log4j的使用方法

转载自：http://blog.csdn.net/frightingforambition/article/details/48373191

这篇博客我们来简单介绍下如何在java中使用log4j自定义输出日志信息。

• 首先在src下建立log4j.property.
  这里，我们采用两种方法进行输出，ConsoleAppender控制台输出、FileAppend文件输出

<code class="hljs avrasm has-numbering">log4j<span class="hljs-preprocessor">.rootLogger</span>=info,etoak1,etoak2log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.etoak</span>1=org<span class="hljs-preprocessor">.apache</span><span class="hljs-preprocessor">.log</span>4j<span class="hljs-preprocessor">.ConsoleAppender</span>log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.etoak</span>1<span class="hljs-preprocessor">.layout</span>=org<span class="hljs-preprocessor">.apache</span><span class="hljs-preprocessor">.log</span>4j<span class="hljs-preprocessor">.TTCCLayout</span>log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.etoak</span>2=org<span class="hljs-preprocessor">.apache</span><span class="hljs-preprocessor">.log</span>4j<span class="hljs-preprocessor">.FileAppender</span>log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.etoak</span>2<span class="hljs-preprocessor">.file</span>=C://log4j<span class="hljs-preprocessor">.html</span>log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.etoak</span>2<span class="hljs-preprocessor">.layout</span>=org<span class="hljs-preprocessor">.apache</span><span class="hljs-preprocessor">.log</span>4j<span class="hljs-preprocessor">.HTMLLayout</span></code><ul style="display: block;" class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li></ul>

• 在需要输出日志的类中调用输出方法，log4j的输出有4中级别：error(错误)、warn(警告)、info(信息)、debug(调试),依据情况进行选择使用：

<code class="hljs cs has-numbering"><span class="hljs-keyword">public</span> <span class="hljs-keyword">class</span> Test2 {    <span class="hljs-keyword">private</span> <span class="hljs-keyword">static</span> Logger logger = Logger.getLogger(Test2.class);    <span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> <span class="hljs-title">main</span>(String[] args) {        logger.error(<span class="hljs-string">"这是一条error级别的日志信息"</span>);        logger.warn(<span class="hljs-string">"这是一条warn级别的日志信息"</span>);        logger.info(<span class="hljs-string">"这是一条info级别的日志信息"</span>);        logger.debug(<span class="hljs-string">"这是一条debug级别的日志信息"</span>);    }}</code><ul style="display: block;" class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li></ul>

运行Test2类，
控制台信息：

log4j.html中信息：（注意这个文件要手动建立）