blog 14. 검색하기

list.jsp

<div class="container">

	<div class="m-2">
		<form class="form-inline d-flex justify-content-end" action="/blog/board">
			<input type="hidden" name="cmd" value="search" /> 
			<input type="hidden" name="page" value="0" /> 
			<input type="text" name="keyword" class="form-control mr-sm-2" placeholder="Search">
			<button class="btn btn-primary m-1">검색</button>

		</form>
	</div>
	<div class="progress col-md-12 m-2">
		<div class="progress-bar" style="width: ${currentPosition}%"></div>
	</div>

위의 form 태그를 유심히 보면 action="/blog/board" 이후에

그 밑에 <input> 들의 name, value가 서버로 전송 될 것임을 알 수 있다.

 

action = "blog/board?cmd=search&page=0&keyword=[검색한단어]"

 

 

 

BoardController.java

else if(cmd.equals("search")) {
			String keyword = request.getParameter("keyword");
			int page = Integer.parseInt(request.getParameter("page"));

			List<Board> boards = boardService.글검색(keyword, page);
			request.setAttribute("boards", boards);

			int boardCount = boardService.글개수(keyword);
			int lastPage = (boardCount-1)/4; // 2/4 = 0, 3/4 = 0, 4/4 = 1, 9/4 = 2 ( 0page, 1page, 2page) 
			double currentPosition = (double)page/(lastPage)*100;



			request.setAttribute("lastPage", lastPage);
			request.setAttribute("currentPosition", currentPosition);
			RequestDispatcher dis = request.getRequestDispatcher("board/list.jsp");
			dis.forward(request, response);
		}

cmd.equals("list")와 코드가 유사하다.

글검색() 의 결과가 저장된 boards 를 setAttribute 하여 dispatcher 를 이용해 list페이지로 이동하게 한다.

 

글검색 된 boards 도 페이지처리가 적용되어야 하기 때문에 글개수(keyword) 함수를 오버로딩하여 새로 만들어야 한다.

 

 

BoardService.java

public List<Board> 글검색(String keyword, int page){
		return boardDao.findByKeyword(keyword, page);
	}

public int 글개수(String keyword) {
		return boardDao.count(keyword);
	}

 

BoardDao.java

public List<Board> findByKeyword(String keyword, int page){
		String sql = "SELECT * FROM  board WHERE title like ? ORDER BY id DESC LIMIT ?, 4"; // 0,4   4,4   8,4
		Connection conn = DB.getConnection();
		PreparedStatement pstmt = null;
		ResultSet rs  = null;
		List<Board> boards = new ArrayList<>();
		try {
			pstmt = conn.prepareStatement(sql);
			pstmt.setString(1, "%"+keyword+"%");
			pstmt.setInt(2, page*4); // 0 -> 0, 1 ->4, 2->8
			rs =  pstmt.executeQuery();

			// Persistence API
			while(rs.next()) { // 커서를 이동하는 함수
				Board board = Board.builder()
						.id(rs.getInt("id"))
						.title(rs.getString("title"))
						.content(rs.getString("content"))
						.readCount(rs.getInt("readCount"))
						.userId(rs.getInt("userId"))
						.createDate(rs.getTimestamp("createDate"))
						.build();
				boards.add(board);	
			}
			return boards;
		} catch (Exception e) {
			e.printStackTrace();
		} finally { // 무조건 실행
			DB.close(conn, pstmt, rs);
		}

		return null;
	}
    
    
    public int count(String keyword) {
		String sql = "SELECT count(*) FROM board WHERE title like ?";
		Connection conn = DB.getConnection();
		PreparedStatement pstmt = null;
		ResultSet rs  = null;

		try {
			pstmt = conn.prepareStatement(sql);
			pstmt.setString(1, "%"+keyword+"%");
			rs =  pstmt.executeQuery();
			if(rs.next()) {
				return rs.getInt(1);
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally { // 무조건 실행
			DB.close(conn, pstmt, rs);
		}
		return -1;
	}

BoardDao.list 와 코드가 유사하다.

 

 

 

list.jsp

<!-- disabled -->
	<ul class="pagination justify-content-center">

		<c:choose>
			<c:when test="${empty param.keyword}">
				<c:set var ="pagePrev" value="/blog/board?cmd=list&page=${param.page-1 }"></c:set>
				<c:set var="pageNext" value="/blog/board?cmd=list&page=${param.page+1}"/>
			</c:when>
			<c:otherwise>
				<c:set var="pagePrev" value="/blog/board?cmd=search&page=${param.page-1}&keyword=${param.keyword}"/>
				<c:set var="pageNext" value="/blog/board?cmd=search&page=${param.page+1}&keyword=${param.keyword}"/>
			</c:otherwise>
		</c:choose>

		<c:choose>
			<c:when test="${param.page == 0}">
				<li class="page-item disabled"><a class="page-link" href="#">Previous</a></li>	
			</c:when>
			<c:otherwise>
				<li class="page-item"><a class="page-link" href="${pageScope.pagePrev}">Previous</a></li>
			</c:otherwise>
		</c:choose>

		<c:choose>
			<c:when test="${lastPage == param.page}">
				<li class="page-item disabled"><a class="page-link" href="#">Next</a></li>		
			</c:when>
			<c:otherwise>
				<li class="page-item"><a class="page-link" href="${pageScope.pageNext}">Next</a></li>
			</c:otherwise>
		</c:choose>

		
	</ul>
</div>
</body>
</html>

페이지 버튼도 동적으로 바뀌게 한다. 이 부분이 가장 머리를 많이 쓰는 부분이긴 한데...

ㅠㅠ