Android中XML的基本操作（增、删、改、查）
本文向大家介绍Android中XML的基本操作（增、删、改、查），包括了Android中XML的基本操作（增、删、改、查）的使用技巧和注意事项，需要的朋友参考一下
Android中XML的一些操作
解析类：
// 构造方法
public XMLParser() {
}
/**
* 从URL获取XML使HTTP请求
*
* @param url
* string
* */
public String getXmlFromUrl(String url) {
String xml = null;
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
xml = EntityUtils.toString(httpEntity, "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return xml;
}
/**
* 获取XML DOM元素
*
* @param XML
* string
* */
public Document getDomElement(InputStream is) {
Document doc = null;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder db = dbf.newDocumentBuilder();
// InputSource is = new InputSource();
// is.setCharacterStream(new StringReader(xml));
doc = db.parse(is);
} catch (ParserConfigurationException e) {
Log.e("Error: ", e.getMessage());
return null;
} catch (SAXException e) {
Log.e("Error: ", e.getMessage());
return null;
} catch (IOException e) {
Log.e("Error: ", e.getMessage());
return null;
}
return doc;
}
public Document getDomDocumentUpdate(String xml) {
Document doc = null;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder db = dbf.newDocumentBuilder();
InputSource is = new InputSource();
is.setCharacterStream(new StringReader(xml));
doc = db.parse(is);
} catch (ParserConfigurationException e) {
Log.e("Error: ", e.getMessage());
return null;
} catch (SAXException e) {
Log.e("Error: ", e.getMessage());
return null;
} catch (IOException e) {
Log.e("Error: ", e.getMessage());
return null;
}
return doc;
}
/**
* 获取节点值
*
* @param elem
* element
*/
public final String getElementValue(Node elem) {
Node child;
if (elem != null) {
if (elem.hasChildNodes()) {
for (child = elem.getFirstChild(); child != null; child = child
.getNextSibling()) {
if (child.getNodeType() == Node.TEXT_NODE) {
return child.getNodeValue();
}
}
}
}
return "";
}
/**
* 获取节点值
*
* @param Element
* node
* @param key
* string
* */
public String getValue(Element item, String str) {
NodeList n = item.getElementsByTagName(str);
return this.getElementValue(n.item(0));
}
//XML文件有更新后，调用此方法
public void output(Document node, String filename) {
TransformerFactory transFactory = TransformerFactory.newInstance();
try {
Transformer transformer = transFactory.newTransformer();
// 设置各种输出属性
transformer.setOutputProperty("encoding", "UTF-8");
transformer.setOutputProperty("indent", "yes");
DOMSource source = new DOMSource(node);
// 将待转换输出节点赋值给DOM源模型的持有者(holder)
// /source.setNode(node);
StreamResult result = new StreamResult();
if (filename == null) {
// 设置标准输出流为transformer的底层输出目标
result.setOutputStream(System.out);
} else {
result.setOutputStream(new FileOutputStream(filename));
}
// 执行转换从源模型到控制台输出流
transformer.transform(source, result);
} catch (TransformerConfigurationException e) {
e.printStackTrace();
} catch (TransformerException e) {
e.printStackTrace();
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
public String writeXml() {
XmlSerializer xml = Xml.newSerializer();
StringWriter writer = new StringWriter();
try {
xml.setOutput(writer);
xml.startDocument("UTF-8", true);
xml.startTag("", "blog");
xml.startTag("", "message");
xml.attribute("", "name", "xia");
xml.startTag("", "age");
xml.text("22");
xml.endTag("", "age");
xml.startTag("", "hobby");
xml.text("play");
xml.endTag("", "hobby");
xml.startTag("", "hight");
xml.text("165");
xml.endTag("", "hight");
xml.endTag("", "message");
xml.startTag("", "message");
xml.attribute("", "name", "chen");
xml.startTag("", "age");
xml.text("21");
xml.endTag("", "age");
xml.startTag("", "hobby");
xml.text("swin");
xml.endTag("", "hobby");
xml.startTag("", "hight");
xml.text("170");
xml.endTag("", "hight");
xml.endTag("", "message");
xml.endTag("", "blog");
xml.endDocument();
} catch (Exception e) {
throw new RuntimeException(e);
}
return writer.toString();
}
public boolean Write(String Filepath, String txt) {
FileOutputStream fos = null;
if (Environment.getExternalStorageState() != null) {// 这个方法在试探终端是否有sdcard!
