本文目錄一覽：
java表之間觸發失效
1、新建Redis監聽配置類。
2、新建Redis監聽類。
3、修改Redis配置文件，redis.conf。
4、測試Java代碼。
5、即可調整java表之間觸發失效的問題。
java的表結構是由開發人員自己設計的嗎
是的。java的表結構都是由內部開發人員自己設計的，但是在設計的過程中，並沒有考慮到性能的因素，所以在規定字段類型的時候，為了省事把許多字段一律設置成varchar類型，varchar類型即為字符串類型，因為varchar類型確實很強大，什麼東西都可以存。如果不考慮性能的話，這一個類型基本就可以滿足日常的需求了，但是如果考慮到性能，那肯定不能全部用java的表結構。
java 的表格模型是什麼?
DefaultTableModel是常用的java表格模型。
參考代碼：
package com.dusd;
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.InputEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.Arrays;
import java.util.Vector;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.ListSelectionModel;
import javax.swing.event.TableModelEvent;
import javax.swing.event.TableModelListener;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.JTableHeader;
import javax.swing.table.TableColumnModel;
/**
* 表格模型事件示例
* p
* liA component generally gains the focus when the user clicks it,
* or when the user tabs between components, or otherwise interacts
* with a component. A component can also be given the focus programmatically,
* such as when its containing frame or dialog-box is made visible.
* The snippet of the codes below shows how to give a particular component
* the focus every time the window gains the focus.
*
* @author HAN
*
*/
public class TableModel extends JFrame {
/**
*
*/
private static final long serialVersionUID = -8581492063632813033L;
public TableModel() {
// TODO Auto-generated constructor stub
final Container container = getContentPane();
VectorString tableColumnNames = new VectorString();
tableColumnNames.add(“A”);
tableColumnNames.add(“B”);
VectorVectorString tableValues = new VectorVectorString();
for (int i = 1; i 5; i++) {
VectorString vector = new VectorString();
vector.add(“A” + i);
vector.add(“B” + i);
tableValues.add(vector);
}
final DefaultTableModel defaultTableModel = new DefaultTableModel(
tableValues, tableColumnNames);
final JTable table = new JTable(defaultTableModel);
JScrollPane scrollPane = new JScrollPane();
scrollPane.setViewportView(table);
container.add(scrollPane, BorderLayout.CENTER);
JPanel panel = new JPanel();
container.add(panel, BorderLayout.SOUTH);
JLabel labelA = new JLabel(“A: “);
final JTextField textFieldA = new JTextField(15);
JLabel labelB = new JLabel(“B: “);
final JTextField textFieldB = new JTextField(15);
JButton buttonAdd = new JButton(“添加”);
JButton buttonDel = new JButton(“刪除”);
JButton buttonDeselected = new JButton(“取消選擇”);
panel.add(labelA);
panel.add(textFieldA);
panel.add(labelB);
panel.add(textFieldB);
panel.add(buttonAdd);
panel.add(buttonDel);
panel.add(buttonDeselected);
buttonAdd.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
int[] selectedRows = table.getSelectedRows(); // table
// 默認情況容許多行選擇
VectorString rowData = new VectorString();
rowData.add(textFieldA.getText());
rowData.add(textFieldB.getText());
if (selectedRows.length == 0) {
defaultTableModel.addRow(rowData);
textFieldA.setText(null);
textFieldB.setText(null);
} else if (selectedRows.length == 1) {
// System.out.println(selectedRows[0]);
defaultTableModel.insertRow(selectedRows[0] + 1, rowData);
textFieldA.setText(null);
textFieldB.setText(null);
} else {
JOptionPane.showMessageDialog(container,
“Your operation is forbidden”, “Warning”,
JOptionPane.WARNING_MESSAGE);
}
}
});
buttonDel.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
int[] selectedRows = table.getSelectedRows(); // table
// 默認情況容許多行選擇
for (int i = 0; i selectedRows.length; i++) {
// System.out.println(selectedRows[i]);
defaultTableModel.removeRow(selectedRows[i] – i);
}
}
});
buttonDeselected.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
table.clearSelection();
}
});
scrollPane.addMouseListener(new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent e) {
// System.out.println(“here”);
if (e.getClickCount() == 1
e.getButton() == MouseEvent.BUTTON1) {
table.clearSelection();
}
}
});
// make the text field focused every time the window is activated
addWindowFocusListener(new WindowAdapter() {
@Override
public void windowGainedFocus(WindowEvent e) {
// TODO Auto-generated method stub
textFieldA.requestFocus();
}
});
// **************************************************************
// This is a standard snippet to realize the desired column selection as in
// Excel
// **************************************************************
// row selection mode
table.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
// column selection mode
TableColumnModel tableColumnModel = table.getColumnModel();
tableColumnModel.getSelectionModel().setSelectionMode(
ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
// allow the column selection (the row selection is allowed by default)
table.setColumnSelectionAllowed(true);
final JTableHeader tableHeader = table.getTableHeader();
tableHeader.addMouseListener(new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent e) {
// TODO Auto-generated method stub
// Extended modifiers represent the state of all modal keys,
// such as ALT, CTRL, META.
