spring Application ended successfully ----------");
    }
}

这将在logs 目录中创建两个日志文件。

1. application-text.log 会是这个样子

[INFO ] 2020-09-11 22:36:13.627 [main] DEMO_IND_PARAM c.a.JsonLogApplication - ---------- Spring Application started successfully ----------
[INFO ] 2020-09-11 22:36:13.630 [main] DEMO_IND_PARAM c.a.JsonLogApplication - This is an info message.
[WARN ] 2020-09-11 22:36:13.630 [main] DEMO_IND_PARAM c.a.JsonLogApplication - This is a warn message.
[ERROR] 2020-09-11 22:36:13.631 [main] DEMO_IND_PARAM c.a.JsonLogApplication - This is an error message.
[INFO ] 2020-09-11 22:36:13.631 [main] DEMO_IND_PARAM c.a.JsonLogApplication - ---------- Spring Application ended successfully ----------

1. application-json.log 会是这个样子

{"@timestamp":"2020-09-11T22:36:13.627+05:30","@version":"1","message":"---------- Spring Application started successfully ----------","logger_name":"com.altafjava.JsonLogApplication","thread_name":"main","level":"INFO","level_value":20000,"id":"DEMO_IND_PARAM"}
{"@timestamp":"2020-09-11T22:36:13.630+05:30","@version":"1","message":"This is an info message.","logger_name":"com.altafjava.JsonLogApplication","thread_name":"main","level":"INFO","level_value":20000,"id":"DEMO_IND_PARAM"}
{"@timestamp":"2020-09-11T22:36:13.630+05:30","@version":"1","message":"This is a warn message.","logger_name":"com.altafjava.JsonLogApplication","thread_name":"main","level":"WARN","level_value":30000,"id":"DEMO_IND_PARAM"}
{"@timestamp":"2020-09-11T22:36:13.631+05:30","@version":"1","message":"This is an error message.","logger_name":"com.altafjava.JsonLogApplication","thread_name":"main","level":"ERROR","level_value":40000,"id":"DEMO_IND_PARAM"}
{"@timestamp":"2020-09-11T22:36:13.631+05:30","@version":"1","message":"---------- Spring Application ended successfully ----------","logger_name":"com.altafjava.JsonLogApplication","thread_name":"main","level":"INFO","level_value":20000,"id":"DEMO_IND_PARAM"}

注意：这里的@Slf4j 是一个 Lombok 注释。这意味着无需创建 LoggerFactory 就可以直接使用日志方法。您需要在 IDE 中安装 Lombok 并在 pom.xml 中添加依赖项

如果您需要演示项目，请访问https://github.com/altafjava/json-log

Answer 2

你可以在 logback.xml 中配置如下 sn-p 为 json 和 text 格式。

    <appender name="json" class="ch.qos.logback.core.ConsoleAppender">
    <layout class="ch.qos.logback.contrib.json.classic.JsonLayout">
        <jsonFormatter
            class="ch.qos.logback.contrib.jackson.JacksonJsonFormatter">
            <prettyPrint>true</prettyPrint>
        </jsonFormatter>
        <timestampFormat>yyyy-MM-dd' 'HH:mm:ss.SSS</timestampFormat>
    </layout>
</appender>




<appender name="FILE" class="ch.qos.logback.core.FileAppender">
        <file>logfile.log</file>
        <append>true</append>
        <encoder>
            <pattern>%-4relative [%thread] %-5level %logger{35} - %msg %n</pattern>
        </encoder>
    </appender>

只需更改此处的类，我将一个打印到 consoleAppender，另一个打印到一个文件，您也可以将两者都指向一个 consoleappender。