【Spring in action】SSM接入log4j日志

前言：

上篇文章 ssm框架已经搭建起来，并且可以通过Mybatis调用数据库，本文是基于上一文章的代码接入log4j日志（其实看不看都不重要，可以直接拿代码过来尝试接入）。

那么这篇文章，我开始接入log日志功能。后端如果没有日志，出错了找谁去呢？

一、导入jar包：

（jar包从哪来？Mybatis的jar包自带Log4j的各种jar包）

二、新建一个配置文件log4j.properties

配置代码如下：第三行起是控制台输出；第8行起是输出到本地绝对路径：

/Users/user/eclipse-workspace/logSpring/WebContent/WEB-INF/logs/error.log

log4j.rootLogger = debug ,  stdout ,  D 

log4j.appender.stdout = org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target = System.out
log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern =  %d{ABSOLUTE} %5p %c{1}:%L - %m%n

log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
log4j.appender.D.File = /Users/user/eclipse-workspace/logSpring/WebContent/WEB-INF/logs/error.log 
log4j.appender.D.Append = true
log4j.appender.D.Threshold = ERROR 
log4j.appender.D.layout = org.apache.log4j.PatternLayout
log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n

三、在web.xml中配置Log4j

<!-- Log4j -->
	<!-- Log4j配置文件 -->
	<context-param>
	<param-name>webAppRootKey</param-name>
	<param-value>webapp.root</param-value>
	</context-param>
    <context-param>
        <param-name>log4jConfigLocation</param-name>
        <param-value>classpath:conf/log4j.properties</param-value>
    </context-param>
    <context-param>
        <param-name>log4jRefreshInterval</param-name>
        <param-value>1000</param-value>
    </context-param>
     <listener>
        <listener-class>
            org.springframework.web.util.Log4jConfigListener
        </listener-class>
    </listener>

四、测试一下：

1、在conf文件夹下新建mybatis配置文件generatorConfig.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN" "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
  <!-- 数据库驱动-->    
    <!-- <classPathEntry  location="mysql-connector-java-5.1.18-bin.jar"/>     -->
    <context id="DB2Tables"  targetRuntime="MyBatis3">    
        <commentGenerator>    
            <property name="suppressDate" value="true"/>    
            <!-- 是否去除自动生成的注释 true：是 ： false:否 -->    
            <property name="suppressAllComments" value="true"/>    
        </commentGenerator>    
        <!--数据库链接URL，用户名、密码 -->    
        <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://localhost:3306/ebook" userId="root" password="haibo1118">    
        </jdbcConnection>    
        <javaTypeResolver>    
            <property name="forceBigDecimals" value="false"/>    
        </javaTypeResolver>    
        <!-- 生成模型的包名和位置-->    
        <javaModelGenerator targetPackage="com.model" targetProject="logSpring/src">    
            <property name="enableSubPackages" value="true"/>    
            <property name="trimStrings" value="true"/>    
        </javaModelGenerator>    
        <!-- 生成映射文件的包名和位置-->    
        <sqlMapGenerator targetPackage="com.mapping" targetProject="logSpring/src">    
            <property name="enableSubPackages" value="true"/>    
        </sqlMapGenerator>    
        <!-- 生成DAO的包名和位置-->    
        <javaClientGenerator type="XMLMAPPER" targetPackage="com.dao" targetProject="logSpring/src">    
            <property name="enableSubPackages" value="true"/>    
        </javaClientGenerator>    
        <!-- 要生成的表 tableName是数据库中的表名或视图名 domainObjectName是实体类名-->    
        <table tableName="biquge" domainObjectName="Book" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table>  
    </context>    
</generatorConfiguration>

2、右键配置文件，生成三个文件。分别为Book.java，BookMapper.xml,BookMapper.java。具体代码就不写了。

3、然后新建service包，写一个接口对外：

package com.service;

import com.model.Book;

public interface IBookService {
	Book getBookById(String bookId); 
}

4、写一个实现类：

package com.service;


import javax.annotation.Resource;

import org.springframework.stereotype.Service;

import com.dao.BookMapper;
import com.model.Book;
@Service("userService")
public class BookServiceImpl implements IBookService{
	@Resource
	private BookMapper bookDao;

	@Override
	public Book getBookById(String bookId) {
		// TODO Auto-generated method stub
		return this.bookDao.selectByPrimaryKey(bookId);
	}
}

5、写一个Controller：

package com.controller;

import java.io.IOException;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import com.alibaba.fastjson.JSONObject;
import com.service.IBookService;
@Controller
public class EbookController {
	@Resource  
    private IBookService bookService = null; 
	@RequestMapping(value="/b.do")
	public void addrShow(HttpServletResponse response) throws IOException{
		response.setContentType("application/json;charset=UTF-8");
		response.getWriter().write(JSONObject.toJSONString(bookService.getBookById("59cc3a7f3ea44b15c1f92ac0")).toString());
	}
}

测试一下。结果可以在本地绝对路径生成日志，控制台也能打印日志。