package com.hcks.cmfds.commons.util;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.HashSet;
import java.util.Set;

import javax.sql.DataSource;

import org.apache.log4j.Logger;

import com.hcks.cmfds.core.exception.JdbcDaoException;

/**
 * 
 * 
 * @Author  刘厦 (liusha.information@gmail.com)
 * @Date  创建时间：2011-7-19,上午10:06:06
 * @Version 0.0.0
 *
 * 类说明: 
 *
 */
public class DataBaseHelper {
	
	protected final Logger logger = Logger.getLogger(DataBaseHelper.class);
	
	/**
	 * 获取数据库表
	 * @param dataSource
	 * @return
	 */
	public static Set<String> getTablesByDataSource(DataSource dataSource){
		Set<String> tables = new HashSet<String>();
		ResultSet _result = null;
		Connection conn = null;
		try {
			conn = dataSource.getConnection();
			_result = conn.getMetaData().getTables(null, "%", "%", new String[]{"TABLE"});
			while (_result.next()) {
				String tableName = _result.getString("TABLE_NAME");
				tables.add(tableName);
			}
		} catch (SQLException e) {
			try {
				conn.close();
			} catch (SQLException e1){
				e.printStackTrace();
			}
			throw new JdbcDaoException("获取元数据错误！");
		} finally{
			_result = null;
			try {
				conn.close();
			} catch (SQLException e2){
				e2.printStackTrace();
			}
		}
		
		return tables;
	}
	
	/**
	 * 获取表的主键集合
	 * @param tableName
	 * @return
	 */
	public static Set<String> getTablePrimaryKeyFieldNames(String tableName,DataSource dataSource) {
		Set<String> pks = new HashSet<String>();
		ResultSet _result = null;
		Connection conn = null;
		try {
			conn = dataSource.getConnection();
			_result = conn.getMetaData().getPrimaryKeys(null, null, tableName);
			while (_result.next()) {
				pks.add(_result.getString(4));
			}
		} catch (SQLException e) {
			try {
				conn.close();
			} catch (SQLException e1){
				e.printStackTrace();
			}
			throw new JdbcDaoException("获取元数据错误！");
		} finally{
			_result = null;
			try {
				conn.close();
			} catch (SQLException e2){
				e2.printStackTrace();
			}
		}
		return pks;
	}
	
	/**
	 * 获取表的所有字段
	 * @param tableName
	 * @return
	 */
	public static Set<String> getTableFieldNames(String tableName,DataSource dataSource){
		Set<String> columns = new HashSet<String>();
		ResultSet _result = null;
		Connection conn = null;
		try {
			conn = dataSource.getConnection();
			_result = conn.getMetaData().getColumns(null, "%", tableName, "%");
			while (_result.next()) {
				String columnName = _result.getString("COLUMN_NAME");
				columns.add(columnName);
			}
		} catch (SQLException e) {
			try {
				conn.close();
			} catch (SQLException e1){
				e.printStackTrace();
			}
			throw new JdbcDaoException("获取元数据错误！");
		} finally{
			_result = null;
			try {
				conn.close();
			} catch (SQLException e2){
				e2.printStackTrace();
			}
		}
		return columns;
	}
	
	
	
	
	
	/**
	 * 判断表是否是单主键
	 * @param tableName
	 * @return
	 */
	public boolean isSinglePk(String tableName,DataSource dataSource){
		return getTablePrimaryKeyFieldNames(tableName,dataSource).size() == 1;
	}

}