Thread: How do I write output from one program to several files?

Hello members, I need to be a able to send output from one program to several files based on some conditions, for instance, my program create several jobs with four different attributes, one of these attribute is priority. There are four different priorities a job could have viz: 'VeryHigh', 'High', 'Medium' and 'Low'. After generating say a thousand jobs with several attributes, my program then select (sort) all the jobs with same priority and print them out in groups.
Now, I want the output sent to different files.
Say all jobs with priority 'VeryHigh' shall be sent to FileA, all jobs with priority 'High' shall be sent to FileB, all jobs with priority 'Medium' shall be sent to FileC and all jobs with priority 'Low' shall be sent to FileD.
Can anyone help on this? How do I go about this task?

The part am having problem with is the part that has to do with writing to the various text files: Here is a snippet of the code

for(JobPriority priority:JobPriority.values())
{
System.out.println("Getting all jobs with priority " + priority);
SingleJob[] jobs = despatcher.getJobs(priority);

for(SingleJob job:jobs){
//for ( int i=0; i<jobs.length; i++) {
if (priority == JobPriority.VeryHigh){
String outputFileName = "Desktop/testResultsA.txt";

}

else if ( priority == JobPriority.High){
String outputFileName = "/Desktop/testResultsB.txt";

}


else if (priority == JobPriority.Medium){
String outputFileName = "testResultsC.txt";
}
else{
String outputFileName = "testResultsD.txt";

Am finding it difficult to send outputs to the various files as the system only allows me to specify only one output file at the beginning
Attempts to specify other output files returns the following message: Variable outputFileName is already defined in method.
May split declaration into a declaration and assignment.

Why can't you use outputFileName1/2/3 ... etc?

Ok, I think I ll need to declare each output file with different names as suggested above, thanks

--- Update ---

<for(JobPriority priority:JobPriority.values())
{
System.out.println("Getting all jobs with priority " + priority);
SingleJob[] jobs = despatcher.getJobs(priority);
 
for(SingleJob job:jobs){
//for ( int i=0; i<jobs.length; i++) { 
if (priority == JobPriority.VeryHigh){
String outputFileName = "Desktop/testResultsA.txt";
 
}
 
else if ( priority == JobPriority.High){
String outputFileName = "/Desktop/testResultsB.txt"; 
 
}
 
 
else if (priority == JobPriority.Medium){
String outputFileName = "testResultsC.txt";
}
else{
String outputFileName = "testResultsD.txt";>

I think I ll need to declare each output file with a different name as suggested above. Now, how do I send the output to each file after each condition is met?

We can't see the whole program, but what I would do is call a separate method (or class) to write the file and pass it the file name as a parameter.

This option will be very difficult at my level of programming

--- Update ---

Originally Posted by Starstreak

We can't see the whole program, but what I would do is call a separate method (or class) to write the file and pass it the file name as a parameter.

This option will be quite difficult for my level of java programming

I think you should post all the code. Then we can be clearer about what is expected at your level.

Originally Posted by Starstreak

I think you should post all the code. Then we can be clearer about what is expected at your level.

[code=java]
OK, HERE IS THE FULL CODE

<
public class SeveralJobs {
 
    /**
     * @param args the command line arguments
     */
    {
 
       SingleJob[] someJobs = SingleJob.createManyJobs(0, 1000);
 
        System.out.println("Moving through jobs one by one with a loop:");
 
        for(int i=0; i<someJobs.length; i++) // here, the number of jobs specified are created, the method to generate the jobs are from a different file 
        {
            SingleJob job = someJobs[i];
 
            // do soemthing with job 
            // ...
            System.out.println(job.toString()); // I need the entire jobs generated to be written a a main file say 'Jobfile'
 
        }
 
        System.out.println("Creating a dispatcher"); // here the jobs are selected based on their priorities. 
      // Currently, jobs with same priority are printed in same group on the screen. What I need is for the jobs to be printed to several files.
 
