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Thread: Generating array (or arraylist) matrix from txt file

  1. #1
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    Default Generating array (or arraylist) matrix from txt file

    Hey guys, im trying to generate matrix to store info from a txt file. My code reads every line from the file, counts the number of lines,
    creates an array of that size. Then stores every line into a string array slot and splits each line by space character and creates another array of of it.
    then by doing two "for" cycles i insert the information into my matrix. Im not sure if it works or how to test it. i could use some help fixing the code
    and/or doing the same but with arraylists (i have no clue how to use them). I have to store information into a matrix the size of lines and then fill each column
    with the number of elements i find in my file when spliting a line. If someone can think of an alternative way of procesing my files id Thanks!

    PS: my nodos.txt file stores info as follows. Ex:

    4
    1 1
    3 2
    4 -3
    EOF




     
    public String[][] LectorNodos( ) throws IOException{
     
    			int LargoArchivo=0;
    			String [] infoNodos;
    			File HojaNodos=new File("nodos.txt");
    			String [][] matrizInfoNodos;
     
    			String [] aux;
     
     
    			if(HojaNodos.exists()){
     
    				Scanner lector = new Scanner(HojaNodos);
     
    				while(lector.hasNext()){
    					lector.nextLine();
    					LargoArchivo++;	
    				}
    				lector.close();
     
    				lector= new Scanner(HojaNodos);
    				infoNodos = new String [LargoArchivo];
     
     
    				for(int i=0;i<infoNodos.length;i++){
     
    					infoNodos[i]=lector.nextLine();
    				}
     
    				lector.close();
     
    				matrizInfoNodos=new String [LargoArchivo][3];
     
    				for(int k=0;k<infoNodos.length;k++){
     
    				aux=infoNodos[k].split("\\s+");
     
    					for(int j=0; j<aux.length;j++){
     
    						matrizInfoNodos[k][j]=aux[j];					
     
    					}
     
    				}
     
    				for(int i=0;i<matrizInfoNodos.length;i++){
     
    					for(int j=0;j<matrizInfoNodos[0].length;j++){
     
    						Usuario.mensaje(matrizInfoNodos[i][j]);
     
    					}
    				}
     
     
     
    				return matrizInfoNodos;
    			}
     
     
    			return null;
     
    		}
    Last edited by benjalizana; November 13th, 2011 at 01:44 PM.


  2. #2
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    Default Re: Generating array (or arraylist) matrix from txt file

    Hi benjalizana,
    here I post you my solution that has been tested ONLY with your file.
    You have to stress test it.

    ...edited by moderator

    Do you like this solution?
    Bye
    Last edited by copeg; November 14th, 2011 at 07:09 PM.

  3. #3
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    Default Re: Generating array (or arraylist) matrix from txt file

    lucasantos, please read the forum rules and the following article: The Problem with Spoon-feeding

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