XML解析的第二种方法是PULL解析。
PULL解析是以事件常量的的方法进行解析，何为事件常量？
当解析器从头到尾解析XML文件时，解析到文档开头定义为解析到一个常量XmlPullParser.START_DOCUMENT，当解析到开始标签定义为解析到一个常量XmlPullParser.START_TAG，当解析到结束标签定义为解析到一个常量XmlPullParser.END_TAG，当解析到文档结尾定义为解析到一个常量XmlPullParser.END_DOCUMENT。
下面是PULL解析的过程:
PULL解析的核心过程:
1 public class PullPaser1 {
2
3 public List<Person> pullParser() throws XmlPullParserException, IOException
4 {
5 List<Person> list = null;
6 Person person = null;
7
8 //1.创建解析器工厂对象
9 XmlPullParserFactory factory =XmlPullParserFactory.newInstance();
10 //2.创建解析器对象
11 XmlPullParser parser = factory.newPullParser();
12 //3.创建读取被解析的文件的字符读取流
13 //FileReader fileReader = new FileReader("user.xml");
14 FileInputStream fis = new FileInputStream("user.xml");
15 parser.setInput(fis, "utf-8");//可以设置编码
16 //得到解析时返回的第一个编号
17 int event = parser.getEventType();
18
19 //4.具体的解析过程
20 while(event!=XmlPullParser.END_DOCUMENT)
21 {
22 switch(event)
23 {
24 case XmlPullParser.START_DOCUMENT:
25 list = new ArrayList<Person>();break;
26 case XmlPullParser.START_TAG:
27 String tagName = parser.getName();//得到开始标签名称
28 if("person".equals(tagName))
29 {
30 person = new Person();
31 }
32 else if("name".equals(tagName))
33 person.setName(parser.nextText());//获取开始标签后边的数据
34 else if("age".equals(tagName))
35 person.setAge(Integer.parseInt(parser.nextText()));
36 else if("sex".equals(tagName))
37 person.setSex(parser.nextText());
38 break;
39 case XmlPullParser.END_TAG:
40 if("person".equals(parser.getName()))
41 {
42 list.add(person);
43 }
44 break;
45 }
46 //获取下一个编号
47 event = parser.next();
48 }
49 return list;
50 }
51
52 }
观察上面代码可知:PULL解析核心的过程和SAX解析很相似，对于SAX解析，是以事件通知的方法，即解析不同部分，调用不同的方法，而对于PULL解析，是以事件常量的方法，即解析不同部分，认为是不同的常量加以区分，执行不同的操作，而它们都需要先创建一个解析工厂，通过工厂来获取一个解析器对象。
PULL解析的步骤
1.获取PULL解析的工厂实例
XmlPullParserFactory factory =XmlPullParserFactory.newInstance();
2.通过工厂实例，获取PULL解析器对象
XmlPullParser parser = factory.newPullParser();
3.创建读取xml文件的流(若xml文件是本地)，设置编码
FileInputStream fis = new FileInputStream("user.xml");
parser.setInput(fis, "utf-8");//可以设置编码
4.获取第一个事件常量，然后循环解析XML文件
int event = parser.getEventType();
while(event!=XmlPullParser.END_DOCUMENT)
{
switch(event)
{
case XmlPullParser.START_DOCUMENT:
...
break;
case XmlPullParser.START_TAG:
String tagName = parser.getName();//得到开始标签名称
....
break;
case XmlPullParser.END_TAG:
....
