/**
 *  Title  pams
 *  @author: dzc
 *  Company: hust
 *  @version 1.0
 *  Date  :   2006-04
 *  Filename:DBConnect.java
 **/

package pams.database; 

import java.sql.*;
import pams.database.DBConnectionManager;

public class DBConnect {
	private Connection conn = null;

	private Statement stmt = null;

	private PreparedStatement prepstmt = null;

	private DBConnectionManager dcm = null;

	void init() {
		dcm = DBConnectionManager.getInstance();
		conn = dcm.getConnection("sqlserver");
	}

	/**
	 * 構造數據庫的連接和訪問類
	 */
	public DBConnect() throws Exception {
		init();
		stmt = conn.createStatement();
	}

	public DBConnect(int resultSetType, int resultSetConcurrency)
			throws Exception {
		init();
		stmt = conn.createStatement(resultSetType, resultSetConcurrency);
	}

	/**
	 * 構造數據庫的連接和訪問類 預編譯SQL語句
	 * 
	 * @param sql
	 *            SQL語句
	 */
	public DBConnect(String sql) throws Exception {
		init();
		this.prepareStatement(sql);
	}

	public DBConnect(String sql, int resultSetType, int resultSetConcurrency)
			throws Exception {
		init();
		this.prepareStatement(sql, resultSetType, resultSetConcurrency);
	}

	/**
	 * 返回連接
	 * 
	 * @return Connection 連接
	 */
	public Connection getConnection() {
		return conn;
	}

	/**
	 * PreparedStatement
	 * 
	 * @param  sql 預設SQL語句
	 */
	public void prepareStatement(String sql) throws SQLException {
		prepstmt = conn.prepareStatement(sql);
	}

	public void prepareStatement(String sql, int resultSetType,
			int resultSetConcurrency) throws SQLException {
		prepstmt = conn.prepareStatement(sql, resultSetType,
				resultSetConcurrency);
	}

	/**
	 * 設置對應值
	 * 
	 * @param index
	 *            參數索引
	 * @param value
	 *            對應值
	 */
	public void setString(int index, String value) throws SQLException {
		prepstmt.setString(index, value);
	}

	public void setInt(int index, int value) throws SQLException {
		prepstmt.setInt(index, value);
	}

	public void setBoolean(int index, boolean value) throws SQLException {
		prepstmt.setBoolean(index, value);
	}

	public void setDate(int index, Date value) throws SQLException {
		prepstmt.setDate(index, value);
	}

	public void setTimestamp(int index, Timestamp value) throws SQLException {
		prepstmt.setTimestamp(index, value);
	}

	public void setLong(int index, long value) throws SQLException {
		prepstmt.setLong(index, value);
	}

	public void setFloat(int index, float value) throws SQLException {
		prepstmt.setFloat(index, value);
	}

	public void setBytes(int index, byte[] value) throws SQLException {
		prepstmt.setBytes(index, value);
	}

	public void clearParameters() throws SQLException {
		prepstmt.clearParameters();
		prepstmt = null;
	}

	/**
	 * 返回預設狀態
	 */
	public PreparedStatement getPreparedStatement() {
		return prepstmt;
	}

	/**
	 * 返回狀態
	 * 
	 * @return Statement 狀態
	 */
	public Statement getStatement() {
		return stmt;
	}

	/**
	 * 執行SQL語句返回字段集
	 * 
	 * @param sql
	 *            SQL語句
	 * @return ResultSet 字段集
	 */
	public ResultSet executeQuery(String sql) throws SQLException {
		if (stmt != null) {
			return stmt.executeQuery(sql);
		} else
			return null;
	}

	public ResultSet executeQuery() throws SQLException {
		if (prepstmt != null) {
			return prepstmt.executeQuery();
		} else
			return null;
	}

	/**
	 * 執行SQL語句
	 * 
	 * @param sql
	 *            SQL語句
	 */
	public void executeUpdate(String sql) throws SQLException {
		if (stmt != null)
			stmt.executeUpdate(sql);
	}

	public void executeUpdate() throws SQLException {
		if (prepstmt != null)
			prepstmt.executeUpdate();
	}

	/**
	 * 關閉連接
	 */
	public void close() throws Exception {
		if (stmt != null) {
			stmt.close();
			stmt = null;
		}
		if (prepstmt != null) {
			prepstmt.close();
			prepstmt = null;
		}
		if (conn != null) {

			dcm.freeConnection("sqlserver", conn);

		}

	}
}