xml解析工具类_xmlutil.getnodetext-优快云博客

本文链接：https://blog.youkuaiyun.com/smile3670/article/details/7692289

本文介绍了一个用于解析XML字符串的Java工具类，提供了从XML中提取节点值、属性值等功能，并通过示例展示了如何使用这些方法来解析包含不同层级的XML数据。

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public class XmlUtil {

private DocumentBuilderFactory factory = null;
private DocumentBuilder builder = null;

/**
*example, node string: <a> 1 <c>3</c> </a>,
* return the first node named $nodeName's value
* 
* if namespaceUri is null ,ignore it.
*
* @param node
* @param namespaceUri
* @param nodeName
* @return
*/
public String getNodeValue(Node pNode, String namespaceUri,
String nodeName) {
return getNodeText(getSingleNode(pNode, namespaceUri, nodeName));
}

/**
* parse xml from xmlstring
*
* @param xmlString
* @param useNamespace
* @return
* @throws ParserConfigurationException
* @throws SAXException
* @throws IOException
*/
public Document parseFromString(String xmlString,
boolean useNamespace) throws ParserConfigurationException,
SAXException, IOException, Exception {
if (xmlString == null || xmlString.trim().length() == 0) {
throw new Exception("empty xml string.");
}
ByteArrayInputStream bais = new ByteArrayInputStream(xmlString
.getBytes());

return parse(bais, useNamespace);
}

public Document parse(InputStream is, boolean useNamespace)
throws ParserConfigurationException, SAXException, IOException {
// if (factory == null) {
factory = DocumentBuilderFactory.newInstance();
// }
factory.setNamespaceAware(useNamespace);
// if (builder == null) {
builder = factory.newDocumentBuilder();
// }
Document dom = builder.parse(is);
return dom;
}

/**
* example, node string: <a>2</a>,return "2";
*
* @param node
* @return
*/
public String getNodeText(Node node) {

String s = null;
if (node == null) {
return null;
}
Node innerText = node.getFirstChild();
if (innerText != null && innerText.getNodeType() == Node.TEXT_NODE) {
s = innerText.getNodeValue();
}
// if innerText is null such as <a></a>, return ""
if (innerText == null) {
s = "";
}
return s;
}

/**
* example, node string: <a> 1 <c>3</c> </a>,return
* that first node named $nodeName
* 
* if namespaceUri is null ,ignore it.
*
* @param parent
* @param namespaceUri
* @param nodeName
* @return
*/
public Node getSingleNode(Node pNode, String namespaceUri,
String nodeName) {
NodeList nodelist = pNode.getChildNodes();
for (int i = 0; nodelist != null && i < nodelist.getLength(); i++) {
Node child = nodelist.item(i);

// Log.e("xmlutil--", "getLocalName:"+child.getLocalName()+"getNodeName:"+child.getNodeName()+"getNamespaceURI:"+child.getNamespaceURI());
if (namespaceUri != null) {
// namespace is not null, compare it
if (namespaceUri.equals(child.getNamespaceURI())
&& child.getLocalName().equals(nodeName))
return child;
} else {
if (child.getNodeName().equals(nodeName))
return child;
}
}
return null;
}

/**
* example, node string: <a> 1
* 23</a>,return all nodes named $nodeName;
* 
* if namespaceUri is null ,ignore it.
*
* @param pNode
* @param namespaceUri
* @param nodeName
* @return
*/
public List<Node> getNodeList(Node pNode, String namespaceUri,
String nodeName) {
NodeList nodelist = pNode.getChildNodes();
List<Node> nodesNeeds = new ArrayList<Node>();
for (int i = 0; nodelist != null && i < nodelist.getLength(); i++) {
Node child = nodelist.item(i);
if (namespaceUri != null) {
// namespace is not null, compare it
if (namespaceUri.equals(child.getNamespaceURI())
&& child.getLocalName().equals(nodeName)) {
nodesNeeds.add(child);
}
} else {
if (child.getNodeName().equals(nodeName)) {
nodesNeeds.add(child);
}
}
}
return nodesNeeds;
}

/**
* get first none text node.
*
* @param pNode
* @return
*/
public Node getFirstNode(Node pNode) {
Node node = null;
NodeList nodelist = pNode.getChildNodes();
for (int i = 0; nodelist != null && i < nodelist.getLength(); i++) {
Node child = nodelist.item(i);
if (child.getNodeType() != Node.TEXT_NODE) {
node = child;
return node;
}
}
return node;
}

/**
* example, node string: <a b="1"></a>,if $nodeName="b",return
* "1";
* 
* if namespaceUri is null ,ignore it.
*
* @param node
* @param namespaceUri
* @param attName
* @return
*/
public String getAttributeValue(Node node, String namespaceUri,
String attName) {
NamedNodeMap map = node.getAttributes();
if (namespaceUri == null) {
return map.getNamedItem(attName) == null ? null : map.getNamedItem(
attName).getNodeValue();
} else {
return map.getNamedItemNS(namespaceUri, attName) == null ? null
: map.getNamedItemNS(namespaceUri, attName).getNodeValue();
}
}

}

public static Msg parseFromString(String xmlString) throws Exception{
Msg msg=new Msg();
XmlUtil xmlUtil=new XmlUtil();
Document dom = null;
try{
dom = xmlUtil.parseFromString(xmlString, false);
Element root = dom.getDocumentElement();
//获取头信息
NodeList nodeList1=root.getElementsByTagName("HEAD");
if(nodeList1.getLength()>0){
Node head=nodeList1.item(0);
msg.setID(xmlUtil.getNodeValue(head, null, "ID"));
msg.setENCRYTION(xmlUtil.getNodeValue(head, null, "ENCRYTION"));
msg.setLOGINNAME(xmlUtil.getNodeValue(head, null, "LOGINNAME"));
msg.setPASSWORD(xmlUtil.getNodeValue(head, null, "PASSWORD"));
msg.setSERIALNUM(xmlUtil.getNodeValue(head, null, "SERIALNUM"));
msg.setSERVICEID(xmlUtil.getNodeValue(head, null, "SERVICEID"));
msg.setTIMESTAMP(xmlUtil.getNodeValue(head, null, "TIMESTAMP"));
msg.setVERSION(xmlUtil.getNodeValue(head, null, "VERSION"));
}
List<Node> nodeList2=xmlUtil.getNodeList(root,null,"BODY");

List<BODY> list=getBODY(nodeList2);
msg.setBodylist(list);
return msg;
}catch (Exception e) {
e.printStackTrace();
throw new Exception("parse message error.");
}
}