将XML信息提取到列表< Map>使用XPath [英] Extract XML Information to List<Map> using XPath
问题描述
我有来自SOAP Response的XML数据,如下例所示:
I have a XML data from a SOAP Response like in the following example:
<EMP>
<PERSONAL_DATA>
<EMPLID>AA0001</EMPLID>
<NAME>Adams<NAME>
</PERSONAL_DATA>
<PERSONAL_DATA>
<EMPLID>AA0002<EMPLID>
<NAME>Paul<NAME>
</PERSONAL_DATA>
</EMP>
我想在地图中存储有关每位员工的信息(KEY,VALUE )KEY = tagname,VALUE = value
并且想要为在java中使用XPATH的所有员工创建 LIST< MAP>
。这是怎么做到的?
I want to store information about each employee in a Map(KEY,VALUE) KEY=tagname, VALUE=value
and want to create a LIST<MAP>
for all employees using XPATH in java. How is this done?
我尝试了以下内容:
public static List createListMap(String path, SOAPMessage response,Map map) {
List<Map<String,Object>> list = new ArrayList<Map<String,Object>>();
try {
XPath xpath = XPathFactory.newInstance().newXPath();
XPathExpression expr = xpath.compile("//" + path + "/*");
Object re =expr.evaluate(response.getSOAPBody(), XPathConstants.NODESET);
NodeList nodes = (NodeList)res;
for (int i = 0; i < nodes.getLength(); i++) {
if (nodes.item(i).getFirstChild() != null &&
nodes.item(i).getFirstChild().getNodeType() == 1) {
Map<String, Object> map1 = new HashMap<String, Object>();
map.put(nodes.item(i).getLocalName(), map1);
createListMap(nodes.item(i).getNodeName(), response,map1);
list.add(map);
}
else {
map.put(nodes.item(i).getLocalName(),nodes.item(i).getTextContent());
}
return list;
}
我调用了一个类似的方法createListMap(EMP ,响应,地图);
(响应是SoapResponse)。
在XPATH // PERSONAL_DATA / *
中出现问题。在递归中,它列出了关于两个员工的数据,但我想将每个员工的数据存储在自己的地图中,然后创建这些MAP的列表...我该怎么做?
I called a method like createListMap("EMP",response,map);
(response is a SoapResponse).
The problem is coming when in XPATH //PERSONAL_DATA/*
. In recursion it listed data about both of the employees, but I want to store each employee's data in its own map, then create a LIST of those MAP's... How do I do this?
推荐答案
表达式 // PERSONAL_DATA / *
选择每个 PERSONAL_DATA的所有子元素
元素,导致您描述的问题。相反,选择 PERSONAL_DATA
元素并迭代他们的孩子。
The expression //PERSONAL_DATA/*
selects all child elements of every PERSONAL_DATA
element, causing exactly the problem you describe. Instead, select the PERSONAL_DATA
elements themselves and iterate their children.
示例:
public NodeList eval(final Document doc, final String pathStr)
throws XPathExpressionException {
final XPath xpath = XPathFactory.newInstance().newXPath();
final XPathExpression expr = xpath.compile(pathStr);
return (NodeList) expr.evaluate(doc, XPathConstants.NODESET);
}
public List<Map<String, String>> fromNodeList(final NodeList nodes) {
final List<Map<String, String>> out = new ArrayList<Map<String,String>>();
int len = (nodes != null) ? nodes.getLength() : 0;
for (int i = 0; i < len; i++) {
NodeList children = nodes.item(i).getChildNodes();
Map<String, String> childMap = new HashMap<String, String>();
for (int j = 0; j < children.getLength(); j++) {
Node child = children.item(j);
if (child.getNodeType() == Node.ELEMENT_NODE)
childMap.put(child.getNodeName(), child.getTextContent());
}
out.add(childMap);
}
return out;
}
像这样使用:
List<Map<String, String>> nodes = fromNodeList(eval(doc, "//PERSONAL_DATA"));
System.out.println(nodes);
输出:
[{NAME=Adams, EMPLID=AA0001}, {NAME=Paul, EMPLID=AA0002}]
如果你实际上正在处理一个更复杂的结构,有额外的嵌套元素(我怀疑你是这样),那么你需要分别迭代这些层或使用像 JAXB 。
If you're actually dealing with a more complicated structure, with additional nested elements (which I suspect you are), then you'll need to iterate those layers separately or model your data using something like JAXB.
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