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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, Object[])
41   * @author agata
42   */
43  public class TokenTag extends DynamicAttributesTagSupport {
44  
45  	private String name;
46  
47  	public void setName(final String name) {
48  		this.name = name;
49  	}
50  
51  	@Override
52  	public void doTag() throws JspException, IOException {
53  		final PageContext context = (PageContext) getJspContext();
54  		final JspWriter out = context.getOut();
55  
56  		final String token = TokenHelper.generateGUID();
57  		out.append("<input type=\"hidden\" name=\"");
58  		if (StringUtil.isEmpty(name)) {
59  			out.append(TokenHelper.DEFAULT_TOKEN_NAME);
60  		} else {
61  			out.append(name);
62  		}
63  		out.append("\" value=\"");
64  		out.append(token);
65  		out.append("\" ");
66  		out.write(toAttr(getDynamicAttribute()));
67  		out.append("/>");
68  		final HttpSession session = ThreadContext.getRequest().getSession();
69  		TokenHelper.setToken(session, token);
70  	}
71  }