如何在Java的GridBagLayout中使网格不同？

我想要实现的是这样的目标：

这是我的代码：

JDialog messageDialog = new JDialog();
messageDialog.setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
messageDialog.setBounds(0, 0, 350, 250);
messageDialog.setLocationRelativeTo(null);
messageDialog.setVisible(true);

JPanel btnPanel = new JPanel();
JPanel clearPanel = new JPanel();
JPanel labelsPanel = new JPanel();
JPanel txtPanel = new JPanel();
JButton newMessage = new JButton("New");
JButton recievedMessages = new JButton("Recieved");
JButton sendMessages = new JButton("Sent");
JButton refreshMessages = new JButton("Refresh");
JLabel recievedMessLab = new JLabel("Messages get:");
JTextPane txtToSend = new JTextPane();

btnPanel.setLayout(new GridLayout(4, 1));
btnPanel.add(newMessage);
btnPanel.add(recievedMessages);
btnPanel.add(sendMessages);
btnPanel.add(refreshMessages);

c.gridx = 0;
c.gridy = 0;
messageDialog.add(clearPanel, c);

c.gridx = 1;
c.gridy = 0;
messageDialog.add(labelsPanel, c);

c.gridx = 0;
c.gridy = 1;
messageDialog.add(btnPanel, c);

c.gridx = 1;
c.gridy = 1;
messageDialog.add(txtPanel, c);

labelsPanel.add(recievedMessLab);

我不知道为什么我在所有面板周围都有一些空闲空间，我不知道如何调整网格的大小。Oracle教程也没有帮助。调整大小的最简单方法是什么？如何消除这些可用空间？

您需要将权重和填充信息添加到GridBagConstraints中，以便布局管理器知道要在可用空间上分布哪些组件

请尝试以下操作：

c.gridx = 0;
c.gridy = 0;
c.fill = c.NONE;  // dont fill (strech)
messageDialog.add(clearPanel, c);

c.gridx = 1;
c.gridy = 0;
c.weightx = 1; // horizontal weight: 1
c.fill = c.HORIZONTAL; // fill (strech) horizontally
messageDialog.add(labelsPanel, c);

c.gridx = 0;
c.gridy = 1;
c.weightx = 0; // horizontal weight: back to 0
c.weighty = 1; // vertical weight: 1
c.fill = c.VERTICAL; // fill (strech) vertically
messageDialog.add(btnPanel, c);

c.gridx = 1;
c.gridy = 1;
c.weightx = 1; // both weights: 1
c.weighty = 1; // both weights: 1
c.fill = c.BOTH; // and fill both ways, vertically and horizontally
messageDialog.add(txtPanel, c);

重温关于weightx和weighty的部分，并填写教程以了解它们是如何工作的

PS:txtPanel是空的，txtToSend从未使用过