        JobDespatcher despatcher = new JobDespatcher();
        despatcher.despatch(someJobs);
 
       // SingleJob[] higestPriorityJobs = despatcher.getJobs(JobPriority.VeryHigh);
 
        for(JobPriority priority:JobPriority.values())
        {
            System.out.println("Getting all jobs with priority " + priority);
            SingleJob[] jobs = despatcher.getJobs(priority);
 
            for(SingleJob job:jobs){
            //for ( int i=0; i<jobs.length; i++) {    
            if (priority == JobPriority.VeryHigh){
              System.out.println(job.toString()+ "Sending Jobs Immediately"); // I want this set of output to written to FileA instead of screen 
              }
             else if ( priority == JobPriority.High){
              System.out.println(job.toString()+"Sending Jobs a day later"); // I need this set of output written to FileB instead of screen   
             }
            else if (priority == JobPriority.Medium){
              System.out.println(job.toString()+"Sending Jobs a week later");// This set of output should be written to FileC instead of screen
             }
            else{
             System.out.println(job.toString()+"Sending Jobs a month later");This set of output should be written to FileD instead of screen
            }
          }
       }
    }
}
 
 
>

Here is the full code as was requested:

<
 
public class SeveralJobs { // This class uses a method from another class to generate jobs with different sizes and priorities 
 
    /**
     * @param args the command line arguments
     */
    {
 
       SingleJob[] someJobs = SingleJob.createManyJobs(0, 1000); // an array object that generate one thousand jobs here
 
        System.out.println("Moving through jobs one by one with a loop:");
 
        for(int i=0; i<someJobs.length; i++)
        {
            SingleJob job = someJobs[i];
 
            // do soemthing with job 
            // ...
            System.out.println(job.toString()); // HERE THE JOB IS PRINTED TO THE SCREEN BUT I WANT THIS PRINTED TO 'MAINFILE'
 
        }
 
        System.out.println("Creating a dispatcher");
 
        JobDespatcher despatcher = new JobDespatcher(); // HERE JOBS ARE SELECTED FOR GROUP PRINTING BASED ON THEIR PRIORITY
        despatcher.despatch(someJobs);
 
       // SingleJob[] higestPriorityJobs = despatcher.getJobs(JobPriority.VeryHigh);
 
        for(JobPriority priority:JobPriority.values())
        {
            System.out.println("Getting all jobs with priority " + priority);
            SingleJob[] jobs = despatcher.getJobs(priority);
 
            for(SingleJob job:jobs){
            //for ( int i=0; i<jobs.length; i++) {    
            if (priority == JobPriority.VeryHigh){
              System.out.println(job.toString()+ "Sending Jobs Immediately");// JOBS WITH THIS PRIORITY ARE PRINTED TO SCREEN 
              // BUT I WANT THIS OUTPUT SENT TO 'FILEA'
              }
             else if ( priority == JobPriority.High){
              System.out.println(job.toString()+"Sending Jobs a day later");  // THIS OUTPUT IS PRINTED TO SCREEN BUT I WANT IT PRINTED TO FILEB  
             }
            else if (priority == JobPriority.Medium){
              System.out.println(job.toString()+"Sending Jobs a week later");
             }
            else{
             System.out.println(job.toString()+"Sending Jobs a month later");
            }
          }
       }
    }
}
 
 
>

Here is the full code:

<
 
public class SeveralJobs { // This class uses a method from another class to generate jobs with different sizes and priorities 
 
    /**
     * @param args the command line arguments
     */
    {
 
       SingleJob[] someJobs = SingleJob.createManyJobs(0, 1000); // an array object that generate one thousand jobs here
 
        System.out.println("Moving through jobs one by one with a loop:");
 
        for(int i=0; i<someJobs.length; i++)
        {
            SingleJob job = someJobs[i];
 
            // do soemthing with job 
            // ...
            System.out.println(job.toString()); // HERE THE JOB IS PRINTED TO THE SCREEN BUT I WANT THIS PRINTED TO 'MAINFILE'
 
        }
 
        System.out.println("Creating a dispatcher");
 
        JobDespatcher despatcher = new JobDespatcher(); // HERE JOBS ARE SELECTED FOR GROUP PRINTING BASED ON THEIR PRIORITY
        despatcher.despatch(someJobs);
 
