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calc3.html
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<style>
input {
width : 50px;
height: 50px;
}
.output {
height: 50px;
background: #e9e9e9;
font-size: 24px;
font-weight: bold;
text-align:right;
padding: 0px 5px;
}
</style>
</head>
<body>
<form action="calc3" method="post">
<table>
<tr>
<td class="output" colspan="4">0</td>
</tr>
<tr>
<td><input type="submit" name="operator" value="CE"></td>
<td><input type="submit" name="operator" value="C"></td>
<td><input type="submit" name="operator" value="BS"></td>
<td><input type="submit" name="operator" value="/"></td>
</tr>
<tr>
<td><input type="submit" name="value" value="7"></td>
<td><input type="submit" name="value" value="8"></td>
<td><input type="submit" name="value" value="9"></td>
<td><input type="submit" name="operator" value="*"></td>
</tr>
<tr>
<td><input type="submit" name="value" value="4"></td>
<td><input type="submit" name="value" value="5"></td>
<td><input type="submit" name="value" value="6"></td>
<td><input type="submit" name="operator" value="-"></td>
</tr>
<tr>
<td><input type="submit" name="value" value="1"></td>
<td><input type="submit" name="value" value="2"></td>
<td><input type="submit" name="value" value="3"></td>
<td><input type="submit" name="operator" value="+"></td>
</tr>
<tr>
<td></td>
<td><input type="submit" name="value" value="0"></td>
<td><input type="submit" name="dot" value="."></td>
<td><input type="submit" name="operator" value="="></td>
</tr>
</table>
</form>
</body>
</html>Calc3.java
package com.web;
import java.io.IOException;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
@WebServlet("/calc3")
public class Calc3 extends HttpServlet {
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Cookie[] cookies = request.getCookies();
String value = request.getParameter("value");
String operator = request.getParameter("operator");
String dot = request.getParameter("dot");
String exp = "";
if(cookies != null) {
for(Cookie c: cookies) {
if(c.getName().equals("exp")) {
exp = c.getValue();
break;
}
}
}
if(operator != null && operator.equals("=")) {
ScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn");
try {
exp = String.valueOf(engine.eval(exp));
} catch (ScriptException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} else {
exp += (value == null) ? "" : value;
exp += (operator == null) ? "" : operator;
exp += (dot == null) ? "" : dot;
}
Cookie expCookie = new Cookie("exp", exp);
response.addCookie(expCookie);
response.sendRedirect("calcpage");
}
}
calcPage.java
package com.web;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
@WebServlet("/calcpage")
public class calcPage extends HttpServlet {
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setCharacterEncoding("UTF-8");
response.setContentType("text/html; charset=utf-8");
PrintWriter out = response.getWriter();
Cookie[] cookies = request.getCookies();
String exp = "0";
if(cookies != null) {
for(Cookie c: cookies) {
if(c.getName().equals("exp")) {
exp = c.getValue();
break;
}
}
}
out.write("<!DOCTYPE html>");
out.write("<html>");
out.write("<head>");
out.write("<meta charset=\"UTF-8\">");
out.write("<title>Insert title here</title>");
out.write("<style>");
out.write("input {");
out.write("width : 50px;");
out.write("height: 50px;");
out.write("}");
out.write(".output {");
out.write("height: 50px;");
out.write("background: #e9e9e9;");
out.write("font-size: 24px;");
out.write("font-weight: bold;");
out.write("text-align:right;");
out.write("padding: 0px 5px;");
out.write("}");
out.write("</style>");
out.write("</head>");
out.write("<body>");
out.write("<form action=\"calc3\" method=\"post\">");
out.write("<table>");
out.write("<tr>");
out.printf("<td class=\"output\" colspan=\"4\">%s</td>", exp);
out.write("</tr>");
out.write("<tr>");
out.write("<td><input type=\"submit\" name=\"operator\" value=\"CE\"></td>");
out.write("<td><input type=\"submit\" name=\"operator\" value=\"C\"></td>");
out.write("<td><input type=\"submit\" name=\"operator\" value=\"BS\"></td>");
out.write("<td><input type=\"submit\" name=\"operator\" value=\"/\"></td>");
out.write("</tr>");
out.write("<tr>");
out.write("<td><input type=\"submit\" name=\"value\" value=\"7\"></td>");
out.write("<td><input type=\"submit\" name=\"value\" value=\"8\"></td>");
out.write("<td><input type=\"submit\" name=\"value\" value=\"9\"></td>");
out.write("<td><input type=\"submit\" name=\"operator\" value=\"*\"></td>");
out.write("</tr>");
out.write("<tr>");
out.write("<td><input type=\"submit\" name=\"value\" value=\"4\"></td>");
out.write("<td><input type=\"submit\" name=\"value\" value=\"5\"></td>");
out.write("<td><input type=\"submit\" name=\"value\" value=\"6\"></td>");
out.write("<td><input type=\"submit\" name=\"operator\" value=\"-\"></td>");
out.write("</tr>");
out.write("<tr>");
out.write("<td><input type=\"submit\" name=\"value\" value=\"1\"></td>");
out.write("<td><input type=\"submit\" name=\"value\" value=\"2\"></td>");
out.write("<td><input type=\"submit\" name=\"value\" value=\"3\"></td>");
out.write("<td><input type=\"submit\" name=\"operator\" value=\"+\"></td>");
out.write("</tr>");
out.write("<tr>");
out.write("<td></td>");
out.write("<td><input type=\"submit\" name=\"value\" value=\"0\"></td>");
out.write("<td><input type=\"submit\" name=\"dot\" value=\".\"></td>");
out.write("<td><input type=\"submit\" name=\"operator\" value=\"=\"></td>");
out.write("</tr>");
out.write("</table>");
out.write("</form>");
out.write("</body>");
out.write("</html>");
// - "\ quite앞에 \" -> 변경
}
}References
- 뉴렉처:
Servlet / JSP - 🎈vscode 정리
- 🎈2020.12.24
안녕하세요:)