java程序中输出console的日志到文本

http://blog.sina.com.cn/s/blog_76a8411a01010u2h.html

首先：当我们引入data-integration\lib文件夹下的所有jar包后 运行java程序要求我们必须引入log4j，由此我们可以确认控制台输出的信息为log4j做的：

程序如下：

public static void main(String[] args) throws Exception{
  KettleEnvironment.init();
  try {

JobMeta
jobMeta = new JobMeta("E:\\BI\\sample.kjb", null,null);
   Job job = new
Job(null, jobMeta);
   jobMeta.setArguments(new
String[]{"aaaaa","bbbbbb"});//传参数
           
job.getJobMeta().setInternalKettleVariables(job);

job.setLogLevel(LogLevel.BASIC);
           
// Start the Job, as it is a Thread itself by Kettle.
           
job.start();
           
job.waitUntilFinished();

if (job.getResult() != null &&
job.getResult().getNrErrors() != 0) {
           
 //Do something here.
           
}
           
// Now the job task is finished, mark it as finished.
           
job.setFinished(true);

// Cleanup the parameters used by the job. Post that invoke
GC.
           
jobMeta.eraseParameters();
           
job.eraseParameters();
       
} catch (Exception e) {
            
e.printStackTrace();
       
}

}

 解决步骤：

1、首先想到查看输出这些日志的来源：Job类

2、通过反编译软件 或者 查看源文件 查看代码
找到：this.log = new LogChannel(this);

3、进入LogChannel找到：  private static
LogWriter log = LogWriter.getInstance();

可以看出是单例

4、查看LogWiter的构造方法：

private LogWriter()
  {
   
this.pentahoLogger = Logger.getLogger("org.pentaho.di");
   
this.pentahoLogger.setAdditivity(false);

   
this.pentahoLogger.setLevel(Level.ALL);

   
layout = new Log4jKettleLayout();

   
boolean consoleAppenderFound = false;
    Enumeration
appenders = this.pentahoLogger.getAllAppenders();
    while
(appenders.hasMoreElements()) {
     
Appender appender = (Appender)appenders.nextElement();
     
if ((appender instanceof ConsoleAppender)) {
       
consoleAppenderFound = true;
       
break;
     
}

   
}

    if
(!consoleAppenderFound) {
     
Layout patternLayout = new PatternLayout("%-5p %d{dd-MM
HH:mm:ss,SSS} - %m%n");
     
ConsoleAppender consoleAppender = new
ConsoleAppender(patternLayout);
     
consoleAppender.setName("ConsoleAppender:org.pentaho.di");
     
this.pentahoLogger.addAppender(consoleAppender);
   
}

   
LogManager.getLogger("org.apache.commons.vfs").setLevel(Level.WARN);

}
5、看出 原来 他们是判断有没有控制台输出的，如果没有就加入一个控制台输出的，

log的识别符为：Logger.getLogger("org.pentaho.di");

6、==============================================================

=================================================================

由此，我们可以再我们程序中加入一行代码：
手动的去加入一个FileAppender

在try中第一行加入：

Logger.getLogger("org.pentaho.di").addAppender(new
FileAppender(new SimpleLayout(),
"E:\\logger.log"));

这样我们就可以把console端打印出来的log
直接输入到一个log文件中去了