扩展Log4j支持JNDI数据源

log4j.properties配置文件：

log4j.rootLogger=INFO,db

#使用log4j扩展支持JNDI数据源
log4j.appender.db=com.qdgswx.log4j.ds.JndiDSAppender
log4j.appender.db.jndiName=wstjndi
log4j.appender.db.BufferSize=1
log4j.appender.db.sql=insert into wx_log (openid,nsrsbh,logtype,classname,methodname,oprtime,loglevel,content) values ('%X{openid}','%X{nsrsbh}','%X{logtype}','%C','%M','%d{yyyy-MM-dd HH:mm:ss}','%p','%m')  
log4j.appender.db.layout=org.apache.log4j.PatternLayout

扩展类JndiDSAppender.java

public class JndiDSAppender extends JDBCAppender {

    protected DataSource ds = null;
    protected String jndiName;

    public void setJndiName(String jndiName) {
        this.jndiName = jndiName;
    }
    
    protected synchronized void init() {
        if (ds != null) {
            return;
        }
        try {
            InitialContext context = new InitialContext();
            ds = (DataSource) context.lookup(jndiName);
        } catch (NamingException e) {
            this.errorHandler.error(e.getMessage());
        }
    }
    
     @Override  
    protected Connection getConnection() throws SQLException {  
        while(ds==null){
            init();
        }
        
        Connection conn = ds.getConnection();
        conn.setAutoCommit(true);
        
        return conn;
    }
    
    @Override  
    protected void closeConnection(Connection conn) {  
        try {  
            if(conn!=null&&!conn.isClosed()) {
                conn.close();  
            } 
        } catch (SQLException e) {  
            this.errorHandler.error(e.getMessage());  
        }  
    }  
}