Struts1.x系列教程（19）：LookupDispatchAction类处理一个form多个submit

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有时在HTML form中需要提供多个提交按钮，这时LookupDispatchAction类就派上用场了。LookupDispatchAction是DispatchAction的子类，用于处理客户端代码中有一个Form含有多个提交按钮的情况。为了使用LookupDispatchAction，首先来编写客户端代码，代码如下：

<!--<br /> <br /> Code highlighting produced by Actipro CodeHighlighter (freeware)<br /> http://www.CodeHighlighter.com/<br /> <br /> --><html:formaction="myaction">

<html:submitproperty="action">
<bean:messagekey="submit.print"/>
</html:submit>
<html:submitproperty="action">
<bean:messagekey="submit.save"/>
</html:submit>
</html:form>

<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <meta name="ProgId" content="Word.Document"> <meta name="Generator" content="Microsoft Word 11"> <meta name="Originator" content="Microsoft Word 11"> <link rel="File-List" href="file:///C:%5CDOCUME%7E1%5CADMINI%7E1%5CLOCALS%7E1%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml"> <!--[if gte mso 9]><xml> Normal 0 7.8 磅 0 2 false false false MicrosoftInternetExplorer4 </xml><![endif]--><!--[if gte mso 9]><![endif]--><style> <!-- /* Font Definitions */ &#64;font-face {font-family:宋体; panose-1:2 1 6 0 3 1 1 1 1 1;} &#64;font-face {font-family:""&#64;宋体"; panose-1:2 1 6 0 3 1 1 1 1 1;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; text-align:justify; text-justify:inter-ideograph; font-size:10.5pt; font-family:"Times New Roman";} /* Page Definitions */ &#64;page {} &#64;page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt;} div.Section1 {page:Section1;} --> </style> <!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable { mso-style-parent:""; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} </style> <![endif]-->

其中submit.print和submit.save是属性文件中的key。action实际上是提交按钮的name属性值。在提交时，会将property和<bean:message key="..." />作为请求参数和参数值传给Struts动作。如save按钮被单击时，请求URL为http://localhost:8080/.../myaction.do?action=save。其中save为submit.save在属性文件中对应的属性值，也就是说submit.save = save。

接下来我们编写一个LookupDispatchAction的子类，代码如下：

<!--<br /> <br /> Code highlighting produced by Actipro CodeHighlighter (freeware)<br /> http://www.CodeHighlighter.com/<br /> <br /> -->packageaction;
importorg.apache.struts.actions.LookupDispatchAction;

publicclassMyLookupDispatchActionextendsLookupDispatchAction
{
//为了方便描述，在这里未使用属性文件，只是直接将key和value的映射添加到Map对象中
//读者可以在getKeyMethodMap方法中从属性文件中读取相应的key-value对
//来添加到Map对象中
protectedMapgetKeyMethodMap()
{
Mapm=newHashMap();
m.put("submit.print","print");
m.put("submit.save","save");
returnm;
}
publicActionForwardprint(ActionMappingmapping,ActionFormform,
HttpServletRequestrequest,HttpServletResponseresponse)
{
//处理print代码
}
publicActionForwardsave(ActionMappingmapping,ActionFormform,
HttpServletRequestrequest,HttpServletResponseresponse)
{
//处理save代码
}
}

<meta http-equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 11"><meta name="Originator" content="Microsoft Word 11"><link rel="File-List" href="file:///C:%5CDOCUME%7E1%5CADMINI%7E1%5CLOCALS%7E1%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml"><!--[if gte mso 9]><xml> Normal 0 7.8 磅 0 2 false false false MicrosoftInternetExplorer4 </xml><![endif]--><!--[if gte mso 9]><![endif]--><style> <!-- /* Font Definitions */ &#64;font-face {font-family:宋体; panose-1:2 1 6 0 3 1 1 1 1 1;} &#64;font-face {font-family:""&#64;宋体"; panose-1:2 1 6 0 3 1 1 1 1 1;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; text-align:justify; text-justify:inter-ideograph; font-size:10.5pt; font-family:"Times New Roman";} /* Page Definitions */ &#64;page {} &#64;page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt;} div.Section1 {page:Section1;} --> </style><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable { mso-style-parent:""; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} </style> <![endif]-->

在编写LookupDispatchAction的子类时要注意必须实现getKeyMethodMap方法，在这个方法中需要进行key和Action方法的映射。下面的代码用来配置MyLookupDispatchAction。

<!--<br /> <br /> Code highlighting produced by Actipro CodeHighlighter (freeware)<br /> http://www.CodeHighlighter.com/<br /> <br /> --><actionpath="/moresubmit"type="action.MyLookupDispatchAction"parameter="action"/>

<meta http-equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 11"><meta name="Originator" content="Microsoft Word 11"><link rel="File-List" href="file:///C:%5CDOCUME%7E1%5CADMINI%7E1%5CLOCALS%7E1%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml"><!--[if gte mso 9]><xml> Normal 0 7.8 磅 0 2 false false false MicrosoftInternetExplorer4 </xml><![endif]--><!--[if gte mso 9]><![endif]--><style> <!-- /* Font Definitions */ &#64;font-face {font-family:宋体; panose-1:2 1 6 0 3 1 1 1 1 1;} &#64;font-face {font-family:""&#64;宋体"; panose-1:2 1 6 0 3 1 1 1 1 1;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; text-align:justify; text-justify:inter-ideograph; font-size:10.5pt; font-family:"Times New Roman";} /* Page Definitions */ &#64;page {} &#64;page Section1 {size:595.3pt 841.9pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; layout-grid:15.6pt;} div.Section1 {page:Section1;} --> </style><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable { mso-style-parent:""; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} </style> <![endif]-->

其中parameter属性指定了请求URL中由提交按钮生成的请求参数名。

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