浅谈文件描述符与文件指针

log4j.xml 文件放到src文件下，并且如果文件log，最好目录建好

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">

<appender name="stdout" class="org.apache.log4j.ConsoleAppender">
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%-5p (%F:%L) - %m%n" />
</layout>
<filter class="org.apache.log4j.varia.LevelRangeFilter">
<param name="LevelMin" value="INFO" />
<param name="LevelMax" value="FATAL" />
</filter>
</appender>
<appender name="access"
class="org.apache.log4j.RollingFileAppender">
<param name="File" value="/home1/ams/log/access.log" />
<param name="Append" value="false" />
<param name="MaxFileSize" value="1024" />
<param name="MaxBackupIndex" value="2" />
<param name="Threshold" value="INFO" />
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d [%t] %p - %m%n" />
</layout>
<filter class="org.apache.log4j.varia.LevelRangeFilter">
<param name="LevelMin" value="INFO" />
<param name="LevelMax" value="WARN" />
<param name="AcceptOnMatch" value="true" />
</filter>
</appender>

<appender name="error"
class="org.apache.log4j.RollingFileAppender">
<param name="Append" value="false" />
<param name="File" value="/home1/ams/log/error.log" />
<param name="MaxFileSize" value="1024KB" />
<param name="MaxBackupIndex" value="2" />
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d [%t] %p - %m%n" />
</layout>
<filter class="org.apache.log4j.varia.LevelRangeFilter">
<param name="LevelMin" value="ERROR" />
<param name="LevelMax" value="ERROR" />
<param name="AcceptOnMatch" value="true" />
</filter>
</appender>

<appender name="IBatisTest"
class="org.apache.log4j.RollingFileAppender">
<param name="Append" value="true" />
<param name="File" value="/home1/ams/log/sql.log" />
<param name="MaxFileSize" value="1024M" />
<param name="MaxBackupIndex" value="2" />
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%-4r [%t] %-5p %c %x - %m%n" />
</layout>
<filter class="org.apache.log4j.varia.LevelRangeFilter">
<param name="LevelMin" value="DEBUG" />
<param name="LevelMax" value="ERROR" />
<param name="AcceptOnMatch" value="true" />
</filter>
</appender>

<logger name="com.ibatis" additivity="true">
<level value="DEBUG" />
<appender-ref ref="IBatisTest" />
</logger>

<logger name="java.sql.Connection" additivity="true">
<level value="DEBUG" />
<appender-ref ref="IBatisTest" />
<appender-ref ref="IBatis" />
</logger>

<logger name="java.sql.Statement" additivity="true">
<level value="DEBUG" />
<appender-ref ref="IBatisTest" />
</logger>

<logger name="java.sql.PreparedStatement" additivity="true">
<level value="DEBUG" />
<appender-ref ref="IBatisTest" />
<appender-ref ref="IBatis" />
</logger>

<logger name="java.sql.ResultSet" additivity="true">
<level value="DEBUG" />
<appender-ref ref="IBatisTest" />
<appender-ref ref="IBatis" />
</logger>

<root>
<priority value="debug" />
<appender-ref ref="stdout" />
<appender-ref ref="access" />
<appender-ref ref="error" />
<appender-ref ref="IBatisTest" />
<appender-ref ref="IBatis" />
</root>

<appender name="IBatis" class="org.apache.log4j.ConsoleAppender">
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%-4r [%t] %-5p %c %x - %m%n" />
</layout>
<filter class="org.apache.log4j.varia.LevelRangeFilter">
<param name="LevelMin" value="DEBUG" />
<param name="LevelMax" value="DEBUG" />
</filter>
</appender>

</log4j:configuration>

引入log4j的jar包，附件有

在文件java文件中写入代码：
protected final Logger logger = Logger.getLogger(this.getClass());

启动就可以调用了。