java 在 Apache Derby 中找不到数据库错误
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时间：2020-10-31 09:43:00 来源:igfitidea点击:
Database not found error in Apache Derby
提问by Lemon Juice
First, this is my first time with Apache Derby. I am using netbeans, willing to use embedded apache derby, and I followed the following tutorial for configuring and installing the database
首先，这是我第一次使用 Apache Derby。我正在使用netbeans，愿意使用嵌入式apache derby，我按照以下教程配置和安装数据库
http://netbeans.org/kb/docs/ide/java-db.html#starting
http://netbeans.org/kb/docs/ide/java-db.html#starting
The attached image will show my database status in netbeans
附加的图像将显示我在 netbeans 中的数据库状态
My database name is "contact". Table name is "FRIENDS".
我的数据库名称是“联系人”。表名是“朋友”。
Following is my test code
以下是我的测试代码
DatabaseConnector.java
数据库连接器
import java.sql.*;
public class DataBaseConnector
{
private Connection con;
public DataBaseConnector()
{
}
private void createConnection()
{
try
{
Class.forName("org.apache.derby.jdbc.EmbeddedDriver");
con = DriverManager.getConnection("jdbc:derby:contact","yohan","xyz");
}
catch(Exception e)
{
e.printStackTrace();
}
}
private void closeConnection()
{
try
{
con.close();
}
catch(Exception e)
{
e.printStackTrace();
}
}
public void insertData(int id, String firstName, String lastName)
{
createConnection();
try
{
PreparedStatement ps = con.prepareStatement("insert into FRIENDS values(?,?,?)");
ps.setInt(1, id);
ps.setString(1, firstName);
ps.setString(2, lastName);
int result = ps.executeUpdate();
if(result>0)
{
System.out.println("Data Inserted");
}
else
{
System.out.println("Something happened");
}
}
catch(Exception e)
{
e.printStackTrace();
}
finally
{
closeConnection();
}
}
}
DatabaseUI.java
数据库界面.java
import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
public class DatabaseUI extends JFrame
{
private JLabel firstName, id, lastName;
private JTextField idTxt, firstNameTxt, lastNameTxt;
private JButton ok;
public DatabaseUI()
{
firstName = new JLabel("First Name: ");
lastName = new JLabel("Last Name: ");
id = new JLabel("ID: ");
firstNameTxt = new JTextField(10);
lastNameTxt = new JTextField(10);
idTxt = new JTextField(10);
ok = new JButton("OK");
ok.addActionListener(new OKAction());
JPanel centerPanel = new JPanel();
centerPanel.setLayout(new GridLayout(4,2));
centerPanel.add(id);
centerPanel.add(idTxt);
centerPanel.add(firstName);
centerPanel.add(firstNameTxt);
centerPanel.add(lastName);
centerPanel.add(lastNameTxt);
centerPanel.add(new JPanel());
centerPanel.add(ok);
getContentPane().add(centerPanel,"Center");
this.pack();
this.setVisible(true);
}
private class OKAction implements ActionListener
{
public void actionPerformed(ActionEvent ae)
{
DataBaseConnector db = new DataBaseConnector();
int id = Integer.parseInt(idTxt.getText());
db.insertData(id, firstNameTxt.getText().trim(), lastNameTxt.getText().trim());
}
}
public static void main(String[]args)
{
new DatabaseUI();
}
}
But, when I am trying to insert data into the database, it is giving me the following error
但是，当我尝试将数据插入数据库时，它给了我以下错误
run:
java.sql.SQLException: Database 'contact' not found.