       // SingleJob[] higestPriorityJobs = despatcher.getJobs(JobPriority.VeryHigh);
 
        for(JobPriority priority:JobPriority.values())
        {
            System.out.println("Getting all jobs with priority " + priority);
            SingleJob[] jobs = despatcher.getJobs(priority);
 
            for(SingleJob job:jobs){
            //for ( int i=0; i<jobs.length; i++) {    
            if (priority == JobPriority.VeryHigh){
              System.out.println(job.toString()+ "Sending Jobs Immediately");// THIS SET OF JOBS ARE PRINTED TO SCREEN 
              // BUT I WANT THIS OUTPUT SENT TO 'FILEA'
              }
             else if ( priority == JobPriority.High){
              System.out.println(job.toString()+"Sending Jobs a day later");  // THIS SET OF OUTPUT IS PRINTED TO SCREEN 
              // BUT I WANT IT PRINTED TO 'FILEB'  
             }
            else if (priority == JobPriority.Medium){
              System.out.println(job.toString()+"Sending Jobs a week later"); // THIS SET OF OUTPUT IS ALSO PRINTED ON SCREEN 
             //BUT I NEED THEM PRINTED TO 'FILEC'
             }
            else{
             System.out.println(job.toString()+"Sending Jobs a month later"); // AND I NEED THIS SET OF OUTPUT PRINTED TO 'FILED'
            }
          }
       }
    }
}
 
 
>

Starstreak, I ve posted the entire code twice but I can't find it, maybe the admins have not authorized it

Yes Norm, that is exactly what I want to do

--- Update ---

Originally Posted by Norm

Your posts have been made visible now.

Is this what you are trying to do:
Open some output files to write items to
loop through a list of items
write item to one of the files based on its content
end loop
close files

Yes Norm, That is exactly what am trying to do

The code was supposed to select the generated jobs from the first file and write them all to the other files based on their priority, for instance all jobs with priority high were supposed to be written to one output file and so for all other jobs. For now, only one job each from each category is been written to the specified output file

Originally Posted by Norm

Did you notice after posting the above that the code was not formatted?


Is that what you wanted to happen?
If not, please explain what you want the code to do that it did not do.

Did you look at the steps I posted in post #15?
Did you try to write the code to follow those steps?


You need to format the code so that the }s are properly positioned

        }
 
        }
        }
        }
        }

The }s should NOT be all in a column. The nested statements within each pair of {}s should be indented 3-4 spaces so the logic of the code can be read and understood. The code that was posted is very hard to read and understand.

Please fix the formatting of the {}s.

Ok, here is the formatted code:

<
import java.io.FileNotFoundException;
import utilities.FileOutput;
 
public class SendToOutputFile 
{ 
 
 
 
   /**
     * @param args the command line arguments
     */
      public static void main(String[] args) throws FileNotFoundException  
     {
 
        SingleJob[] someJobs = SingleJob.createManyJobs(0, 30);
 
        System.out.println("Moving through jobs one by one with a loop:");
        FileOutput file = new FileOutput("C:/Users/Desktop/TextDoc2.txt", null);
        for(int i=0; i<someJobs.length; i++)
        {
           SingleJob job = someJobs[i];
           String jobAsString = job.toString(); 
           try
              {
               file.open();
               file.println(jobAsString, true);
 
               }
               catch(Exception e)
               {
                 e.printStackTrace(System.err);
               }
               finally
               {
               file.close();
               }
 
 
        }     
           System.out.println("Creating a dispatcher");
 
           JobDespatcher despatcher = new JobDespatcher();
           despatcher.despatch(someJobs);
 
        for(JobPriority priority:JobPriority.values())
        {
            System.out.println("Getting all jobs with priority " + priority);
            SingleJob[] jobs = despatcher.getJobs(priority);
 
           for(SingleJob job:jobs)
             {
               String jobAsString = job.toString();
 
               if (priority == JobPriority.VeryHigh)
                 {
                    FileOutput fileA = new FileOutput("C:/Users/Desktop/TextDocA.txt", null);
 
                  try
                     {
                        fileA.open();
                        fileA.println(jobAsString, true);
 
                      }
                         catch(Exception e)
                          {
                             e.printStackTrace(System.err);
                          }
                          finally
                       {
                        fileA.close();
                       }
 
                }
                   else if ( priority == JobPriority.High){
                   FileOutput fileB = new FileOutput("C:/Users/Desktop/TextDocB.txt", null);
 
                      try
                         {
                            fileB.open();
                            fileB.println(jobAsString, true);
 