if (e.getClickCount() == 1
e.getButton() == MouseEvent.BUTTON1) {
// Point point = new Point(e.getX(), e.getY());
Point point = new Point(e.getPoint());
int columnNum = tableHeader.columnAtPoint(point);
// System.out.println(columnNum);
int[] selectedColumns = table.getSelectedColumns();
if (selectedColumns.length != 0) {
// System.out.println(“here1”);
// System.out.println(InputEvent.getModifiersExText(e.getModifiersEx()));
if (e.getModifiersEx() == (InputEvent.CTRL_DOWN_MASK)) {
// System.out.println(“ctrl”);
if (Arrays.binarySearch(selectedColumns, columnNum) = 0) {
table.removeColumnSelectionInterval(columnNum,
columnNum);
} else {
table.addColumnSelectionInterval(columnNum,
columnNum);
}
} else if (e.getModifiersEx() == (InputEvent.SHIFT_DOWN_MASK)) {
// System.out.println(“shift”);
table.setColumnSelectionInterval(
selectedColumns[0], columnNum);
} else {
table.setColumnSelectionInterval(columnNum,
columnNum);
}
} else {
// System.out.println(“here2”);
table.setColumnSelectionInterval(columnNum, columnNum);
}
table.setRowSelectionInterval(0, table.getRowCount() – 1);
}
}
});
defaultTableModel.addTableModelListener(new TableModelListener() {
public void tableChanged(TableModelEvent e) {
// TODO Auto-generated method stub
int type = e.getType();
int firstRow = e.getFirstRow();
// int lastRow = e.getLastRow(); // the last row seems to be always equal to the first row
int column = e.getColumn();
switch (type) {
case TableModelEvent.DELETE:
System.out.print(“此次事件由 刪除 行觸發：”);
System.out.println(“此次刪除的是第 ” + firstRow + ” 行”);
break;
case TableModelEvent.INSERT:
System.out.print(“此次事件由 插入 行觸發：”);
System.out.println(“此次插入的是第 ” + firstRow + ” 行”);
break;
case TableModelEvent.UPDATE:
System.out.print(“此次事件由 更新 行觸發：”);
System.out.println(“此次更新的是第 ” + firstRow + ” 行第 ” + column + ” 列”);
break;
default:
System.out.println(“此次事件由 其他原因 觸發”);
}
}
});
}
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
TableModel frame = new TableModel();
frame.setTitle(“表格模型事件示例”);
frame.pack(); //Realize the components.
// frame.setBounds(100, 100, 600, 300);
// textFieldA.requestFocus();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true); //Display the window.
}
}
java主表和副表可以共用一個實體類么?
java主表和副表不可以共用一個實體類。根據查詢相關信息顯示：一個實體只能對應一張表，否則在插入和修改時會報錯。
原創文章，作者：小藍，如若轉載，請註明出處：https://www.506064.com/zh-hk/n/256604.html
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