re: "java.lang.NoClassDefFoundError"錯(cuò)誤——一個(gè)關(guān)于classpath設(shè)置的問題
2006-11-19 16:10 |
這是我拷的一個(gè)例子，在編譯的時(shí)候可以通過，但在執(zhí)行的時(shí)候去總出現(xiàn)先您那樣的錯(cuò)誤。不知如何解決。我是一個(gè)初學(xué)者還請(qǐng)您多多指點(diǎn)。
package stuman;
import java.io.*;
import java.sql.*;
public class sqlBean{///
public Connection conn=null;
public ResultSet rs=null;
private String DatabaseDriver="com.microsoft.jdbc.sqlserver.SQLServerDriver";
private String DatabaseConnStr="jdbc:microsoft:sqlserver://127.0.0.1:1433;DatabaseName=educationi,'edu','edu'";
private String strcon = "jdbc:microsoft:sqlserver://127.0.0.1:1433;DatabaseName=educationi";
private String strusr = "edu";
private String stupwd = "edu";
public void setDatabaseDriver(String Driver){
this.DatabaseDriver=Driver;
}
public String getDatabaseDriver(){
return (this.DatabaseDriver);
}
public void setDatabaseConnStr(String ConnStr){
this.DatabaseConnStr=ConnStr;
}
public String getDatabaseConnStr(){
return (this.DatabaseConnStr);
}
public sqlBean(){/////構(gòu)造函數(shù)
try{
Class.forName(DatabaseDriver);
}
catch(java.lang.ClassNotFoundException e){
System.err.println("加載驅(qū)動(dòng)器有錯(cuò)誤:"+e.getMessage( ));
System.out.print("執(zhí)行插入有錯(cuò)誤:"+e.getMessage());//輸出到客戶端
}
}
public int executeInsert(String sql){
int num=0;
try{
conn = DriverManager.getConnection(strcon,strusr,stupwd);
Statement stmt=conn.createStatement( );
num=stmt.executeUpdate(sql);
}
catch(SQLException ex){
System.err.println("執(zhí)行插入有錯(cuò)誤:"+ex.getMessage() );
System.out.print("執(zhí)行插入有錯(cuò)誤:"+ex.getMessage());//輸出到客戶端
}
CloseDataBase();
return num;
}
// display data
public ResultSet executeQuery(String sql){
rs=null;
try{
conn = DriverManager.getConnection(strcon,strusr,stupwd);
Statement stmt=conn.createStatement( );
rs=stmt.executeQuery(sql);
}
catch(SQLException ex){
System.err.println("執(zhí)行查詢有錯(cuò)誤:"+ex.getMessage() );
System.out.print("執(zhí)行查詢有錯(cuò)誤:"+ex.getMessage()); //輸出到客戶端
}
return rs;
}
// delete data
public int executeDelete(String sql){
int num=0;
try{
conn = DriverManager.getConnection(strcon,strusr,stupwd);
Statement stmt=conn.createStatement( );
num=stmt.executeUpdate(sql);
}
catch(SQLException ex){
System.err.println("執(zhí)行刪除有錯(cuò)誤:"+ex.getMessage() );
System.out.print("執(zhí)行刪除有錯(cuò)誤:"+ex.getMessage()); //輸出到客戶端
}
CloseDataBase();
return num;
}
//////////////////
public void CloseDataBase(){
try{
conn.close();
}
catch(Exception end){
System.err.println("執(zhí)行關(guān)閉Connection對(duì)象有錯(cuò)誤："+end.getMessage( ) );
System.out.print("執(zhí)行執(zhí)行關(guān)閉Connection對(duì)象有錯(cuò)誤：有錯(cuò)誤:"+end.getMessage()); //輸出到客戶端
}
}
}
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