end0tknr's kipple - web写経開発

太宰府天満宮の狛犬って、妙にカワイイ

log4j2 for java による SprintBoot2 へのログ出力

以下のurlの写経。

こばやしたかはるblog: SpringでLog4j2

いつも思いますが、ログ出力って、ごく単純な機能なのに、なんで、こんなにもPG言語やライブラリ毎に利用法に違いがあるんでしょ?

毎度、使用方法を忘れている気がします。

STEP 1 - pom.xml の編集

以下にPOM全体を記載していますが、「spring-boot-starter-logging」「spring-boot-starter-log4j2」あたりを追記。

<?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>2.4.4</version>
    <relativePath/> <!-- lookup parent from repository -->
  </parent>
  <groupId>jp.co.sexy.spak2</groupId>
  <artifactId>SpakSpring</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>SpakSpring</name>
  <description>Spak written from SEASAR2 to SpringBoot</description>
  <properties>
    <java.version>1.8</java.version>
  </properties>
  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
        <dependency>
      <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
        <exclusions>
          <!-- LOG4J2 のよる出力の為、以下を追加 -->
          <exclusion>
             <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-logging</artifactId>
          </exclusion>
        </exclusions>
      </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
    </dependency>
    <!-- HTML TEMPLATEは thymeleafでなく、昔ながらのjsp -->
    <dependency>
       <groupId>org.apache.tomcat.embed</groupId>
         <artifactId>tomcat-embed-jasper</artifactId>
    </dependency>
    <!-- ログ出力は、LOG4J2 -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-log4j2</artifactId>
    </dependency>
  </dependencies>

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

STEP 2 - src/main/resources/log4j2.xml の作成

参考にさせて頂いたurlでは、様々設定されていますが、今回、とりあえず出力するだけですので、以下の程度です。

<?xml version="1.0" encoding="UTF-8"?>
<configuration status="OFF">
    <Properties>
        <Property name="app_name">demo</Property>
        <Property name="date">%d{yyyy-MM-dd HH:mm:ss.SSS}</Property>
        <Property name="daily_log">logs/app${app_name}_%d{yyyy-MM-dd}.log</Property>
    </Properties>
    <appenders>
        <Console
            name="Console"
            target="SYSTEM_OUT"
        >
            <PatternLayout pattern="${date}, [${app_name}], [ %-5level ], %logger{10}, %msg %n" />
        </Console>
        <RollingFile
            name="File"
            fileName="logs/app.log"
            filePattern="${daily_log}.gz">
            <PatternLayout pattern="${date}, [${app_name}], [ %-5level ], %logger{10}, %msg %n" />
            <Policies>
                <TimeBasedTriggeringPolicy />
            </Policies>
        </RollingFile>
    </appenders>
    <loggers>
        <root level="info">
            <appender-ref ref="Console" />
            <appender-ref ref="File" />
        </root>
    </loggers>
</configuration>

STEP 3 - *.java での出力処理

「★」の部分を追記します。

package jp.end0tknr.action;

import org.apache.logging.log4j.LogManager; // ★
import org.apache.logging.log4j.Logger;     // ★
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;


@Controller
public class IndexAction {
    // ★
    static protected Logger logger = LogManager.getLogger(IndexAction.class);

    @RequestMapping("/")
    public String index(Model model) {
        logger.info("start index()"); // ★ 
        return "index";
    }

}

STEP4 - 出力確認

以上により、コンソール & $APP_ROOT/logs/app.log へ、以下のように出力されます。

2021-03-20 15:18:50.894, [demo], [ INFO  ], jp.co.sexy.spak.SpakSpringApplication, Starting SpakSpringApplication using Java 1.8.0_202 on LAPTOP-Q767CC9I with PID 23104 (C:\Users\end0t\workspace_eclipse_2020\SpakSpring\target\classes started by end0t in C:\Users\end0t\workspace_eclipse_2020\SpakSpring) 
2021-03-20 15:18:50.976, [demo], [ INFO  ], jp.co.sexy.spak.SpakSpringApplication, No active profile set, falling back to default profiles: default 
2021-03-20 15:18:52.103, [demo], [ INFO  ], org.springframework.boot.web.embedded.tomcat.TomcatWebServer, Tomcat initialized with port(s): 8080 (http) 
2021-03-20 15:18:52.125, [demo], [ INFO  ], org.apache.coyote.http11.Http11NioProtocol, Initializing ProtocolHandler ["http-nio-8080"] 
2021-03-20 15:18:52.126, [demo], [ INFO  ], org.apache.catalina.core.StandardService, Starting service [Tomcat] 
2021-03-20 15:18:52.127, [demo], [ INFO  ], org.apache.catalina.core.StandardEngine, Starting Servlet engine: [Apache Tomcat/9.0.44] 
2021-03-20 15:18:52.340, [demo], [ INFO  ], org.apache.jasper.servlet.TldScanner, At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time. 
2021-03-20 15:18:52.345, [demo], [ INFO  ], org.apache.catalina.core.ContainerBase.[Tomcat].[localhost].[/], Initializing Spring embedded WebApplicationContext 
2021-03-20 15:18:52.345, [demo], [ INFO  ], org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext, Root WebApplicationContext: initialization completed in 1294 ms 
2021-03-20 15:18:52.568, [demo], [ INFO  ], org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor, Initializing ExecutorService 'applicationTaskExecutor' 
2021-03-20 15:18:52.682, [demo], [ INFO  ], org.springframework.boot.autoconfigure.web.servlet.WelcomePageHandlerMapping, Adding welcome page template: index 
2021-03-20 15:18:52.806, [demo], [ INFO  ], org.apache.coyote.http11.Http11NioProtocol, Starting ProtocolHandler ["http-nio-8080"] 
2021-03-20 15:18:52.850, [demo], [ INFO  ], org.springframework.boot.web.embedded.tomcat.TomcatWebServer, Tomcat started on port(s): 8080 (http) with context path '' 
2021-03-20 15:18:52.985, [demo], [ INFO  ], jp.co.sexy.spak.SpakSpringApplication, Started SpakSpringApplication in 2.632 seconds (JVM running for 5.894) 
2021-03-20 15:19:11.227, [demo], [ INFO  ], org.apache.catalina.core.ContainerBase.[Tomcat].[localhost].[/], Initializing Spring DispatcherServlet 'dispatcherServlet' 
2021-03-20 15:19:11.227, [demo], [ INFO  ], org.springframework.web.servlet.DispatcherServlet, Initializing Servlet 'dispatcherServlet' 
2021-03-20 15:19:11.228, [demo], [ INFO  ], org.springframework.web.servlet.DispatcherServlet, Completed initialization in 1 ms 
2021-03-20 15:19:11.268, [demo], [ INFO  ], jp.co.sexy.spak.action.IndexAction, start index()