6段階目（DAOのデータ更新メソッドを作成→更新処理完成）

src/com/rhizome/example/dao/EmployeeDAO.java

@@ -61,13 +61,9 @@ public class EmployeeDAO {
 			this.stmt = con.prepareStatement(sql.toString());
 			rs = stmt.executeQuery();
 			while (rs.next()) {
-				EmployeeDTO dto = new EmployeeDTO();
+				EmployeeDTO dto = new EmployeeDTO(rs.getInt(ID_EMPLOYEE), rs.getString(NM_EMPLOYEE),
-				dto.setID_EMPLOYEE(rs.getInt("ID_EMPLOYEE"));
+						rs.getString(KN_EMPLOYEE), rs.getString(MAIL_ADDRESS), rs.getString(PASSWORD),
-				dto.setNM_EMPLOYEE(rs.getString("NM_EMPLOYEE"));
+						rs.getInt(ID_DEPARTMENT));
-				dto.setKN_EMPLOYEE(rs.getString("KN_EMPLOYEE"));
-				dto.setMAIL_ADDRESS(rs.getString("MAIL_ADDRESS"));
-				dto.setPASSWORD(rs.getString("PASSWORD"));
-				dto.setID_DEPARTMENT(rs.getInt("ID_DEPARTMENT"));
 				rtnList.add(dto);
 			}
 		} finally {
@@ -76,42 +72,159 @@ public class EmployeeDAO {
 		return rtnList;
 	}
 
-	//社員テーブルから指定された社員IDに一致するデータを取得し、DTOに設定の上、リスト形式で戻
+	/**
-	public List<EmployeeDTO> selectById(int id_employee) throws SQLException {
+	 * 社員テーブルから社員IDに合致する情報を取得する
-		List<EmployeeDTO> list = new ArrayList<>();
+	 * @param id
-		String sql = "SELECT * FROM employee WHERE ID_EMPLOYEE = ?";
+	 * 			検索する社員ID
+	 * @return 検索結果
+	 * @throws SQLException
+	 * @throws ClassNotFoundException
+	 * @throws NumberFormatException
+	 */
+	public List<EmployeeDTO> selectById​(int id)
+			throws SQLException, ClassNotFoundException, NumberFormatException {
+		List<EmployeeDTO> rtnList = new ArrayList<>();
+		StringBuilder sql = new StringBuilder();
+		sql.append(" SELECT ");
+		sql.append("    " + "*");
+		sql.append(" FROM ");
+		sql.append("    " + TBL_NAME);
+		sql.append(" WHERE ");
+		sql.append("    " + ID_EMPLOYEE);
+		sql.append(" = ");
+		sql.append("    " + id);
 		try {
 
 			this.stmt = con.prepareStatement(sql.toString());
-			this.stmt.setInt(1, id_employee);
+			rs = stmt.executeQuery();
-			this.rs = this.stmt.executeQuery();
 			while (rs.next()) {
-				EmployeeDTO dto = new EmployeeDTO();
+
-				dto.setID_EMPLOYEE(rs.getInt("ID_EMPLOYEE"));
+				EmployeeDTO dto = new EmployeeDTO(rs.getInt(ID_EMPLOYEE), rs.getString(NM_EMPLOYEE),
-				dto.setNM_EMPLOYEE(rs.getString("NM_EMPLOYEE"));
+						rs.getString(KN_EMPLOYEE), rs.getString(MAIL_ADDRESS), rs.getString(PASSWORD),
-				dto.setKN_EMPLOYEE(rs.getString("KN_EMPLOYEE"));
+						rs.getInt(ID_DEPARTMENT));
-				dto.setMAIL_ADDRESS(rs.getString("MAIL_ADDRESS"));
+				rtnList.add(dto);
-				dto.setPASSWORD(rs.getString("PASSWORD"));
+
-				dto.setID_DEPARTMENT(rs.getInt("ID_DEPARTMENT"));
-				list.add(dto);
 			}
 		} finally {
 			DbUtil.closeStatement(this.stmt);
-
 		}
-		return list;
+		if (rtnList.size() == 0) {
+			System.out.println("入力された値で情報がみつかりませんでした");
+		}
+		return rtnList;
 	}
 
