struts-bean.html

struts api,学习使用struts必备的文档

<tr class="evenRow">
<td align="center">toScope</td>
<td>
      <p>Specifies the variable scope into which the newly defined bean will
      be created.  If not specified, the bean will be created in
      <code>page</code> scope.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">type</td>
<td>
        <p>Specifies the fully qualified class name of the value to be exposed
        as the <code>id</code> attribute.</p>
      
            [
        java.lang.String (if you specify a value
        attribute) or java.lang.Object otherwise.
      ]
          
            [RT Expr]
          </td>
</tr>
<tr class="evenRow">
<td align="center">value</td>
<td>
      <p>The <code>java.lang.String</code> value to which the exposed bean
      should be set.  This attribute is required unless you specify the
      <code>name</code> attribute or nested body content.</p>
      
            [RT Expr]
          </td>
</tr>
</table>
</div>
<p>
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</p>
<h3 id="header">
<strong>header</strong> - 
    Define a scripting variable based on the value(s) of the specified
    request header.
    </h3>
<div class="indent">
    <p>Retrieve the value of the specified request header (as a single
    value or multiple values, depending on the <code>multiple</code> attribute),
    and define the result as a page scope attribute of type <code>String</code>
    (if <code>multiple</code> is not specified) or <code>String[]</code>
    (if <code>multiple</code> is specified).</p>

    <p>If no header with the specified name can be located, and no default
    value is specified, a request time exception will be thrown.</p>
    <table class="tag-attributes">
<thead>
<tr>
<th class="attribute">Attribute Name</th>
<th>Description</th>
</tr>
</thead>
<tr class="evenRow">
<td align="center">id</td>
<td>
      <p>Specifies the name of the scripting variable (and associated page
      scope attribute) that will be made available with the value of the
      specified request header.</p>
      
            [Required]
          </td>
</tr>
<tr class="oddRow">
<td align="center">multiple</td>
<td>
      <p>If any arbitrary value for this attribute is specified, causes a call
      to <code>HttpServletRequest.getHeaders()</code> and a definition of the
      result as a bean of type <code>String[]</code>.  Otherwise,
      <code>HttpServletRequest.getHeader()</code> will be called, and a
      definition of the result as a bean of type <code>String</code>
      will be performed.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="evenRow">
<td align="center">name</td>
<td>
      <p>Specifies the name of the request header whose value, or values,
      is to be retrieved.</p>
      
            [Required]
          
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">value</td>
<td>
      <p>The default header value to return if no header with the
      specified name was included in this request.</p>
      
            [RT Expr]
          </td>
</tr>
</table>
</div>
<p>
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</p>
<h3 id="include">
<strong>include</strong> - 
    Load the response from a dynamic application request and make it available
    as a bean.
    </h3>
<div class="indent">
    <p>Perform an internal dispatch to the specified application component
    (or external URL)
    and make the response data from that request available as a bean of
    type <code>String</code>.  This tag has a function similar to that of
    the standard <code>&lt;jsp:include&gt;</code> tag, except that the
    response data is stored in a page scope attribute instead of being
    written to the output stream.  If the current request is part of a
    session, the generated request for the include will also include the
    session identifier (and thus be part of the same session).</p>

    <p>The URL used to access the specified application component is
    calculated based on which of the following attributes you specify
    (you must specify exactly one of them):</p>
    <ul>
    <li>
<em>forward</em> - Use the value of this attribute as the name
        of a global <code>ActionForward</code> to be looked up, and
        use the module-relative or context-relative URI found there.</li>
    <li>
<em>href</em> - Use the value of this attribute unchanged (since
        this might link to a resource external to the application, the
        session identifier is <strong>not</strong> included.</li>
    <li>
<em>page</em> - Use the value of this attribute as an
        module-relative URI to the desired resource.</li>
    </ul>
    <table class="tag-attributes">
<thead>
<tr>
<th class="attribute">Attribute Name</th>
<th>Description</th>
</tr>
</thead>
<tr class="evenRow">
<td align="center">anchor</td>
<td>
      <p>Optional anchor tag ("#xxx") to be added to the generated
      hyperlink.  Specify this value <strong>without</strong> any
      "#" character.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">forward</td>
<td>
      <p>Logical name of a global <code>ActionForward</code> that contains
      the actual content-relative URI of the resource to be included.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="evenRow">
<td align="center">href</td>
<td>
      <p>Absolute URL (including the appropriate protocol prefix such as
      "http:") of the resource to be included.  Because this URL could be
      external to the current web application, the session identifier will
      <strong>not</strong> be included in the request.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">id</td>
<td>
      <p>Specifies the name of the scripting variable (and associated page
      scope attribute) that will be made available with the value of the
      specified web application resource.</p>
      
