wintertreey 님의 블로그
JSTL DB연동, Servlet 연습 본문
DB연동 연습
<h2>상품 정보(Beans: 전통적 방법으로 출력)</h2>
<table border="1">
<tr>
<th>코드</th><th>품명</th><th>수량</th><th>단가</th>
</tr>
<%
ArrayList<SangpumDto> list= connclass.getDataAll();
for(SangpumDto s:list){
%>
<tr>
<td><%=s.getCode() %></td>
<td><%=s.getSang() %></td>
<td><%=s.getSu() %></td>
<td><%=s.getDan() %></td>
</tr>
<%
}
%>
</table>
<br>
<h2>상품정보(Beans:EL, JSTL로 출력)</h2>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%ArrayList<SangpumDto> list2= connclass.getDataAll(); %>
<table border="1">
<tr>
<th>코드</th><th>품명</th><th>수량</th><th>단가</th>
</tr>
<c:forEach var="s" items="<%=list2 %>">
<tr>
<td>${s.code}</td>
<td>${s.sang}</td>
<td>${s.su}</td>
<td>${s.dan}</td>
</tr>
</c:forEach>
</table>
Servlet 연습
TestJstl.java
@WebServlet("/TestJstl")
public class TestJstl extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String irum = "홍길동";
request.setAttribute("irum", irum);
Person person = new Person();
person.setName("한국인");
request.setAttribute("person", person);
Student student = new Student();
student.setAge(22);
request.setAttribute("student", student);
String[] ani = {"댕댕이", "냥이", "뽀미"};
request.setAttribute("animal", ani);
String[] foods = {"당근", "시금치", "오이"};
List<Object> list = new ArrayList<Object>();
list.add(ani);
list.add(foods);
request.setAttribute("list", list);
//response.sendRedirect("testjstl.jsp?irum=irum&person=person&list=list");
//이렇게 적으면, 첫번째적은 irum만 넘어간다.
request.getRequestDispatcher("testjstl.jsp").forward(request, response);
}
testjstl.jsp
전통적: 안녕 <%=request.getAttribute("irum") %>
<%
out.println(request.getAttribute("irum"));
%>
<br>
EL: 반가워 ${irum } ${requestScope.irum }
<br> <br>
전통적:
<% Person p = (Person)request.getAttribute("person"); %>
<%=p.getName() %>
<% Student s= (Student)request.getAttribute("student"); %>
<%=s.getAge() %>
<br>
EL: ${person.name} ${student.age}
<br><br>
동물 : ${animal[0]} ${animal[1]} ${animal["2"]}
<br><br>
<c:if test="${list != null }">
<c:forEach var="a" items="${list }">
${a[0]}, ${a[1]}, ${a[2]}
</c:forEach>
</c:if>
<br>
<c:if test="${list != null }">
<c:forEach var="a" items="${list }">
<c:forEach var="b" items="${a }">
${b }
</c:forEach>
</c:forEach>
</c:if>
<br>
<c:choose>
<c:when test="${list eq null }">자료없음</c:when>
<c:otherwise>자료있음</c:otherwise>
</c:choose>
예외 처리 <br>
<c:catch var="myErr">
<%
int a = 10/0;
out.println("a: "+a);
%>
</c:catch>
<c:if test="${myErr != null }">
에러 발생 : ${myErr.message }
</c:if>
<hr>
계속
<br>
다른 문서 포함<br>
include 지시어 사용: <%@include file="poham.jsp" %>
<br>
jstl 사용: <c:import url="poham.jsp"></c:import>
ProductList.java
@WebServlet("/ProductList")
public class ProductList extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
List<Product> products = new ArrayList<Product>();
products.add(new Product("아메리카노", 2000.0, "짱 시원해요", new Date()));
products.add(new Product("카페라떼", 2500.0, "짱 부드러워요", new Date()));
products.add(new Product("수박주스", 3000.0, "편하게 마셔요", new Date()));
products.add(new Product("망고블랜디드", 4000.0, "짱 달콤해요", new Date()));
request.setAttribute("products", products);
request.getRequestDispatcher("/pshow.jsp").forward(request, response);
}
pshow.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %>
<%@taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn" %>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<style type="text/css">
.expensive {
color: red;
font-weight: bold;
}
</style>
</head>
<body>
<h2>* 제품목록 *</h2>
<c:choose>
<c:when test="${empty products}">
<p>제품이 없어요.</p>
</c:when>
<c:otherwise>
<table border="1">
<thead>
<tr>
<th>제품명</th><th>가격</th><th>설명</th><th>출시일</th>
</tr>
</thead>
<tbody>
<c:forEach var="pro" items="${products }">
<tr>
<td>${pro.name}</td>
<td class='<c:if test="${pro.price >= 3000.0 }">expensive</c:if>'>
${pro.price}
</td>
<td>${pro.description}</td>
<td>${pro.releaseDate}</td>
</tr>
</c:forEach>
</tbody>
</table>
</c:otherwise>
</c:choose>
<h2>제품 통계</h2>
<c:set var="totalProducts" value="${fn:length(products)}"/>
<c:set var="totalPrice" value="0"/>
<c:forEach var="p" items="${products}" varStatus="status">
<c:set var="totalPrice" value="${totalPrice+ p.price}"/>
</c:forEach>
<p>전체건수: ${totalProducts}</p>
<p>가격평균: <fmt:formatNumber value="${totalPrice / totalProducts}" type="currency" /></p>
<h3> 제품 설명 </h3>
<ul>
<c:forEach var="p" items="${products}">
<li><c:out value="${fn:substring(p.description, 0, 5)}"/></li>
</c:forEach>
</ul>
</body>
</html>
JSTL연동 결과 출력하기
<sql:setDataSource var="ds" url="jdbc:mariadb://localhost:3306/test"
driver="org.mariadb.jdbc.Driver"
user="root" password="123"
/>
<sql:query var="rs" dataSource="${ds}">
select * from sangdata where code >= ? and code <= ?
<sql:param value="1"/>
<sql:param value="3"/>
</sql:query>
<table border="1">
<tr>
<th>코드</th><th>품명</th><th>수량</th><th>단가</th>
</tr>
<c:forEach var="r" items="${rs.rows}">
<tr>
<td>${r.code}</td>
<td>${r.sang}</td>
<td>${r.su}</td>
<td>${r.dan}</td>
</tr>
</c:forEach>
</table>
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