-	// 社員テーブルから指定された社員IDに一致するデータを削除する
+	/**
-	public void empDelete(int id_employee) throws SQLException {
+	 * 社員テーブルの社員IDに合致する情報を削除する
-		String sql = "DELETE FROM employee WHERE ID_EMPLOYEE = ?";
+	 *
+	 * @param id
+	 *			削除ID
+	 * @throws ClassNotFoundException
+	 * @throws SQLException
+	 * @throws NumberFormatException
+	 */
+	public void empDelete​(int id)
+			throws ClassNotFoundException, SQLException, NumberFormatException {
+		StringBuilder sql = new StringBuilder();
+		sql.append(" DELETE ");
+		sql.append(" FROM ");
+		sql.append("    " + TBL_NAME);
+		sql.append(" WHERE ");
+		sql.append("    " + ID_EMPLOYEE);
+		sql.append(" = ");
+		sql.append("    " + id);
+
 		try {
-			this.stmt = con.prepareStatement(sql);
+			this.stmt = con.prepareStatement(sql.toString());
-			this.stmt.setInt(1, id_employee);
+			stmt.executeUpdate();
-			this.stmt.executeUpdate();
+			System.out.println("削除が完了しました");
+		} finally {
+			DbUtil.closeStatement(this.stmt);
+		}
 
+	}
+
+	/**
+	 * 社員テーブルに指定された情報を新規登録する
+	 *
+	 * @param name - 社員名
+	 * @param kana - 社員名カナ
+	 * @param mail - メールアドレス
+	 * @param pass - パスワード
+	 * @param depId - 部署ID
+	 * @throws NumberFormatException
+	 * @throws SQLException
+	 * @throws ClassNotFoundException
+	 */
+	public void empInsert​(String name, String kana, String mail, String pass, int depId)
+			throws NumberFormatException, SQLException, ClassNotFoundException {
+		StringBuilder sql = new StringBuilder();
+		sql.append(" INSERT ");
+		sql.append(" INTO ");
+		sql.append("    " + TBL_NAME);
+		sql.append(" ( " + NM_EMPLOYEE);
+		sql.append(" , " + KN_EMPLOYEE);
+		sql.append(" , " + MAIL_ADDRESS);
+		sql.append(" , " + PASSWORD);
+		sql.append(" , " + ID_DEPARTMENT + " ) ");
+		sql.append(" VALUES ");
+		sql.append(" ( '" + name);
+		sql.append("' , '" + kana);
+		sql.append("' , '" + mail);
+		sql.append("' , '" + pass);
+		sql.append("' , " + depId + " ) ");
+
+		try {
+			this.stmt = con.prepareStatement(sql.toString());
+			stmt.executeUpdate();
+			System.out.println("登録が完了しました");
 		} finally {
 			DbUtil.closeStatement(this.stmt);
 		}
 	}
+
+	/**
+	 * 社員テーブルの社員IDに合致する情報を更新する
+	 *
+	 * @param id - 社員ID
+	 * @param name - 社員名
+	 * @param kana - 社員名カナ
+	 * @param mail - メールアドレス
+	 * @param pass - パスワード
+	 * @param depId - 部署ID
+	 * @throws ClassNotFoundException
+	 * @throws SQLException
+	 * @throws NumberFormatException
+	
+	 */
+	public void empUpdate​(int id, String name, String kana, String mail, String pass, int depId)
+			throws ClassNotFoundException, SQLException, NumberFormatException {
+		StringBuilder sql = new StringBuilder();
+		sql.append(" UPDATE ");
+		sql.append("    " + TBL_NAME);
+		sql.append(" SET ");
+		sql.append("    " + NM_EMPLOYEE);
+		sql.append(" = '" + name + " ' ");
+		sql.append(" , " + KN_EMPLOYEE);
+		sql.append(" = '" + kana + " ' ");
+		sql.append(" , " + MAIL_ADDRESS);
+		sql.append(" = '" + mail + " ' ");
+		sql.append(" , " + PASSWORD);
+		sql.append(" = '" + pass + " ' ");
+		sql.append(" , " + ID_DEPARTMENT);
+		sql.append(" = " + depId);
+		sql.append(" WHERE ");
+		sql.append("    " + ID_EMPLOYEE);
+		sql.append(" = ");
+		sql.append("    " + id);
+
+		try {
+			this.stmt = con.prepareStatement(sql.toString());
+			stmt.executeUpdate();
+			System.out.println("更新が完了しました");
+		} finally {
+			DbUtil.closeStatement(this.stmt);
+		}
+
+	}
 }

