compare two ArrayLists

[shana07]

Friends, I need some inputs about my java program. My program is supposed to store 3 information into an ArrayList so-called arrayOne at each runtime:
1. Unique ID
2. Boolean Value
3. data.

Let's assume I give first input a = 5, compile & run: Result - arrayOne.
Second Input a = 24, compile & run: Result - arrayOne.
Aim: To compare these two result arrays after runtime.

How to extract the results & compare these 2 result arrays after runtime that can automatically check the data & boolean value?

please advise and I'll post my program then...

[r035198x]

Friends, I need some inputs about my java program. My program is supposed to store 3 information into an ArrayList so-called arrayOne at each runtime:
1. Unique ID
2. Boolean Value
3. data.

Let's assume I give first input a = 5, compile & run: Result - arrayOne.
Second Input a = 24, compile & run: Result - arrayOne.
Aim: To compare these two result arrays after runtime.

How to extract the results & compare these 2 result arrays after runtime that can automatically check the data & boolean value?

please advise and I'll post my program then...

If you want the results after the program has exited then you need to write the results to a file or database.

[shana07]

If you want the results after the program has exited then you need to write the results to a file or database.

Please give me some pointer on how to write result into a file ..
and compare them ...at least any web page for my reading..thanks a lot

[r035198x]

Please give me some pointer on how to write result into a file ..
and compare them ...at least any web page for my reading..thanks a lot

Last week's tip of the week talked about writing to a textfile. In this case however you should write the Arraylist to the file as an object using serialization.

[shana07]

Last week's tip of the week talked about writing to a textfile. In this case however you should write the Arraylist to the file as an object using serialization.

Yes, I've gone through it and I do remember last time you taught me how to transfer/export result into a file using FileOutputStrea m.
Now I managed to get it done. Next, how am I supposed to do to compare the second result(new input) after second program has exited?
hope you can guide me please...

o ya I print result in a txt file...or maybe I need to print in other format in order for me to compare them automatically? idea please...thank you

[r035198x]

Yes, I've gone through it and I do remember last time you taught me how to transfer/export result into a file using FileOutputStrea m.
Now I managed to get it done. Next, how am I supposed to do to compare the second result(new input) after second program has exited?
hope you can guide me please...

o ya I print result in a txt file...or maybe I need to print in other format in order for me to compare them automatically? idea please...thank you

If you wrote the ArrayList to the file as an object like you should have then you can retrieve it using the readObject method of ObjectInputStre am and type cast it to the ArrayList.

[shana07]

If you wrote the ArrayList to the file as an object like you should have then you can retrieve it using the readObject method of ObjectInputStre am and type cast it to the ArrayList.

From my understanding, what you mean is while the second program is still running retrieve the first output from text file using the readObject() from ObjectInputStre am class and automatically compare them?

please correct me if I'm wrong...

[r035198x]

From my understanding, what you mean is while the second program is still running retrieve the first output from text file using the readObject() from ObjectInputStre am class and automatically compare them?

please correct me if I'm wrong...

I'm not too sure about the "automatica lly" part but that's the jists of it.

[shana07]

I'm not too sure about the "automatica lly" part but that's the jists of it.

Alright, thanks for your valuable idea. Please guide me how to retrieve the first executed program result...Do I need to call readObject() from the ArrayList place or create another new method - ObjectInputStre am or from here:

public static void print(String s) 
  {      
      try
        {
            FileOutputStream fout;	
	    fout = new FileOutputStream ("output.txt",true);    
            new PrintStream(fout).println (s);   
	    fout.close();
        }

      catch (IOException ex) 
      {
	      System.out.println("There was a problem creating/writing to the temp file");
	      ex.printStackTrace();
      }   
  }

[r035198x]

Alright, thanks for your valuable idea. Please guide me how to retrieve the first executed program result...Do I need to call readObject() from the ArrayList place or create another new method - ObjectInputStre am or from here:

public static void print(String s) 
{ 
try
{
FileOutputStream fout;	
	 fout = new FileOutputStream ("output.txt",true); 
new PrintStream(fout).println (s); 
	 fout.close();
}
 
catch (IOException ex) 
{
	 System.out.println("There was a problem creating/writing to the temp file");
	 ex.printStackTrace();
} 
}

What is that code suppposed to be doing?

You should write the ArrayList to the file using an ObjectOutputstr eam first in the first program, then you can retrieve it from the file in the second program

[shana07]

What is that code suppposed to be doing?

You should write the ArrayList to the file using an ObjectOutputstr eam first in the first program, then you can retrieve it from the file in the second program

In general the final result of my program is to collect/store 3 types of data:
1. Unique ID
2. Boolean Value
3. data.
I use ArrayList to store those information

List listOne = new ArrayList();
....
//looping for collect required data
....
listOne.add(new Entry(ID, data, value));  
                    print("ID: " +uniqueID);
                    print("Data: " +data);
                    print("value: " +value);

Now you mean I have to change the ArrayList to the file using an ObjectOutputstr eam? But how..please gimme some pointer...

[r035198x]

In general the final result of my program is to collect/store 3 types of data:
1. Unique ID
2. Boolean Value
3. data.
I use ArrayList to store those information

List listOne = new ArrayList();
....
//looping for collect required data
....
listOne.add(new Entry(ID, data, value)); 
print("ID: " +uniqueID);
print("Data: " +data);
print("value: " +value);

Now you mean I have to change the ArrayList to the file using an ObjectOutputstr eam? But how..please gimme some pointer...

You write the whole arraylist as one object to a file and then retrieve it later. You write it to a file using ObjectOutputStr eam. Look at the docs for this class and see how can use it to store the whole arraylist into a file.

[shana07]

You write the whole arraylist as one object to a file and then retrieve it later. You write it to a file using ObjectOutputStr eam. Look at the docs for this class and see how can use it to store the whole arraylist into a file.

Firstly, I've tried to write ArrayList as one object to a file, is that something like this? please check as I compile everything okay..but problem during runtime.

try
        {
            //  Create a stream for writing.
            FileOutputStream fout  = new FileOutputStream ("output.txt",true);  
            //  Next, create an object that can write to that file.
            ObjectOutputStream oOutStream = new ObjectOutputStream( fout );
            
            //  Save each object.
            oOutStream.writeObject(listOne);            
            
            oOutStream.flush();            
            new PrintStream(fout).println (s);   
            fout.close();         
        
        }

[r035198x]

Firstly, I've tried to write ArrayList as one object to a file, is that something like this? please check as I compile everything okay..but problem during runtime.

try
{
// Create a stream for writing.
FileOutputStream fout = new FileOutputStream ("output.txt",true); 
// Next, create an object that can write to that file.
ObjectOutputStream oOutStream = new ObjectOutputStream( fout );
 
// Save each object.
oOutStream.writeObject(listOne); 
 
oOutStream.flush(); 
new PrintStream(fout).println (s); 
fout.close(); 
 
}

Should be fine. I'm not sure what the line

new PrintStream(fout).println (s);

is doing there though

[shana07]

Should be fine. I'm not sure what the line

new PrintStream(fout).println (s);

is doing there though

Still the same if I comment the line ..it's okay. i'll figure it out...
How about to retrieve back the data...? Let say after I finish this phase which is in the first program run - write result into a file namely A.
Second time I run program with different input produce new result, I do comparison directly in here by retrieve file A? Do I have to write to a new file namely B first or how, any idea...? thank you