JSP Number Guess Bean : UseBean « JSP « Java Tutorial






Jsp code

<!--
 Licensed to the Apache Software Foundation (ASF) under one or more
  contributor license agreements.  See the NOTICE file distributed with
  this work for additional information regarding copyright ownership.
  The ASF licenses this file to You under the Apache License, Version 2.0
  (the "License"); you may not use this file except in compliance with
  the License.  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.

  Number Guess Game
  Written by Jason Hunter, CTO, K&A Software
  http://www.servlets.com
-->

<%@ page import = "beans.*" %>

<jsp:useBean id="numguess" class="beans.MyBean" scope="session"/>
<jsp:setProperty name="numguess" property="*"/>

<html>
<head><title>Number Guess</title></head>
<body bgcolor="white">
<font size=4>

<% if (numguess.getSuccess()) { %>

  Congratulations!  You got it.
  And after just <%= numguess.getNumGuesses() %> tries.<P>

  <% numguess.reset(); %>

  Care to <a href="numguess.jsp">try again</a>?

<% } else if (numguess.getNumGuesses() == 0) { %>

  Welcome to the Number Guess game.<P>

  I'm thinking of a number between 1 and 100.<P>

  <form method=get>
  What's your guess? <input type=text name=guess>
  <input type=submit value="Submit">
  </form>

<% } else { %>

  Good guess, but nope.  Try <b><%= numguess.getHint() %></b>.

  You have made <%= numguess.getNumGuesses() %> guesses.<P>

  I'm thinking of a number between 1 and 100.<P>

  <form method=get>
  What's your guess? <input type=text name=guess>
  <input type=submit value="Submit">
  </form>

<% } %>

</font>
</body>
</html>

MyBean.java

/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License.  You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package beans;

import java.beans.*;
import javax.servlet.http.*;
import javax.servlet.*;
import java.text.DateFormat;
import java.util.*;

public class MyBean {

  int answer;
  boolean success;
  String hint;
  int numGuesses;

  public MyBean() {
    reset();
  }

  public void setGuess(String guess) {
    numGuesses++;

    int g;
    try {
      g = Integer.parseInt(guess);
    }
    catch (NumberFormatException e) {
      g = -1;
    }

    if (g == answer) {
      success = true;
    }
    else if (g == -1) {
      hint = "a number next time";
    }
    else if (g < answer) {
      hint = "higher";
    }
    else if (g > answer) {
      hint = "lower";
    }
  }

  public boolean getSuccess() {
    return success;
  }

  public String getHint() {
    return "" + hint;
  }

  public int getNumGuesses() {
    return numGuesses;
  }

  public void reset() {
    answer = Math.abs(new Random().nextInt() % 100) + 1;
    success = false;
    numGuesses = 0;
  }
}
  Download:  JSPNumberGuessBean.zip( 93 k)








23.43.UseBean
23.43.1.Import JavaBeans In JSP Page
23.43.2.Load JavaBeans In JSP Page
23.43.3.Using 'useBean' To Reference A Java Bean
23.43.4.Using initialized field in jsp page
23.43.5.Reference Package Name in JSP Page
23.43.6.Reference Calendar Bean
23.43.7.JSP Number Guess Bean
23.43.8.JSP Helper Bean HTMLFilter
23.43.9.Get/Set Value Using JSP Set Property
23.43.10.Call Setter In Java Bean To Change its Property Value
23.43.11.Call Bean Constructor To Pass In Message
23.43.12.Using the Date Class
23.43.13.Fields of the Calendar Class