直接从JSF / richfaces访问基于java的DOM树 [英] Accessing java-based DOM tree directly from JSF/richfaces

问题描述

基于这个问题我有一个其他几个问题：

Based on this question I have a couple of other questions:

1）这个问题中可用于jsf的地图实际上是一个数字，所以我现在不确定是什么支持bean方法的返回类型现在应该是。如果我修改它的当前数组< String> 返回类型为数组< Map Integer，Map< String，String []>>> （或 ArrayList< Map Integer，Map< String，String []>>> ？）它是否只是进一步嵌套的情况jsf端的迭代器？麻烦是一个Array / ArrayList不是Map，我不确定它在jsf中的表现如何。这是正确的：

1) the map in this question which is made available to jsf is actually one of a number, so i'm now not sure what the backing bean method's return type should now be. if i modify it's current Array<String> return type to Array<Map Integer, Map<String, String[]>>> (or ArrayList<Map Integer, Map<String, String[]>>> ?) would it just be a case of further nesting the iterator on the jsf side? Trouble is an Array/ArrayList isn't a Map and I'm unsure how this then looks in jsf. would this be correct:

<c:forEach items="#{bean.map}" var="entry">                     <!-- array -->
  <c:forEach items="#{entry.value}" var="nentry">               <!-- map -->
    <h:outputText value="Key: #{nentry.key}, Values:" />        <!-- integer -->
    <c:forEach items="#{nentry.value}" var="nnentry">           <!-- sub map -->
      <h:outputText value="Key: #{nnentry.key}, Values:" />     <!-- string -->
      <c:forEach items="#{nnentry.value}" var="nnnentry">       <!-- string[] -->
        <h:outputText value="#{nnnentry}" />
      </c:forEach><br />
    </c:forEach><br />
  </c:forEach><br />
</c:forEach>

？

2）我是什么真正存储在这个映射中的是从java端解析的XML DOM树中的xpath rips。我现在想我可以直接从JSF访问这个基于java的DOM树而不必使用XPath - > ArrayOfMaps并返回它。在看起来像这样的XML文件中，有比使用上述方法更好的方法吗？：

2) what i'm really storing in this map is xpath rips from an XML DOM tree parsed on the java side. i'm now thinking i can access this java-based DOM tree from JSF directly without having to use XPath -> ArrayOfMaps and return that. In an XML file which looks something like this, is there a better way than using the above method?:

 <test>                                              
  <testid>1</testid>                          
  <testname>myName</testname>

  <inst>                                      
   <id>1</id>                  
   <src>C:\my\path</src>               
   <mask>.*\.\w{3}</mask>      
   <mask>.*\.x</mask>          
  </inst>

  <inst>                                      
   <id>2</id>                  
   <src>C:\my\otherpath</src>               
   <mask>.*\.\w{3}</mask>      
   <mask>.*\.x</mask>          
  </inst>
</test>

再次感谢
Mark

Thanks again Mark

推荐答案

<c:forEach items="#{bean.map}" var="entry">                     <!-- array -->
  <c:forEach items="#{entry.value}" var="nentry">               <!-- map -->

这是错误的。对于 ArrayList 的每次迭代都不会像您想象的那样返回 Map.Entry 对象。它只返回 List 的单个元素（在您的情况下为 Map ）。以下是它的外观：

This is wrong. Each iteration over an ArrayList doesn't return a Map.Entry object at all as you seem to think. It just returns the individual element of the List (which is in your case a Map). Here's how it should look like:

<c:forEach items="#{bean.list}" var="map">                        <!-- array -->
  <c:forEach items="#{map}" var="entry">                          <!-- map -->

简而言之， a c：forEach 迭代列表或对象[] 如下

In nutshell, a c:forEach iteration over an List or Object[] as follows

<c:forEach items="${array}" var="item">
    ...
</c:forEach>

最好在原始Java代码中解释为

is best to be interpreted in raw Java code as

for (Object item : array) {
    // ...
}

而 c：forEach 迭代超过地图如图所示在上一主题中最好在原始Java代码中解释为：

while a c:forEach iteration over Map as demonstrated in your previous topic is best to be interpreted in raw Java code as:

for (Entry<K, V> entry : map.entrySet()) {
    K key = entry.getKey();       // ${entry.key}
    V value = entry.getValue();   // ${entry.value}
}

这篇关于直接从JSF / richfaces访问基于java的DOM树的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！