ArrayList 输出到 JTable

Question

是的，我用谷歌搜索过，是的，我读过，是的，我仍然卡住了......

我在 ClassB 中有一个对象的 ArrayList，我通过从 B 中的 A 调用一个方法返回到 ClassA 中的对象的 ArrayList。（相同的返回类型：）在 CLassB 中，我完成所有的处理和存储对象属性转换为类类型的对象数组。

B 类：

ClassB object = new ClassB();
ArrayList<ClassB> arrayOfObjects = new ArrayList<>();
int count = 0;
while(count<10){
   ///alot going on here but the general concept is this;
  object.attribute1 = "something read in"
  object.attribute2 = "something read in"
  object.attribute3 = "something read in"
  object.attribute4 = "something read in"
  object.attribute5 = "something read in"   

  arrayOfObjects.add(object);
  count++;  

}

A 类：

ArrayList<ClassB> arrayOfObjects = ClassBObject.method();



String[] columns = {"Column1","Column2","Column3", "Column4", "Column5"};

      DefaultTableModel tableModel = new DefaultTableModel(columns, 0);

      JTable table = new JTable(tableModel);

      int i = 0;
      while(i < arrayOfObjects.size()) {

         //v for variable       
         String v1 = arrayOfObjects .get(i).attribute1;
         String v2 = arrayOfObjects .get(i).attribute2;
         String v3 = arrayOfObjects .get(i).attribute3;
         String v4 = arrayOfObjects .get(i).attribute4;
         String v5 = arrayOfObjects .get(i).attribute5;

         Object[] row = {v1,v2,v3,v4,v5};

         tableModel.addRow(row);
         i++;
      }
         JFrame frame = new JFrame("Title of Table");

            JPanel panel = new JPanel();
            panel.setLayout(new BorderLayout());

            JScrollPane tableContainer = new JScrollPane(table);

            panel.add(tableContainer, BorderLayout.CENTER);
            frame.getContentPane().add(panel);

            frame.pack();
            frame.setVisible(true);

问题：使用上面的代码，表格只显示最后一个对象，该对象重复的次数与 while 循环执行的次数一样多。我想从对象数组中提取每个对象的属性，其中计数器用于匹配对象数组的元素。

我希望我足够详细，可以提供足够的背景知识来找到问题的根源。提前致谢！

Answer 1

好的，现在我们看到了您的问题（可能）！

ClassB object = new ClassB();
ArrayList<ClassB> arrayOfObjects = new ArrayList<>();
int count = 0;
while(count<10){
   ///alot going on here but the general concept is this;
  object.attribute1 = "something read in"
  object.attribute2 = "something read in"
  object.attribute3 = "something read in"
  object.attribute4 = "something read in"
  object.attribute5 = "something read in"   

  arrayOfObjects.add(object);
  count++;  
}

您不会在循环中每次都重新创建一个新对象！

改为尝试：

// ***** don't create object *once* outside of the while loop!
//  ClassB object = new ClassB();

ArrayList<ClassB> arrayOfObjects = new ArrayList<>();
int count = 0;
while(count<10){

   // *** instead create a new one for each iteration of the loop!
   ClassB object = new ClassB(); // *****************

   ///alot going on here but the general concept is this;
  object.attribute1 = "something read in"
  object.attribute2 = "something read in"
  object.attribute3 = "something read in"
  object.attribute4 = "something read in"
  object.attribute5 = "something read in"   

  arrayOfObjects.add(object);
  count++;  
}