log4j2 扩展日志级别,支持将系统日志与业务处理日志拆分

　　项目中，有时候需要对系统中已处理的一些业务数据日志进行提取分析，通常log4j默认提供的日志级别可能不够用，这时候我们就需要对日志级别进行扩展，以满足我们的需求.

本文就简单介绍一下log4j2的日志级别扩展，直接上代码：

  1 import org.apache.logging.log4j.Level;
  2 import org.apache.logging.log4j.LogManager;
  3 import org.apache.logging.log4j.Logger;
  4 import org.apache.logging.log4j.Marker;
  5 import org.apache.logging.log4j.message.Message;
  6 import org.apache.logging.log4j.message.MessageFactory;
  7 import org.apache.logging.log4j.spi.AbstractLogger;
  8 import org.apache.logging.log4j.spi.ExtendedLoggerWrapper;
  9 import org.apache.logging.log4j.util.MessageSupplier;
 10 import org.apache.logging.log4j.util.Supplier;
 11 
 12 /**log4j2日志扩展，支持业务日志
 13  * 业务日志为最高级别
 14  * 使用方式与扩展前基本相同：</br>
 15  * 使用CustomLogger  log=CustomLogger.getLogger(loggerName);</br>
 16  * 替代原来的：Logger log=LogManager.getLogger(loggerName);</br>
 17  * 记录用于数据分析的业务日志 使用log.business(msg);</br>
 18  * @author jessezeng
 19  *
 20  */
 21 public final class CustomLogger extends ExtendedLoggerWrapper {
 22     private static final long serialVersionUID = 103418572168532L;
 23     private final ExtendedLoggerWrapper logger;
 24 
 25     private static final String FQCN = CustomLogger.class.getName();
 26     private static final Level BUSINESS = Level.forName("BUSINESS", 50);
 27 
 28     private CustomLogger(final Logger logger) {
 29         super((AbstractLogger) logger, logger.getName(), logger.getMessageFactory());
 30         this.logger = this;
 31     }
 32 
 33     public static CustomLogger getLogger() {
 34         final Logger wrapped = LogManager.getLogger();
 35         return new CustomLogger(wrapped);
 36     }
 37 
 38     public static CustomLogger getLogger(final Class<?> loggerName) {
 39         final Logger wrapped = LogManager.getLogger(loggerName);
 40         return new CustomLogger(wrapped);
 41     }
 42 
 43     public static CustomLogger getLogger(final Class<?> loggerName, final MessageFactory factory) {
 44         final Logger wrapped = LogManager.getLogger(loggerName, factory);
 45         return new CustomLogger(wrapped);
 46     }
 47 
 48     public static CustomLogger getLogger(final Object value) {
 49         final Logger wrapped = LogManager.getLogger(value);
 50         return new CustomLogger(wrapped);
 51     }
 52 
 53     public static CustomLogger getLogger(final Object value, final MessageFactory factory) {
 54         final Logger wrapped = LogManager.getLogger(value, factory);
 55         return new CustomLogger(wrapped);
 56     }
 57 
 58     public static CustomLogger getLogger(final String name) {
 59         final Logger wrapped = LogManager.getLogger(name);
 60         return new CustomLogger(wrapped);
 61     }
 62 
 63     public static CustomLogger getLogger(final String name, final MessageFactory factory) {
 64         final Logger wrapped = LogManager.getLogger(name, factory);
 65         return new CustomLogger(wrapped);
 66     }
 67 
 68     public void business(final Marker marker, final Message msg) {
 69         logger.logIfEnabled(FQCN, BUSINESS, marker, msg, (Throwable) null);
 70     }
 71 
 72     public void business(final Marker marker, final Message msg, final Throwable t) {
 73         logger.logIfEnabled(FQCN, BUSINESS, marker, msg, t);
 74     }
 75 
 76     public void business(final Marker marker, final Object message) {
 77         logger.logIfEnabled(FQCN, BUSINESS, marker, message, (Throwable) null);
 78     }
 79 
 80     public void business(final Marker marker, final Object message, final Throwable t) {
 81         logger.logIfEnabled(FQCN, BUSINESS, marker, message, t);
 82     }
 83 
 84     public void business(final Marker marker, final String message) {
