Spring 如何集成Log4J呢？

日志功能简介

日志是所有软件中必须拥有的功能，下文讲述Spring中集成Log4j的示例分享，如下所示:

集成Log4j前，需准备以下步骤:
   下载相应的jar包https://logging.apache.org/log4j
     log4j-x.y.z.jar

采用以下的方法集成Log4j

1. 创建 SpringDemo 项目
2. 在 src 目录下创建 com.java265 包
3. 导入 Spring 相关 JAR 包及 log4j-x.y.z.jar
4. 在 com.java265 包下创建 HelloWorld、MainApp、Beans.xml 和 log4j.properties
5. 运行 SpringDemo 项目

HelloWorld 类

package com.java265;
public class HelloWorld {
    private String message;
    public void setMessage(String message) {
        this.message = message;
    }
    public void getMessage() {
        System.out.println("消息：" + message);
    }
}

MainApp 类

package com.java265;
import org.apache.log4j.Logger;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class MainApp {
    static Logger log = Logger.getLogger(MainApp.class.getName());
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml");
        log.info("Going to create HelloWord Obj");
        HelloWorld obj = (HelloWorld) context.getBean("helloWorld");
        obj.getMessage();
        log.info("Exiting the program");
    }
}

Beans.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
    <bean id="helloWorld" class="com.java265.HelloWorld">
        <property name="message" value="Hello,java265!" />
    </bean>
</beans>

log4j.properties配置内容如下

# Define the root logger with appender file
log4j.rootLogger = DEBUG, FILE

# Define the file appender
log4j.appender.FILE=org.apache.log4j.FileAppender
# Set the name of the file
log4j.appender.FILE.File=E:\\log.out

# Set the immediate flush to true (default)
log4j.appender.FILE.ImmediateFlush=true

# Set the threshold to debug mode
log4j.appender.FILE.Threshold=debug

# Set the append to false, overwrite
log4j.appender.FILE.Append=false

# Define the layout for file appender
log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
log4j.appender.FILE.layout.conversionPattern=%m%n

运行结果---
消息：Hello,java265!
log.out 文件内容如下。
Going to create HelloWord Obj
Exiting the program