                          }
                          catch(Exception e)
                              {
                                 e.printStackTrace(System.err);
                               }
                             finally
                             {
                                fileB.close();
                             }
                         }
                  else if (priority == JobPriority.Medium)
                  {
                     FileOutput fileC = new FileOutput("C:/Users/Desktop/TextDocC.txt", null);
 
                     try
                       {
                           fileC.open();
                           fileC.println(jobAsString, true);
 
                        }
                        catch(Exception e)
                            {
                               e.printStackTrace(System.err);
                             }
                      finally
                         {
                           fileC.close();
                          }
                     }
 
               else
                  {
                     FileOutput fileD = new FileOutput("C:/Users/Desktop/TextDocD.txt", null);
 
                   try
                      {
                         fileD.open();
                         fileD.println(jobAsString, true);
 
                       }
                       catch(Exception e)
                         {
                             e.printStackTrace(System.err);
                         }
                         finally
                       {
                          fileD.close();
                       }
 
                    }
              }
         }
    }
}
>

Originally Posted by Norm

That makes it easier to read and understand.

Now you need to move the open and close of the file outside the loop.
Every time you open a file, write to it and close it, the file's previous contents is replaced with the new contents.

Ok, thanks, I ll try that out and give feedback

Originally Posted by atgoodprogram

Ok, thanks, I ll try that out and give feedback

I ve tried it and Its not working, its bringing a nullpointer error, or nothing is being written to all the outputfiles, even the first file (TextDoc2) where all the jobs are first generated into has but only one job in it then that one job alone is sent to its category of output file.
Here is the code :

<
 
import java.io.FileNotFoundException;
import utilities.FileOutput;
 
public class SendToOutputFile 
{ 
 
 
 
   /**
     * @param args the command line arguments
     */
      public static void main(String[] args) throws FileNotFoundException  
     {
        FileOutput file = new FileOutput("C:/Users/Desktop/TextDoc2.txt", null);
 
        SingleJob[] someJobs = SingleJob.createManyJobs(0, 30);
 
        System.out.println("Moving through jobs one by one with a loop:");
 
        for(int i=0; i<someJobs.length; i++)
        {
           SingleJob job = someJobs[i];
           String jobAsString = job.toString(); 
           try
              {
               file.open();
               file.println(jobAsString, true);
 
               }
               catch(Exception e)
               {
                 e.printStackTrace(System.err);
               }
 
 
 
        }     
           System.out.println("Creating a dispatcher");
 
           JobDespatcher despatcher = new JobDespatcher();
           despatcher.despatch(someJobs);
 
        for(JobPriority priority:JobPriority.values())
 
        {
 
           FileOutput fileA = new FileOutput("C:/Users/Desktop/TextDocA.txt", null);
           FileOutput fileB = new FileOutput("C:/Users/Desktop/TextDocB.txt", null); 
           FileOutput fileC = new FileOutput("C:/Users/Desktop/TextDocC.txt", null);
           FileOutput fileD = new FileOutput("C:/Users/Desktop/TextDocD.txt", null); 
            System.out.println("Getting all jobs with priority " + priority);
            SingleJob[] jobs = despatcher.getJobs(priority);
            fileA.open();
            fileB.open();
            fileC.open();
            fileD.open();
           for(SingleJob job:jobs)
 
             {
               String jobAsString = job.toString();
 
               if (priority == JobPriority.VeryHigh)
                 {
 
                  try
                     {
 
                        fileA.println(jobAsString, true);
 
                      }
                  catch(Exception e)
                   {
                      e.printStackTrace(System.err);
                   }
 
 
                 }
               else if ( priority == JobPriority.High){
 
                  try
                      {
                         fileB.println(jobAsString, true);
                       }
                  catch(Exception e)
                      {
                         e.printStackTrace(System.err);
                      }
 
               }
              else if (priority == JobPriority.Medium)
                 {
 
                    try
                       {
                           fileC.println(jobAsString, true);
                       }
                   catch(Exception e)
                      {
                         e.printStackTrace(System.err);
                       }
 
               }
 
               else
                  {
 
                   try
                      {
                         fileD.println(jobAsString, true);
 
                       }
                     catch(Exception e)
                         {
                             e.printStackTrace(System.err);
                         }
 
 
 
 
             finally
                  {
 
 
                    fileA.close();
                    fileB.close();
                    fileC.close();
                    fileD.close();
                  }
               }
           }
        }
     }
}
 
 
 
 
>