关于这两者的组合应用带来的好处，google都有 就不说了。

首先说下配置，

工作笔记:在myeclipse 中创建一个java project

创建一个 TestSlf4J 类

package com.joyce.quartz.main;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

public class TestSlf4J {

private static final Logger logger =LoggerFactory.getLogger(TestSlf4J.class);

public static void main(String[] args) {

logger.error("Hello world {}");

System.out.println("2323");

try {

int i = 1/0;

} catch (Exception e) {

logger.error("出现异常",e);

}

}

}

同时把slf4j-api-1.1.jar    slf4j-log4j12-1.6.1.jar   log4j-1.2.16.jar 放入项目里。

再添加一个log4j.properties

# An example log4j configuration file that outputs both to System.out

# and a file named 'test'.

# For the general syntax of property based configuration files see the

# documenation of org.apache.log4j.PropertyConfigurator.

# WARNING: Location information can be useful but is very costly in

# terms of computation.

# The root logger uses the appender called A1. 

# The root logger uses the appenders called A1 and A2. Since no level

# is specified, note the empty string between the comma (",") and the

# equals sign ("="), the level of the root logger remains

# untouched. Log4j always initializes the level for the root logger to

# DEBUG. The root logger is the only logger that has a default

# level. Bu default, all other loggers do not have an assigned level,

# such that they inherit their level instead.

log4j.rootLogger=, A1, A2

# A1 is set to be ConsoleAppender sending its output to System.out

log4j.appender.A1=org.apache.log4j.ConsoleAppender

# A1 uses PatternLayout.

log4j.appender.A1.layout=org.apache.log4j.PatternLayout

# The conversion pattern consists of date in ISO8601 format, level,

# thread name, logger name truncated to its rightmost two components

# and left justified to 17 characters, location information consisting

# of file name (padded to 13 characters) and line number, nested

# diagnostic context, the and the application supplied message

log4j.appender.A1.layout.ConversionPattern=%d %-5p [%t] %-17c{2} (%13F:%L) %3x - %m%n

# Appender A2 writes to the file "test".

log4j.appender.A2=org.apache.log4j.FileAppender

log4j.appender.A2.File=e:/test.log

# Truncate 'test' if it aleady exists.

log4j.appender.A2.Append=false

# Appender A2 uses the PatternLayout.

log4j.appender.A2.layout=org.apache.log4j.PatternLayout

log4j.appender.A2.layout.ConversionPattern=%-5r %-5p [%t] %c{2}   %d{yyyy-MM-dd HH:mm:ss,SSS} [%c]-[%p]%m%n

# In this example, we are not interested in INNER loop or SWAP

# messages.  You might try to set INNER and SWAP to DEBUG for more

# verbose output.

log4j.logger.org.apache.log4j.examples.SortAlgo.INNER=INFO

log4j.logger.org.apache.log4j.examples.SortAlgo.SWAP=INFO

项目结构如图：

最后 运行TestSlf4J类在e盘就生成了一个test.log文件  生成内容如下：

注意：

slf4j-log4j12-1.6.1.jar是连接包，我们在java里直接用slf4j创建的log,如果没有这个连接包，是创建不出log的

还要注意的是，在没加这个连接包的时候，

会报

SLF4J: Failed to load class “org.slf4j.impl.StaticLoggerBinder”