在另一个 class 实例中获取 class 实例变量的值

Question

我已经使用 jTable 实现了传播 sheet。现在我需要从另一个 class 的实例中获取该传播 sheet 的单元格值。

我试图将当前对象的 class 扩展到包含 jTable 的 class，但它给了我包含 jTable 的 class 的另一个实例。

有没有办法在不将当前对象的 class 扩展到那个 class 的情况下访问另一个 class 实例中的变量？

提前谢谢你:)

package spreadsheet;

import java.awt.Dimension;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.DefaultCellEditor;
import javax.swing.JFrame;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.ListSelectionModel;
import javax.swing.Timer;
import javax.swing.event.*;
import javax.swing.text.BadLocationException;

public class SpreadSheetUI extends javax.swing.JFrame implements TableModelListener {

public NewCell[][] cellArray=new NewCell[20][9];

public SpreadSheetUI() {

    initComponents();

    jTable1.setModel(new javax.swing.table.DefaultTableModel(
    new Object [][] {
        {1, null, null, null, null, null, null, null, null, null},
        {2, null, null, null, null, null, null, null, null, null},
        {3, null, null, null, null, null, null, null, null, null},
        {4, null, null, null, null, null, null, null, null, null},
        {5, null, null, null, null, null, null, null, null, null},
        {6, null, null, null, null, null, null, null, null, null},
        {7, null, null, null, null, null, null, null, null, null},
        {8, null, null, null, null, null, null, null, null, null},
        {9, null, null, null, null, null, null, null, null, null},
        {10, null, null, null, null, null, null, null, null, null},
        {11, null, null, null, null, null, null, null, null, null},
        {12, null, null, null, null, null, null, null, null, null},
        {13, null, null, null, null, null, null, null, null, null},
        {14, null, null, null, null, null, null, null, null, null},
        {15, null, null, null, null, null, null, null, null, null},
        {16, null, null, null, null, null, null, null, null, null},
        {17, null, null, null, null, null, null, null, null, null},
        {18, null, null, null, null, null, null, null, null, null},
        {19, null, null, null, null, null, null, null, null, null},
        {20, null, null, null, null, null, null, null, null, null}
    },
    new String [] {
        "", "A", "B", "C", "D", "E", "F", "G", "H", "I"
    }
    ) {
        boolean[] canEdit = new boolean [] {
            false, true, true, true, true, true, true, true, true, true
        };

        @Override
        public boolean isCellEditable(int rowIndex, int columnIndex) {
            return canEdit [columnIndex];
        }
    });

    jTable1.getModel().addTableModelListener(new TableModelListener() {
        @Override
        public void tableChanged(TableModelEvent e) {
            updateCellAddressText();
            updateFormulaBarText();
        }
    });
    jTable1.setCellSelectionEnabled(true);
    jTable1.getModel().addTableModelListener(this);
    jTable1.getColumnModel().getColumn(0).setPreferredWidth(20);
    jTable1.getColumnModel().getColumn(0).setResizable(false);

    //Create a column selection listener
    final ListSelectionModel sel = jTable1.getColumnModel().getSelectionModel();
    sel.addListSelectionListener(new ListSelectionListener(){
        @Override
        public void valueChanged(ListSelectionEvent e) {                
            //If a cell in column[0] is selected, deselect it and select the respecting row
            if (sel.isSelectedIndex(0))
                sel.setSelectionInterval(9,1);
            //System.out.println(sel.getMinSelectionIndex());

        }
    });

    ((JTextField) ((DefaultCellEditor) jTable1.getDefaultEditor(Object.class)).getComponent()).getDocument().addDocumentListener(
            new DocumentListener() {

                @Override
                public void insertUpdate(DocumentEvent de) {
                    try {
                        jTextFieldFormula.setText(de.getDocument().getText(0, de.getDocument().getLength()));
                    } catch (BadLocationException ex) {
                        Logger.getLogger(SpreadSheetUI.class.getName()).log(Level.SEVERE, null, ex);
                    }
                }

