Java implements SSH remote link server to export Excel and send it to the specified mailbox

Some client projects recently done need to send data to the account executive every day. Because I am lazy to send it every day, I wrote a small tool to realize the remote SSH connection to the server and export the data from the database to Excel and send it to the designated mailbox. I made a timer with linux, and sent it at a fixed time every day. I was lazy. The key code is below. The other tools used are simple to use, so I won't post it.

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;

import com.jcraft.jsch.JSch;
import com.jcraft.jsch.Session;
import com.mysql.jdbc.jdbc2.optional.MysqlDataSource;

import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Random;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

import javax.mail.MessagingException;
import javax.mail.internet.AddressException;


public class SQLConnection {
	private static Connection connection = null;
	private static Session session = null;
	private static String driverName = "com.mysql.jdbc.Driver";
	private static int localPort = 8740;// any free port can be used
	private static String mailUser = "***";
	private static String mailPwd = "***";
	private static String mail = "***";
	private static String mailSmtp = "smtp.qq.com";
	private static String rootPath;
	private static SystemConfig sysConfig;
	
	private static void connectToServer(SSHConfig sshConfig) throws SQLException {
		connectSSH(sshConfig);
		connectToDataBase(sshConfig);
	}
	
	/**
	 * 连接SSH
	 * @param sshConfig
	 * @throws SQLException
	 */
	private static void connectSSH(SSHConfig sshConfig) throws SQLException {
		if(session != null)
		{
			return;
		}
		try 
		{
			java.util.Properties config = new java.util.Properties();
			JSch jsch = new JSch();
			session = jsch.getSession(sshConfig.getSshUserName(), sshConfig.getSshHost(), sshConfig.getSshProt());
			session.setPassword(sshConfig.getSshPassword());
			
			config.put("StrictHostKeyChecking", "no");
			config.put("ConnectionAttempts", "3");
			session.setConfig(config);
			session.connect();

			System.out.println("SSH Connected");

			Class.forName(driverName).newInstance();

			int assinged_port = session.setPortForwardingL(localPort, sshConfig.getDbHost(), sshConfig.getDbProt());

			System.out.println("localhost:" + assinged_port + " -> " + sshConfig.getDbHost() + ":" + sshConfig.getDbProt());
			System.out.println("Port Forwarded");
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	/**
	 * 通过ssh连接数据库
	 * @param sshConfig
	 * @throws SQLException
	 */
	private static void connectToDataBase(SSHConfig sshConfig) throws SQLException {
		if(connection != null)
		{
			return;
		}
		String localSSHUrl = "localhost";
		try {

			// mysql database connectivity
			MysqlDataSource dataSource = new MysqlDataSource();
			dataSource.setServerName(localSSHUrl);
			dataSource.setPortNumber(localPort);
			dataSource.setUser(sshConfig.getDbUser());
			dataSource.setAllowMultiQueries(true);

			dataSource.setPassword(sshConfig.getDbPassword());
			dataSource.setDatabaseName(sshConfig.getDbDataBaseName());

			connection = dataSource.getConnection();

			System.out.print("Connection to server successful!:" + connection + "\n\n");
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	/**
	 * 关闭SSH连接与数据库连接
	 */
	private static void closeConnections() {
		CloseDataBaseConnection();
		CloseSSHConnection();
	}
	
	/**
	 * 关闭数据库
	 */
	private static void CloseDataBaseConnection() {
		try {
			if (connection != null && !connection.isClosed()) {
				System.out.println("Closing Database Connection");
				connection.close();
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}

	}
	
	/**
	 * 切换SSH配置
	 * 自动关闭上一个SSH连接等
	 * @param config
	 * @throws SQLException 
	 */
	public static void switchoverConfig(SSHConfig config) throws SQLException
	{
		closeConnections();
		connectToServer(config);
	}
	
	/**
	 * 关闭SSH
	 */
	private static void CloseSSHConnection() {
		if (session != null && session.isConnected()) {
			System.out.println("Closing SSH Connection");
			session.disconnect();
		}
	}

	/**
	 * 查询数据结果集
	 * @param query
	 * @return
	 */
	public static ResultSet executeMyQuery(String query) {
		ResultSet resultSet = null;
		try {
			Statement stmt = connection.createStatement();
			resultSet = stmt.executeQuery(query);
			System.out.println("Database connection success");
		} catch (SQLException e) {
			e.printStackTrace();
		}

		return resultSet;
	}
	
	public static void sendEmail(SSHConfig config)
	{
		try 
		{
			connectToServer(config);
			String date = DateUtils.getStrYesterdayDate();
			
