Android内置了PULL解析器的XPP3实现,以及SAX解析器等,可以直接使用PULL或SAX解析XML,直接把JAVA中进行PULL或SAX解析的代码直接拿来用,遗忘的话,可以参考java拾遗1,2,3关于XML的解析:
如有如下XmlUtils类实现PULL方式解析XML到List和序列化List到XML:
Student实体类代码:
1 package cn.csc.bean; 2 3 public class Student { 4 5 private String id; 6 7 private String name; 8 9 private String gender; 10 11 private int age; 12 13 public String getId() { 14 15 return id; 16 17 } 18 19 public void setId(String id) { 20 21 this.id = id; 22 23 } 24 25 public String getName() { 26 27 return name; 28 29 } 30 31 public void setName(String name) { 32 33 this.name = name; 34 35 } 36 37 public String getGender() { 38 39 return gender; 40 41 } 42 43 public void setGender(String gender) { 44 45 this.gender = gender; 46 47 } 48 49 public int getAge() { 50 51 return age; 52 53 } 54 55 public void setAge(int age) { 56 57 this.age = age; 58 59 } 60 61 62 63 public Student() { 64 65 super(); 66 67 } 68 69 public Student(String id, String name, String gender, int age) { 70 71 super(); 72 73 this.id = id; 74 75 this.name = name; 76 77 this.gender = gender; 78 79 this.age = age; 80 81 } 82 83 @Override 84 85 public String toString() { 86 87 return "["+id+","+name+","+gender+","+age+"]"; 88 89 } 90 91 }
XmlUtils类的代码:
1 public class XmlUtils { 2 3 public static void serialize(Context context, String filename, List<Student> list){ 4 5 try { 6 7 XmlPullParserFactory factory = XmlPullParserFactory.newInstance(); 8 9 XmlSerializer serializer = factory.newSerializer(); 10 11 serializer.setOutput(context.openFileOutput(filename, Context.MODE_PRIVATE), "utf-8"); 12 13 serializer.startDocument("utf-8", true); 14 15 serializer.startTag(null, "students"); 16 17 for(Student s:list){ 18 19 serializer.startTag(null, "student"); 20 21 serializer.attribute(null, "id", s.getId()); 22 23 serializer.startTag(null, "name"); 24 25 serializer.text(s.getName()); 26 27 serializer.endTag(null, "name"); 28 29 serializer.startTag(null, "gender"); 30 31 serializer.text(s.getGender()); 32 33 serializer.endTag(null, "gender"); 34 35 serializer.startTag(null, "age"); 36 37 serializer.text(s.getAge()+""); 38 39 serializer.endTag(null, "age"); 40 41 serializer.endTag(null, "student"); 42 43 } 44 45 serializer.endTag(null, "students"); 46 47 serializer.endDocument(); 48 49 } catch (Exception e) { 50 51 // TODO Auto-generated catch block 52 53 e.printStackTrace(); 54 55 } 56 57 } 58 59 public static List<Student> parse(Context context, String filename){ 60 61 List<Student> list = new ArrayList<Student>(); 62 63 try { 64 65 XmlPullParserFactory factory = XmlPullParserFactory.newInstance(); 66 67 XmlPullParser parser = factory.newPullParser(); 68 69 parser.setInput(context.openFileInput(filename), "utf-8"); 70 71 Student s = null; 72 73 int eventType = parser.getEventType(); 74 75 while(eventType != XmlPullParser.END_DOCUMENT){ 76 77 if(eventType == XmlPullParser.START_TAG){ 78 79 String tag = parser.getName(); 80 81 if(tag.equals("student")){ 82 83 s = new Student(); 84 85 s.setId(parser.getAttributeValue(0)); 86 87 }else if(tag.equals("name")){ 88 89 s.setName(parser.nextText()); 90 91 }else if(tag.equals("gender")){ 92 93 s.setGender(parser.nextText()); 94 95 }else if(tag.equals("age")){ 96 97 s.setAge(Integer.parseInt(parser.nextText())); 98 99 } 100 101 }else if(eventType == XmlPullParser.END_TAG && parser.getName().equals("student")){ 102 103 list.add(s); 104 105 } 106 107 eventType = parser.next(); 108 109 } 110 111 for(Student stu : list){ 112 113 Log.i("XML_PARSER",stu.toString()); 114 115 } 116 117 } catch (Exception e) { 118 119 // TODO Auto-generated catch block 120 121 e.printStackTrace(); 122 123 return null; 124 125 } 126 127 return list; 128 129 } 130 131 }
使用Android Juit分别测试这两个方法:
1 public class XmlTest extends AndroidTestCase { 2 3 public void testSerializer(){ 4 5 List<Student> list = new ArrayList<Student>(); 6 7 for(int i=0; i<20; i++){ 8 9 list.add(new Student(i+"","dqrcsc","male",25)); 10 11 } 12 13 XmlUtils.serialize(getContext(), "students.xml", list); 14 15 } 16 17 public void testParser(){ 18 19 XmlUtils.parse(getContext(), "students.xml"); 20 21 } 22 23 }
运行结果:
以上代码,除了获取Context上下文对象外,与Java项目中对XML的PULL解析是完全一样的。
实际上,Andoid在android.util包中还提供了一个Xml类,实现了对XML解析、序列化操作的封装,在使用时,可以相对简单一点:
这五个静态方法分别简化了PULL解析器、PULL序列化器、SAX解析的操作:
之前通过工厂类实例获取PULL序列化器的操作,可以从:
1 XmlPullParserFactory factory = XmlPullParserFactory.newInstance(); 2 3 XmlSerializer serializer = factory.newSerializer();
简化为:
XmlSerializer serializer = Xml.newSerializer();
通过工厂类实例获取PULL解析器的操作,也可以从:
1 XmlPullParserFactory factory = XmlPullParserFactory.newInstance(); 2 3 XmlPullParser parser = factory.newPullParser();
简化为:
XmlPullParser parser = Xml.newPullParser();
同样的,SAX解析也简化为直接调用Xml的parse()静态方法,这里就不说明了。
时间: 2024-10-10 13:19:22