解答例 - 実習課題４ - ７．繰り返し機能を持つカスタムタグ

（実習課題４）

実習課題３のタグ・ハンドラクラスを改良しなさい。

「IterationTag」インタフェースではなく、「TagSupport」クラスから作成するようにする事。

解答例

/*
 * ArrayTag.java TECHSCORE Java JSP7実習課題4
 * Copyright (c) 2004 Four-Dimensional Data, Inc.
 */
package com.techscore.jsp.chapter7.exercise4;

import java.io.IOException;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.IterationTag;
import javax.servlet.jsp.tagext.TagSupport;

public class ArrayTag extends TagSupport implements IterationTag {

    private Iterator iterator = null;

    public void setArray(Object[] objects) {
        List list = new LinkedList();
        for (int i = 0; i < objects.length; i++) {
            list.add(objects[i]);
        }
        iterator = list.iterator();
    }

    public int doStartTag() throws JspException {
        return (EVAL_BODY_INCLUDE);
    }

    public int doAfterBody() throws JspException {
        JspWriter writer = pageContext.getOut();
        if (iterator.hasNext()) {
            try {
                writer.println(iterator.next() + "<br>");
            } catch (IOException e) {
                e.printStackTrace();
            }
            return (EVAL_BODY_AGAIN);
        } else {
            return (SKIP_BODY);
        }
    }
}

<!-- taglib.jsp -->
<!-- TECHSCORE Java JSP 7章 実習課題4 -->
<!-- Copyright (c) 2004 Four-Dimensional Data, Inc. -->

<%@page contentType="text/html; charset=Windows-31J" import="java.util.*" %>
<%@taglib uri="http://www.techscore.com/tags/myTag" prefix="myTag" %>
<html>
  <head><title>JSP7章 実習課題4</title></head>
  <body>
    <h3>JSP7章 実習課題4</h3>
    <%
      String[] str = new String[5];
      str[0] = "test1";
      str[1] = "test2";
      str[2] = "test3";
      str[3] = "test4";
      str[4] = "test5";
      %>
      <myTag:arrayTag7_4 array="<%= str %>">
      </myTag:arrayTag7_4>
  </body>
</html>

<?xml version="1.0" ?>
<!DOCTYPE taglib
  PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.2//EN"
  "http://java.sun.com/dtd/web-jsptaglibrary_1_2.dtd">

<taglib>
  <tlib-version>1.0</tlib-version>
  <jsp-version>1.2</jsp-version>
  <short-name>example tags</short-name>

  <tag>
    <name>arrayTag7_4</name>
    <tag-class>com.techscore.jsp.chapter7.exercise4.ArrayTag</tag-class>
    <body-content>JSP</body-content>
    <attribute>
      <name>array</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
    </attribute>
  </tag>

</taglib>

↑このページの先頭へ