break;
}
//获取下一个编号
event = parser.next();
}
示例1:采用PULL解析user.xml文件
1 <?xml version="1.0" encoding="UTF-8"?> 2 <persons> 3 <person> 4 <name>张三</name> 5 <age>30</age> 6 <sex>男</sex> 7 </person> 8 9 <person> 10 <name>李四</name> 11 <age>32</age> 12 <sex>女</sex> 13 </person> 14 15 <person> 16 <name>王五</name> 17 <age>30</age> 18 <sex>男</sex> 19 </person> 20 </persons>
user.xml
1 package com.qianfeng.pull1;
2
3 public class Person {
4
5 private String name;
6 private int age;
7 private String sex;
8
9 public Person(){}
10
11 public Person(String name, int age, String sex) {
12 super();
13 this.name = name;
14 this.age = age;
15 this.sex = sex;
16 }
17
18 public String getName() {
19 return name;
20 }
21
22 public void setName(String name) {
23 this.name = name;
24 }
25
26 public int getAge() {
27 return age;
28 }
29
30 public void setAge(int age) {
31 this.age = age;
32 }
33
34 public String getSex() {
35 return sex;
36 }
37
38 public void setSex(String sex) {
39 this.sex = sex;
40 }
41
42 @Override
43 public String toString() {
44 return "Person [name=" + name + ", age=" + age + ", sex=" + sex + "]";
45 }
46
47
48
49 }
Person.java
1 package com.qianfeng.pull1;
2
3 import java.io.FileInputStream;
4 import java.io.FileNotFoundException;
5 import java.io.FileReader;
6 import java.io.IOException;
7 import java.util.ArrayList;
8 import java.util.List;
9
10 import org.xmlpull.v1.XmlPullParser;
11 import org.xmlpull.v1.XmlPullParserException;
12 import org.xmlpull.v1.XmlPullParserFactory;
13
14 public class PullPaser1 {
15
16 public List<Person> pullParser() throws XmlPullParserException, IOException
17 {
18 List<Person> list = null;
19 Person person = null;
20
21 //创建解析器工厂对象
22 XmlPullParserFactory factory =XmlPullParserFactory.newInstance();
23 //创建解析器对象
24 XmlPullParser parser = factory.newPullParser();
25 //创建读取被解析的文件的字符读取流
26 //FileReader fileReader = new FileReader("user.xml");
27 FileInputStream fis = new FileInputStream("user.xml");
28 parser.setInput(fis, "utf-8");//可以设置编码
29 //得到解析时返回的第一个编号
30 int event = parser.getEventType();
31
32 while(event!=XmlPullParser.END_DOCUMENT)
33 {
34 switch(event)
35 {
36 case XmlPullParser.START_DOCUMENT:
37 list = new ArrayList<Person>();break;
38 case XmlPullParser.START_TAG:
39 String tagName = parser.getName();//得到开始标签名称
40 if("person".equals(tagName))
41 {
42 person = new Person();
43 }
44 else if("name".equals(tagName))
45 person.setName(parser.nextText());//获取开始标签后边的数据
46 else if("age".equals(tagName))
47 person.setAge(Integer.parseInt(parser.nextText()));
48 else if("sex".equals(tagName))
49 person.setSex(parser.nextText());
50 break;
51 case XmlPullParser.END_TAG:
52 if("person".equals(parser.getName()))
53 {
54 list.add(person);
55 }
56 break;
57 }
58 //获取下一个编号
59 event = parser.next();
60 }
61 return list;
62 }
63
64 }
PullPaser1
1 package com.qianfeng.pull1;
2
3 import java.io.IOException;
4 import java.util.List;
5
6 import org.xmlpull.v1.XmlPullParser;
7 import org.xmlpull.v1.XmlPullParserException;
8
9 public class Test {
10
11 /**
12 * @param args
13 * @throws IOException
14 * @throws XmlPullParserException
15 */
16 public static void main(String[] args) throws XmlPullParserException, IOException {
17 // System.out.println(XmlPullParser.START_DOCUMENT);
18 // System.out.println(XmlPullParser.START_TAG);
19 // System.out.println(XmlPullParser.TEXT);
20 // System.out.println(XmlPullParser.END_TAG);
21 // System.out.println(XmlPullParser.END_DOCUMENT);
22
23
24 PullPaser1 pullParser1 = new PullPaser1();
