Sample

BusinessLogic
・EmployeeDAOを使った業務処理


package sample;
import java.sql.SQLException;
import java.util.List;

public class BusinessLogic {
	public static void main(String[] args) {
		EmployeeDAO dao = new EmployeeDAO();

		try {
			Employee employee = new Employee();
			employee.setCode("社員no");
			employee.setName("名前");
			employee.setAge(30);
			employee.setSection("所属");

			int count = dao.insert(employee);
			System.out.println(count + "件のデータを登録しました。");

			System.out.println("*** すべての従業員情報を表示 ***");
			List＜Employee> employeeList = dao.selectAll();

			for (Employee tempEmp : employeeList) {
				String code = tempEmp.getCode();
				String name = tempEmp.getName();
				int age = tempEmp.getAge();
				String section = tempEmp.getSection();

				System.out.print(code + "\t| ");
				System.out.print(name + "\t| ");
				System.out.print(age + "\t| ");
				System.out.print(section + "\n");
			}
		} catch (SQLException e) {
			System.out.println("処理結果：異常が発生しました。");
			e.printStackTrace();
		}
	}
}

ConnectionManager
・


package sample;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class ConnectionManager {
	private final static String URL = "jdbc:mysql://localhost:3306/sampledb?useSSL=false";
	private final static String USER = "userU";
	private final static String PASSWORD = "userP";

	public static Connection getConnection() throws SQLException {
		return DriverManager.getConnection(URL, USER, PASSWORD);
	}
}

Employee
・m_employeeのDTO


package sample;

public class Employee {
	private String code;
	private String name;
	private int age;
	private String section;

	public String getCode() {
		return code;
	}

	public void setCode(String code) {
		this.code = code;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

	public String getSection() {
		return section;
	}

	public void setSection(String section) {
		this.section = section;
	}
}

EmployeeDAO
・m_employeeテーブルのDAO


package sample;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

public class EmployeeDAO {
	public int insert(Employee employee) throws SQLException {
		int count = 0;
		try (Connection con = ConnectionManager.getConnection();
				PreparedStatement pstmt
				= con.prepareStatement("INSERT INTO m_employee VALUES(?, ?, ?, ?)")) {

			String code = employee.getCode();
			String name = employee.getName();
			int age = employee.getAge();
			String section = employee.getSection();
			pstmt.setString(1, code);
			pstmt.setString(2, name);
			pstmt.setInt(3, age);
			pstmt.setString(4, section);

			count = pstmt.executeUpdate();
		}
		return count;
	}

	public List＜Employee> selectAll() throws SQLException {
		List＜Employee> employeeList = new ArrayList＜Employee>();
		try (Connection con = ConnectionManager.getConnection();
				Statement stmt = con.createStatement();
				ResultSet res = stmt.executeQuery("SELECT * FROM m_employee")) {
			while (res.next()) {
				String code = res.getString("code");
				String name = res.getString("name");
				int age = res.getInt("age");
				String section = res.getString("section");

				Employee employee = new Employee();
				employee.setCode(code);
				employee.setName(name);
				employee.setAge(age);
				employee.setSection(section);
				employeeList.add(employee);
			}
		}
		return employeeList;
	}

	public String getName(String code) throws SQLException {

		String name = null; //氏名

		try (Connection con = ConnectionManager.getConnection();
				PreparedStatement pstmt
				= con.prepareStatement("SELECT name FROM m_employee WHERE code = ?")) {

			pstmt.setString(1, code);

			ResultSet res = pstmt.executeQuery();

			if (res.next()) {
				name = res.getString("name");
			}
		}

		return name;
	}

	public List＜String> selectName(String section) throws SQLException {
		List＜String> nameList = new ArrayList＜String>();
		try (Connection con = ConnectionManager.getConnection();
				PreparedStatement pstmt
				= con.prepareStatement("SELECT name FROM m_employee WHERE section = ?")) {

			pstmt.setString(1, section);// プレースホルダへの値の設定
			ResultSet res = pstmt.executeQuery();
			while (res.next()) {
				nameList.add(res.getString("name"));
			}
		}
		return nameList;

	}

	public int delete(String code) throws SQLException {
		int count = 0; //処理件数

		try (Connection con = ConnectionManager.getConnection();
				PreparedStatement pstmt
				= con.prepareStatement("DELETE FROM m_employee WHERE code = ?")) {

			pstmt.setString(1, code);

			count = pstmt.executeUpdate();
		}
		return count;
	}
}


All Rights Reserved. Copyright (C) ITCL