HttpServletRequest 中的 JSP 参数名称

Question

背景

使用 Eclipse Helios、Apache Tomcat、JSP 和 JBoss RichFaces。

输入参数编码如下:

<h:inputHidden name="system_REPORT_RESOURCE" value="city" />
<h:inputHidden name="system_REPORT_FILENAME" value="city" />
<h:inputHidden name="report_REPORT_TITLE" value="City Listing" />
... and others ...

问题

以下代码显示键的值:

@SuppressWarnings( "unchecked" )
protected void setInputParameters() {
  HttpServletRequest request = getServletRequest();
  Enumeration<String> keys = request.getParameterNames();

  while( keys.hasMoreElements() ) {
    String key = keys.nextElement();

    for( String value : request.getParameterValues( key ) ) {
      System.out.println( "KEY: " + key + " VALUE: " + value );
    }
  }
}

框架修改键名:

KEY: j_id2:report_city VALUE: ab
KEY: j_id2:system_REPORT_RESOURCE VALUE: city
KEY: j_id2:j_id11 VALUE: Report
KEY: j_id2:report_REPORT_TITLE VALUE: City Listing
KEY: j_id2:report_int_max_longitude VALUE: 
KEY: j_id2:report_int_min_latitude VALUE: 
KEY: javax.faces.ViewState VALUE: j_id28
KEY: j_id2:system_REPORT_FILENAME VALUE: city
KEY: j_id2 VALUE: j_id2

更新

改变 <h:form>标签包含 id="form"属性结果:

KEY: form:system_REPORT_FILENAME VALUE: city
KEY: form VALUE: form
KEY: form:report_city VALUE: ab
KEY: form:report_int_max_longitude VALUE: 
KEY: form:report_REPORT_TITLE VALUE: Canadian City List
KEY: form:system_REPORT_RESOURCE VALUE: city
KEY: form:report_int_min_latitude VALUE: 
KEY: form:j_id10 VALUE: Report
KEY: javax.faces.ViewState VALUE: j_id1

这样更好，但仍不理想。

更新2

代码需要通用解析输入表单参数名称。到目前为止，以下代码可以删除前缀(但感觉有点老套):

  /**
   * Appends the list of HTTP request parameters to the internal parameter
   * map of user input values. Some frameworks prepend the name of the HTML
   * FORM before the name of the input. This method detects the colon and
   * removes the FORM NAME, if present. This means that input parameter
   * names assigned by developers should not contain a colon in the name.
   * (Technically, it is possible, but to avoid potential confusion it
   * should be avoided.)
   */
  protected void setInputParameters() {
    HttpServletRequest request = getServletRequest();
    Iterator<String> keys = getExternalContext().getRequestParameterNames();
    Parameters p = getParameters();

    while( keys.hasNext() ) {
      String key = keys.next();

      for( String value : request.getParameterValues( key ) ) {
        int i = key.indexOf( ':' );

        if( i >= 0 ) {
          key = key.substring( i + 1 );
        }

        p.put( key, value );
      }
    }
  }

问题

什么 API 调用返回没有 j_id2 的参数名称前缀？

删除 j_id2前缀(和可选的完整冒号)可能会引入依赖于框架的代码。

谢谢!

Answer 1

我不认为有 API 可以做到这一点，j_id2:XXX 是实际的请求参数名称。