一、使用Pull解析器读取XML文件
Android内置Pull解析器解析XML文件。 Pull解析器是一个开源的java项目,既可以用于android,也可以用于JavaEE。android系统本身使用到的各种xml文件,其内部也是采用Pull解析器进行解析的。跟SAX不同的是, Pull解析器产生的事件是一个数字,而非方法,因此可以使用一个switch对感兴趣的事件进行处理。当元素开始解析时,调用parser.nextText()方法可以获取下一个Text类型节点的值
二、使用Pull解析器生成XML文件
生成XML文件的方法有很多,如:可以只使用一个StringBuilder组拼XML内容,然后把内容写入到文件中;或者使用DOM API生成XML文件,或者也可以使用pull解析器生成XML文件.
这里推荐大家使用Pull解析器。
使用代码如下(生成XML文件):
File xmlFile = new File("myljq.xml");
FileOutputStream outStream = new FileOutputStream(xmlFile);
OutputStreamWriter outStreamWriter = new OutputStreamWriter(outStream, "UTF-8");
BufferedWriter writer = new BufferedWriter(outStreamWriter);
writeXML(persons, writer);
writer.flush();
writer.close();
如果只想得到生成的xml字符串内容,可以使用StringWriter:
StringWriter writer = new StringWriter();
writeXML(persons, writer);
String content = writer.toString();
案例:
123.xml
<?xml version='1.0' encoding='UTF-8' standalone='yes' ?> <persons> <person id="1"> <name>zhangsan</name> <age>12</age> </person> <person id="2"> <name>lisi</name> <age>34</age> </person> </persons>
PullPersonService pull解析器操作类
public class PullPersonService { //使用pull解析器生成xml文件 public static String writeXML(List<Person> persons,Writer writer){ XmlSerializer serializer=Xml.newSerializer(); try{ serializer.setOutput(writer); serializer.startDocument("UTF-8", true); //第一个参数为命名空间,如果不使用命名空间,可以设置为null serializer.startTag("", "persons"); for(Person person:persons){ serializer.startTag("", "person"); serializer.attribute("", "id", person.getId().toString()); serializer.startTag("", "name"); serializer.text(person.getName()); serializer.endTag("", "name"); serializer.startTag("", "age"); serializer.text(person.getAge().toString()); serializer.endTag("", "age"); serializer.endTag("", "person"); } serializer.endTag("", "persons"); serializer.endDocument(); }catch(Exception e){ e.printStackTrace(); } return writer.toString(); } //使用pull解析器解析xml文件 public static List<Person> readXML(InputStream inputStream) throws Exception{ XmlPullParser parser=Xml.newPullParser(); parser.setInput(inputStream, "UTF-8"); int eventType=parser.getEventType(); Person currentPerson=null; List<Person> persons=null; while(eventType!=XmlPullParser.END_DOCUMENT){ switch(eventType){ case XmlPullParser.START_DOCUMENT: persons=new ArrayList<Person>(); break; case XmlPullParser.START_TAG: String name=parser.getName(); if(name.equalsIgnoreCase("person")){ currentPerson=new Person(); currentPerson.setId(new Integer(parser.getAttributeValue(null,"id"))); }else if(currentPerson!=null){ if(name.equalsIgnoreCase("name")){ currentPerson.setName(parser.nextText()); }else if(name.equalsIgnoreCase("age")){ currentPerson.setAge(new Short(parser.nextText())); } } break; case XmlPullParser.END_TAG: if(parser.getName().equalsIgnoreCase("person")&¤tPerson!=null){ persons.add(currentPerson); currentPerson=null; } break; } eventType=parser.next(); } inputStream.close(); return persons; } }
PullPersonServiceTest pull解析器测试类
package com.ljq.test; import java.io.BufferedWriter; import java.io.FileOutputStream; import java.io.InputStream; import java.io.OutputStreamWriter; import java.util.ArrayList; import java.util.List; import com.ljq.entity.Person; import com.ljq.service.PullPersonService; import android.content.Context; import android.test.AndroidTestCase; import android.util.Log; public class PullPersonServiceTest extends AndroidTestCase{ private final String TAG = "PullPersonServiceTest"; /** * 使用pull解析器解析xml文件 * * @throws Exception */ public void testReadXML() throws Exception{ //InputStream inputStream = PullPersonServiceTest.class.getClassLoader().getResourceAsStream("ljq.xml"); InputStream inputStream= this.getContext().openFileInput("123.xml"); List<Person> persons = PullPersonService.readXML(inputStream); for(Person person : persons){ Log.i(TAG, person.getId() + " : " + person.getName() + " : " + person.getAge()); } } /** * 使用pull解析器生成xml文件 * * @throws Exception */ public void testWriteXml() throws Exception{ FileOutputStream fileOutputStream = this.getContext().openFileOutput("123.xml", Context.MODE_PRIVATE); OutputStreamWriter outStreamWriter = new OutputStreamWriter(fileOutputStream, "UTF-8"); List<Person> persons = new ArrayList<Person>(); persons.add(new Person(1, "zhangsan", (short)12)); persons.add(new Person(2, "lisi", (short)34)); BufferedWriter writer = new BufferedWriter(outStreamWriter); String string = PullPersonService.writeXML(persons, writer); Log.i(TAG, string.toString()); } }