xml 解析的三种方法

 

dom解析：

 

public class DOMPersonService

{

public static List<Person> readXml(InputStream inStream) throws Exception

{

List<Person> persons=new ArrayList<Person>();

//实例化一个文档构建器工厂

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

//通过文档构建器工厂获取一个文档构建器

DocumentBuilder builder = factory.newDocumentBuilder();

//通过文档通过文档构建器构建一个文档实例

Document document = builder.parse(inStream);

Element root = document.getDocumentElement();

                //获取所有"pre:person"节。点

NodeList nodes = root.getElementsByTagName("pre:person");

for(int i = 0 ;i < nodes.getLength();i++)

{

Element personElement = (Element)nodes.item(i);

Person person =new Person();

person.setId(Integer.valueOf(personElement.getAttribute("id")));

NodeList childNodes = personElement.getChildNodes();

for(int j = 0;j<childNodes.getLength();j++)

{

Node childNode = (Node)childNodes.item(j);

if (childNode.getNodeType()==Node.ELEMENT_NODE)

{

Element childElement = (Element)childNode;

if ("name".equals(childElement.getNodeName()))

{

person.setName(childElement.getFirstChild().getNodeValue());

}

else if (("age".equals(childElement.getNodeName())))

{

person.setAge(new Short(childElement.getFirstChild().getNodeValue()));

}

}

}

persons.add(person);

}

return persons;

}

}

调用此类测试：

public class DOMPersonServiceTest extends AndroidTestCase

{

private static final String TAG="PersonServiceTest";

public void testReadXml() throws Exception

{

InputStream inStream=DOMPersonServiceTest.class.getClassLoader().getResourceAsStream("person.xml");

               //解析出的xml

List<Person> persons=DOMPersonService.readXml(inStream);

for (Person person : persons)

{

Log.i(TAG, person.toString());

}

}

}

SAX解析：

public class SAXPersonService

{

public static List<Person> readXml(InputStream inStream) throws Exception

{

SAXParserFactory spf=SAXParserFactory.newInstance();

SAXParser saxParser=spf.newSAXParser();//创建解析器

XMLContentHandler handler=new XMLContentHandler();

saxParser.parse(inStream, handler);

inStream.close();

return handler.getPersons();

}

}

关键是要实现这个方法：

public class XMLContentHandler extends DefaultHandler

{

private static final String TAG = "XMLContentHandler";

private List<Person> persons;

private Person person;

private String preTag;

public List<Person> getPersons()

{

return persons;

}

@Override

public void startDocument() throws SAXException

{

persons = new ArrayList<Person>();

Log.i(TAG, "开始解析...");

}

/**

* uri：命名空间

* localName：不带命名空间前缀的标签名

* qName：带命名空间前缀的标签名

* attributes：属性集合

*/

@Override

public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException

{

if ("person".equals(localName))

{

person = new Person();

person.setId(new Integer(attributes.getValue("id")));

}

preTag = localName;

Log.i(TAG, "解析元素："+localName);

}

/**

* ch[]：内容

* start：其实位置

* length：长度

*/

@Override

public void characters(char[] ch, int start, int length) throws SAXException

{

if (person!=null)

{

String data = new String(ch, start,length);

if ("name".equals(preTag))

{

person.setName(data);

}

else if ("age".equals(preTag))

{

person.setAge(new Short(data));

}

}

Log.i(TAG, "解析内容："+new String(ch, start,length));

}

@Override

public void endElement(String uri, String localName, String qName) throws SAXException

{

if ("person".equals(localName)&&person!=null)

{

persons.add(person);

person = null;

}

preTag = null;

Log.i(TAG, localName + "解析完毕");

}

@Override

public void endDocument() throws SAXException

{

super.endDocument();

Log.i(TAG, "文档解析完毕");

}

}

调用测试：

public class SAXPersonServiceTest extends AndroidTestCase

{

private static final String TAG="SAXPersonServiceTest";

public void testReadXml() throws Exception

{

InputStream inStream=SAXPersonServiceTest.class.getClassLoader().getResourceAsStream("person.xml");

List<Person> persons=SAXPersonService.readXml(inStream);

for (Person person : persons)

{

Log.i(TAG, person.toString());

}

}

}

3 PULL解析

public class PullPersonService

{

public static List<Person> readXml(InputStream inStream) throws Exception

{

List<Person> persons=null;

XmlPullParser parser=Xml.newPullParser();

parser.setInput(inStream, "UTF-8");

int eventCode=parser.getEventType();

Person person=null;

while(eventCode!=XmlPullParser.END_DOCUMENT)

{

switch (eventCode)

{

case XmlPullParser.START_DOCUMENT: //0 文档开始事件

persons=new ArrayList<Person>();

break;

case XmlPullParser.START_TAG:  //2 开始元素

if ("person".equals(parser.getName()))

{

person=new Person();

person.setId(new Integer(parser.getAttributeValue(0)));

}

else if(null!=person)

{

if ("name".equals(parser.getName()))

{

person.setName(parser.nextText());

}

else if("age".equals(parser.getName()))

{

person.setAge(new Short(parser.nextText()));

}

}

break;

case XmlPullParser.END_TAG: //结束元素

if ("person".equals(parser.getName())&&person!=null)

{

persons.add(person);

person=null;

}

break;

}

eventCode=parser.next();

}

return persons;

}

}

调用测试

public class PullPersonServiceTest extends AndroidTestCase

{

private static final String TAG="PersonServiceTest";

public void testReadXml() throws Exception

{

InputStream inStream=PullPersonServiceTest.class.getClassLoader().getResourceAsStream("person.xml");

List<Person> persons=PullPersonService.readXml(inStream);

for (Person person : persons)

{

Log.i(TAG, person.toString());

}

}

}

要解析的文件：

person.xml

<?xml version="1.0" encoding="UTF-8"?>

<persons xmlns:pre="http://www.baidu.com">

<pre:person id="001">

<name>coolszy</name>

<age>22</age>

</pre:person>

<pre:person id="002">

<name>kuka</name>

<age>22</age>

</pre:person>

</persons>

如果为网络的话，可以直接获得流：

InputStream inputStream = urlConn.getInputStream();

解析的内容存储：

public class Person

{

private Integer id;

private String name;

private Short age;

public Person()

{

super();

}

public Person(Integer id, String name, Short age)

{

super();

this.id = id;

this.name = name;

this.age = age;

}

public Integer getId()

{

return id;

}

public void setId(Integer id)

{

this.id = id;

}

public String getName()

{

return name;

}

public void setName(String name)

{

this.name = name;

}

public Short getAge()

{

return age;

}

public void setAge(Short age)

{

this.age = age;

}

@Override

public String toString()

{

return "id=" + getId() + ",name=" + getName() + ",age=" + getAge();

}

}