java.lang.NullPointerException错误
编译通过,引用bean时,报java.lang.NullPointerException错
代码如下:
package odbcbean;
import java.sql.*;
public class Opendb4 {
String sDBDriver="sun.jdbc.odbc.JdbcOdbcDriver";
String sConnStr="jdbc:odbc:cert";
Connection conn=null;
ResultSet rs=null;
public Opendb4() {
try {
Class.forName(sDBDriver);
}
catch(java.lang.ClassNotFoundException e){
System.err.print(e.getMessage());
}
}
public ResultSet executeQuery(String sql){
rs=null;
try{
Connection conn=DriverManager.getConnection(sConnStr);
Statement stmt=conn.createStatement();
rs=stmt.executeQuery(sql);
}
catch(SQLException ex){
System.err.print(ex.getMessage());
}
return rs;
}
}