Question

jsp中使用<jsp:useBean>，但一定要把bean放进包内，才能正常运行，这是为什么？实在是想不通。

bean文件我已正确放入文件夹中。
C:\Program Files\Apache Software Foundation\Tomcat 5.0\webapps\ROOT\WEB-INF\classes

<jsp:useBean id="bb" scope="page" class="firm.firm" />
package firm;
import java.sql.*;
public class firm{
String sDBDriver="sun.jdbc.odbc.JdbcOdbcDriver";
String sConnStr="jdbc:odbc:db2";
private Connection conn=null;
private Statement stmt=null;
ResultSet rs=null;
public firm(){
try{
Class.forName(sDBDriver);
}catch(java.lang.ClassNotFoundException e){
System.err.println("firm():"+e.getMessage());
}
}
public ResultSet executeQuery(String sql){
rs=null;
try{
conn=DriverManager.getConnection(sConnStr);
stmt=conn.createStatement();
rs=stmt.executeQuery(sql);
}catch(SQLException ex){
System.err.println("aq.executeQuery:"+ex.getMessage());
}
return rs;
}
public void executeUpdate(String sql){
stmt=null;
rs=null;
try{
conn=DriverManager.getConnection(sConnStr);
stmt=conn.createStatement();
stmt.executeQuery(sql);
stmt.close();
conn.close();
}catch(SQLException ex){
System.err.println("aq.executeQuery:"+ex.getMessage());
}
}
public void closeStmt(){
try{
stmt.close();
}catch(SQLException e){
e.printStackTrace();
}
}
public void closeConn(){
try{
conn.close();
}catch(SQLException e){
e.printStackTrace();
}
}
}

Answer 1

java 的规定~~~~~~~~~~~~~