[英]jTable keeps throwing NullPointerException
I have a rather confusing setup for a program that lets the user choose the number of rows in a table in a jDialog, input data, and returns the data in several arrays (for each column) to the main form. 对于程序,我有一个相当混乱的设置,该程序允许用户在jDialog中选择表中的行数,输入数据,然后将几个数组(每个列)的数据返回到主窗体。 I thought things were going pretty smoothly up to last night, but this morning the table keeps giving me a NullPointerException error no matter what I do.
我以为直到昨晚一切都进展顺利,但是今天早晨,无论我做什么,该表一直在给我NullPointerException错误。 I've done some research online and tested the table several times, and I don't know what's wrong.
我已经在网上进行了一些研究,并对该表进行了多次测试,但我不知道出了什么问题。 Here's what I have: (Also, the data from the first column is ignored, it's not a mistake. My table has 7 columns.)
这是我所拥有的:(此外,第一列中的数据将被忽略,这不是错误。我的表有7列。)
This is where the exception is being thrown; 这是引发异常的地方。 I'm trying to access the data of column 7.
我正在尝试访问第7列的数据。
public int[] getWDurabilityEV() {
int rowCount = tbl_Units.getRowCount();
int[] value = new int[rowCount];
for (int i=0;i<value.length;i++) {
value[i] = Integer.parseInt(tbl_Units.getValueAt(i, 6).toString());
}
return value;
}
This is the button click event on the main form (the other gets are exactly like my example with a different column index; the for loop at the end is an example of how I'm updating the table on my main form) 这是主窗体上的按钮单击事件(其他获取与我的示例完全一样,但具有不同的列索引;最后的for循环是我如何在主窗体上更新表的示例)
private void EVButton1ActionPerformed(java.awt.event.ActionEvent evt) {
dialog_EV1 EV1 = new dialog_EV1(new javax.swing.JFrame(), true);
//setting values
EV1.ev1_weapon = ev1_weapon;
EV1.ev1_wstrength = ev1_wstrength;
EV1.ev1_wrange = ev1_wrange;
EV1.ev1_wrate = ev1_wrate;
EV1.ev1_wdurability = ev1_wdurability;
EV1.ev1_wportability = ev1_wportability;
EV1.setData();
EV1.show();
//getting values
ev1_weapon = EV1.getWeapon();
ev1_wstrength = EV1.getWStrengthEV();
ev1_wrange = EV1.getWRangeEV();
ev1_wrate = EV1.getWRateEV();
ev1_wdurability = EV1.getWDurabilityEV();
ev2_wportability = EV1.getWPortabilityEV();
//calcuating values and updating table
for (int i=0;i<ev1_weapon.length;i++) {
tbl_Units.setValueAt(ev1_weapon[i],i,1);
}
}
And finally, the exception thrown: 最后,抛出异常:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at light.dialog_EV1.getWDurabilityEV(dialog_EV1.java:200)
at light.MainGUI.EVButton1ActionPerformed(MainGUI.java:1061)
at light.MainGUI.access$100(MainGUI.java:28)
at light.MainGUI$2.actionPerformed(MainGUI.java:167)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.java:6288)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
at java.awt.Component.processEvent(Component.java:6053)
at java.awt.Container.processEvent(Container.java:2041)
at java.awt.Component.dispatchEventImpl(Component.java:4651)
at java.awt.Container.dispatchEventImpl(Container.java:2099)
at java.awt.Component.dispatchEvent(Component.java:4481)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4577)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
at java.awt.Container.dispatchEventImpl(Container.java:2085)
at java.awt.Window.dispatchEventImpl(Window.java:2478)
at java.awt.Component.dispatchEvent(Component.java:4481)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:643)
at java.awt.EventQueue.access$000(EventQueue.java:84)
at java.awt.EventQueue$1.run(EventQueue.java:602)
at java.awt.EventQueue$1.run(EventQueue.java:600)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
at java.awt.EventQueue$2.run(EventQueue.java:616)
at java.awt.EventQueue$2.run(EventQueue.java:614)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:613)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
nothing much to clear from your question, nor from code, please edit your question with SSCCE 从您的问题或代码中都没有什么要清除的,请使用SSCCE编辑您的问题
1) create public AbstractTableModel for storing data, 1)创建用于存储数据的公共AbstractTableModel ,
2) add TableModel
to the JTable
2)将
TableModel
添加到JTable
3) add ListSelectionMode (SINGLE_SELECTION) to the JTable
, notice test 3)将ListSelectionMode (SINGLE_SELECTION)添加到
JTable
,注意测试
if(selectedRow > -1)
4) JTable knows follows data types , then there no reason for parsing Integer from String ei 4)JTable知道以下数据类型 ,因此没有理由从String ei解析Integer
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.