WEB API練習2

ディレクトリ構造

package kr.or.connect.jdbcexam.dao;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import kr.or.connect.jdbcexam.dto.Role;

public class RoleDao {
	private static String dburl = "jdbc:mysql://localhost:3306/connectdb?serverTimezone=UTC";
	private static String dbUser = "connectuser";
	private static String dbpasswd = "PASSWORD";
    
	public Role getRole(Integer roleId) {
		Role role = null;
		Connection conn = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		
		try {
			Class.forName("com.mysql.cj.jdbc.Driver");
			conn = DriverManager.getConnection(dburl, dbUser, dbpasswd);
            
			String sql = "SELECT role_id, description FROM role WHERE role_id = ?";
			ps = conn.prepareStatement(sql);
			ps.setInt(1, roleId);	// 	arg1 : ?의 순서. arg2 : ?의 값
			rs = ps.executeQuery();
			
			if(rs.next()) {
				int id = rs.getInt("role_id");
				String description = rs.getString(2);
				role = new Role(id, description);
			}
		}catch (Exception e) {
			e.printStackTrace();
		}finally {
			if(rs != null) {
				try {
					rs.close();					
				} catch (SQLException e) {
					e.printStackTrace();
				}
			}
			if(ps != null) {
				try {
					ps.close();					
				} catch (SQLException e) {
					e.printStackTrace();
				}
			}
			if(conn != null) {
				try {
					conn.close();					
				} catch (SQLException e) {
					e.printStackTrace();
				}
			}
		}
		return role;
	}
}

package kr.or.connect.webapiexam.api;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.fasterxml.jackson.databind.ObjectMapper;

import kr.or.connect.jdbcexam.dao.RoleDao;
import kr.or.connect.jdbcexam.dto.Role;

@WebServlet("/roles/*")
public class RoleByIdServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
      
    public RoleByIdServlet() {
        super();
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    	response.setCharacterEncoding("utf-8");
		response.setContentType("application/json");

		String pathInfo = request.getPathInfo(); // /roles/{roleId}
		String[] pathParts = pathInfo.split("/");
		String idStr = pathParts[1];	// {roleId}에 해당. pathParts[0]는 roles
		int id = Integer.parseInt(idStr);

		RoleDao dao = new RoleDao();

		Role role = dao.getRole(id);

		ObjectMapper objectMapper = new ObjectMapper();
		String json = objectMapper.writeValueAsString(role);

		PrintWriter out = response.getWriter();
		out.println(json);
		out.close();
	}
}