Генеричка матрица

import java.util.Scanner;

class Matrix<T>{
    int rows,columns;
    T [][] matrica;


    Matrix(int r,int c){
        matrica=(T[][]) new Object[r][c];
        rows=r;
        columns=c;
    }

    int getNumRows() {
        return rows;
    }

    int getNumColumns() {
        return columns;
    }

    T getElementAt(int row, int col) {
        return matrica[row][col];
    }

    void setElementAt(int row, int col, T value) {
        matrica[row][col]=value;
    }

    void fill(T element) {
        for(int i=0;i<rows;i++) {
            for(int j=0;j<columns;j++) {
                matrica[i][j]=element;
            }
        }
    }

    void insertRow(int row) throws ArrayIndexOutOfBoundsException {
        if(row<0 || row>rows) throw new ArrayIndexOutOfBoundsException();
        T[][] matrica1=(T[][]) new Object[rows+1][columns];

        for(int i=0;i<row;i++) {
            for(int j=0;j<columns;j++) {
                matrica1[i][j]=matrica[i][j];
            }
        }
        for(int i=row+1;i<rows+1;i++) {
            for(int j=0;j<columns;j++) {
                matrica1[i][j]=matrica[i-1][j];
            }
        }

        matrica=matrica1;
        rows++;

    }

    void deleteRow(int row) {
        if(row<0 || row>rows) throw new ArrayIndexOutOfBoundsException();
        T[][] matrica1=(T[][]) new Object[rows-1][columns];

        for(int i=0;i<row;i++) {
            for(int j=0;j<columns;j++) {
                matrica1[i][j]=matrica[i][j];
            }
        }
        for(int i=row+1;i<rows;i++) {
            for(int j=0;j<columns;j++) {
                matrica1[i-1][j]=matrica[i][j];
            }
        }

        matrica=matrica1;
        rows--;
    }

    void insertColumn(int col) {
        if(col<0 || col>columns) throw new ArrayIndexOutOfBoundsException();
        T[][] matrica1=(T[][]) new Object[rows][columns+1];

        for(int i=0;i<rows;i++) {
            for(int j=0;j<col;j++) {
                matrica1[i][j]=matrica[i][j];
            }
        }

        for(int i=0;i<rows;i++) {
            for(int j=col+1;j<columns+1;j++) {
                matrica1[i][j]=matrica[i][j-1];
            }
        }

        matrica=matrica1;
        columns++;

    }

    void deleteColumn(int col) {
        if(col<0 || col>columns) throw new ArrayIndexOutOfBoundsException();
        T[][] matrica1=(T[][]) new Object[rows][columns-1];

        for(int i=0;i<rows;i++) {
            for(int j=0;j<col;j++) {
                matrica1[i][j]=matrica[i][j];
            }
        }

        for(int i=0;i<rows;i++) {
            for(int j=col+1;j<columns;j++) {
                matrica1[i][j-1]=matrica[i][j];
            }
        }
        columns--;
        matrica=matrica1;
    }

    void resize(int newRows,int newCols) {
        T[][] matrica1=(T[][]) new Object[newRows][newCols];
        if(newRows>this.rows && newCols>this.columns) {
            for(int i=0;i<rows;i++) {
                for(int j=0;j<columns;j++) {
                    matrica1[i][j]=matrica[i][j];
                }
            }
            for(int i=rows;i<newRows;i++) {
                for(int j=columns;j<newCols;j++) {
                    matrica1[i][j]=null;
                }
            }

        } else if(newRows<this.rows && newCols<this.columns){
            for(int i=0;i<newRows;i++) {
                for(int j=0;j<newCols;j++) {
                    matrica1[i][j]=matrica[i][j];
                }
            }

        } else if(newRows>this.rows && newCols<this.columns) {
            for(int i=0;i<rows;i++) {
                for(int j=0;j<newCols;j++) {
                    matrica1[i][j]=matrica[i][j];
                }
            }
            for(int i=rows;i<newRows;i++) {
                for(int j=0;j<newCols;j++) {
                    matrica1[i][j]=null;
                }
            }
        } else {
            for(int i=0;i<newRows;i++) {
                for(int j=0;j<columns;j++) {
                    matrica1[i][j]=matrica[i][j];
                }
            }
            for(int i=0;i<newRows;i++) {
                for(int j=columns;j<newCols;j++) {
                    matrica1[i][j]=null;
                }
            }
        }

        rows=newRows;
        columns=newCols;
        matrica=matrica1;

