Log4j记录日志到数据库

1.自定义输出消息

/**
 * 参数化消息
 * @author Johnson.Lee
 *
 */
public interface ParameterizedMessage extends Serializable {

    /**
     * 获取参数列表
     * @return 返回参数列表
     */
    public Object[] getParameters();
    
    /**
     * 获取指定索引位置的参数
     * @param index 索引位置
     * @return 返回参数列表中指定索引位置的参数值
     * @throws IndexOutOfBoundsException 当index >= 参数列表个数时，抛出此异常
     * @see #getParameterCount()
     */
    public Object getParameter(int index) throws IndexOutOfBoundsException;
    
    /**
     * 获取参数个数
     * @return 返回参数个数
     */
    public int getParameterCount();
    
}

/**
 * JDBC日志消息
 * @author Johnson.Lee
 *
 */
public class JDBCLogMessage implements ParameterizedMessage {
    private static final long serialVersionUID = 1709063421963292637L;
    private Object[] params;
    
    public JDBCLogMessage(Object... params) {
        this.params = params;
    }

    public Object[] getParameters() {
        return this.params;
    }

    public Object getParameter(int index) throws IndexOutOfBoundsException {
        return this.params[index];
    }

    public int getParameterCount() {
        return this.params.length;
    }

    @Override
    public String toString() {
        return Arrays.toString(this.params);
    }
}

2.继承Log4j的AppenderSkeleton

/**
 * 使用纯JDBC连接将日志记录到数据库中
 * @author Johnson.Lee
 *
 */
public class JDBCAppender extends AppenderSkeleton {
    private String driver;
    private String url;
    private String userName;
    private String password;
    private String sql;

    @Override
    protected void append(LoggingEvent e) {
        Connection conn = null;
        PreparedStatement pstmt = null;
        try {
            Class.forName(this.driver);
            conn = DriverManager.getConnection(this.url, this.userName, this.password);
            if (e.getMessage() instanceof ParameterizedMessage) {
                try {
                    pstmt = conn.prepareStatement(sql);
                    Object[] params = ((ParameterizedMessage) e.getMessage()).getParameters();
                    for (int i = 0; i < params.length; i++) {
                        pstmt.setObject(i + 1, params[i]);
                    }
                    pstmt.executeUpdate();
                } catch (SQLException ex) {
                    this.errorHandler.error("log into database failed!", ex, 0);
                } finally {
                    AbstractJDBCDao.close(pstmt);
                    AbstractJDBCDao.close(conn);
                }
            }
        } catch (ClassNotFoundException ex) {
            this.errorHandler.error("load jdbc driver [" + this.driver + "] failed!", ex, 0);
        } catch (SQLException ex) {
            this.errorHandler.error("establish connect failed!", ex, 0);
        }
    }
    
    @Override
    public void close() {
    }

    @Override
    public boolean requiresLayout() {
        return false;
    }

    /**
     * 设置JDBC驱动
     * @param driver JDBC驱动类名
     */
    public void setDriver(String driver) {
        this.driver = driver;
    }

    /**
     * 设置连接字符串
     * @param url 数据库连接字符串
     */
    public void setUrl(String url) {
        this.url = url;
    }

    /**
     * 设置数据库用户名
     * @param userName 用户名
     */
    public void setUserName(String userName) {
        this.userName = userName;
    }

    /**
     * 设置数据库密码
     * @param password 密码
     */
    public void setPassword(String password) {
        this.password = password;
    }

    /**
     * 设置插入日志的SQL语句
     * @param sql
     */
    public void setSql(String sql) {
        this.sql = sql;
    }
    
}

3.配置log4j.properties

log4j.rootLogger=INFO, stdout, jdbc

#std appender
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d %p [%c] - %m%n

#file appender
#log4j.appender.file=org.apache.log4j.DailyRollingFileAppender
#log4j.appender.file.File=${application.context}
#log4j.appender.file.DatePattern='_'yyyyMMdd'.log'
#log4j.appender.file.layout=org.apache.log4j.PatternLayout
#log4j.appender.file.layout.ConversionPattern=%d %p [%c] - %m%n

#jdbc appender
log4j.appender.jdbc=net.kinginfo.framework.log.JDBCAppender
log4j.appender.jdbc.driver=com.microsoft.jdbc.sqlserver.SQLServerDriver
log4j.appender.jdbc.url=jdbc:microsoft:sqlserver://192.172.10.106:1433;databaseName=tempdb
log4j.appender.jdbc.userName=sa
log4j.appender.jdbc.password=sa
log4j.appender.jdbc.sql=insert into LogInfo(time, type, info) values(getDate(),?,?)

4.创建日志表

use tempdb;

create table LogInfo (
    id int identity(1,1) primary key not null,
    time datetime,
    type int,
    info varchar(255)
);

select * from LogInfo;

5.编写测试类

public class TestJDBCAppender {
    
    public static void main(String[] args) {
        Logger logger = Logger.getRootLogger();
        ParameterizedMessage msg = new JDBCLogMessage(1, "日志测试");
        logger.info(msg);
    }
}