			String sql = config.getSql().replace("{startDate}", date).replace("{endDate}", date);
			
			System.out.println(sql);
			ResultSet rs = executeMyQuery(sql);
			
			ResultSetMetaData rsmd = rs.getMetaData();
			
			int titleCount = rsmd.getColumnCount();
			
			String[][] titleName = new String[titleCount][2];
			
			for(int i = 0;i < titleCount;i++)
			{
				titleName[i][0] = rsmd.getColumnName(i + 1);
				titleName[i][1] = rsmd.getColumnName(i + 1);
			}
			
			List<Map<String,String>> dataMapList = new ArrayList<Map<String,String>>();
			Map<String,String> objectMap = null;
			
			while(rs.next()) {  
				objectMap = new HashMap<>();
				
				for(int i = 0;i < titleCount;i++)
				{
					objectMap.put(titleName[i][0], rs.getString(i + 1));
				}
				
				dataMapList.add(objectMap);
			}
			
			ExportExcel excel = null;
			
			String title = config.getTitle() + DateUtils.getStrDate();
			String content = title + "数据 ,发送时间 ：" + DateUtils.getStrDateTime();
			
			excel = new ExportExcel("Sheet1", titleName, dataMapList);
			String filePath = rootPath + title + ".xls";
			
			excel.save(rootPath, title + ".xls");
			
			MailUtil.send(config.getToEmail(), mail, title, content, mailSmtp, mailUser, mailPwd,"自动发送", filePath);
			System.out.println("source send Email!");
		} catch (Exception s) {
			s.printStackTrace();
		}
	}
	
	/** 
	 * 获取指定时间对应的毫秒数 
	 * @param time "HH:mm:ss" 
	 * @return 
	 */  
	private static long getTimeMillis(String time) {  
	    try {  
	        DateFormat dateFormat = new SimpleDateFormat("yy-MM-dd HH:mm:ss");  
	        DateFormat dayFormat = new SimpleDateFormat("yy-MM-dd");  
	        Date curDate = (Date) dateFormat.parse(dayFormat.format(new Date()) + " " + time);  
	        return curDate.getTime();  
	    } catch (ParseException e) {  
	        e.printStackTrace();  
	    }  
	    return 0;  
	}  
	
	public static void main(String[] args) {
		
		sysConfig = SystemConfig.instants();
		
		rootPath = sysConfig.getValue("rootPath");
		
		SSHConfig config = new SSHConfig();
		
		config.setSshHost(sysConfig.getValue("sshHost"));
		config.setSshProt(sysConfig.getIntValue("sshProt"));
		config.setSshUserName(sysConfig.getValue("sshUserName"));
		config.setSshPassword(sysConfig.getValue("sshPassword"));
		
		config.setDbHost(sysConfig.getValue("dbHost"));
		config.setDbProt(sysConfig.getIntValue("dbProt"));
		config.setDbUser(sysConfig.getValue("dbUser"));
		config.setDbPassword(sysConfig.getValue("dbPassword"));
		config.setDbDataBaseName(sysConfig.getValue("dbDataBaseName"));
		
		config.setTitle(sysConfig.getValue("title"));
		config.setSql(sysConfig.getValue("sql"));
		config.setToEmail(sysConfig.getValue("toEmail"));
		
		sendEmail(config);
		/*
		Runnable runnable = new Runnable() {  
            public void run() {  
            	try {  
                    Thread.sleep(50);  
                } catch (InterruptedException e) {  
                    e.printStackTrace();  
                }  
                System.out.println("This is a echo server. The current time is " +  System.currentTimeMillis() + ".");  
                
            }  
        };  
        
        long oneDay = 24 * 60 * 60 * 1000;  
        long initDelay  = getTimeMillis("12:29:00") - System.currentTimeMillis();  
        
        System.out.println(initDelay);
        System.out.println(oneDay);
        
        initDelay = initDelay > 0 ? initDelay : oneDay + initDelay;  
        
        
        ScheduledExecutorService service = Executors.newSingleThreadScheduledExecutor();  
        // 第二个参数为首次执行的延时时间，第三个参数为定时执行的间隔时间  
       // service.scheduleAtFixedRate(runnable, 1, 1, TimeUnit.MINUTES);  
        
        service.scheduleAtFixedRate(  
        		runnable,  
                initDelay,  
                oneDay,  
                TimeUnit.MILLISECONDS); 
                */
	}
	
}