java程序中輸出console的日志到文本

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

 

 

 

 

 

首先：當我們引入data-integration\lib文件夾下的所有jar包后 運行java程序要求我們必須引入log4j，由此我們可以確認控制台輸出的信息為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"});//傳參數
            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();
        }  

 }

 解決步驟：

1、首先想到查看輸出這些日志的來源：Job類

2、通過反編譯軟件 或者 查看源文件 查看代碼 找到：this.log = new LogChannel(this);

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

可以看出是單例

4、查看LogWiter的構造方法：

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 原來 他們是判斷有沒有控制台輸出的，如果沒有就加入一個控制台輸出的，

log的識別符為：Logger.getLogger("org.pentaho.di");

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

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

由此，我們可以再我們程序中加入一行代碼： 手動的去加入一個FileAppender

在try中第一行加入：

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

 

這樣我們就可以把console端打印出來的log 直接輸入到一個log文件中去了