将值设置为JTable时，索引超出范围异常 [英] Index Out of Bound Exception when setting value to JTable

问题描述

我在面板中有一个JTable和表格模型.我在表中有一个复选框，该复选框应控制另一行是可编辑的，而其他行是食物对象的数据.但是，当我单击复选框时，在this.bools.set(row, (Boolean)vlaue) ;行出现了java.lang.IndexOutOfBoundsException异常.

I have a JTable and table model in a panel. I have check box in the table which should control another row to be editable and the other rows are data of food object. But when I click on check box I get java.lang.IndexOutOfBoundsException exception at this.bools.set(row, (Boolean)vlaue) ; line.

为什么会出现此错误?

import com.sun.org.apache.xpath.internal.operations.Bool;
import Food;
import FoodDAO;

import javax.swing.*;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.TableCellRenderer;
import java.awt.*;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Vector;

/**
* Created by debian on 8/20/16.
 */
public class FoodListPanel extends JPanel{
JTable jTable;
FoodTableModel fm;

public FoodListPanel() {

    try {
         fm = new FoodTableModel(FoodDAO.getAllFoodsFromDB(), new ArrayList<Boolean>(), new ArrayList<Integer>());

        jTable = new JTable(fm) {

            public boolean isCellEditable(int data, int columns) {
               if(columns<5){
                   return false;
               }
               else if(columns ==5){
                   return true;
               }
                else if(columns ==6){

                  if(getValueAt(data, 5)==Boolean.FALSE){
                      return false;
                  }
                   else {
                      return true;
                  }
               }
                else{
                   return true;
               }
            }

            public Component prepareRenderer(TableCellRenderer r, int data, int columns) {
                Component c = super.prepareRenderer(r, data, columns);
                return c;
            }


        };


        jTable.setPreferredScrollableViewportSize(new Dimension(650, 420));
        jTable.setFillsViewportHeight(true);

        JScrollPane jScrollPane = new JScrollPane(jTable);

        add(jScrollPane);

    } catch (SQLException e) {
        e.printStackTrace();
    }
}

class FoodTableModel extends AbstractTableModel {
    protected String[] cols = {"نام‌غذا", "دسته‌بندی", "قیمت", "توضیحات", "عکس" , "انتخاب", "تعداد"};
    protected Class[] colClasses = {String.class, Integer.class, String.class, String.class,
    JLabel.class, Boolean.class, Integer.class};
    ArrayList<Food> al;
    ArrayList<Boolean> bools;
    ArrayList<Integer> vals;
    public FoodTableModel(ArrayList<Food> foods, ArrayList<Boolean> boxes,ArrayList<Integer> val) {
        al = new ArrayList<Food>();
        bools = new ArrayList<>(al.size());
        for(Boolean b: bools){
            b=Boolean.FALSE;
        }
        vals = new ArrayList<Integer>(al.size());
        al.addAll(foods);
        bools.addAll(boxes);

    }


    ////// TODO: 8/20/16 make dynamic from DB
    public int getColumnCount (){return cols.length;}
    public int getRowCount (){return al.size();}
    public String getColumnName(int col) { return cols[col]; }
    public Class getColumnClass(int col) { return colClasses[col]; }

    public Object getValueAt(int row, int col){
        switch (col) {

            case 0:
                return al.get(row).getName();
            case 1:
                return al.get(row).getType();
            case 2:
                return al.get(row).getPrice();
            case 3:
                return al.get(row).getDiscreption();
            //// TODO: 8/20/16  CASE 4  + PICTURE

            default:
                return null;
        }
    }


    public void setValueAt(Object vlaue, int row, int column){
        if(column==5){
            this.bools.set(row, (Boolean)vlaue) ;
        }else if (column==6){
            this.vals.set(row, (Integer)vlaue);
        }
    }

    /*public void setCols(String[] columns){
        cols = columns;
    }
    public void setClasses(Class[] classes){
        colClasses = classes;
    }*/
}
}

推荐答案

原因是您试图在ArrayList中某个位置设置一个值，该值大于列表的大小.最初创建的ArrayList的大小为0.请阅读有关ArrayList的文档和教程.

The reason is that you are trying to set a value at a position in the ArrayList that is bigger then the size of the list. Initially ArrayList is created with size 0. Please read the documentation and tutorials about ArrayList.

代码中还有其他问题，例如当您尝试为布尔值赋值时:

There are also other problems in the code, e.g. when you try to assign a value to a boolean:

    al = new ArrayList<Food>();
    bools = new ArrayList<>(al.size());
    for(Boolean b: bools){
        b=Boolean.FALSE;
    }

这基本上什么都不做.首先，列表在创建时为空，其次，赋值仅给b赋了一个新值，而不像您期望的那样更改bool中任何元素的内容.

This basically does nothing. First of all, the list is empty when created, second, the assignment only assigns a new value to b, but doesn't change the contents of any elements in bools, as you might expect it to do.

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