1、日志工厂
-
SLF4J
-
LOG4J(deprecated since 3.5.9) 【要掌握】
-
LOG4J2
-
JDK_LOGGING
-
COMMONS_LOGGING
-
STDOUT_LOGGING 【要掌握】
-
NO_LOGGING
在mybatis中具体使用哪一个日志实现,在设置中设定!
STDOUT_LOGGING标准日志输出
<settings>
<!-- 标准的日志工程实现-->
<!-- <setting name="logImpl" value="STDOUT_LOGGING"/>-->
<setting name="logImpl" value="LOG4J"/>
</settings>
输出结果:
2、Log4J
什么是Log4J:
-
Log4j是Apache的一个开源项目,通过使用Log4j,我们可以控制日志信息输送的目的地是控制台、文件、GUI组件;
-
我们也可以控制每一条日志的输出格式;
-
通过定义每一条日志信息的级别,我们能够更加细致地控制日志的生成过程;
(1)导入log4j的包
<!-- https://mvnrepository.com/artifact/log4j/log4j -->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
(2)log4j.properties
#将等级为DEBUG的日志输出到console和file这两个目的地,console和file的定义在下面配置中
log4j.rootLogger=DEBUG, console, file
#控制台输出的相关配置
log4j.appender.console=org.apache.log4j.ConsoleAppender
log4j.appender.console.Target = System.out
log4j.appender.console.Threshold=DEBUG
log4j.appender.console.layout=org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern=%d %p [%c] - %m%n
#文件输出的相关配置
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.File=./log/gt.log
log4j.appender.file.MaxFileSize=10MB
log4j.appender.file.Threshold=DEBUG
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d %p [%c] - %m%n
#日志输出级别
log4j.logger.org.mybatis=DEBUG
log4j.logger.java.sql=DEBUG
log4j.logger.java.sql.Statement=DEBUG
log4j.logger.java.sql.ResultSet=DEBUG
log4j.logger.java.sql.PreparedStatement=DEBUG
(3)配置log4j为mybatis日志的实现
<settings>
<setting name="logImpl" value="LOG4J"/>
</settings>
(4)使用log4j,运行测试
package com.gt.dao;
import com.gt.pojo.User;
import com.gt.utils.MybatisUtils;
import com.sun.rowset.internal.Row;
import org.apache.ibatis.session.RowBounds;
import org.apache.ibatis.session.sqlSession;
import org.apache.log4j.Logger;
import org.junit.Test;
import java.util.HashMap;
import java.util.List;
public class UserDaoTest {
static Logger logger = Logger.getLogger(UserDaoTest.class);
//分页
@Test
public void getUserByLimit() {
sqlSession sqlSession = MybatisUtils.getsqlSession();
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
HashMap<String, Integer> map = new HashMap<String, Integer>();
map.put("startIndex", 0);
map.put("pageSize", 2);
List<User> userList = mapper.getUserByLimit(map);
for (User user : userList) {
System.out.println(user);
}
sqlSession.close();
}
// 分页查询2
@Test
public void getUserByRowBounds() {
sqlSession sqlSession = MybatisUtils.getsqlSession();
//RowBounds实现
RowBounds rowBounds = new RowBounds(1, 2);
//通过Java代码层面实现分页
List<User> userList = sqlSession.selectList("com.gt.dao.UserMapper.getUserByRowBounds", null, rowBounds);
for (User user : userList) {
System.out.println(user);
}
sqlSession.close();
}
@Test
public void getUserLike() {
sqlSession sqlSession = MybatisUtils.getsqlSession();
logger.info("测试,进入getUserLike方法成功!");
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
User user = mapper.getUserById(1);
System.out.println(user);
sqlSession.close();
}
@Test
public void testLog4j() {
logger.info("info:进入了testLog4j");
logger.debug("debug:进入了testLog4j");
logger.error("error:进入了testLog4j");
}
}
//select * from mybatis.users where id = #{id}
//类型处理器
//select id,name,pwd from mybatis.users where id = #{id}
//起别名
//select id,name,pwd as password from mybatis.users where id = #{id}
输出结果:
简单使用
(1)在要使用log4j的类中,导入包import org.apache.log4j.Logger;
(2)日志对象,参数为当前类的class
static Logger logger = Logger.getLogger(UserDaoTest.class);
(3)日志级别
@Test
public void print() {
logger.info("info...");
logger.debug("info...");
logger.error("info...");
}