package com.zhel.jdbc2.jdbcUtil;

import java.lang.reflect.Field;
import java.sql.*;
import java.util.*;

import com.mchange.v2.c3p0.ComboPooledDataSource;


public class JdbcUtilsDao {
    private static ComboPooledDataSource cpds = new ComboPooledDataSource();
    private Connection connection;

    /**
     * 获得数据库的连接
     */
    public Connection getConnection() throws SQLException {
        this.connection = cpds.getConnection();
        return connection;
    }

    /**
     * 释放数据库
     */
    private void release(ResultSet resultSet, PreparedStatement pstmt) throws SQLException {
        if (resultSet != null) {
            resultSet.close();
        }
        if (pstmt != null) {
            pstmt.close();
        }
    }
    
    /**
     * 关闭数据库
     */
    public void closeConn() throws SQLException {
        this.connection.close();
    }

    
    /**
     * 增加、删除、改 操作<br/>
     * 
     * @param sql 使用占位符的 sql 语句
     * @param params
     */
    public int update(String sql, List<Object> params) throws SQLException {
        int result = -1;
        PreparedStatement pstmt = connection.prepareStatement(sql);
        int index = 1;
        if (params != null && !params.isEmpty()) {
            for (int i = 0; i < params.size(); i++) {
                pstmt.setObject(index++, params.get(i));
            }
        }
        result = pstmt.executeUpdate();
        this.release(null,pstmt);
        return result;
    }

    /**
     * 查询单条或单列记录
     * 
     * @param sql 使用占位符的 sql 语句
     * @param params
     */
    public Map<String, Object> querySimple(String sql, List<Object> params) throws SQLException {
        Map<String, Object> map = new HashMap<String, Object>();
        int index = 1;
        PreparedStatement pstmt = connection.prepareStatement(sql);
        if (params != null && !params.isEmpty()) {
            for (int i = 0; i < params.size(); i++) {
                pstmt.setObject(index++, params.get(i));
            }
        }
        ResultSet resultSet = pstmt.executeQuery();
        
        ResultSetMetaData metaData = resultSet.getMetaData(); // 查询结果的系统信息类
        int col_len = metaData.getColumnCount();
        while (resultSet.next()) {
            for (int i = 0; i < col_len; i++) {
                String cols_name = metaData.getColumnName(i + 1);
                Object cols_value = resultSet.getObject(cols_name);
                if (cols_value == null) {
                    cols_value = "";
                }
                map.put(cols_name, cols_value);
            }
        }
        this.release(resultSet,pstmt);
        return map;
    }

    /**
     * 查询多条记录
     * 
     * @param sql 使用占位符的 sql 语句
     * @param params
     */
    public List<Map<String, Object>> queryComplex(String sql, List<Object> params) throws SQLException {
        List<Map<String, Object>> list = new LinkedList<Map<String, Object>>();
        int index = 1;
        PreparedStatement pstmt = connection.prepareStatement(sql);
        if (params != null && !params.isEmpty()) {
            for (int i = 0; i < params.size(); i++) {
                pstmt.setObject(index++, params.get(i));
            }
        }
        ResultSet resultSet = pstmt.executeQuery();
        
        ResultSetMetaData metaData = resultSet.getMetaData(); // 查询结果的系统信息类
        int cols_len = metaData.getColumnCount();
        while (resultSet.next()) {
            Map<String, Object> map = new HashMap<String, Object>();
            for (int i = 0; i < cols_len; i++) {
                String cols_name = metaData.getColumnName(i + 1);
                Object cols_value = resultSet.getObject(cols_name);
                if (cols_value == null) {
                    cols_value = "";
                }
                map.put(cols_name, cols_value);
            }
            list.add(map);
        }
        this.release(resultSet,pstmt);
        return list;
    }

    /**
     * 通过反射机制查询单条或单列记录
     * 
     * @param sql 使用占位符的 sql 语句
     * @param params
     * @param cls
     */
    public <T> T querySimpleRef(String sql, List<Object> params, Class<T> cls) throws SQLException,
            InstantiationException, IllegalAccessException, NoSuchFieldException, SecurityException {
        T resultObject = null;
        int index = 1;
        PreparedStatement pstmt = connection.prepareStatement(sql);
        if (params != null && !params.isEmpty()) {
            for (int i = 0; i < params.size(); i++) {
                pstmt.setObject(index++, params.get(i));
            }
        }
        ResultSet resultSet = pstmt.executeQuery();
        
        ResultSetMetaData metaData = resultSet.getMetaData(); // 查询结果的系统信息类
        int cols_len = metaData.getColumnCount();
        while (resultSet.next()) {
            resultObject = cls.newInstance(); // 通过反射机制创建一个实例
            for (int i = 0; i < cols_len; i++) {
                String cols_name = metaData.getColumnName(i + 1).toLowerCase();
                Object cols_value = resultSet.getObject(cols_name);
                if (cols_value == null) {
                    cols_value = "";
                }
                Field field = cls.getDeclaredField(cols_name);
                field.setAccessible(true); // 打开javabean的访问权限
                field.set(resultObject, cols_value);
            }
        }
        this.release(resultSet,pstmt);
        return resultObject;
    }

    /**
     * 通过反射机制查询多条记录
     * 
     * @param sql 使用占位符的 sql 语句
     * @param params
     * @param cls
     */
    public <T> List<T> queryComplexRef(String sql, List<Object> params, Class<T> cls) throws SQLException,
            InstantiationException, IllegalAccessException, NoSuchFieldException, SecurityException {
        List<T> list = new LinkedList<T>();
        int index = 1;
        PreparedStatement pstmt = connection.prepareStatement(sql);
        if (params != null && !params.isEmpty()) {
            for (int i = 0; i < params.size(); i++) {
                pstmt.setObject(index++, params.get(i));
            }
        }
        ResultSet resultSet = pstmt.executeQuery();
        
        ResultSetMetaData metaData = resultSet.getMetaData();  // 查询结果的系统信息类
        int cols_len = metaData.getColumnCount();
        while (resultSet.next()) {
            T resultObject = cls.newInstance(); // 通过反射机制创建一个实例
            for (int i = 0; i < cols_len; i++) {
                String cols_name = metaData.getColumnName(i + 1).toLowerCase();
                Object cols_value = resultSet.getObject(cols_name);
                if (cols_value == null) {
                    cols_value = "";
                }
                Field field = cls.getDeclaredField(cols_name);
                field.setAccessible(true); // 打开javabean的访问权限
                field.set(resultObject, cols_value);
            }
            list.add(resultObject);
        }
        this.release(resultSet,pstmt);
        return list;
    }

}