dbmanager.java

这是我在北大青鸟accp4.0 第一学期 的java 项目<员工管理系统>,采用db,model,view,三层关系. 连接数据库驱动为jdbc 用eclipse完成的手写的窗体代码,

package com.accp.db;
import java.util.Vector;
import java.sql.*;

import javax.swing.table.DefaultTableModel;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.DefaultMutableTreeNode;
/**
 * 数据层
 * @author Administrator
 *
 */
public class DBManager {
	
	private Connection conn = null;
	private Statement stmt = null;
	private ResultSet rs = null;
	
	public String url="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=t52project";
	public String driver="com.microsoft.jdbc.sqlserver.SQLServerDriver";
	
	//得到连接语句对象
	private void getStmt() {
	    try {
	      //加载驱动
	      Class.forName(driver);	      
	      conn = DriverManager.getConnection(url,"sa","123");
	      //创建语句对象
	      stmt = conn.createStatement();
	    }
	    catch (Exception ex) {
	      System.out.println(ex.getMessage());
	    }
	  }	
	
   //增删改方法
   public int exeSql(String sql) {
     int i = 0;
     try {
       getStmt();
       i = stmt.executeUpdate(sql);
       stmt.close();
       conn.close();
     }
     catch (Exception ex) {
       System.out.println(ex.getMessage());
     }
     return i;
   }
   
   //查询方法(返回值为结果集)
   public ResultSet getRs(String sql) {
     try {
       getStmt();
       rs = stmt.executeQuery(sql);
     }
     catch (Exception ex) {
       System.out.println(ex.getMessage());
     }
     return rs;
   }
   
   //关闭方法
   public void close() {
     try {
       if (rs != null) {
         rs.close();
       }
       if (stmt != null) {
         stmt.close();
       }
       if (conn != null) {
         conn.close();
       }
     }
     catch (Exception ex) {
       System.out.println(ex.getMessage());
     }
   }

   public boolean display(String name,String pass){
	   getStmt();
           try
           {
                   stmt=conn.createStatement();
                   rs=stmt.executeQuery("select * from OPERATOR where name='"+name+"'");
                   while(rs.next()){
               
                      if(rs.getString(2).equals(pass))
                           {
                                 return true;
                           }else{
                        	   	 return false;
                           }
                   }
           }
           catch (SQLException e)
           {
                   e.printStackTrace();
           }
           finally{
                   if(conn!=null){
                           try
                           {
                                   conn.close();
                           }
                           catch (SQLException e)
                           {
                                   e.printStackTrace();
                           }

                   }
           }
           return false;
   }
   
	public DefaultTableModel getTableModel(String sql){
		   getStmt();
		Vector data=new Vector();
		Vector colName=null;
		try
		{
			stmt=conn.createStatement();
			rs=stmt.executeQuery(sql);
			ResultSetMetaData rsmd=rs.getMetaData();
			int col=rsmd.getColumnCount();

			while(rs.next()){
				Vector rowData=new Vector();
				colName=new Vector();
				for(int i=1;i<=col;i++){
					rowData.add(rs.getObject(i));
					colName.add(rsmd.getColumnName(i));
				}
				data.add(rowData);
			}
		}
		catch (Exception e)
		{
			e.printStackTrace();
		}	
	
		return new DefaultTableModel(data,colName);
	}
	public ResultSet getRowData(int id){		
		   getStmt();
		String sql="select * from region where id="+id+"";
		try {
			stmt=conn.createStatement();
			rs=stmt.executeQuery(sql);			
		} catch (Exception e) {
			e.printStackTrace();
		}
		return rs;		
	}
}