                @Override
                public void removeUpdate(DocumentEvent de) {
                    try {
                        jTextFieldFormula.setText(de.getDocument().getText(0, de.getDocument().getLength()));
                    } catch (BadLocationException ex) {
                        Logger.getLogger(SpreadSheetUI.class.getName()).log(Level.SEVERE, null, ex);
                    }
                }

                @Override
                public void changedUpdate(DocumentEvent de) {
                    try {
                        jTextFieldFormula.setText(de.getDocument().getText(0, de.getDocument().getLength()));
                    } catch (BadLocationException ex) {
                        Logger.getLogger(SpreadSheetUI.class.getName()).log(Level.SEVERE, null, ex);
                    }
                }

            }
    );

    Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
    this.setLocation(dim.width/2-this.getSize().width/2, dim.height/2-this.getSize().height/2);//location
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    this.setVisible(true);
}

package spreadsheet;

import java.awt.Frame;
import java.io.Serializable;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class NewCell implements Serializable {

//** fields
String userInput=null,dataType=null,calculatedValue=null;
String strArr[];
StringTokenizer tokenizer;
DataType data;   

//** constructor
public NewCell(String newData) {
    userInput=newData;
    //  two ways of tokenizing is used as the user may input,
    //  1.) A formula which needs to be calculated and then stored in a cell
    //  2.) A normal data which needs to be split into datatypes and stored
    //  user input is identified as a formula if the first character is "="
    if(userInput.startsWith("=")) {
        String pattern = "(.*)(\d+)";
        String row,column;
        Pattern ptn = Pattern.compile(pattern);     // Create a Pattern object
        Matcher matcher;                            // Create Matcher object.
        tokenize("=^*/+-(),",true);

        ArrayList<String> outputList=new ArrayList<>();            
        Stack stackOperators=new Stack();
        String[] duplicateArr=new String[strArr.length-1];
        //insert every token except the starting '=' to 'duplicateArr'            
        for(int i=0;i<duplicateArr.length;i++){
            duplicateArr[i]=strArr[i+1];
            // In here I want to get the cell value of jTable1 
            // Example: Assume duplicateArr[i]="A1"
            // then I need the value of the cell in 1st row 2nd column
            // and then convert it to a string and give that value back
            // to the duplicateArr[i]
            //*********************************************************
            // Or else if I can get values from cellArray[][] in
            // jTable1 that's also fine.             
        }
        for (String strArr1 : duplicateArr) {
            if(strArr1.matches("-?\d+(\.\d+)?"))
            //checks whether the element is numerical
            {
                outputList.add(strArr1);
            }else if(strArr1.equals("(")) {
                stackOperators.push(strArr1);
            }else if(strArr1.equals(")")) {
                while(!(String.valueOf(stackOperators.peek()).equals("("))){
                    outputList.add(String.valueOf(stackOperators.pop()));
                }
                stackOperators.pop();
            }else{
                while(!stackOperators.empty() && (operaorPrecedence(String.valueOf(stackOperators.peek()))>operaorPrecedence(strArr1))){
                    outputList.add(String.valueOf(stackOperators.pop()));
                }
                stackOperators.push(strArr1);
            }
        }
        while(!stackOperators.empty()){
            outputList.add(String.valueOf(stackOperators.pop()));
        }
        int currentIndex=0;
        float a,b;
        while(1!=outputList.size()){
            if(!outputList.get(currentIndex+2).matches("-?\d+(\.\d+)?")){
                a=Float.parseFloat(outputList.remove(currentIndex));
                b=Float.parseFloat(outputList.remove(currentIndex));
                switch(outputList.get(currentIndex)){
                    case "+":
                        outputList.set(currentIndex,String.valueOf(a+b));
                        break;
                    case "-":
                        outputList.set(currentIndex,String.valueOf(a-b));
                        break;
                    case "*":
                        outputList.set(currentIndex,String.valueOf(a*b));
                        break;
                    case "/":
                        outputList.set(currentIndex,String.valueOf(a/b));
                        break;
                    case "^":
                        outputList.set(currentIndex,String.valueOf(Math.pow(a,b)));
                        break;
                }
                //check whether currentIndex+2 is larger than the maximum currentIndex of outputList
                if(outputList.size()-1<=currentIndex+2)
                    currentIndex--;
            }else{
                currentIndex++;
            }
        }
        tokenizer=null; //tokenizer is made null to escape the 'NotSerializableException'
                        //when calling for 'Save' or 'Open' methods
        calculatedValue=outputList.get(0);
        if(Float.valueOf(calculatedValue)==Math.ceil(Float.valueOf(calculatedValue))){
            calculatedValue=String.valueOf((int)Math.ceil(Float.valueOf(calculatedValue)));
            dataType="Integer Formula";
        }else{
            dataType="Float Formula";
        }