 85         logger.logIfEnabled(FQCN, BUSINESS, marker, message, (Throwable) null);
 86     }
 87 
 88     public void business(final Marker marker, final String message, final Object... params) {
 89         logger.logIfEnabled(FQCN, BUSINESS, marker, message, params);
 90     }
 91 
 92     public void business(final Marker marker, final String message, final Throwable t) {
 93         logger.logIfEnabled(FQCN, BUSINESS, marker, message, t);
 94     }
 95 
 96     public void business(final Message msg) {
 97         logger.logIfEnabled(FQCN, BUSINESS, null, msg, (Throwable) null);
 98     }
 99 
100     public void business(final Message msg, final Throwable t) {
101         logger.logIfEnabled(FQCN, BUSINESS, null, msg, t);
102     }
103 
104     public void business(final Object message) {
105         logger.logIfEnabled(FQCN, BUSINESS, null, message, (Throwable) null);
106     }
107 
108     public void business(final Object message, final Throwable t) {
109         logger.logIfEnabled(FQCN, BUSINESS, null, message, t);
110     }
111 
112     public void business(final String message) {
113         logger.logIfEnabled(FQCN, BUSINESS, null, message, (Throwable) null);
114     }
115 
116     public void business(final String message, final Object... params) {
117         logger.logIfEnabled(FQCN, BUSINESS, null, message, params);
118     }
119 
120     public void business(final String message, final Throwable t) {
121         logger.logIfEnabled(FQCN, BUSINESS, null, message, t);
122     }
123 
124     public void business(final Supplier<?> msgSupplier) {
125         logger.logIfEnabled(FQCN, BUSINESS, null, msgSupplier, (Throwable) null);
126     }
127 
128     public void business(final Supplier<?> msgSupplier, final Throwable t) {
129         logger.logIfEnabled(FQCN, BUSINESS, null, msgSupplier, t);
130     }
131 
132     public void business(final Marker marker, final Supplier<?> msgSupplier) {
133         logger.logIfEnabled(FQCN, BUSINESS, marker, msgSupplier, (Throwable) null);
134     }
135 
136     public void business(final Marker marker, final String message, final Supplier<?>... paramSuppliers) {
137         logger.logIfEnabled(FQCN, BUSINESS, marker, message, paramSuppliers);
138     }
139 
140     public void business(final Marker marker, final Supplier<?> msgSupplier, final Throwable t) {
141         logger.logIfEnabled(FQCN, BUSINESS, marker, msgSupplier, t);
142     }
143 
144     public void business(final String message, final Supplier<?>... paramSuppliers) {
145         logger.logIfEnabled(FQCN, BUSINESS, null, message, paramSuppliers);
146     }
147 
148     public void business(final Marker marker, final MessageSupplier msgSupplier) {
149         logger.logIfEnabled(FQCN, BUSINESS, marker, msgSupplier, (Throwable) null);
150     }
151 
152     public void business(final Marker marker, final MessageSupplier msgSupplier, final Throwable t) {
153         logger.logIfEnabled(FQCN, BUSINESS, marker, msgSupplier, t);
154     }
155 
156     public void business(final MessageSupplier msgSupplier) {
157         logger.logIfEnabled(FQCN, BUSINESS, null, msgSupplier, (Throwable) null);
158     }
159 
160     public void business(final MessageSupplier msgSupplier, final Throwable t) {
161         logger.logIfEnabled(FQCN, BUSINESS, null, msgSupplier, t);
162     }
163 }

代码实际上很简单，需要注意的地方是：

 26     private static final Level BUSINESS = Level.forName("BUSINESS", 50);  // 50用于指定级别

注意上面红色的数字，这个数字用于指定级别的高低，可以根据自己的需要定义不同的值，log4j2中默认级别值可以参考如下：

 1     OFF(0),
 2 
 3 
 4     FATAL(100),
 5 
 6 
 7     ERROR(200),
 8 
 9  
10     WARN(300),
11 
12 
13     INFO(400),
14 
15 
16     DEBUG(500),
17 
18 
19     TRACE(600),
20 
21 
22     ALL(Integer.MAX_VALUE);