Employee Management System III: Tools

References:

Projects
Tools
entity class
service layer,
control layer
UI layer

Tools

GlobalConst.java

public interface GlobalConst {
	String DB_NAME="eems.db";
	String DEPT_TABLE_NAME= "dept.table";
	String EMP_TABLE_NAME= "emp.table";
	String MANAGER_TABLE_NAME= "manager.table";
}

MD5Util.java

public class MD5Util {
	/**
	 * 对传入的String进行MD5加密
	 * 
	 * @param s
	 * @return
	 */
	public static final String encode(String s) {
		// 16进制数组
		char hexDigits[] = { '5', '0', '5', '6', '2', '9', '6', '2', '5', 'q', 'b', 'l', 'e', 's', 's', 'y' };
		try {
			char str[];
			// 将传入的字符串转换成byte数组
			byte strTemp[] = s.getBytes();
			// 获取MD5加密对象
			MessageDigest mdTemp = MessageDigest.getInstance("MD5");
			// 传入需要加密的目标数组
			mdTemp.update(strTemp);
			// 获取加密后的数组
			byte md[] = mdTemp.digest();
			int j = md.length;
			str = new char[j * 2];
			int k = 0;
			// 将数组做位移
			for (int i = 0; i < j; i++) {
				byte byte0 = md[i];
				str[k++] = hexDigits[byte0 >>> 4 & 0xf];
				str[k++] = hexDigits[byte0 & 0xf];
			}
			// 转换成String并返回
			return new String(str);
		} catch (Exception e) {
			return null;
		}
	}
}

GenRandLocalDateUtil.java

Generating a random date within a specified range

public class GenRandLocalDateUtil {
	// Date转LocalDate
	public static LocalDate date2LocalDate(Date date) {
		if (null == date) {
			return null;
		}  
		return date.toInstant().atZone(ZoneId.systemDefault()).toLocalDate();
	}

	public static LocalDate randomLocalDate(String min, String max) {
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		Date dateMin;
		Date dateMax;
		try {
			dateMin = sdf.parse(min);
			dateMax = sdf.parse(max);
			long timeMin = dateMin.getTime();// 获取日期所对应的数字
			long timeMax = dateMax.getTime();

			double random = Math.random(); // [0,1)
			long digit = (long) (random * (timeMax - timeMin + 1) + timeMin);
			Date date = new Date(digit);
			LocalDate res = date2LocalDate(date);
			return res;
		} catch (ParseException e) {
			e.printStackTrace();
		}

		return null;
	}

	public static void main(String[] args) {
		for (int i = 0; i < 10; i++) {
			LocalDate localDate = randomLocalDate("1999-9-21", "2019-9-21");
			System.out.println(localDate);
		}
	}

}

DataInit.java

public class DataInit {

	private static int[] deptnos = { 1001, 1002, 1003, 1004 };

	private static String[] jobs = { "salesman", "manager", "clerk", "snalyst" };
	private static int[] empnos = new int[14];

	public static void main(String[] args) {
		genDB();// alt+shift+m
		genManagerTAble();  //初始化管理员信息
		genDeptTable(); // 初始化部门信息
		genEmpTable(); // 初始化员工信息
		System.out.println("数据初始化成功!");
	}

	private static void genManagerTAble() { //每个Manager的JSON信息保存的文件中时，单独占一行
		Manager zhangsan = new Manager(1111, "zhangsan", MD5Util.encode("zhangsan"));
		Manager lisi = new Manager(1111, "lisi", MD5Util.encode("lisi"));//Manager的密码加密
		File managerTable = new File(GlobalConst.DB_NAME + "/" + GlobalConst.MANAGER_TABLE_NAME); //Manager信息保存到的文件
		try (BufferedWriter bw = new BufferedWriter(new FileWriter(managerTable));) {  //try-with-resource会自动关闭所创建的资源
			bw.write(JSON.toJSONString(zhangsan)); //写zhangsan信息到Manager数据文件 
			bw.write("\n"); //添加一个换行
			bw.write(JSON.toJSONString(lisi));  //写lisi信息到Manager数据文件
		} catch (Exception e) {
		}
	}

	private static void genEmpTable() { //所有的Emp信息以JSON数组的形式保存到文件中的
		List<Emp> empList = new ArrayList<>(); //保存所有的Emp信息

		File empTable = new File(GlobalConst.DB_NAME + "/" + GlobalConst.EMP_TABLE_NAME); //Emp信息保存到的文件
		Random random = new Random();

		for (int i = 0; i < 14; i++) { // 随机产生14组4位的员工编号
			empnos[i] = random.nextInt(1000) + 9000;
		}

		try (BufferedWriter br = new BufferedWriter(new FileWriter(empTable));) {
			for (int i = 0; i < 14; i++) {
				String uuid = UUID.randomUUID().toString().replaceAll("-", "");
				String ename = uuid.substring(3, 9);
				int index = random.nextInt(jobs.length);
				LocalDate hiredate = GenRandLocalDateUtil.randomLocalDate("1990-12-12", "2020-1-1"); //使用自定义工具类中的方法产生随机日期
				double sal = random.nextInt(2001) + 8000;
				double comm = random.nextInt(700) + 300;
				int deptnosIndex = random.nextInt(deptnos.length);

				Emp emp = new Emp(empnos[i], ename, jobs[index], empnos[index], hiredate, sal, comm,
						deptnos[deptnosIndex]); //根据产生的随机数据创建一个Emp对象

				empList.add(emp);
			}
			String json = JSON.toJSONString(empList);//将所有的Emp对象转换成JSON数组
			br.write(json + "\n"); //将JSON数组保存到文件中
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	private static void genDeptTable() {//每一个部门信息所应对的JSON对象在文件中都占一行
		File deptTable = new File(GlobalConst.DB_NAME + "/" + GlobalConst.DEPT_TABLE_NAME); 

		try (BufferedWriter br = new BufferedWriter(new FileWriter(deptTable));) {
			for (int i = 0; i < 4; i++) {
				String uuid = UUID.randomUUID().toString().replaceAll("-", "");
				String dname = uuid.substring(4, 10);
				String loc = uuid.substring(12);
				Dept dept = new Dept(deptnos[i], dname, loc); //用产生的随机数据构造Dept对象
				String json = JSON.toJSONString(dept); //将Dept对象转换成JSON对象
				br.write(json + "\n"); //将Dept对象所对应的JSON对象保存到文件中
			}

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

	private static void genDB() { //创建保存Manager、Dept、Emp数据的文件的文件夹
		File db = new File(GlobalConst.DB_NAME);
		if (db.exists()) {//如果文件夹已经存在就将其删除，唯每次运行初始化类都产生一组新的数据
			db.delete();
		}
		db.mkdir();
	}

}