            [Required]
          </td>
</tr>
<tr class="evenRow">
<td align="center">name</td>
<td>
      <p>Module-relative name (starting with a '/') of the web application
      resource to be dispatched, and whose response data is to be made
      available as a bean.</p>
      <p class="deprecated">
<strong>DEPRECATED:</strong>
      Use the "page" attribute instead.
      </p>
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">page</td>
<td>
      <p>Module-relative URI (starting with a '/') of the web application
      resource to be included.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="evenRow">
<td align="center">transaction</td>
<td>
        <p>Set to <code>true</code> if you want the current
        transaction control token included in the generated
        URL for this include.</p>
      
            [RT Expr]
          </td>
</tr>
</table>
</div>
<p>
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</p>
<h3 id="message">
<strong>message</strong> - 
    Render an internationalized message string to the response.
    </h3>
<div class="indent">
    <p>Retrieves an internationalized message for the specified locale,
    using the specified message key, and write it to the output stream.
    Up to five parametric replacements (such as "{0}") may be specified.</p>

    <p>The message key may be specified directly, using the <code>key</code>
    attribute, or indirectly, using the <code>name</code> and
    <code>property</code> attributes to obtain it from a bean.</p>
    
    <p>
    <strong>JSTL</strong>:  The equivalent JSTL tag is &lt;fmt:message&gt;.  For example,
    <br />
    <code>
    	&lt;fmt:message key="my.msg.key"&gt;
    	  &lt;fmt:param value="replacement text"/&gt;
    	&lt;/fmt:message&gt;
    </code>
    </p>
    <table class="tag-attributes">
<thead>
<tr>
<th class="attribute">Attribute Name</th>
<th>Description</th>
</tr>
</thead>
<tr class="evenRow">
<td align="center">arg0</td>
<td>
      <p>First parametric replacement value, if any.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">arg1</td>
<td>
      <p>Second parametric replacement value, if any.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="evenRow">
<td align="center">arg2</td>
<td>
      <p>Third parametric replacement value, if any.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">arg3</td>
<td>
      <p>Fourth parametric replacement value, if any.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="evenRow">
<td align="center">arg4</td>
<td>
      <p>Fifth parametric replacement value, if any.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">bundle</td>
<td>
      <p>The name of the application scope bean under which the
      <code>MessageResources</code> object containing our messages
      is stored.</p>
      
            [Globals.MESSAGES_KEY]
          
            [RT Expr]
          </td>
</tr>
<tr class="evenRow">
<td align="center">key</td>
<td>
      <p>The message key of the requested message, which must have
      a corresponding value in the message resources. If not specified,
      the key is obtained from the <code>name</code> and
      <code>property</code> attributes.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">locale</td>
<td>
      <p>The name of the session scope bean under which our currently
      selected <code>Locale</code> object is stored.</p>
      
            [Globals.LOCALE_KEY]
          
            [RT Expr]
          </td>
</tr>
<tr class="evenRow">
<td align="center">name</td>
<td>
      <p>Specifies the attribute name of the bean whose property is accessed
      to retrieve the value specified by <code>property</code> (if
      specified).  If <code>property</code> is not specified, the value of
      this bean itself will be used as the message resource key.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">property</td>
<td>
      <p>Specifies the name of the property to be accessed on the bean
      specified by <code>name</code>.  This value may be a simple, indexed,
      or nested property reference expression.  If not specified, the value
      of the bean identified by <code>name</code> will itself be used as the
      message resource key.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="evenRow">
<td align="center">scope</td>
<td>
      <p>Specifies the variable scope searched to retrieve the bean specified
      by <code>name</code>.  If not specified, the default rules applied by
      <code>PageContext.findAttribute()</code> are applied.</p>
      
            [RT Expr]
          </td>
</tr>
</table>
</div>
<p>
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</p>
<h3 id="page">
<strong>page</strong> - 
    Expose a specified item from the page context as a bean.
    </h3>
<div class="indent">
    <p>Retrieve the value of the specified item from the page context
    for this page, and define it as a scripting variable, and a page scope
    attribute accessible to the remainder of the current page.</p>

    <p>If a problem occurs while retrieving the specified configuration
    object, a request time exception will be thrown.</p>
    <table class="tag-attributes">
<thead>
<tr>
<th class="attribute">Attribute Name</th>
<th>Description</th>
</tr>
</thead>
<tr class="evenRow">
<td align="center">id</td>
<td>
      <p>Specifies the name of the scripting variable (and associated
      page scope attribute) that will be made available with the value of
      the specified page context property.</p>
      
            [Required]
          </td>
</tr>
<tr class="oddRow">
<td align="center">property</td>
<td>
      <p>Name of the property from our page context to be retrieved and
      exposed.  Must be one of <code>application</code>, <code>config</code>,
      <code>request</code>, <code>response</code>, or <code>session</code>.
      </p>
      
            [Required]
          
            [RT Expr]
          </td>
</tr>
</table>
</div>
<p>
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</p>
<h3 id="parameter">
<strong>parameter</strong> - 
    Define a scripting variable based on the value(s) of the specified
    request parameter.
    </h3>
<div class="indent">
    <p>Retrieve the value of the specified request parameter (as a single