当一个JTextField是类型化的提取从数据库到数据的JTextField [英] Fetch data from database into Jtextfield when One Jtextfield is Typed
问题描述
大家好我有一个连接到Oracle数据库的Swing应用程序，我希望它这样，一旦我键入一个值到JTextField中，在JFrame的其他JTextFields将被加载从数据库中后续的数据，但我不知道似乎实现这一目标。我曾尝试以下code，但它获取什么。
txtNo.addKeyListener（新KeyAdapter（）{
公共无效的keyTyped（KeyEvent的KE）{
康涅狄格州的连接= NULL;
尝试{
的Class.forName（oracle.jdbc.driver.OracleDriver）; 康恩=的DriverManager.getConnection（JDBC：神谕：薄：@localhost：1521：XE，用户名，密码）;
声明ST = conn.createStatement（）;
字符串负荷='+ txtNo.getText（）+从哪里Store_info_table = PART_NUMBER选择*';
结果集RS = st.executeQuery（负载）;
而（rs.next（））{
txtName.setText（rs.getString（SPARE_DESC））;
}
}赶上（例外AE）{ }
}
}）;
你知道，如果你的数据库连接是否正常？例如，你可以监听外部运行数据库部分和它的作品？
如果是这样，我会建议使用的ActionListener 或的FocusListener 来代替。 KeyListeners（虽然有时是必要的）一般笨拙 - 通常有一种更好的方法（见的Java Swing：使用的ActionMap 并交代）：
进口java.awt.event中。*;
进口的javax.swing *。公共类例子扩展盒{ JLabel的txtName的=新的JLabel（没什么进入了）; 公共温度（）{
超（BoxLayout.Y_AXIS）;
//添加的FocusListener第一场
最终的JTextField txtNo =新的JTextField（20）;
txtNo.addFocusListener（新CustomFocusListener（txtNo））;
加（txtNo）; //添加的TextListener第一场
最终的JTextField txtNo2 =新的JTextField（20）;
txtNo2.addFocusListener（新CustomFocusListener（txtNo2））;
加（txtNo2）; //添加的TextListener第一场
最终的JTextField txtNo3 =新的JTextField（20）;
txtNo3.addFocusListener（新CustomFocusListener（txtNo3））;
加（txtNo3）; 添加（新的JButton（有所作为））; 加（txtName的）; }
公共静态无效的主要（字串[] args）{
最终的JFrame帧=新的JFrame（）;
frame.setDefaultCloseOperation（JFrame.EXIT_ON_CLOSE）;
frame.add（新实例（））;
frame.pack（）;
frame.setLocationRelativeTo（NULL）;
frame.setVisible（真）;
} / **
*您定制focust听众，做你的所有SQL工作
* /
公共类CustomFocusListener扩展FocusAdapter {
JTextField的领域; 公共CustomFocusListener（JTextField的领域）{
this.field =领域;
} @覆盖
公共无效指定者（FocusEvent e）在{
//假设你的数据库连接的作品，这给你一个榜样
txtName.setText（field.getText（））;
/ *连接康恩= NULL;
尝试{
的Class.forName（oracle.jdbc.driver.OracleDriver）; 康恩=的DriverManager.getConnection（JDBC：神谕：薄：@localhost：1521：XE，用户名，密码）;
声明ST = conn.createStatement（）;
字符串负荷='+ field.getText（）+从哪里Store_info_table = PART_NUMBER选择*';
结果集RS = st.executeQuery（负载）;
而（rs.next（））{
txtName.setText（rs.getString（SPARE_DESC））;
}
}赶上（例外AE）{ } * /
}
}
}
Hi Guys I have a Swing Application that is connected to an oracle database, I want it such that Once I type a Value into the JTextField, the other JTextfields on the JFrame are loaded with subsequent data from the database but I do not seem to achieve this. I have tried the Following code but it fetched nothing.
txtNo.addKeyListener(new KeyAdapter() {
public void keyTyped(KeyEvent ke) {
Connection conn = null;
try{
Class.forName("oracle.jdbc.driver.OracleDriver");
conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:XE", "Username", "Password");
Statement st = conn.createStatement();
String load = "Select * from Store_info_table where PART_NUMBER = '" + txtNo.getText() + "'";
ResultSet rs = st.executeQuery(load);
while(rs.next()){
txtName.setText(rs.getString("SPARE_DESC"));
}
}catch(Exception ae){
}
}
});
Do you know if you're database connection is working? For example, can you run the database portion outside of the listener and it works?
If so, I would suggest using ActionListeneror a FocusListener instead. KeyListeners (while sometimes necessary) are generally clumsy - there's usually a better approach (see Java Swing: Using ActionMap for and explaination):
import java.awt.event.*;
import javax.swing.*;
public class Example extends Box{
JLabel txtName = new JLabel("Nothing Entered");
public temp(){
super(BoxLayout.Y_AXIS);
// Add FocusListener to first field
final JTextField txtNo = new JTextField(20);
txtNo.addFocusListener(new CustomFocusListener(txtNo));
add(txtNo);
// Add TextListener to first field
final JTextField txtNo2 = new JTextField(20);
txtNo2.addFocusListener(new CustomFocusListener(txtNo2));
add(txtNo2);
// Add TextListener to first field
final JTextField txtNo3 = new JTextField(20);
txtNo3.addFocusListener(new CustomFocusListener(txtNo3));
add(txtNo3);
add(new JButton("Do Something"));
add(txtName);
}
public static void main(String[] args){
final JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new Example());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
/**
* Your custom focust listener that does all your SQL Work
*/
public class CustomFocusListener extends FocusAdapter{
JTextField field;
public CustomFocusListener(JTextField field){
this.field = field;
}
@Override
public void focusLost(FocusEvent e) {
//Assuming your database connection works, this gives you an example to follow
txtName.setText(field.getText());
/*Connection conn = null;
try{
Class.forName("oracle.jdbc.driver.OracleDriver");
conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:XE", "Username", "Password");
Statement st = conn.createStatement();
String load = "Select * from Store_info_table where PART_NUMBER = '" + field.getText() + "'";
ResultSet rs = st.executeQuery(load);
while(rs.next()){
txtName.setText(rs.getString("SPARE_DESC"));
}
}catch(Exception ae){
}*/
}
}
}
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