Clases Vector_Matriz

package vector;

import java.util.Vector;
import java.util.Arrays;

import java.io.BufferedReader;
import java.io.InputStreamReader;
/**
 *
 * @author ALUMNO
 */
public class Main {
    public static int Leer(BufferedReader buff){
    int lee=0; boolean error;

    do{
        error=false;
        try{
            lee=Integer.parseInt(buff.readLine());}
         catch(NumberFormatException ex){
             System.out.println("Se a procucido un error");
             error=true;
            }
        catch (Exception ex){ex.printStackTrace(System.err);}
    }while(error);
    return lee;
    }
public static void Cargar(int v[]){
  BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
   for(int i=0; i<v.length;i++){
       System.out.print("Ingrese un valor:=" );
       v[i]=Leer(br);
   }
}
public static void Mostrar(int v[]){
 for(int i=0; i<v.length;i++){
   System.out.print("["+i+"]="+v[i]+"|");
 }
}

CLASE ALUMNO

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here

        int v1[]=new int[5];

        Cargar(v1);
        Mostrar(v1);
    }

}


*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package alumno;

/**
 *
 * @author ALUMNO
 */
public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        Alumno A[]=new Alumno[5];
        A[0]=new Alumno(2345,"Ana gil","Derecho");

        A[1]=new Alumno(654,"Juan Rocha","Pedagogia");
          A[2]=new Alumno(987,"Pedro Paz","Derecho");
             A[3]=new Alumno(6543, "Juana Arnez","Derecho");

             for(int i=0; i<A.length;i++){
              System.out.println(A[i].VerAlumno());
             }

    }

}

 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package alumno;

/**
 *
 * @author ALUMNO
 */
public class Alumno {
    private int RU;
    private String nombre;
    private String carrera;

public Alumno(){
   RU=0;nombre=carrera="";
}
public Alumno(int r, String n, String c){
    RU=r;
    nombre=n;
    carrera=c;

}
public void setRU(int r){RU=r;}
public void setnombre(String nom){nombre=nom;}
public void setcarrera(String carre){carrera=carre;}

public  int getRU(){return RU;}
public String getRnombre(){return nombre ;}
public  String getcarrera(){return carrera;}

public String VerAlumno(){
 return ("RU:"+RU+"\nNombre:"+nombre+"\nCarrera: "+carrera);
}

}

CLASE MATRIZ

package laboratorio1;

public class Matriz {

    public int n;
    private double[][] x;

    public Matriz(int n){
    this.n=n;
    x=new double[n][n];
    for(int i=0;i<n;i++){
       for(int j=0;j<n;j++){
          x[i][j]=0.0;
       }
    }
    }

    public Matriz(double[][] x){
    this.x=x;
    n=x.length;
    }

    public String toString(){
    String texto="";
    for(int i=0;i<n;i++){
       for(int j=0;j<n;j++){
          texto+="\t"+(double)Math.round(1000*x[i][j])/1000;
       }
       texto+="\n";
    }
    texto+="\n";
    return texto;
    }

    public double Diagonal(double[][] x){
    double s=0;
    for(int i=0;i<n;i++){
       for(int j=0;j<n;j++){
       if(i==j){
       s=s + x[i][j];
       }
       }
    }
    return s;
    }

    public static void main(String[] args){

    }
}