`
show213
  • 浏览: 6604 次
社区版块
存档分类
最新评论

xml sax解析

    博客分类:
  • Java
xml 
阅读更多
最近一直在做接口,主要用对xml的解析用的是sax,下面我对sax的几种写法做了一个测试:

public class TestSax {
	MyHandler handler;
	public List<Student> inFile01(String str){
			SAXParserFactory spf=SAXParserFactory.newInstance();
			SAXParser sap;
			try {
				sap = spf.newSAXParser();
				handler=new MyHandler();
				sap.parse(str, handler);
			} catch (Exception e){
				
				
			}
		return handler.getList();		
	}
	
	public List<Student> inFile02(File file){
		InputStream is;		
		SAXParserFactory spf=SAXParserFactory.newInstance();
		SAXParser sap;
		try {
			is = new FileInputStream(file);			
			sap = spf.newSAXParser();
			handler=new MyHandler();
			sap.parse(is, handler);
		} catch(Exception e){			
			
		}	
		return handler.getList();		
	}
	public List<Student> inFile03(File file){
		InputStream is;		
		SAXParserFactory spf=SAXParserFactory.newInstance();
		SAXParser sap;
		try {
			is = new FileInputStream(file);			
			sap = spf.newSAXParser();
			XMLReader xr=sap.getXMLReader();			
			handler=new MyHandler();
			xr.setContentHandler(handler);
			xr.parse(new InputSource(is));
		} catch(Exception e){			
			
		}	
		return handler.getList();		
	}
	
	
	
	public static void main(String args[]) throws FileNotFoundException{
		TestSax ts=new TestSax();
		
		long start=System.currentTimeMillis();
		long freeMemory01 =Runtime.getRuntime().freeMemory();
		
		//List<Student> list=ts.inFile02(new File("F:/student.xml"));	
		List<Student> list=ts.inFile01("F:/student.xml");
		
		long end=System.currentTimeMillis();
		long freeMemory02 =Runtime.getRuntime().freeMemory();
		
		System.out.println("耗时:"+(end-start));
		System.out.println("当前 Java 虚拟机中的使用内存量:" + (freeMemory01-freeMemory02) + " 字节");
		
		for(Student stu:list){	
			System.out.println(stu.getName());
			System.out.println(stu.getAge());
			System.out.println(stu.getEnglish());
		}
		
	}

}




public class MyHandler extends DefaultHandler {
	
	
	 Student st=null;
	 String preTag = null;
	 String currentTag=null;
	 
	

	List<Student> list;
	
	@Override
	public void startDocument() throws SAXException {
		super.startDocument();
		list=new ArrayList<Student>();
	}
	
	
	@Override
	public void startElement(String uri, String localName, String qName,
			Attributes attributes) throws SAXException {		
		super.startElement(uri, localName, qName, attributes);
		currentTag=qName;		
		if(currentTag.equals("info"))
		st=new Student();
		preTag=qName;			//将正在解析的节点名称赋给preTag	
	
	}
	
	@Override
	public void characters(char[] ch, int start, int length)
			throws SAXException {
		super.characters(ch, start, length);
		String text = new String(ch, start, length);
		
		if(preTag==null) return;    		
		
		if(currentTag.equals("name"))
		{
			st.setName(text);  
				
		}else if(currentTag.equals("age")){
		
			st.setAge(Integer.parseInt(text));   			
		}else if(currentTag.endsWith("english")){
			
			st.setEnglish(Integer.parseInt(text));  
		}
		
	}
	
	
	@Override
	public void endElement(String uri, String localName, String qName)
			throws SAXException {
		super.endElement(uri, localName, qName);
		if("info".equals(qName)){ 			
			list.add(st);
			st=null;
		} 
		preTag=null;
	
	}
	
	 public List<Student> getList() {
			return list;
	 }

}



public class Student {
	
	
	public Student(){		
		
	}
	
	
	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;
	}
	public int getEnglish() {
		return English;
	}
	public void setEnglish(int english) {
		English = english;
	}

	private String name;
	private int age;
	private int English;

}



<?xml version='1.0' encoding='utf-8' standalone='yes' ?>
<students>
	<info>
		<name>Lily</name>
		<age>18</age>
		<english>60</english>
	</info>
	<info>
		<name>Bobi</name>
		<age>19</age>
		<english>70</english>
	</info>
	<info>
		<name>Lucky</name>
		<age>20</age>
		<english>80</english>
	</info>
	<info>
		<name>Lucy</name>
		<age>21</age>
		<english>80</english>
	</info>
	<info>
		<name>Amy</name>
		<age>23</age>
		<english>90</english>
	</info>

	<info>
		<name>Jeff</name>
		<age>20</age>
		<english>56</english>
	</info>
	
	<info>
		<name>Michel</name>
		<age>25</age>
		<english>56</english>
	</info>
	
	<info>
		<name>Jay</name>
		<age>30</age>
		<english>56</english>
	</info>
</students>



对上面的三个方法我测试了一下:
93 milliseconds 2071984 字节   inFile01
93 milliseconds 2055512 字节   inFile02
78 milliseconds 2055504 字节   inFile03

从上面的测试结果来看,如果有可能,尽可能的用到xmlReader这个。
分享到:
评论

相关推荐

Global site tag (gtag.js) - Google Analytics