创建并使用CallableStatement对象;

package com.test;
import java.sql.*;

/** *//**
* 此例说明的问题:创建并使用CallableStatement对象;
* @author     chb
*/

class Hello
...{
    
    /** *//**
    * 该方法用以显示结果集;
    */
    private static void showResultSet( ResultSet rs ) throws Exception...{
        System.out.println(" 编号 图书名称 图书单价 图书数量");
        while(rs.next())
        ...{
                int id=rs.getInt("ID");
                String book_name=rs.getString("book_name");
                double book_price=rs.getDouble("book_price");
                int book_quantity=rs.getInt("book_quantity");
                System.out.println(id+" "+book_name+" "+book_price+" "+book_quantity);
        }
    }
    
    public static void main(String args[])
    ...{
        try
        ...{
            /** *//**
            * 第一步：加载JDBC驱动;
            */
            Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
            
            /** *//**
            * 第二步：建立连接;
            */            
            String url="jdbc:odbc:bookdsn";         
            Connection con=DriverManager.getConnection(url,"sa","");
            
            /** *//**
            * 第三步：创建Statement，执行查询并得到结果集；
            */
            Statement stmt=con.createStatement(
                ResultSet.TYPE_SCROLL_INSENSITIVE,
                ResultSet.CONCUR_READ_ONLY);
            ResultSet rs=stmt.executeQuery("SELECT ID,book_name,book_price,book_quantity from book_stock");
            showResultSet(rs);

            /** *//**
            * 第四步：创建CallableStatement用于调用存储过程;
            * cstmt.getInt(3) -- 只能得到输出参数值;
            */
            CallableStatement cstmt=con.prepareCall("{call getQuantity(?,?,?)}");
            cstmt.setInt(1,3);
            cstmt.setString(2,"JAVA基础");
            cstmt.registerOutParameter(3,java.sql.Types.INTEGER);
            cstmt.execute();
            System.out.println( "图书数量:" + cstmt.getInt(3) );
            
            /** *//**
            * 第五步：关闭连接、结果集;
            */            
            rs.close();
            stmt.close();
            cstmt.close();
            con.close();
        }
         catch(Exception e)
        ...{
            System.out.println("发生异常:"+e);
        }
    }
}