Java使用Log日志系统（common-logging和log4j）

配置common-logging.properties文件

只需要一行即可，放在classpath下，如果是Maven中就在src/resources下

<code class="hljs avrasm has-numbering">org<span class="hljs-preprocessor">.apache</span><span class="hljs-preprocessor">.commons</span><span class="hljs-preprocessor">.logging</span><span class="hljs-preprocessor">.Log</span>=org<span class="hljs-preprocessor">.apache</span><span class="hljs-preprocessor">.commons</span><span class="hljs-preprocessor">.logging</span><span class="hljs-preprocessor">.impl</span><span class="hljs-preprocessor">.Log</span>4JLogger</code><ul style="" class="pre-numbering"><li>1</li></ul><ul style="" class="pre-numbering"><li>1</li></ul>

配置log4j.properties文件

放在classpath下，如果是Maven中就在src/resources下。具体意义看注释。

<code class="hljs avrasm has-numbering"><span class="hljs-preprocessor">### set log levels ###</span>
log4j<span class="hljs-preprocessor">.rootLogger</span> = debug , stdout , D , E

<span class="hljs-preprocessor">### 输出到控制台 ###</span>
log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.stdout</span> = 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">.stdout</span><span class="hljs-preprocessor">.Target</span> = System<span class="hljs-preprocessor">.out</span>
<span class="hljs-preprocessor">## 输出INFO级别以上的日志</span>
log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.stdout</span><span class="hljs-preprocessor">.Threshold</span> = INFO
log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.stdout</span><span class="hljs-preprocessor">.layout</span> = org<span class="hljs-preprocessor">.apache</span><span class="hljs-preprocessor">.log</span>4j<span class="hljs-preprocessor">.PatternLayout</span>
log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.stdout</span><span class="hljs-preprocessor">.layout</span><span class="hljs-preprocessor">.ConversionPattern</span> = %d{ABSOLUTE} %<span class="hljs-number">5</span>p %c{<span class="hljs-number">1</span>}:%L - %m%n

<span class="hljs-preprocessor">### 输出到日志文件 ###</span>
log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.D</span> = org<span class="hljs-preprocessor">.apache</span><span class="hljs-preprocessor">.log</span>4j<span class="hljs-preprocessor">.DailyRollingFileAppender</span>
log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.D</span><span class="hljs-preprocessor">.File</span> = D:/logs/log<span class="hljs-preprocessor">.log</span>
log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.D</span><span class="hljs-preprocessor">.Append</span> = true
<span class="hljs-preprocessor">## 输出DEBUG级别以上的日志</span>
log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.D</span><span class="hljs-preprocessor">.Threshold</span> = DEBUG
log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.D</span><span class="hljs-preprocessor">.layout</span> = org<span class="hljs-preprocessor">.apache</span><span class="hljs-preprocessor">.log</span>4j<span class="hljs-preprocessor">.PatternLayout</span>
log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.D</span><span class="hljs-preprocessor">.layout</span><span class="hljs-preprocessor">.ConversionPattern</span> = %-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n

<span class="hljs-preprocessor">### 保存异常信息到单独文件 ###</span>
log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.E</span> = org<span class="hljs-preprocessor">.apache</span><span class="hljs-preprocessor">.log</span>4j<span class="hljs-preprocessor">.DailyRollingFileAppender</span>
<span class="hljs-preprocessor">## 异常日志文件名</span>
log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.E</span><span class="hljs-preprocessor">.File</span> = D:/logs/error<span class="hljs-preprocessor">.log</span>
log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.E</span><span class="hljs-preprocessor">.Append</span> = true
<span class="hljs-preprocessor">## 只输出ERROR级别以上的日志!!!</span>
log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.E</span><span class="hljs-preprocessor">.Threshold</span> = ERROR
log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.E</span><span class="hljs-preprocessor">.layout</span> = org<span class="hljs-preprocessor">.apache</span><span class="hljs-preprocessor">.log</span>4j<span class="hljs-preprocessor">.PatternLayout</span>
log4j<span class="hljs-preprocessor">.appender</span><span class="hljs-preprocessor">.E</span><span class="hljs-preprocessor">.layout</span><span class="hljs-preprocessor">.ConversionPattern</span> = %-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n</code><ul style="" 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><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li><li>22</li><li>23</li><li>24</li><li>25</li><li>26</li><li>27</li><li>28</li><li>29</li></ul><ul style="" 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><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li><li>22</li><li>23</li><li>24</li><li>25</li><li>26</li><li>27</li><li>28</li><li>29</li></ul>

测试

<code class="hljs java has-numbering"><span class="hljs-keyword">package</span> com.zzkun;

<span class="hljs-keyword">import</span> org.apache.commons.logging.Log;
<span class="hljs-keyword">import</span> org.apache.commons.logging.LogFactory;

<span class="hljs-javadoc">/**
* Created by kun on 2016/5/13.
*/</span>
<span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">LogTest</span> {</span>

<span class="hljs-keyword">private</span> <span class="hljs-keyword">static</span> Log logger = LogFactory.getLog(LogTest.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.trace(<span class="hljs-string">"我是trace信息"</span>);
logger.debug(<span class="hljs-string">"我是debug信息"</span>);
logger.info(<span class="hljs-string">"我是info信息"</span>);
logger.warn(<span class="hljs-string">"我是warn信息"</span>);
logger.error(<span class="hljs-string">"我是error信息"</span>);
logger.fatal(<span class="hljs-string">"我是fatal信息"</span>);
}
}</code><ul style="" 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><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li></ul><ul style="" 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><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li></ul>

Intellij IDEA中显示颜色

默认是不显示颜色的，安装一个插件后即可显示：Grep Console

运行结果

运行结果：



文件输出：