src/com/rhizome/example/dto/EmployeeDTO.java

@@ -0,0 +1,79 @@
+package com.rhizome.example.dto;
+
+public class EmployeeDTO {
+	private int ID_EMPLOYEE;
+	private String NM_EMPLOYEE;
+	private String KN_EMPLOYEE;
+	private String MAIL_ADDRESS;
+	private String PASSWORD;
+	private int ID_DEPARTMENT;
+
+	public EmployeeDTO() {
+
+	}
+
+	public EmployeeDTO(int ID_EMPLOYEE, String NM_EMPLOYEE, String KN_EMPLOYEE, String MAIL_ADDRESS, String PASSWORD,
+			int ID_DEPARTMENT) {
+		setID_EMPLOYEE(ID_EMPLOYEE);
+		setNM_EMPLOYEE(NM_EMPLOYEE);
+		setKN_EMPLOYEE(KN_EMPLOYEE);
+		setMAIL_ADDRESS(MAIL_ADDRESS);
+		setPASSWORD(PASSWORD);
+		setID_DEPARTMENT(ID_DEPARTMENT);
+	}
+
+	public int getID_EMPLOYEE() {
+		return ID_EMPLOYEE;
+	}
+
+	public void setID_EMPLOYEE(int iD_EMPLOYEE) {
+		ID_EMPLOYEE = iD_EMPLOYEE;
+	}
+
+	public String getNM_EMPLOYEE() {
+		return NM_EMPLOYEE;
+	}
+
+	public void setNM_EMPLOYEE(String nM_EMPLOYEE) {
+		NM_EMPLOYEE = nM_EMPLOYEE;
+	}
+
+	public String getKN_EMPLOYEE() {
+		return KN_EMPLOYEE;
+	}
+
+	public void setKN_EMPLOYEE(String kN_EMPLOYEE) {
+		KN_EMPLOYEE = kN_EMPLOYEE;
+	}
+
+	public String getMAIL_ADDRESS() {
+		return MAIL_ADDRESS;
+	}
+
+	public void setMAIL_ADDRESS(String mAIL_ADDRESS) {
+		MAIL_ADDRESS = mAIL_ADDRESS;
+	}
+
+	public String getPASSWORD() {
+		return PASSWORD;
+	}
+
+	public void setPASSWORD(String pASSWORD) {
+		PASSWORD = pASSWORD;
+	}
+
+	public int getID_DEPARTMENT() {
+		return ID_DEPARTMENT;
+	}
+
+	public void setID_DEPARTMENT(int iD_DEPARTMENT) {
+		ID_DEPARTMENT = iD_DEPARTMENT;
+	}
+
+	public void showInfo() {
+		System.out.println(ID_EMPLOYEE + "\t" + NM_EMPLOYEE +
+				"\t" + KN_EMPLOYEE + "\t" + MAIL_ADDRESS +
+				"\t" + PASSWORD + "\t" + ID_DEPARTMENT);
+	}
+
+}

src/com/rhizome/example/main/Main.java

@@ -54,11 +54,13 @@ public class Main {
 			empSelect();
 			break;
 		case "2":
+			empInsert​();
 			break;
 		case "3":
+			empUpdate​();
 			break;
 		case "4":
-			empDelete();
+			empDelete​();
 			break;
 		case "9":
 			return;
@@ -71,6 +73,93 @@ public class Main {
 		}
 	}
 
