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launching a java application in background

DISCUSSION Miguel González Castaños 2 participants 2 messages Feb 2, 2005 – Feb 3, 2005

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#0 lore raw

Dear all,

I need to launch a java proccess as a daemon, in background.

It would be like the following:

java bin/aplicacion.jar

In interactive mode works fine. We have tried to launch it in background using nohup.

If I send everything (all redirections <> ) to /dev/null it works, but I do not get the logs

We have tried:

java bin/aplication.jar < /dev/null > output.log 2>&1 &

But I get in the output file carachters like "->"

Any time of getting those logs?

I hope I have explained myself fine

Regards

Miguel

#1 lore raw
Quoted 21 lines · El Miércoles, 2 de Febrero de 2005 16:24, escribió:

Dear all,

I need to launch a java proccess as a daemon, in background.

It would be like the following:

java bin/aplicacion.jar

In interactive mode works fine. We have tried to launch it in background using nohup.

If I send everything (all redirections <> ) to /dev/null it works, but I do not get the logs

We have tried:

java bin/aplication.jar < /dev/null > output.log 2>&1 &

But I get in the output file carachters like "->"

Quoted 7 lines

Any time of getting those logs?

I hope I have explained myself fine

Regards

Miguel

To deal with this I change on my Java applications, the System.out.* By calls to other kind of OUT, then you can make a simple pointer by default from System.out, System.err, or substitute this by file output, then you can pass an extra argumento to your software to log by default on a file, and use the same object (could be static code).
Java have a mechanism to put a thread on a background, in daemon mode, you should find more about. Here is an example how I use an objet to have properties, like out, and err, you can establish a socket, or open a file for writing and you can set the new output calling setOut or setErr.

------------------
package com.compunauta.util;

/**
* Title: RUNTimeManager
* Description: OUT, ERR, PROPERTIES, handler for threads.
* for html parser.
* Copyright: Copyright (c) 2001
* Company: www.compunauta.com
* @author Gustavo Guillermo Pérez
* @version 1.0
*/
import java.io.PrintStream;
import java.io.BufferedReader;
import java.util.Properties;
import java.util.Hashtable;
public class RunTimeManager {
public int EXIT_CODE=0;
public boolean BIGFAILURE=false;
public boolean DEBUG=false;
public boolean CHILDREN_MODE=false;
public boolean STOP=false;
public PrintStream out=System.out;
public PrintStream err=System.err;
public static String WORK_DIR="./";
public Properties p=(Properties)null;
public static Properties sp=new Properties(); public static Hashtable h=new Hashtable(10); public BufferedReader in=new BufferedReader(new java.io.InputStreamReader(System.in));
public RunTimeManager(){}
public RunTimeManager(boolean debug){this.DEBUG=debug;} public RunTimeManager(boolean debug,boolean standalone)
{this.DEBUG=debug;this.CHILDREN_MODE=!standalone;}

  public void setChildren(boolean value){CHILDREN_MODE=value;}
  public void setStandAlone(boolean value){CHILDREN_MODE=!value;}
  public void setChildren(){CHILDREN_MODE=true;}
  public void setStandAlone(){CHILDREN_MODE=false;}
  public boolean VERVOSE=true;
  public boolean exit(int EXIT_CODE){
  this.EXIT_CODE=EXIT_CODE;
  this.STOP=true;
    if (EXIT_CODE!=0){BIGFAILURE=true;}
    if (CHILDREN_MODE) return true;
    else System.exit(EXIT_CODE);
    return false;
  }//end exit

  public void reset(){
    this.BIGFAILURE=false;
    this.EXIT_CODE=0;
    this.STOP=false;
  }//end reset

  public void setOut(PrintStream out){
    this.out=out;
  }//end out

  public void setErr(PrintStream err){
    this.err=err;
  }//end err

  public void setIn(BufferedReader in){
    this.in=in;
  }//end err
  public void setPropertiesFromHash(String Key){
    Object ob=h.get(Key);
    Properties p;
    if (ob==null) {p=new Properties();h.put(Key,p);}
    else {p=(Properties)ob;}
  }//end setpropfromhash
  public void setDebugOn(){this.DEBUG=true;}
  public void setDebugOff(){this.DEBUG=false;}

public void setProperty(String Key, String Value){
if (this.p==null){sp.setProperty(Key,Value); return;} this.p.setProperty(Key,Value);
}//end setproperty

public String getProperty(String Key, String Default){
if (this.p==null){return sp.getProperty(Key,Default);}

  else {String ob=p.getProperty(Key,Default);
    if (ob==null){
      return sp.getProperty(Key,Default);
    }else return ob;

}

}//end getProperty

public String getProperty(String Key){
return getProperty(Key,null);
}//end getProp
public static String getEnvironOs(){
//REQManipulation env=new REQManipulation(System.getProperty("os.name"));
String env=System.getProperty("os.name");
// System.out.println(System.getProperties());
if (env.toLowerCase().indexOf("linux")!=-1) return "l";
if (env.toLowerCase().indexOf("windows")!=-1) return "w";
if (env.toLowerCase().indexOf("sol")!=-1) return "s";
return "w";
}//end getEnvironOs

}//end class

Signature · 7 lines
Gustavo Guillermo Pérez
Compunauta uLinux
www.ulinux.tk
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