25 List<Person> list = pullParser1.pullParser();
26
27 for(Person person:list)
28 {
29 System.out.println(person);
30 }
31
32 }
33
34 }
Test.java
示例2:采用PULL解析worker.xml文件
1 <?xml version="1.0" encoding="UTF-8"?> 2 <workers> 3 <worker id="AQ01"> 4 <name>Mark</name> 5 <sex>男</sex> 6 <status>经理</status> 7 <address>北京</address> 8 <money>4000</money> 9 </worker> 10 <worker id="AD02"> 11 <name>Luch</name> 12 <sex>女</sex> 13 <status>员工</status> 14 <address>上海</address> 15 <money>1000</money> 16 </worker> 17 <worker id="AD03"> 18 <name>Lily</name> 19 <sex>女</sex> 20 <status>员工</status> 21 <address>北京</address> 22 <money>2000</money> 23 </worker> 24 <worker> 25 <name>Lily</name> 26 <sex>女</sex> 27 <status>员工</status> 28 <address>北京</address> 29 <money>2000</money> 30 </worker> 31 </workers>
worker.xml
1 package com.qianfeng.pull2;
2
3 public class Worker {
4
5 private String id;
6 private String name;
7 private char sex;
8 private String status;
9 private String address;
10 private double money;
11
12 public Worker(){}
13
14 public Worker(String id, String name, char sex, String status,
15 String address, double money) {
16 super();
17 this.id = id;
18 this.name = name;
19 this.sex = sex;
20 this.status = status;
21 this.address = address;
22 this.money = money;
23 }
24
25 public String getId() {
26 return id;
27 }
28
29 public void setId(String id) {
30 this.id = id;
31 }
32
33 public String getName() {
34 return name;
35 }
36
37 public void setName(String name) {
38 this.name = name;
39 }
40
41 public char getSex() {
42 return sex;
43 }
44
45 public void setSex(char sex) {
46 this.sex = sex;
47 }
48
49 public String getStatus() {
50 return status;
51 }
52
53 public void setStatus(String status) {
54 this.status = status;
55 }
56
57 public String getAddress() {
58 return address;
59 }
60
61 public void setAddress(String address) {
62 this.address = address;
63 }
64
65 public double getMoney() {
66 return money;
67 }
68
69 public void setMoney(double money) {
70 this.money = money;
71 }
72
73 @Override
74 public String toString() {
75 return "Worker [id=" + id + ", name=" + name + ", sex=" + sex
76 + ", status=" + status + ", address=" + address + ", money="
77 + money + "]";
78 }
79
80
81
82 }
Worker.java
1 package com.qianfeng.pull2;
2
3 import java.io.FileInputStream;
4 import java.io.FileNotFoundException;
5 import java.io.IOException;
6 import java.util.ArrayList;
7 import java.util.List;
8
9 import org.xmlpull.v1.XmlPullParser;
10 import org.xmlpull.v1.XmlPullParserException;
11 import org.xmlpull.v1.XmlPullParserFactory;
12
13 public class PullParser2 {
14
15 public List<Worker> pullParser() throws XmlPullParserException, IOException
16 {
17 List<Worker> list = null;
18 Worker worker = null;
19
20 XmlPullParserFactory factory = XmlPullParserFactory.newInstance();
21 XmlPullParser parser = factory.newPullParser();
22
23 FileInputStream fis = new FileInputStream("worker.xml");
24
25 parser.setInput(fis, "utf-8");
26
27 int event = parser.getEventType();
28
29 while(event!=XmlPullParser.END_DOCUMENT){
30 switch(event)
31 {
32 case XmlPullParser.START_DOCUMENT:
33 list = new ArrayList<Worker>();
34 break;
35 case XmlPullParser.START_TAG:
36 String tagName = parser.getName();
37 if("worker".equals(tagName))
38 {
39 worker = new Worker();
40 int count = parser.getAttributeCount();//得到属性数量
41 for(int i=0;i<count;i++)
42 {
43 //得到属性名
44 String attrName = parser.getAttributeName(i);
45 //得到属性值
46 String attrValue = parser.getAttributeValue(i);
47
48 if("id".equals(attrName))
49 {
50 worker.setId(attrValue);