at org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.Util.newEmbedSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.Util.newEmbedSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.Util.generateCsSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedConnection.newSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedConnection.handleDBNotFound(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedConnection.<init>(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedConnection30.<init>(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedConnection40.<init>(Unknown Source)
at org.apache.derby.jdbc.Driver40.getNewEmbedConnection(Unknown Source)
at org.apache.derby.jdbc.InternalDriver.connect(Unknown Source)
at org.apache.derby.jdbc.AutoloadedDriver.connect(Unknown Source)
at java.sql.DriverManager.getConnection(DriverManager.java:579)
at java.sql.DriverManager.getConnection(DriverManager.java:221)
at DataBaseConnector.createConnection(DataBaseConnector.java:17)
at DataBaseConnector.insertData(DataBaseConnector.java:40)
at DatabaseUI$OKAction.actionPerformed(DatabaseUI.java:52)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6504)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6269)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4860)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4686)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2713)
at java.awt.Component.dispatchEvent(Component.java:4686)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:707)
at java.awt.EventQueue.accesscon = DriverManager.getConnection("jdbc:derby:contact","yohan","xyz");
0(EventQueue.java:101)
at java.awt.EventQueue.run(EventQueue.java:666)
at java.awt.EventQueue.run(EventQueue.java:664)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue.run(EventQueue.java:680)
at java.awt.EventQueue.run(EventQueue.java:678)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:677)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
Caused by: java.sql.SQLException: Database 'contactDB' not found.
at org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.SQLExceptionFactory40.wrapArgsForTransportAcrossDRDA(Unknown Source)
... 53 more
java.lang.NullPointerException
at DataBaseConnector.insertData(DataBaseConnector.java:43)
at DatabaseUI$OKAction.actionPerformed(DatabaseUI.java:52)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6504)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6269)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4860)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4686)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2713)
at java.awt.Component.dispatchEvent(Component.java:4686)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:707)
at java.awt.EventQueue.access"jdbc:derby://localhost:1527/contact"
0(EventQueue.java:101)
at java.awt.EventQueue.run(EventQueue.java:666)
at java.awt.EventQueue.run(EventQueue.java:664)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue.run(EventQueue.java:680)
at java.awt.EventQueue.run(EventQueue.java:678)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:677)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
java.lang.NullPointerException
at DataBaseConnector.closeConnection(DataBaseConnector.java:29)
at DataBaseConnector.insertData(DataBaseConnector.java:65)
at DatabaseUI$OKAction.actionPerformed(DatabaseUI.java:52)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6504)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6269)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4860)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4686)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2713)
at java.awt.Component.dispatchEvent(Component.java:4686)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:707)
at java.awt.EventQueue.access##代码##0(EventQueue.java:101)
at java.awt.EventQueue.run(EventQueue.java:666)
at java.awt.EventQueue.run(EventQueue.java:664)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue.run(EventQueue.java:680)
at java.awt.EventQueue.run(EventQueue.java:678)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:677)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
Please help me. Thanks
请帮我。谢谢
回答by Bryan Pendleton
The connection URL "jdbc:derby:contact" specifies that the 'contact' database should be found in the current working directory of your process, but that's probably not where it's actually located. When your Java program is run, the current working directory is probably been set somewhere else. You can confirm this by printing out the current working directory at the start of your program.
连接 URL "jdbc:derby:contact" 指定应该在进程的当前工作目录中找到 'contact' 数据库，但这可能不是它实际所在的位置。当您的 Java 程序运行时，当前工作目录可能已设置在其他地方。您可以通过在程序开始时打印出当前工作目录来确认这一点。
To get around this for now, you can specify the full path to your database: "jdbc:derby:/path/to/my/db/contact".
为了暂时解决这个问题，您可以指定数据库的完整路径：“jdbc:derby:/path/to/my/db/contact”。
If that gets you farther, then you can keep going, but at some point you'll have to think more about where you want your database to be permanently located and how you want to specify that in your program.
如果这能让您走得更远，那么您可以继续前进，但在某些时候，您将不得不更多地考虑您希望数据库永久位于何处以及您希望如何在程序中指定它。
回答by arjayosma
Kindly look at your derby/jdbc connection, This line here:
请查看您的 derby/jdbc 连接，这里是这一行：
##代码##Check if it looks similar to:
检查它是否类似于：
##代码##Or, as what I've seen, the name of your database is ContactDB... Kindly check...
或者，正如我所看到的，您的数据库的名称是 ContactDB...请检查...
Thanks...
谢谢...