File path = new File("sdcard/test");// 创建目录
File f = new File(Filepath);// 创建文件
if (!path.exists()) {// 目录不存在返回false
path.mkdirs();// 创建一个目录
}
if (!f.exists()) {// 文件不存在返回false
try {
f.createNewFile();
fos = new FileOutputStream(f);
fos.write((txt).getBytes("UTF-8"));
fos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}// 创建一个文件
}
}
return true;
}
private static XMLParser uniqueInstance = null;
public static XMLParser getInstance() {
if (uniqueInstance == null) {
uniqueInstance = new XMLParser();
}
return uniqueInstance;
}
}
上面的这个类中用了单例！分别定义了XML的创建，获取XML的节点值，更新后执行的操作！
MainActivity：
public class MainActivity extends Activity {
public static final String XMLPath = "sdcard/test/message.xml";
private Button create = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
create = (Button) findViewById(R.id.create);
}
// 自动创建XML
private void createXml() {
// sdcard/test/message.xml
XMLParser.getInstance().Write(XMLPath,
XMLParser.getInstance().writeXml());
}
// 遍历节点，找到特定节点并进行更换！
private void selectNode() {
Document document = null;
try {
FileInputStream fin = new FileInputStream(XMLPath);
document = XMLParser.getInstance().getDomElement(fin);
Node root = document.getDocumentElement();
if (root.hasChildNodes()) {
NodeList ftpnodes = root.getChildNodes();
Log.e("eee", root.getNodeName());// 根节点 blog
for (int i = 0; i < ftpnodes.getLength(); i++) {
NodeList ftplist = ftpnodes.item(i).getChildNodes();
Node su = ftpnodes.item(i);
Log.e("eee", su.getNodeName());// message
Element e = (Element) ftpnodes.item(i);
Log.e("eee", e.getAttribute("name"));// message= xia
for (int k = 0; k < ftplist.getLength(); k++) {
Node subnode = ftplist.item(k);
Log.e("eee",
" subnode.getNodeName()"
+ subnode.getNodeName());
Log.e("eee",
"subnode.getNodeType()" + subnode.getNodeType());
Log.e("eee", subnode.getFirstChild().getNodeValue());
if (subnode.getNodeType() == Node.ELEMENT_NODE
&& subnode.getNodeName().equals("hight")) {
subnode.getFirstChild().setNodeValue("175");
XMLParser.getInstance().output(document, XMLPath);
}
}
}
}
} catch (Exception e) {
}
}
// 添加一个新的根节点
private void insertNode() {
Document document = null;
try {
FileInputStream fin = new FileInputStream(XMLPath);
document = XMLParser.getInstance().getDomElement(fin);
// 插入根节点message
/**
* <message name="wang"> <hight>180</hight> <age>22</age> </message>
*
* */
Element eltStu = document.createElement("message");
Element eltName = document.createElement("hight");
Element eltAge = document.createElement("age");
Attr attr = document.createAttribute("name");
attr.setValue("wang");
Text txtName = document.createTextNode("180");
Text txtAge = document.createTextNode("22");
eltName.appendChild(txtName);
eltAge.appendChild(txtAge);
eltStu.appendChild(eltName);
eltStu.appendChild(eltAge);
eltStu.setAttributeNode(attr);
Element eltRoot = document.getDocumentElement();
eltRoot.appendChild(eltStu);
XMLParser.getInstance().output(document, XMLPath);
} catch (Exception e) {
}
}
private void instertChildNode() {
Document document = null;
try {
FileInputStream fin = new FileInputStream(XMLPath);
document = XMLParser.getInstance().getDomElement(fin);
// 在某个根节点下面添加节点
/**
* <message name="wang"> <hight>180</hight> <age>22</age>
* <hobby>music</hobby>//这句是新添加的 </message>
*
* */
Node root = document.getDocumentElement();
NodeList ftpnodes = root.getChildNodes();
Log.e("eee", root.getNodeName());// 根节点 blog
NodeList ftplist = ftpnodes.item(1).getChildNodes();
Node su = ftpnodes.item(1);
Log.e("eee", su.getNodeName());// message
Element e = (Element) ftpnodes.item(5);// message= wang
Log.e("eee", e.getAttribute("name"));
if (e.getAttribute("name").equals("wang")) {
Element elthoby = document.createElement("hobby");
Text txthoby = document.createTextNode("music");
elthoby.appendChild(txthoby);
Node stNode = document.getElementsByTagName("message").item(2);
stNode.appendChild(elthoby);
}
XMLParser.getInstance().output(document, XMLPath);
} catch (Exception e) {
}
}
private void removeNode() {
Document document = null;
try {
FileInputStream fin = new FileInputStream(XMLPath);
document = XMLParser.getInstance().getDomElement(fin);
// 删除blog下的message的0个节点
NodeList nl = document.getElementsByTagName("message");
Node nodeDel = (Element) nl.item(0);
nodeDel.getParentNode().removeChild(nodeDel);
XMLParser.getInstance().output(document, XMLPath);
} catch (Exception e) {
}
}
@Override
protected void onDestroy() {
super.onDestroy();
}
}
最后记得添加读写SDcard的权限！
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