+	/**
+	 * 社員テーブルの社員IDに合致する情報を更新する
+	 *
+	 * @throws ClassNotFoundException
+	 * @throws SQLException
+	 * @throws NumberFormatException
+	 */
+	public static void empUpdate​()
+			throws ClassNotFoundException, SQLException, NumberFormatException {
+		Connection con = DbUtil.getConnection();
+		EmployeeDAO empDao = new EmployeeDAO(con);
+		int id = Integer.parseInt(inputCheck("ID", true));
+
+		if (empDao.selectById​(id).size() == 0) {
+			return;
+		}
+		String name = inputCheck("社員名", false);
+		String kana = inputCheck("フリガナ", false);
+		String mail = inputCheck("メールアドレス", false);
+		String pass = inputCheck("パスワード", false);
+		int depId = Integer.parseInt(inputCheck("部署ID", true));
+
+		try {
+			empDao.empUpdate​(id, name, kana, mail, pass, depId);
+		} finally {
+			DbUtil.closeConnection(empDao.con);
+		}
+	}
+
+	/**
+	 * 社員テーブルに指定された情報を新規登録する
+	 * @throws NumberFormatException
+	 * @throws SQLException
+	 * @throws ClassNotFoundException
+	 */
+	public static void empInsert​()
+			throws NumberFormatException, SQLException, ClassNotFoundException {
+		Connection con = DbUtil.getConnection();
+		EmployeeDAO empDao = new EmployeeDAO(con);
+
+		String name = inputCheck("社員名", false);
+		String kana = inputCheck("フリガナ", false);
+		String mail = inputCheck("メールアドレス", false);
+		String pass = inputCheck("パスワード", false);
+		int depId = Integer.parseInt(inputCheck("部署ID", true));
+
+		try {
+			empDao.empInsert​(name, kana, mail, pass, depId);
+		} finally {
+			DbUtil.closeConnection(empDao.con);
+		}
+
+	}
+
+	/**
+	 * 社員テーブルの社員IDに合致する情報を削除する
+	 *
+	 * @throws ClassNotFoundException
+	 * @throws SQLException
+	 */
+	public static void empDelete​()
+			throws ClassNotFoundException, SQLException, NumberFormatException {
+		List<EmployeeDTO> rtnList = new ArrayList<>();
+		Connection con = DbUtil.getConnection();
+		EmployeeDAO empDao = new EmployeeDAO(con);
+		int id = Integer.parseInt(inputCheck("ID", true));
+		rtnList = empDao.selectById​(id);
+		if (rtnList.size() == 0) {
+			return;
+		}
+
+		System.out.println("指定されたIDの情報を削除します？ Y/y\r\n"
+				+ "（Y/y以外の入力であればキャンセル）");
+
+		String str = inputCheck(false);
+
+		if (!str.equalsIgnoreCase("y")) {
+			System.out.println("キャンセルしました");
+			return;
+		}
+		try {
+			empDao.empDelete​(id);
+		} finally {
+			DbUtil.closeConnection(empDao.con);
+		}
+	}
+
 	/**
 	 * 社員テーブルから情報を検索する
 	 *
@@ -89,58 +178,19 @@ public class Main {
 				empList = empDao.selectAll();
 				break;
 			case "2":
-				String inputId = inputCheck("検索する社員ID", true);
+				empList = empDao.selectById​(Integer.parseInt(inputCheck("ID", true)));
-				int input = Integer.parseInt(inputId);
-				empList = empDao.selectById(input);
 				break;
 			default:
 				return;
 			}
 			for (EmployeeDTO emp : empList) {
-				System.out.println(emp);
+				emp.showInfo();
 			}
 		} finally {
 			DbUtil.closeConnection(empDao.con);
 		}
 	}
 
