java - JTable 第一次执行时不显示结果

Question

该代码是将数据添加到JTable中。

            String [] header = new String [] {"No","Customer","Video","Date","Days","Status-Closed"};
            Contract [] contractArray = contractList.toArray(new Contract [contractList.size()]);
            Object [][] datarow = new Object [contractArray.length][6];

            try{
               //Read the objects from file and store in the List
                ObjectInputStream inputStream = new ObjectInputStream(
                          new FileInputStream("contractfile"));
                Object o = inputStream.readObject();

                while(o != null){
                    Contract c = (Contract) o;
                    contractList.add(c);
                    o = inputStream.readObject();
                }

            inputStream.close();                

            } catch (EOFException ex) {
                //
            } 

            //Push data to the array
            int no = 0; 
            for(int i = 0; i < contractArray.length; i++){
                no++;
                datarow[i][0] = no;
                datarow[i][1] = contractArray[i].getAccount().getName();
                datarow[i][2] = contractArray[i].getVideo().getName();
                datarow[i][3] = contractArray[i].getDate();
                datarow[i][4] = contractArray[i].getDay();
                datarow[i][5] = contractArray[i].getClosed();
            }

            //set the table model
            TableModel mod = new DefaultTableModel(datarow,header);
            table.setModel(mod);

第一次点击按钮时，表格只显示标题，第二次点击则将数据放入表格中。调试时，第一次 datarow[][] 没有元素，第二次则包含所有对象。为什么，有人可以帮我吗？

Answer 1

在从文件加载列表之前，您可以调用 Contract [] ContractArray = ContractList.toArray(new Contract [contractList.size()]); 。所以 size() == 0。

之后datarow = new Object [contractArray.length][6];但长度为0