dbconnection.java

这个QQ通信系统项目是我之前发过类似的一个大的整合

package dao;

import java.sql.Connection;
import java.sql.DriverManager;
//import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class DBConnection {
	private static String driver = "com.microsoft.jdbc.sqlserver.SQLServerDriver";

	private static String url = "jdbc:microsoft:sqlserver://localhost:1433;DataBaseName=ohun";

	private static String user = "sa";

	private static String password = "sa";

	private static Connection conn = null;

	public DBConnection() {

	}

	public DBConnection(String serverName, String dataBase, String userName,
			String passWord) {
		this.connect(serverName, dataBase, userName, passWord);
	}

	public void connect(String serverName, String dataBase, String userName,
			String passWord) {
		try {
			Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
			conn = DriverManager.getConnection("jdbc:microsoft:sqlserver://"
					+ serverName + ":1433;databasename=" + dataBase, userName,
					passWord);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public static Connection getConn() { // 获得连接
		if (conn == null) { // 单例模式！
			try {
				Class.forName(driver);
				conn = DriverManager.getConnection(url, user, password);
			} catch (ClassNotFoundException e) {
				System.out.println("数据库驱动找不到！");
				e.printStackTrace();
			} catch (SQLException e) {
				while (e != null) {
					System.out.println("数据库没有启动！！");
					// e.printStackTrace();
					// e = e.getNextException();
				}
			}
		}

		return conn;
	}

	public static void close(Statement st) {
		try {
			if (st != null) {
				st.close();
			}

			if (conn != null) {
				conn.close();
				conn = null;
			}

		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

	public static void close(ResultSet rs, Statement st) {
		try {
			if (rs != null) {
				rs.close();
			}
			if (st != null) {
				st.close();
			}

			if (conn != null) {
				conn.close();
				conn = null;
			}

		} catch (SQLException e) {
			e.printStackTrace();
		}

	}
}