获取XML文件的基本思路是，通过getResources().getXml()获的XML原始文件，得到XmlResourceParser对象，通过该对象来判断是文档的开头还是结尾，是某个标签的开始还是结尾，并通过一些获取属性的方法来遍历XML文件，从而访问XML文件的内容，下面是一个访问XML文件内容的例子，并将内容更显示在一个TextView上
数据写入xml:
ReadXMLTest.java
private String WriteToString() {
XmlSerializer serializer = Xml.newSerializer();
StringWriter writer = new StringWriter();
try {
serializer.setOutput(writer);
serializer.startDocument("utf-8", true);
serializer.startTag("", "users");
serializer.startTag("", "userName");
serializer.text(txtUser.getText().toString());
serializer.endTag("", "userName");
serializer.startTag("", "userEmail");
serializer.text(txtEmail.getText().toString());
serializer.endTag("", "userEmail");
serializer.startTag("", "passWord");
serializer.text(txtPass.getText().toString());
serializer.endTag("", "passWord");
serializer.endTag("", "users");
serializer.endDocument();
} catch (IllegalArgumentException e) {
// TODO: handle exception
e.printStackTrace();
} catch (IllegalStateException e) {
// TODO: handle exception
e.printStackTrace();
} catch (IOException e) {
// TODO: handle exception
e.printStackTrace();
}
return writer.toString();
}
//将字符串保存为apk的私有文件
private boolean writeToXml(String str) {
try {
OutputStream out = openFileOutput("users.xml",MODE_PRIVATE);
OutputStreamWriter outWriter = new OutputStreamWriter(out);
try {
outWriter.write(str);
outWriter.close();
out.close();
return true;
} catch (IOException e) {
// TODO: handle exception
return false;
}
} catch (Exception e) {
// TODO: handle exception
return false;
}
}
调用时:
if(writeToXml(WriteToString()))
{
//成功
}
数据读取 xml:
private String ReadXmlUser(String tag)
{
String re="";
DocumentBuilderFactory documentBuilderFactory;
DocumentBuilder documentBuilder;
Document document;
try {
documentBuilderFactory=DocumentBuilderFactory.newInstance();
documentBuilder=documentBuilderFactory.newDocumentBuilder();
//xml文件放到assets目录下
document=documentBuilder.parse(this.openFileInput("users.xml"));
org.w3c.dom.Element root= document.getDocumentElement();
NodeList nodeList=root.getElementsByTagName(tag);
Node nd=nodeList.item(0);
re= nd.getFirstChild().getNodeValue();
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}finally{
document=null;
documentBuilder=null;
documentBuilderFactory=null;
}
return re;
}
以上转载于 http://blog.csdn.net/hanjingjingpan/article/details/8812770
顺便介绍三种xml解析
public class MainActivity extends Activity implements OnClickListener {
private static final String TAG = "MainActivity";
Button Sax_praseXml, Dom_praseXml, Pull_praseXml, Write_xml;
TextView Sax_contentXml, Dom_contentXml, Pull_contentXml;
String xmlContent;
MyHandler myhandler;
List<PersonDetail> list;
InputStream inputStream;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
xmlContent = "";
Sax_praseXml = (Button) findViewById(R.id.btn_sax);
Dom_praseXml = (Button) findViewById(R.id.btn_dom);
Pull_praseXml = (Button) findViewById(R.id.btn_pull);
Sax_contentXml = (TextView) findViewById(R.id.view_sax);
Dom_contentXml = (TextView) findViewById(R.id.prase_dom);
Pull_contentXml = (TextView) findViewById(R.id.prase_pull);
Sax_praseXml.setOnClickListener(this);
Dom_praseXml.setOnClickListener(this);
Pull_praseXml.setOnClickListener(this);
}
public void onClick(View v) {
switch (v.getId()) {
case R.id.btn_sax:
inputStream = MainActivity.class.getClassLoader()
.getResourceAsStream("test.xml");
try {
Log.v(TAG, "-------sax");
StringBuffer sb = new StringBuffer();
list = SAXpraseTransiaction.SaxPrase(inputStream);
for (PersonDetail tail : list) {
sb.append(tail.toString() + "\n");
}
Sax_contentXml.setText("SaxResult:" + sb.toString());
Log.v(TAG, "" + "----------------------" + sb.toString());
} catch (Exception E) {
Log.v(TAG, "" + "----------------------解析失败");
}
break;
case R.id.btn_dom:
inputStream = MainActivity.class.getClassLoader()
.getResourceAsStream("test.xml");
try {
Log.v(TAG, "-------DOM");
StringBuffer sbDOM = new StringBuffer();
list = DomPraserTransaction.getPraserList(inputStream);
for (PersonDetail tail : list) {
sbDOM.append(tail.toString() + "\n");
}
Dom_contentXml.setText("DOMResult:" + sbDOM.toString());
Log.v(TAG, "" + "----------------------" + sbDOM.toString());
} catch (Exception E) {
Log.v(TAG, "" + "----------------------解析失败");
}
break;
case R.id.btn_pull:
inputStream = MainActivity.class.getClassLoader()
.getResourceAsStream("test.xml");
try {
Log.v(TAG, "-------PULL");
StringBuffer sbPULL = new StringBuffer();
list = PullPraserTransaction.GetResultList(inputStream);
for (PersonDetail tail : list) {