51 }
52 }
53 }
54 else if("name".equals(tagName))
55 worker.setName(parser.nextText());
56 else if("sex".equals(tagName))
57 worker.setSex(parser.nextText().charAt(0));
58 else if("status".equals(tagName))
59 worker.setStatus(parser.nextText());
60 else if("address".equals(tagName))
61 worker.setAddress(parser.nextText());
62 else if("money".equals(tagName))
63 worker.setMoney(Double.parseDouble(parser.nextText()));
64 break;
65 case XmlPullParser.END_TAG:
66 if("worker".equals(parser.getName()))
67 {
68 list.add(worker);
69 }
70 break;
71
72 }
73 event = parser.next();
74 }
75
76 return list;
77 }
78
79 }
PullParser2
1 package com.qianfeng.pull2;
2
3 import java.io.IOException;
4 import java.util.List;
5
6 import org.xmlpull.v1.XmlPullParserException;
7
8 public class Test {
9
10 /**
11 * @param args
12 * @throws IOException
13 * @throws XmlPullParserException
14 */
15 public static void main(String[] args) throws XmlPullParserException, IOException {
16
17 PullParser2 pullParser2 = new PullParser2();
18
19 List<Worker> list = pullParser2.pullParser();
20
21 for(Worker worker:list)
22 {
23 System.out.println(worker);
24 }
25
26 }
27
28 }
Test.java
示例3:上次采用了SAX解析了citys_weather.xml，这次用PULL解析比较复杂的xml文件
citys_weather.xml文件见上篇数据解析1:XML解析(2)
1 package com.qianfeng.pull4;
2
3 import java.util.List;
4
5 public class Province {
6
7 private String id;
8 private String name;
9 private List<City> citys;
10
11 public Province(){}
12
13 public Province(String id, String name, List<City> citys) {
14 super();
15 this.id = id;
16 this.name = name;
17 this.citys = citys;
18 }
19
20 public String getId() {
21 return id;
22 }
23
24 public void setId(String id) {
25 this.id = id;
26 }
27
28 public String getName() {
29 return name;
30 }
31
32 public void setName(String name) {
33 this.name = name;
34 }
35
36 public List<City> getCitys() {
37 return citys;
38 }
39
40 public void setCitys(List<City> citys) {
41 this.citys = citys;
42 }
43
44 @Override
45 public String toString() {
46 return name;
47 }
48
49
50
51
52 }
Province.java
1 package com.qianfeng.pull4;
2
3 import java.util.List;
4
5 public class City {
6
7 private String id;
8 private String name;
9 private List<District> districts;
10
11 public City(){}
12
13 public City(String id, String name, List<District> districts) {
14 super();
15 this.id = id;
16 this.name = name;
17 this.districts = districts;
18 }
19
20 public String getId() {
21 return id;
22 }
23
24 public void setId(String id) {
25 this.id = id;
26 }
27
28 public String getName() {
29 return name;
30 }
31
32 public void setName(String name) {
33 this.name = name;
34 }
35
36 public List<District> getDistricts() {
37 return districts;
38 }
39
40 public void setDistricts(List<District> districts) {
41 this.districts = districts;
42 }
43
44 @Override
45 public String toString() {
46 return name;
47 }
48
49
50
51 }
City.java
1 package com.qianfeng.pull4;
2
3 public class District {
4
5 private String id;
6 private String name;
7
8 public District(){}
9
10 public District(String id, String name) {
11 super();
12 this.id = id;
13 this.name = name;
14 }
15
16 public String getId() {
17 return id;
18 }
19
20 public void setId(String id) {
21 this.id = id;
22 }
23
24 public String getName() {
25 return name;
26 }
27
28 public void setName(String name) {
29 this.name = name;
30 }
31
32 @Override
33 public String toString() {
34 return name;
35 }
36
37
38
39 }
District.java
1 package com.qianfeng.pull4;
2
3 import java.io.FileInputStream;
4 import java.io.FileNotFoundException;
