inventory.java

这是一个库存管理系统

import java.sql.*;

import javax.swing.JOptionPane;


public class Inventory extends SortedList {
	//存货清单构造函数
	public Inventory() {
		super(100, new ItemComparer());
		String str1,str2;
		double p;
		int  u; 
		String sqlstr;
		sqlstr="select * from 库存";
		
		
		try
		{  Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
           Connection con=DriverManager.getConnection("jdbc:odbc:库存");
		   Statement stmt=con.createStatement();
		   ResultSet result=stmt.executeQuery(sqlstr);
		      
	     while(result.next())
	         {  
	    	 str1=result.getString(1);
	          str2=result.getString(2);
	          p=result.getDouble(3);
	          u=result.getInt(4);
	          add(new InventoryItem(str1,str2,p,u));
	         }
		}
		catch(ClassNotFoundException e)
		 {System.err.println(e.getMessage());
		 }
		catch(SQLException e)
		 {System.err.println(e.getMessage());
		 }
		
	}

	//根据用户输入的id，返回相应的存货条目，不存在的话，返回null
	public InventoryItem getPart(String _id) {
		int index = indexOf(new Item(_id));
		if (index >= 0)
			return (InventoryItem) get(index);
		else
			return null;
	}

	//在存货清单中，根据用户输入的id和用户输入的数量，增加相应货物的数量
	public void addUnits(String _id, int _number) {
		InventoryItem item = getPart(_id);
		if (item != null)
		{   int n=_number;
           
             String sqlstr="update 库存 set units=units+'"+n+"' where ID="+"'"+_id+"'";
		    try
		   {  Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
              Connection con=DriverManager.getConnection("jdbc:odbc:库存");
		      Statement stmt=con.createStatement();
		   // ResultSet result=stmt.executeQuery(sqlstr);
		   }
		  catch(ClassNotFoundException e)
		   {System.err.println(e.getMessage());
		    }
		   catch(SQLException e)
		 {System.err.println(e.getMessage());
		 }
			item.add(_number);} 
		else
			JOptionPane.showMessageDialog(null, "没有找到和输入ID对应的项！", "警告",
					JOptionPane.ERROR_MESSAGE);
	}

	//在存货清单中，根据用户输入的id和用户输入的数量，减少相应货物的数量
	public void removeUnits(String _id, int _number) {
		InventoryItem item = getPart(_id);
		if ((item != null) && (item.units >= _number) && (_number >= 0))
			   {     
			int n=_number;
            String sqlstr;
            sqlstr="update 库存 set units=units-'"+n+"' where ID="+"'"+_id+"'";
		    try
		       {  Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
                  Connection con=DriverManager.getConnection("jdbc:odbc:库存");
		         Statement stmt=con.createStatement();
		         ResultSet result=stmt.executeQuery(sqlstr);
		       }
		  catch(ClassNotFoundException e)
		       {System.err.println(e.getMessage());
		       }
		   catch(SQLException e)
		       {System.err.println(e.getMessage());
		       }
			         item.remove(_number);
			    }
		else
			JOptionPane.showMessageDialog(null, "没有找到和输入ID对应的项或空间不足！", "警告",
					JOptionPane.ERROR_MESSAGE);
	}
}