如果您使用的是mysql。创建一个文件log4j.properties。这对我有用。将其放在应用程序的根文件夹中。即所有软件包的根。我也有一个表日志，其中包含字段id，date，user，message和class。
log4j.rootLogger=DEBUG,DBlog4j.appender.DB=org.apache.log4j.jdbc.JDBCAppenderlog4j.appender.DB.URL=jdbc:mysql://localhost:3306/testlog4j.appender.DB.user=rootlog4j.appender.DB.password=rootlog4j.appender.DB.sql=INSERT INTO logs(date, user, message,class) VALUES ('%d{yyyy-MM-dd HH:mm:ss}', '%X{User}','%m','%c')log4j.appender.DB.layout=org.apache.log4j.PatternLayoutlog4j.appender.CA.layout.ConversionPattern=INSERT INTO logs (date, user,message,class) VALUES ('%d{yyyy-MM-dd HH:mm:ss}', '%X{User}','%m','%c')log4j.category.ke.co=ERRORlog4j.category.ke.co.appender-ref=DB然后按如下方式使用它。
package com.zeddarn;import java.sql.Connection;import java.sql.DriverManager;import java.sql.SQLException;import org.apache.log4j.Logger;import org.apache.log4j.MDC;public class MySQLDatabaseConnector {static ThreadLocal<Connection> connection = new ThreadLocal<Connection>();private static Logger logger = Logger.getLogger(MySQLDatabaseConnector.class);public static Connection getDBConnection() { //check if a mysql connection already exits. This is to avoid reconnecting if (connection.get() == null) { try { //loading the mysql driver. This means you also have to add mysql libary. You can add manually or via maven Class.forName("com.mysql.jdbc.Driver"); } catch (ClassNotFoundException e) { //do something to deal with the error of missing mysql driver e.g notification to the user. MDC.put("User", "loggeduser"); logger.error(e.getMessage()); MDC.getContext().clear(); } try { connection.set(DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "root")); } catch (SQLException e) { MDC.put("User", "loggeduser"); logger.error(e.getMessage()); MDC.getContext().clear(); } } return connection.get();}public static void main(String args[]) { MDC.put("User", "loggeduser"); logger.error("message from exception.getMessage() method"); MDC.getContext().clear();}}
