Thread: 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;
 
		}

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

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Bye

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