        //System.out.println(outputList.toString());
        /*
        if(strArr[1].equals("sum")) {}
        else if(strArr[1].equals("avg")) {}
        else if(strArr[1].equals("concat")) {}
        else {
        }*/
    }else{
        String datePattern="\d{4}/\d{1,2}/\d{1,2}";
        if (userInput.matches(datePattern)) {
                //** Find DateDT inside the input
                data=new DateDT(userInput);
                dataType="Date";
        }else{
            try{
                //**Find IntegerDT inside the input
                data=new IntegerDT(Integer.parseInt(userInput));
                dataType="Integer";
            }catch(NumberFormatException nfe1){
                try{
                    //** Find FloatDT inside the input
                    data=new FloatDT(Float.valueOf(userInput));
                    dataType="Float";
                }catch(NumberFormatException nfe2){
                    //** Obviously userInput is StringDT
                    data=new StringDT(userInput);
                    dataType="String";
                }
            }
        }
    }
}

//** getters & setters
public String getUserInput() {
    return userInput;
}

public void setCalculatedValue(String calculatedValue) {
    this.calculatedValue = calculatedValue;
}

public String getCalculatedValue() {
    return calculatedValue;
}

public void setUserInput(String userInput) {
    this.userInput = userInput;
}

//** methods
private void tokenize(String delimiter,boolean delimStatus) {
    int j=0;
    tokenizer=new StringTokenizer(userInput, delimiter,delimStatus);
    strArr=new String[tokenizer.countTokens()];
    while(tokenizer.hasMoreTokens()){
        strArr[j]=tokenizer.nextToken();
        j++;
    }
}

private int operaorPrecedence(String Operator){
    switch(Operator){
        case "+":
            return 0;
        case "-":
            return 0;
        case "*":
            return 1;
        case "/":
            return 1;
        case "^":
            return 2;
        default:
            return -1;
    }
}

}

Answer 1

你得试试这个逻辑。

 Class Jtable
private Object cellx;

public Object getCellx(){

return this.cellx; }
public setCellx(Object cellx){
this.cellx=cellx;}
}

和：

 Class AnotherClass
{
private Jtable jtable; 
getter and setter

public void function() {
this.jtable.getCellx();
  }
}

Answer 2

好的。我找到了答案。我们只需要将 SpreadSheetUI class 中的 cellArray[][] 设为 static 变量即可。

public static NewCell[][] cellArray=new NewCell[20][9];

然后从NewCell的实例class；我们可以像这样访问 cellArray[][] 的值。

SpreadSheetUI.cellArray[row][column].userInput=<Expression>;

否则，使用 getter 和 setter；

String data=SpreadSheetUI.cellArray[row][column].getUserInput();

在另一个 class 实例中获取 class 实例变量的值

Get a value of a variable of a class instance while being at another class instance

java

variables

swing

class

jtable