sbPULL.append(tail.toString() + "\n");
}
Pull_contentXml.setText("PULLResult:" + sbPULL.toString());
Log.v(TAG, "" + "----------------------" + sbPULL.toString());
} catch (Exception E) {
Log.v(TAG, "" + "----------------------解析失败");
}
break;
}
}
/**
* 实用于文件比较小的Xml解析,简单实用 2011/9/29
*
* @author:1314hwl
*
*/
public class DomPraserTransaction {
public static List<PersonDetail> getPraserList(InputStream inputStream) {
List<PersonDetail> Resultlist = null;
PersonDetail Person = null;
XmlPullParser pullpraser = Xml.newPullParser();
try {
pullpraser.setInput(inputStream, "UTF-8");
int eventtype = pullpraser.getEventType();
while (eventtype != XmlPullParser.END_DOCUMENT) {
switch (eventtype) {
case XmlPullParser.START_DOCUMENT:
Resultlist = new ArrayList<PersonDetail>();
break;
case XmlPullParser.START_TAG:
if ("person".equals(pullpraser.getName())) {
Person = new PersonDetail();
Person.setId(new Integer(pullpraser
.getAttributeValue(0)));
} else if (Person != null) {
if ("name".equals(pullpraser.getName())) {
Person.setName(pullpraser.nextText());
} else if ("age".equals(pullpraser.getName())) {
Person.setAge(new String(pullpraser.nextText()));
}
}
break;
case XmlPullParser.END_TAG:
if ("person".equals(pullpraser.getName()) && Person != null) {
Resultlist.add(Person);
Person = null;
}
break;
}
eventtype = pullpraser.next();
}
} catch (Exception e) {
e.printStackTrace();
}
try {
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
return Resultlist;
}
}
/**
* pull解析XML pull写入XML
*
* @author 1314hwl 2011/9/29
*
*/
public class PullPraserTransaction {
public static List<PersonDetail> GetResultList(InputStream inputStream)
throws Exception {
List<PersonDetail> Resultlist = new ArrayList<PersonDetail>();
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
Document document = builder.parse(inputStream);
Element element = document.getDocumentElement();
NodeList nodes = element.getElementsByTagName("person");
int len = nodes.getLength();
for (int i = 0; i < len; i++) {
Element personElement = (Element) nodes.item(i);
PersonDetail person = new PersonDetail();
person.setId(new Integer(personElement.getAttribute("id")));
NodeList childNodes = personElement.getChildNodes();
for (int y = 0; y < childNodes.getLength(); y++) {
Node childNode = (Node) childNodes.item(y);
if (childNode.getNodeType() == Node.ELEMENT_NODE) {
Element childElement = (Element) childNode;
if ("name".equals(childElement.getNodeName())) {
person.setName(childElement.getFirstChild()
.getNodeValue());
}
if ("age".equals(childElement.getNodeName())) {
person.setAge(childElement.getFirstChild()
.getNodeValue());
}
}
}
Resultlist.add(person);
}
inputStream.close();
return Resultlist;
}
}
/**
* @author 1314hwl SAX解析 2011/9/29
*/
public class SAXpraseTransiaction {
public static List<PersonDetail> SaxPrase(InputStream inputStream) {
SAXParserFactory factory = SAXParserFactory.newInstance();//解析工厂
// try {
// SAXParser saxparser=factory.newSAXParser(); //解析器对象
//
// MyHandler myhandler=new MyHandler();
//
// saxparser.parse(inputStream, myhandler);
//
// inputStream.close();
// } catch (Exception e) {
//
// } 这里两种方式：SAXParser or XMLReader 都可以
MyHandler myhandler = new MyHandler();
try {
XMLReader xmlreader = factory.newSAXParser().getXMLReader();//实现一个XMLReader
xmlreader.setContentHandler(myhandler); //defualthandler
xmlreader.parse(new InputSource(inputStream));//要解析的流加入解析中
} catch (Exception e) {
e.printStackTrace();
}
try {
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
return myhandler.resultList();
}
}
**
* SAX解析的defaultHandler
*
* @author 1314hwl 2011/9/29
*/
public class MyHandler extends DefaultHandler {
private static final String TAG = "MyHandler";
String name, age;
String tagname;
PersonDetail Person;
List<PersonDetail> personList = null;
public MyHandler() {
super();
personList = new ArrayList<PersonDetail>();
}
public void characters(char[] ch, int start, int length)
throws SAXException {
super.characters(ch, start, length);
if (Person != null) {
String content = new String(ch, start, length);
if ("name".equals(tagname)) {
Person.setName(content);
} else if ("age".equals(tagname)) {
Person.setAge(content);
}
}
}
public void endDocument() throws SAXException {
super.endDocument();
Log.v(TAG, "解析结束");
}
public void endElement(String uri, String localName, String qName)
throws SAXException {
super.endElement(uri, localName, qName);
if (localName.equals("person") && Person != null) {
personList.add(Person);
Person = null;
}
tagname=null;
}
public void startDocument() throws SAXException {