5 import java.io.IOException;
6 import java.util.ArrayList;
7 import java.util.List;
8
9 import org.xmlpull.v1.XmlPullParser;
10 import org.xmlpull.v1.XmlPullParserException;
11 import org.xmlpull.v1.XmlPullParserFactory;
12
13 public class PullParser4 {
14
15 public List<Province> pullParser() throws XmlPullParserException, IOException
16 {
17 List<Province> provinces = null;
18 Province province = null;
19 List<City> citys = null;
20 City city = null;
21 List<District> districts = null;
22 District district = null;
23
24 XmlPullParserFactory factory = XmlPullParserFactory.newInstance();
25 XmlPullParser parser = factory.newPullParser();
26
27 FileInputStream fis = new FileInputStream("citys_weather.xml");
28
29 parser.setInput(fis, "utf-8");
30 int event = parser.getEventType();
31 while(event!=XmlPullParser.END_DOCUMENT)
32 {
33 switch(event)
34 {
35 case XmlPullParser.START_DOCUMENT:
36 provinces = new ArrayList<Province>();break;
37 case XmlPullParser.START_TAG:
38 String tagName = parser.getName();
39 if("p".equals(tagName))
40 {
41 province = new Province();
42 citys = new ArrayList<City>();
43 int count = parser.getAttributeCount();
44 for(int i=0;i<count;i++)
45 {
46 String attrName = parser.getAttributeName(i);
47 String attrValue = parser.getAttributeValue(i);
48 if("p_id".equals(attrName))
49 {
50 province.setId(attrValue);
51 }
52 }
53 }
54 if("pn".equals(tagName))
55 province.setName(parser.nextText());
56 if("c".equals(tagName))
57 {
58 city = new City();
59 districts = new ArrayList<District>();
60 int count = parser.getAttributeCount();
61 for(int i=0;i<count;i++)
62 {
63 String atrrName = parser.getAttributeName(i);
64 String attrValue = parser.getAttributeValue(i);
65 if("c_id".equals(atrrName))
66 city.setId(attrValue);
67 }
68 }
69 if("cn".equals(tagName))
70 city.setName(parser.nextText());
71 if("d".equals(tagName))
72 {
73 district = new District();
74 int count = parser.getAttributeCount();
75 for(int i=0;i<count;i++)
76 {
77 String atrrName = parser.getAttributeName(i);
78 String attrValue = parser.getAttributeValue(i);
79 if("d_id".equals(atrrName))
80 district.setId(attrValue);
81 }
82 district.setName(parser.nextText());
83 districts.add(district);
84 }
85 break;
86 case XmlPullParser.END_TAG:
87 if("c".equals(parser.getName()))
88 {
89 city.setDistricts(districts);
90 citys.add(city);
91 }
92 if("p".equals(parser.getName()))
93 {
94 province.setCitys(citys);
95 provinces.add(province);
96 }
97 break;
98 }
99 event = parser.next();
100 }
101 return provinces;
102 }
103
104 }
PullParser4
1 package com.qianfeng.pull4;
2
3 import java.io.IOException;
4 import java.util.List;
5
6 import org.xmlpull.v1.XmlPullParserException;
7
8 public class Test {
9
10 /**
11 * @param args
12 * @throws IOException
13 * @throws XmlPullParserException
14 */
15 public static void main(String[] args) throws XmlPullParserException, IOException {
16
17 PullParser4 pullParser4 = new PullParser4();
18
19 List<Province> list =pullParser4.pullParser();
20
21 for(int i=0;i<list.size();i++)
22 {
23 Province province = list.get(i);
24 System.out.println("省:"+province);
25 List<City> citys = province.getCitys();
26 for(int j=0;j<citys.size();j++)
27 {
28 City city = citys.get(j);
29 System.out.println("市===:"+city);
30 List<District> districts = city.getDistricts();
31 for(int k =0;k<districts.size();k++)
32 {
33 District district =districts.get(k);
34 System.out.println("县=======:"+district);
35 }
36 }
37 }
38
39
40
41 }
42
43 }
Test
未完，待续。
时间： 2024-10-12 00:33:21