增删节

增删改
package com.commom;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Map;
import java.util.TreeMap;

import com.commom.ReadXml;

public class BaseDao {

    public Connection conn =null;//连接变量
    public ResultSet rs=null;//数据集
    public PreparedStatement pstmt=null;//预处理
   
    //打开连接
    public void openConnection(){
    if(conn==null){
    try{
    Class.forName("com.mysql.jdbc.Driver");
conn=DriverManager.getConnection(new ReadXml().Constring());
System.out.println("连接成功");
    }
    catch(SQLException ex){
     System.out.println(ex.getMessage()+"路径错误");
     }
catch(ClassNotFoundException ex){
     System.out.println(ex.getMessage()+"驱动错误");
}
finally{
}
    }
    }
    //关闭连接释放资源
    public void dispose(){
    try {
if(rs!=null)rs.close();
if(pstmt!=null)pstmt.close();
if(conn!=null)conn.close();
System.out.println("关闭成功");
}
catch (SQLException e) {
e.printStackTrace();
}
    }

   /*
    * 添加
   */  
    public int Insert(String tablename,Map map) throws Exception{
    String[] s=this.getInsert(map);
    String sqlstr="Insert into "+tablename+" ("+s[0]+")values("+s[1]+")";
    System.out.println(sqlstr);
    return ExecuteNonQuery(sqlstr);
    }
      /*
    * 修改
   */
    public void Update(String tablename,Map map,String where) throws Exception{
    String sqlstr="UPDATE "+tablename+" set "+getUpdate(map)+" WHERE "+where;
    this.ExecuteNonQuery(sqlstr);
    }
      /*
    * 删除
   */
    public boolean Delete(String tablename,String where) throws Exception{
    String sqlstr="DELETE FROM "+tablename+" WHERE "+where;
    return ExecuteNonQuery(sqlstr)>0? true:false;
    }

    /*
     * Update语句
     */
    private String getUpdate(Map map){
    int i=map.size();
    String s="";
    if(i>0){
    Iterator iter=map.keySet().iterator();
    while(iter.hasNext()){
    Object key=iter.next();
    if(i>1){
         s+=key.toString()+"="+this.getvalue(map.get(key))+",";
         i--;
         }else{
        s+=key.toString()+"="+this.getvalue(map.get(key));
         }
    }
    }
    return s;
    }
   
    /*
     * 添加语句
     */
    private String[] getInsert(Map map){
    int i=map.size();
    String s1="";
    String s2="";
    if(i>0){
    Iterator iter=map.keySet().iterator();
    while(iter.hasNext()){
    Object key=iter.next();
    if(i>1){
         s1+=key.toString()+",";
         s2+=this.getvalue(map.get(key))+",";
         i--;
         }else{
        s1+=key.toString();
        s2+=this.getvalue(map.get(key));
         }
    }
    }
    String[] s=new String[]{s1,s2};
    return s;
    }
   
    /*
     * 传入object返回所需string，判断类型形成语句
     */
    private String getvalue(Object o){
    //System.out.println(o);
    if (o instanceof Integer) {
            return o.toString();
        } else if (o instanceof String) {
            String s = (String) o;
            s=this.sql_inj(s);
            return "'"+s+"'";
        } else if (o instanceof Double) {
        return o.toString();
        }else if (o instanceof Short) {
        return o.toString();
        }
        else{
        return "''";
        }
    }
     /*
      * 过滤防注入
      */
    public String sql_inj(String s){
    String key="select|update|delete|count|*|sum|master|script|'|declare|or|execute|alter|statement|executeQuery|count|executeUpdate";
    String f[] = key.split("|");
    for(int i=0; i<f.length;i++) {
    s.replace(f[i], "");
    }
    return s;
    }
   
    /** 
     * 用于执行语句（eg：insert语句，update语句，delete语句） 
     *  
     * @param String 
     *            sqlstr,SQL语句 
     * @param sqlParameter[] 
     *            parms,参数集合 
     * @return int,SQL语句影响的行数 
    */ 
    public int ExecuteNonQuery(String sqlstr)  
    throws Exception {      
        try {  
             this.openConnection();
            pstmt = conn.prepareStatement(sqlstr); 
            System.out.println(pstmt.toString());
            int i=pstmt.executeUpdate(); 
            rs= pstmt.getGeneratedKeys();
            if ( rs != null && rs.next() )
            {
            return rs.getInt(1);
            }else{
            return i;
            }
        } catch (Exception e) {  
            throw new Exception("executeNonQuery方法出错:" + e.getMessage());  
        } finally {  
        this.dispose();
        }  
    }        
}