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1   /*
2    * Copyright 2004-2008 the Seasar Foundation and the Others.
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *     http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
13   * either express or implied. See the License for the specific language
14   * governing permissions and limitations under the License.
15   */
16  package org.seasar.cubby.tags;
17  
18  import static org.seasar.cubby.tags.TagUtils.toAttr;
19  
20  import java.io.IOException;
21  
22  import javax.servlet.http.HttpSession;
23  import javax.servlet.jsp.JspException;
24  import javax.servlet.jsp.JspWriter;
25  import javax.servlet.jsp.PageContext;
26  
27  import org.seasar.cubby.controller.ThreadContext;
28  import org.seasar.cubby.util.TokenHelper;
29  import org.seasar.cubby.validator.validators.TokenValidator;
30  import org.seasar.framework.util.StringUtil;
31  
32  /**
33   * 2重サブミット防止用の<input type="hidden"/>を出力するタグ。
34   * <p>
35   * このタグが呼び出されると一意なトークン文字列を生成してhiddenとセッションに格納します。
36   * サブミットされた先の処理の検証フェーズで、ポストされたhidden値とセッション中の値を比較して、
37   * 一致しない場合、不正な経路からのアクセスとみなしてエラー処理を行います。
38   * </p>
39   * 
40   * @see TokenValidator#validate(org.seasar.cubby.validator.ValidationContext,
41   *      Object[])
42   * @author agata
43   * @since 1.0.0
44   */
45  public class TokenTag extends DynamicAttributesTagSupport {
46  
47  	private String name;
48  
49  	/**
50  	 * name属性を設定します。
51  	 * 
52  	 * @param name
53  	 *            name属性
54  	 */
55  	public void setName(final String name) {
56  		this.name = name;
57  	}
58  
59  	/**
60  	 * {@inheritDoc}
61  	 */
62  	@Override
63  	public void doTag() throws JspException, IOException {
64  		final PageContext context = (PageContext) getJspContext();
65  		final JspWriter out = context.getOut();
66  
67  		final String token = TokenHelper.generateGUID();
68  		out.append("<input type=\"hidden\" name=\"");
69  		if (StringUtil.isEmpty(name)) {
70  			out.append(TokenHelper.DEFAULT_TOKEN_NAME);
71  		} else {
72  			out.append(name);
73  		}
74  		out.append("\" value=\"");
75  		out.append(token);
76  		out.append("\" ");
77  		out.write(toAttr(getDynamicAttribute()));
78  		out.append("/>");
79  		final HttpSession session = ThreadContext.getRequest().getSession();
80  		TokenHelper.setToken(session, token);
81  	}
82  }