Java 未报告的异常类NotFoundException;必须是catch或抛出的class.forName(sun.jdbc.odbc.JdbcOdbcDriver)
如果Class.forNameString无法加载传递给它的名称的类(例如,如果类路径中缺少一个jar),它将抛出ClassNotFoundException。这是一个已检查的异常,必须向上抛出,例如,将抛出ClassNotFoundException添加到方法的声明中,或者捕获:Java 未报告的异常类NotFoundException;必须是catch或抛出的class.forName(sun.jdbc.odbc.JdbcOdbcDriver),java,Java,如果Class.forNameString无法加载传递给它的名称的类(例如,如果类路径中缺少一个jar),它将抛出ClassNotFoundException。这是一个已检查的异常,必须向上抛出,例如,将抛出ClassNotFoundException添加到方法的声明中,或者捕获: import java.sql.*; import java.awt.*; import java.awt.event.*; import javax.swing.*; class Delet
import java.sql.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class DeleteDemo extends Frame implements
ActionListener {
Label l1;
Button b1;
TextField t1;
DeleteDemo()
{
setVisible(true);
setSize(400,400);
l1=new Label("Enter Id");
b1=new Button("Delete");
t1=new TextField(20);
setLayout(new FlowLayout());
add(l1);add(t1);
add(b1);
b1.addActionListener(this);
}
public void actionPerformed(ActionEvent e)
{
if(e.getSource()==b1)
{
try
{
System.out.println("Data try to delete");
String id=t1.getText();
l1.setText("hi");
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection con=DriverManager.getConnection("Jdbc:Odbc:xyz","","");
Statement st=con.createStatement();
st.executeUpdate("delete from tblEmp where id ='"+id+"' ");
System.out.println("Data has been deleted");
}catch(SQLException eb){}
}
}
public static void main(String args[ ]) {
DeleteDemo dtl=new DeleteDemo(); }
}
对于Java 7,您可以简单地省略Class.forName语句,因为它实际上不是必需的?如果问题是关于程序没有编译,那么您需要做的就是为ClassNotFoundException再添加一个catch块编译错误说明问题所在。您的问题是什么?在控制台上运行时,显示的消息无法加载JDBC驱动程序我想从数据库tble加载一行,但它不起作用。运行程序控制台窗口后,显示messege无法加载JDBC驱动程序
try {
System.out.println("Data try to delete");
String id=t1.getText();
l1.setText("hi");
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection con=DriverManager.getConnection("Jdbc:Odbc:xyz","","");
Statement st=con.createStatement();
st.executeUpdate("delete from tblEmp where id ='"+id+"' ");
System.out.println("Data has been deleted");
} catch(ClassNotFoundException cne) {
System.err.println("Could not load JDBC driver");
} catch(SQLException eb) {
System.err.println("Could not delete data");
}