一：JAXP使用SAX方式解析XML文件
1：dom解析与sax解析异同点
2：sax解析特点
二：代码案例
1：xml文件
1 <?xml version="1.0" encoding="UTF-8" standalone="no"?> 2 <students> 3 <student> 4 <name sid="111">李四</name> 5 <age>23</age> 6 <gender>男</gender> 7 </student> 8 <student> 9 <name sid="222">张三</name> 10 <age>21</age> 11 <gender>女</gender> 12 </student> 13 </students>
2：测试主体部分
1 @Test
2 public void testParseXml() throws ParserConfigurationException,
3 SAXException, IOException {
4 // 1:获取解析器工厂
5 SAXParserFactory factory = SAXParserFactory.newInstance();
6 // 2:获取解析器
7 SAXParser parser = factory.newSAXParser();
8 // 3:获取读取器
9 XMLReader reader = parser.getXMLReader();
10 // 4:设置内容格式
11 reader.setContentHandler(new GetSecondNameHandler());
12 // 5:解析文件
13 reader.parse("xml/exam.xml");
14 }
a:获取整个xml文档标签的处理事件
1 // 定义一个解析全文的解析器
2 class MyHandler implements ContentHandler {
3
4 @Override
5 public void setDocumentLocator(Locator locator) {
6
7 }
8
9 @Override
10 public void startDocument() throws SAXException {
11
12 }
13
14 @Override
15 public void endDocument() throws SAXException {
16
17 }
18
19 @Override
20 public void startPrefixMapping(String prefix, String uri)
21 throws SAXException {
22
23 }
24
25 @Override
26 public void endPrefixMapping(String prefix) throws SAXException {
27
28 }
29
30 @Override
31 public void startElement(String uri, String localName, String qName,
32 Attributes atts) throws SAXException {
33 System.out.println("<" + qName + ">");
34 // 获取元素的属性
35 for (int i = 0; i < atts.getLength(); i++) {
36 String attrName = atts.getQName(i);
37 String attrValue = atts.getValue(i);
38 System.out.println(attrName + "=" + attrValue);
39 }
40 }
41
42 @Override
43 public void endElement(String uri, String localName, String qName)
44 throws SAXException {
45 System.out.println("<" + qName + "/>");
46 }
47
48 @Override
49 public void characters(char[] ch, int start, int length)
50 throws SAXException {
51 System.out.println(new String(ch, start, length));
52 }
53
54 @Override
55 public void ignorableWhitespace(char[] ch, int start, int length)
56 throws SAXException {
57
58 }
59
60 @Override
61 public void processingInstruction(String target, String data)
62 throws SAXException {
63
64 }
65
66 @Override
67 public void skippedEntity(String name) throws SAXException {
68
69 }
70
71 }
b：定义“获取指定内容,获取第二个学生的名字”事件
1 class GetSecondNameHandler extends DefaultHandler {
2
3 private String contentTag;
4 private int currentTag = 0;
5 private int getTag = 2;
6
7 @Override
8 public void startElement(String uri, String localName, String qName,
9 Attributes attributes) throws SAXException {
10 contentTag = qName;
11 }
12
13 @Override
14 public void endElement(String uri, String localName, String qName)
15 throws SAXException {
16 contentTag = null;
17 }
18
19 @Override
20 public void characters(char[] ch, int start, int length)
21 throws SAXException {
22 if ("name".equals(contentTag)) {
23 currentTag++;
24 if (currentTag == getTag) {
25 System.out.println(new String(ch, start, length));
26 }
27
28 }
29 }
30
31 }
c:将xml信息封装成javabean对象，然后放到list集合中
1 / 将xml中student元素内容封装成对象，然后放到list集合中
2 class BeanListHandler extends DefaultHandler {
3 private List<Student> list = new ArrayList<Student>();
4 private String tagName;
5 private Student stu;
6
7 @Override
8 public void startElement(String uri, String localName, String qName,
9 Attributes attributes) throws SAXException {
10 tagName = qName;
11 if ("student".equals(tagName)) {
12 stu = new Student();
13 }
14 }
15
16 @Override
17 public void characters(char[] ch, int start, int length)
18 throws SAXException {
19
20 if ("name".equals(tagName)) {
21 stu.setName(new String(ch, start, length));
22 }
23 if ("age".equals(tagName)) {
24 stu.setAge(Integer.parseInt(new String(ch, start, length)));
25 }
26 if ("gender".equals(tagName)) {
27 stu.setGender(new String(ch, start, length));
28 }
29
30 }
31
32 @Override
33 public void endElement(String uri, String localName, String qName)
34 throws SAXException {
35 if ("student".equals(qName)) {
36 list.add(stu);
37 stu = null;
38 }
39
40 tagName = null;
41 }
42
43 public List<Student> getStudents() {
44 return list;
45 }
46
47 }
测试程序代码修改为：
1 @Test
2 public void testParseXml() throws ParserConfigurationException,
3 SAXException, IOException {
4 // 1:获取解析器工厂
5 SAXParserFactory factory = SAXParserFactory.newInstance();
6 // 2:获取解析器
7 SAXParser parser = factory.newSAXParser();
8 // 3:获取读取器
9 XMLReader reader = parser.getXMLReader();
10 // 4:设置内容格式
11 BeanListHandler beanListHandler = new BeanListHandler();
12 reader.setContentHandler(beanListHandler);
13 // 5:解析文件
14 reader.parse("xml/exam.xml");
15
16 List<Student> list = beanListHandler.getStudents();
17 for (Student stu : list) {
18 System.out.println("name=" + stu.getName() + " age=" + stu.getAge()
19 + " gender=" + stu.getGender());
20 }
21 }
来源：https://www.cnblogs.com/warrior4236/p/5861576.html