super.startDocument();
Log.v(TAG, "解析开始");
}
public void startElement(String uri, String localName, String qName,
Attributes attributes) throws SAXException {
super.startElement(uri, localName, qName, attributes);
Log.v("startElement", localName);
tagname = localName;
if (localName.equals("person")) {
Person = new PersonDetail();
Person.setId(new Integer(attributes.getValue(0)));
}
}
public List<PersonDetail> resultList() {
return personList;
}
}
public class PersonDetail {
String name, age;
int id;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public PersonDetail(int id, String name, String age) {
super();
this.id = id;
this.name = name;
this.age = age;
}
public PersonDetail() {
super();
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAge() {
return age;
}
public void setAge(String age) {
this.age = age;
}
public String toString() {
return "person [id=" + id + ", name=" + name + ", age=" + age + "]";
}
}
以及 详解Java反射机制实例
import java.lang.reflect.*;
public class ReflectTester {
public Object copy(Object object) throws Exception {
// 获得对象的类型
Class classType = object.getClass();
System.out.println("Class:" + classType.getName());
// 通过默认构造方法创建一个新的对象
Object objectCopy = classType.getConstructor(new Class[] {})
.newInstance(new Object[] {});
// 获得对象的所有属性
Field fields[] = classType.getDeclaredFields();
for (int i = 0; i < fields.length; i++) {
Field field = fields[i];
String fieldName = field.getName();
String firstLetter = fieldName.substring(0, 1).toUpperCase();
// 获得和属性对应的getXXX()方法的名字
String getMethodName = "get" + firstLetter + fieldName.substring(1);
// 获得和属性对应的setXXX()方法的名字
String setMethodName = "set" + firstLetter + fieldName.substring(1);
// 获得和属性对应的getXXX()方法
Method getMethod = classType.getMethod(getMethodName,
new Class[] {});
// 获得和属性对应的setXXX()方法
Method setMethod = classType.getMethod(setMethodName,
new Class[] { field.getType() });
// 调用原对象的getXXX()方法
Object value = getMethod.invoke(object, new Object[] {});
System.out.println(fieldName + ":" + value);
// 调用复制对象的setXXX()方法
setMethod.invoke(objectCopy, new Object[] { value });
}
return objectCopy;
}
public static void main(String[] args) throws Exception {
Customer customer = new Customer("Tom", 21);
customer.setId(new Long(1));
Customer customerCopy = (Customer) new ReflectTester().copy(customer);
System.out.println("Copy information:" + customerCopy.getName() + " "
+ customerCopy.getAge());
}
}
class Customer { // Customer类是一个JavaBean
private Long id;
private String name;
private int age;
public Customer() {
}
public Customer(String name, int age) {
this.name = name;
this.age = age;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
阅读完以上的内容
我们的第一个方法 WriteToString() 就可以通过反射直接写出，不需要每次都写好多属性
举例说明：Product.Java
private String name;
private String price;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPrice() {
return price;
}
public void setPrice(String price) {
this.price = price;
}
Test.java
public static void main(String[] args) throws Exception {
List<Product> plist = new ArrayList<Product>();
Product p1= new Product();
p1.setName("空气净化器1");
p1.setPrice("3799");
plist.add(p1);
Product p2= new Product();
p2.setName("空气净化器2");
p2.setPrice("3799");
plist.add(p2);
produceXml(Product.class , plist);
}
public static String produceXml(Class clazz,List plist) throws Exception{
System.out.println("<" +clazz.getName().toLowerCase()+"s" +">");
for(Object o:plist){
System.out.println( "<" +clazz.getName().toLowerCase()+">");
for(int i=0;i< clazz.getDeclaredFields().length;i++){
System.out.print("<" + clazz.getDeclaredFields()[i].getName() +">");
for(int j = 0; j < Product.class.getDeclaredMethods().length; j++) {
if ( ("get"+clazz.getDeclaredFields()[i].getName().substring(0,1).toUpperCase()+( clazz.getDeclaredFields()[i].getName().substring(1)) ).equals( clazz.getDeclaredMethods()[j].getName() )){
Method getMethod = clazz.getMethod(clazz.getDeclaredMethods()[j].getName(), new Class[]{});
Object result = getMethod.invoke( o, new Object[] {});
System.out.print( result.toString());
}
}
System.out.println("</"+ clazz.getDeclaredFields()[i].getName() +">");
}
System.out.println( "</"+clazz.getName().toLowerCase()+">");
}
System.out.println( "</"+clazz.getName().toLowerCase()+"s"+">");
return null;
}
运行结果：
<products>
<product>
<name>空气净化器1</name>
<price>3799</price>
</product>
<product>
<name>空气净化器2</name>
<price>3799</price>
</product>
</products>
System.out.println( "</"+ ……+">"); 替换成xmlSerializer.endTag(null, ……);就ok了哦！
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