序列化和xmlPull解析

发表于:，更新于:，By Sally
大纲
  1. 1. xml文件示例
  2. 2. 将xml文件写到本地
    1. 2.1. 首先，需要一个对象，如上xml文件所示，这里需要一个person对象
    2. 2.2. 准备一点假数据🏠🌲
    3. 2.3. 开始写
  3. 3. pull解析xml文件

xml文件示例

1
2
3
4
5
6
7
<?xml version="1.0" encoding="utf-8" standalone="true"?>
<persons>
  <person id="0">
    <name>zhangsan</name>
    <age>20</age>
  </person>
</persons>

将xml文件写到本地

首先，需要一个对象，如上xml文件所示，这里需要一个person对象

1
2
3
4
5
6
public class Person {
  private int id;
  private String name;
  private int age;
  // 构造方法，get，set，toString方法等等...
}

准备一点假数据🏠🌲

1
2
3
4
List<Person> persons = new ArrayList<Person>();
for(int i=0; i<20; i++) {
  persons.add(new Person(i, ("zhangsan" + i), (10 + i)));
}

开始写

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
// 获得序列化对象
XmlSerializer serializer = Xml.newSerializer();
try {
  // 写到sd卡的person.xml文件中
  File file = new File(Environment.getExternalStorageDirectory(), "person.xml");
  FileOutputStream fos = new FileOutputStream(file);

  serializer.setOutput(fos, "utf-8");
  serializer.startDocument("utf-8", true);
  serializer.startTag(null, "persons");
  for(Person person : persons) {
    serializer.startTag(null, "person");
    serializer.attribute(null, "id", String.valueOf(person.getId()));
    serializer.startTag(null, "name");
    serializer.text(person.getName());
    serializer.endTag(null, "name");
    serializer.startTag(null, "age");
    serializer.text(String.valueOf(person.getAge()));
    serializer.endTag(null, "age");
    serializer.endTag(null, "person");
  }
  serializer.endTag(null, "persons");
  serializer.endDocument();
} catch(Exception e) {
  e.printStackTrace();
}

pull解析xml文件

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
try {
  File file = new File(Environment.getExternalStorageDirectory(), "person.xml");
  FileInputStream fis = new FileInputStream(file);

  XmlPullParser parse = Xml.newPullParse();
  parse.setInput(fis, "utf-8");

  List<Person> persons = null;
  Person person = null

  int eventType = parse.getEventType();
  while(eventType != XmlPullParser.END_DOEUMENT) {
    String tagName = parse.getName();
    switch(eventType) {
      case XmlPullParser.START_TAG:
        if("persons".equals(tagName)) {
          persons = new ArrayList<Person>();
        } else if("person".equals(tagName)) {
          person = new Person();
          person.setId(Integer.valueOf(parse.getAttributeValue(null, "id")));
        } else if("name".equals(tagName)) {
          person.setName(parse.nextText());
        } else if("age".equals(tagName)) {
          person.setAge(Integer.valueOf(parse.nextText()));
        }
        break;
      case XmlPullParser.END_TAG:
        if("person".equals(tagName)) {
          persons.add(person);
        }
        break;
    }
    eventType = parse.next();
  }
  return persons;
} catch(Exception e) {
  e.printStackTrace();
}