    }

}

public class MatrixTest {

    public static void main(String[] args) {
        Scanner jin = new Scanner(System.in);
        int t = jin.nextInt();
        if ( t == 0 ) {
            int r = jin.nextInt();
            int c = jin.nextInt();
            Matrix<Integer> matrix = new Matrix<Integer>(r,c);
            print(matrix);
        }
        if ( t == 1 ) {
            int r = jin.nextInt();
            int c = jin.nextInt();
            Matrix<Integer> matrix = new Matrix<Integer>(r,c);
            for ( int i = 0 ; i < r ; ++i ) {
                for ( int k = 0 ; k < c ; ++k ) {
                    matrix.setElementAt(i, k, jin.nextInt());
                }
            }
            print(matrix);
        }
        if ( t == 2 ) {
            int r = jin.nextInt();
            int c = jin.nextInt();
            Matrix<String> matrix = new Matrix<String>(r,c);
            for ( int i = 0 ; i < r ; ++i ) {
                for ( int k = 0 ; k < c ; ++k ) {
                    matrix.setElementAt(i, k, jin.next());
                }
            }
            print(matrix);
        }
        if ( t == 3 ) {
            int r = jin.nextInt();
            int c = jin.nextInt();
            Matrix<String> matrix = new Matrix<String>(r,c);
            for ( int i = 0 ; i < r ; ++i ) {
                for ( int k = 0 ; k < c ; ++k ) {
                    matrix.setElementAt(i, k, jin.next());
                }
            }
            print(matrix);
            matrix.deleteRow(jin.nextInt());
            matrix.deleteRow(jin.nextInt());
            print(matrix);
            int ir = jin.nextInt();
            matrix.insertRow(ir);
            for ( int k = 0 ; k < c ; ++k ) {
                matrix.setElementAt(ir, k, jin.next());
            }
            ir = jin.nextInt();
            matrix.insertRow(ir);
            for ( int k = 0 ; k < c ; ++k ) {
                matrix.setElementAt(ir, k, jin.next());
            }
            print(matrix);
            matrix.deleteColumn(jin.nextInt());
            matrix.deleteColumn(jin.nextInt());
            print(matrix);
            int ic = jin.nextInt();
            matrix.insertColumn(ir);
            for ( int i = 0 ; i < r ; ++i ) {
                matrix.setElementAt(i, ic, jin.next());
            }
            ic = jin.nextInt();
            matrix.insertColumn(ic);
            for ( int i = 0 ; i < r ; ++i ) {
                matrix.setElementAt(i, ic, jin.next());
            }
            print(matrix);
        }
        if ( t == 4 ) {
            int r = jin.nextInt();
            int c = jin.nextInt();
            Matrix<Integer> matrix = new Matrix<Integer>(r,c);
            for ( int i = 0 ; i < r ; ++i ) {
                for ( int k = 0 ; k < c ; ++k ) {
                    matrix.setElementAt(i, k, jin.nextInt());
                }
            }
            print(matrix);
            int nr = jin.nextInt();
            int nc = jin.nextInt();
            matrix.resize(nr, nc);
            print(matrix);
            matrix.fill(jin.nextInt());
            print(matrix);
        }
    }

    public static void print ( Matrix<?> m ) {
        int r = m.getNumRows();int c = m.getNumColumns();
        System.out.println("  "+r+" x "+c);
        System.out.print("    ");
        for ( int k = 0 ; k < c ; ++k ) {
            System.out.print(k+"    ");
        }
        System.out.println();
        System.out.print("  ");
        for ( int k = 0 ; k < c ; ++k ) {
            System.out.print("-----");
        }
        System.out.println();
        for ( int i = 0 ; i < r ; ++i ) {
            System.out.print(i+"|");
            for ( int k = 0 ; k < c ; ++k ) {
                if ( k > 0 ) System.out.print(" ");
                System.out.print(m.getElementAt(i, k));
            }
            System.out.println();
        }
        System.out.println();
    }

}