-	public static void empDelete() throws ClassNotFoundException, SQLException {
-
-		Connection con = DbUtil.getConnection();
-		EmployeeDAO empDao = new EmployeeDAO(con);
-		try {
-			System.out.println("IDを入力してください");
-			String input = sc.nextLine();
-			// 空文字が入力された場合
-			if (input.strip().isEmpty()) {
-				System.out.println("入力された値で情報がみつかりませんでした");
-				return;
-			}
-			int inputId = Integer.parseInt(input.strip());
-			List<EmployeeDTO> empList = empDao.selectById(inputId);
-			// 検索結果が存在しないIDの場合
-			if (empList.isEmpty()) {
-				System.out.println("入力された値で情報がみつかりませんでした");
-				return;
-			}
-
-			System.out.println("指定されたIDの情報を削除します？ Y/y");
-			System.out.println("(Y/y以外の入力であればキャンセル)");
-			String confilm = sc.nextLine();
-			// 検索結果が存在した場合
-			if ("Y".equalsIgnoreCase(confilm)) {
-				empDao.empDelete(inputId);
-				System.out.println("社員ID" + input + "のデータを削除しました");
-			} else {
-				System.out.println("削除をキャンセルしました");
-			}
-		} catch (NumberFormatException e) {
-			System.out.println("入力された値で情報がみつかりませんでした");
-		} finally {
-			DbUtil.closeConnection(empDao.con);
-		}
-	}
-
 	/**
 	 * フラグを判定し、テーブル名を取得する
 	 *
@@ -190,4 +240,26 @@ public class Main {
 		}
 		return str;
 	}
+
+	public static String inputCheck(boolean flg) {
+		String str = null;
+		while (true) {
+			str = sc.nextLine();
+			if (str.trim().length() == 0) {
+
+				continue;
+			}
+			if (flg) {
+				if (str.trim().length() > 0) {
+					try {
+						Integer.parseInt(str);
+					} catch (NumberFormatException e) {
+						continue;
+					}
+				}
+			}
+			break;
+		}
+		return str;
+	}
 }

src/com/rhizome/example/util/DbUtil.java

@@ -4,6 +4,7 @@ import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
+import java.util.Objects;
 
 public class DbUtil {
 	// 定数定義（共通）
@@ -44,9 +45,12 @@ public class DbUtil {
 	 * 				  生成されたConnectionを返却する
 	 * 				  ※Connection生成には上記の定数を活用してください
 	 */
-	public static Connection getConnection() throws ClassNotFoundException, SQLException {
-		Class.forName(DB_DRIVER);
 
+	public static Connection getConnection() throws ClassNotFoundException, SQLException {
+		if (con != null && con.isValid(1)) {
+			return con;
+		}
+		Class.forName(DB_DRIVER);
 		return con = DriverManager.getConnection(DB_URL, DB_USER, DB_PASS);
 	}
 
@@ -59,11 +63,10 @@ public class DbUtil {
 	 * 例外			：SQLException
 	 * 処理			：引数のDBステートメントがnullでない場合、そのDBステートメントをクローズする
 	 */
-	public static void closeStatement(PreparedStatement stmt) throws SQLException {
-		if (stmt != null) {
-			stmt.close();
-		}
 
+	public static void closeStatement(PreparedStatement ps) throws SQLException {
+		if (Objects.nonNull(ps))
+			ps.close();
 	}
 
 	/*
@@ -76,9 +79,8 @@ public class DbUtil {
 	 * 処理			：引数のコネクションがnullでない場合、そのコネクションを切断する
 	 */
 	public static void closeConnection(Connection con) throws SQLException {
-		if (con != null) {
+		if (Objects.nonNull(con))
 			con.close();
 	}
-	}
 
 }