程序如下：
import java.sql.*;
class CourseAppl{
private Connection con;
private String url;
private String serverName;
private String portNumber;
private String databaseName;
private String userName;
private String password;
private String sql;
CourseAppl(){
url="jdbc:microsoft:sqlserver://";
serverName="webmaster";
portNumber="1433";
databaseName="friends";
userName="sa";
password="";
}
private String getConnectionUrl(){
return url+serverName+":"
+portNumber+";databaseName="+databaseName+";";
}
private Connection getConnection(){
try{
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
//建立连接
con=DriverManager.getConnection(getConnectionUrl(),userName,password);
if(con!=null){
System.out.println ("数据库连接成功！");
}
}catch(Exception e){
e.printStackTrace();
System.out.println ("getConnection()内的错误跟踪："+e.getMessage());
}
return con;
}
// public void display(){
// try{
// con=getConnection();
// PreparedStatement pstmt=con.prepareStatement(
// "update friends set salary=? where name like ?");
// pstmt.setInt(1,9000);
// pstmt.setString(2,"张三");
// pstmt.executeUpdate();
// System.out.println ("记录已经更新");
// Statement s=con.createStatement();
// String sql="select * from friends";
// ResultSet rs=s.executeQuery(sql);
// while(rs.next()){
// System.out.println ("");
// System.out.print(rs.getInt(1)+" ");
// System.out.println (rs.getInt(5)+" ");
//
// }
//
// }catch(SQLException ce){
// System.out.println (ce);
// }
// }
public static void main(String args[]){
CourseAppl retObj=new CourseAppl();
//retObj.display();
}
}
错误提示：
java.lang.ClassNotFoundException: com.microsoft.jdbc.sqlserver.SQLServerDriver
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:164)
at CourseAppl.getConnection(CourseAppl.java:25)
at CourseAppl.display(CourseAppl.java:40)
at CourseAppl.main(CourseAppl.java:63)
getConnection()内的错误跟踪：com.microsoft.jdbc.sqlserver.SQLServerDriver
Exception in thread "main" java.lang.NullPointerException
at CourseAppl.display(CourseAppl.java:41)
at CourseAppl.main(CourseAppl.java:63)
[此贴子已经被作者于2007-3-22 19:50:42编辑过]
