daoimp.java

企业进销存源码

package com.dao.util;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.sql.*;
import javax.sql.*;

/**
 * @author 
 *
 * 数据库操作的实现
 */
public class DaoImp {

	/**
	 * @see com.westcn.util.business.core.dao.Dao#insert(String)
	 */
	public int insert(String sql) throws Exception {
		
		Connection conn=null;
		Statement stmt=null;
		int result=0;
		try{
			DbConnect db = new DbConnect();
			conn=db.getConnection();
			stmt=conn.createStatement();
			result=stmt.executeUpdate(sql);
			return result;
			
		}catch(Exception e){
			Exception ke=new Exception("操作数据库出错！DAO Insert方法!!SQL:"+sql);
			e.printStackTrace();
			throw ke;
		}finally{
			try {
				conn.close();
				stmt.close();
			} catch (SQLException e) {
				//System.out.println("关闭连接失败");
			}
		}
	}

	/**
	 * @see com.westcn.util.business.core.dao.Dao#delete(String)
	 */
	public int delete(String sql) throws Exception {
		Connection conn=null;
		Statement stmt=null;
		int result=0;
		try{
			DbConnect db = new DbConnect();
			conn=db.getConnection();
			stmt=conn.createStatement();
			result=stmt.executeUpdate(sql);
			return result;
			
		}catch(Exception e){
			Exception ke=new Exception("操作数据库出错！DAO Delete方法!!SQL:"+sql);
			throw ke;
		}finally{
			try {
				conn.close();
				stmt.close();
			} catch (SQLException e) {
				//System.out.println("关闭连接失败");
			}
		}
	}

	/**
	 * @see com.westcn.util.business.core.dao.Dao#find(String)
	 */
	public HashMap find(String sql) throws Exception {
		Connection conn=null;
		Statement stmt=null;
		ResultSet rs=null;
		try{
			DbConnect db = new DbConnect();
			conn=db.getConnection();
			stmt=conn.createStatement();
			rs=stmt.executeQuery(sql);
			HashMap map=new HashMap();
			ResultSetMetaData meta;
			meta=rs.getMetaData();
			int cc;
			cc=meta.getColumnCount();
			if(rs.next()){
				String tbl=meta.getTableName(1);
				
				for(int i=1;i<=cc;i++){
					String name=meta.getColumnLabel(i).toUpperCase();
					Object val=rs.getObject(i);
					if(val==null){
						val="";
					}
					if(val.equals("null")){
						val="";
					}
					map.put(name,val);
				}
				
			}
			
			return map;
		}catch(Exception e){
			Exception ke=new Exception("操作数据库出错！DAO Find方法!!SQL:"+sql);
			throw ke;
		}finally{
			try {
				rs.close();
				stmt.close();
				conn.close();
				
			} catch (Exception e) {
				//System.out.println("关闭连接失败");
			}
		}
	}

	/**
	 * @see com.westcn.util.business.core.dao.Dao#select(String)
	 */
	public List select(String sql) throws Exception {
		Connection conn=null;
		Statement stmt=null;
		ResultSet rs=null;
		List list=new ArrayList(); 
		
		try{
			
			DbConnect db = new DbConnect();
			conn=db.getConnection();
			stmt=conn.createStatement();
			rs=stmt.executeQuery(sql);
			ResultSetMetaData meta;
			meta=rs.getMetaData();
			int cc;
			cc=meta.getColumnCount();
			
			while(rs.next()){
				
				HashMap map=new HashMap();
				String tbl=meta.getTableName(1);
				
				for(int i=1;i<=cc;i++){
					String name=meta.getColumnLabel(i).toUpperCase();
					Object val=rs.getObject(i);
					if(val==null){
						val="";
					}
					if(val.equals("null")){
						val="";
					}
					map.put(name,val);
				}
				list.add(map);
				
			}
			return list;
		}catch(Exception e){
			Exception ke=new Exception("操作数据库出错！DAO Find方法!!SQL:"+sql);
			throw ke;
		}finally{
			try {
				conn.close();
				stmt.close();
				rs.close();
			} catch (Exception e) {
				//System.out.println("关闭连接失败");
			}
		}
	}

	/**
	 * @see com.westcn.util.business.core.dao.Dao#insertN(String)
	 */
	public int insertN(String sql) throws Exception {
		return 0;
	}

	/**
	 * @see com.westcn.util.business.core.dao.Dao#update(String)
	 */
	public int update(String sql) throws Exception {
		Connection conn=null;
		Statement stmt=null;
		int result=0;
		try{
			DbConnect db = new DbConnect();
			conn=db.getConnection();
			stmt=conn.createStatement();
			result=stmt.executeUpdate(sql);
			return result;
			
		}catch(Exception e){
			Exception ke=new Exception("操作数据库出错！DAO Update方法!!SQL:"+sql);
			throw ke;
		}finally{
			try {
				conn.close();
				stmt.close();
			} catch (SQLException e) {
				//System.out.println("关闭连接失败");
			}
		}
	}

	/**
	 * @see com.westcn.util.business.core.dao.Dao#updateN(String)
	 */
	public Collection updateN(String sql) throws Exception {
		return null;
	}

}