android开发

安卓中使用XmlPullParser解析xml文件

有个升级项目需要使用到xml文件，由于XmlPullParser最简单所以选择它也完全满足当前的需求应用。
下面就简要的说明一下具体的用法。

1、基本原理：
常用的有：
XmlPullParser.END_DOCUMENT
XmlPullParser.START_DOCUMENT
XmlPullParser.START_TAG
XmlPullParser.END_TAG
XmlPullParser.TEXT
分别代表着XML文档的结束，开始，标签的开始，标签的结束，内容

按照以上的格式依次进行解析即可。

2、介绍了三种不同的xml格式及解析方法

新建一个新的activiy文件，其实就是程序启动发源地而已。

<span style="font-size: 18px;">public class MainActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);       
        xmltest xl = new xmltest();
        xl.test(getResources());
    }
   }</span>

为了便于xml解析内容的存取，新建了一个Person.java类,内容如下：

package com.test.xmlactivity;
class Person{
    private int id = -1;
    private int age = 0;
    private String name = null;
    private String title = null;
    public Person(){
        //TODO
    }
    public Person(int _id,int _age,String _name,String _title){
        this.id = _id ;
        this.age = _id;
        this.name = _name;
        this.title = _title;
    }
    public void setID(int id){
        this.id = id;
    }
    public int getID(){
        return this.id;
    }
    public void setAge(int age){
        this.age = age;
    }
    public int getAge(){
        return this.age;
    }
    public void setName(String name){
        this.name = name;
    }
    public String getName(){
        return this.name;
    }
    public void setTitle(String title){
        this.title = title;
    }
    public String getTitle(){
        return this.title;
    }
};

为方便其它程序简洁使用xml的读取及解析，封装了一个xmlReader.java类，内容如下：

package com.test.xmlactivity;
import java.io.IOException;
import java.io.StringReader;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlPullParserFactory;
import android.util.Log;
class XmlReader{
    private final static String TAG = "XmlReader";
    private XmlPullParser xmlparser = null;
    public static final String charset = "utf-8";
    public XmlReader(){
        try {
            XmlPullParserFactory factory = XmlPullParserFactory.newInstance();
            factory.setNamespaceAware(true);
            xmlparser = factory.newPullParser();
        } catch (Exception e) {
            e.printStackTrace();
            Log.e(TAG,"create xml reader failed");
        }
    }
    public void setXML(String xml) throws IOException{
        try {
            xmlparser.setInput(new StringReader(xml));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    public int getNextEvent() throws IOException {
        try {
            return xmlparser.next();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return -1;
    }
    public String getNextText() throws IOException{
        try {
            return xmlparser.nextText();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
    public int getEventType() throws IOException {
        try {
            return xmlparser.getEventType();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return -1;
    }
    public String getName() {
        return xmlparser.getName();
    }
    public String getText() {
        return xmlparser.getText();
    }  
    public int attributeCount() {
        return xmlparser.getAttributeCount();
    }
    public String getAttributeName(int i) {
        return xmlparser.getAttributeName(i);
    }
    public String getAttributeValue(String name) {
        String v = xmlparser.getAttributeValue(null, name);
        return v;
    }
    public int getDepth() {
        return xmlparser.getDepth();
    }
};

需要读取的xml资源文件放在 res\xm;\person.xml,其具体内容如下：

<?xml version="1.0" encoding="utf-8"?>
<White-collars>
    <employee id="1">
        <name>tom</name>
        <age>25</age>
        <title>engineer</title>
    </employee>
    <employee  id="2">
        <name>kite</name>
        <age>21</age>
        <title>tester</title>
    </employee>
    <employee id="3">
        <name>rose</name>
        <age>28</age>
        <title>manager</title>
    </employee>
</White-collars>

a、从资源文件中读取
需要使用系统资源，必须有Context对象，而Activity可以持有，所以需要在测试前将其资源句柄传入
xl.test(getResources());
而在具体的类中记录下来即可使用
private XmlReader XR = null;
private ArrayList mperlist = new ArrayList();
private Resources mRes = null;

public void test(Resources _res){
this.mRes = _res;
xml_test_main();
}

下面说明一下具体的xml内容解析：

 /* 1、使用文件测试 */
    private void xml_file_test(){
        int eventType = -1;
        Person ps = null;  
        XmlResourceParser xrp = mRes.getXml(R.xml.personal);       
        try {
            eventType = xrp.getEventType();
            while (eventType != XmlPullParser.END_DOCUMENT) {
                switch (eventType) {
                case XmlPullParser.START_DOCUMENT:
                    break;
                case XmlPullParser.END_DOCUMENT:
                    break;
                case XmlPullParser.START_TAG: {
                    String tagName = xrp.getName();
                    if (tagName != null && tagName.equals("employee")) {
                        ps = new Person();
                        int id = Integer.parseInt(xrp.getAttributeValue(null, "id"));
                        ps.setID(id);
                    }
                    if (tagName != null && tagName.equals("name")) {
                        String name;
                        try {
                            name = xrp.nextText();;
                            ps.setName(name);
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                    if (tagName != null && tagName.equals("title")) {
                        String title;
                        try {
                            title = xrp.nextText();
                            ps.setTitle(title);
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                    if (tagName != null && tagName.equals("age")) {
                        String age;
                        try {
                            age = xrp.nextText();
                            ps.setAge(Integer.parseInt(age));
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
                    break;
                case XmlPullParser.END_TAG: {
                    if (xrp.getName().equals("employee")) {
                        mperlist.add(ps);
                    }
                }
                    break;
                case XmlPullParser.TEXT:
                    break;
                default:
                    break;
                }
                eventType = xrp.next();
            }
        } catch (Exception e) {
            // TODO: handle exception
        }
        for(int i=0;i<mperlist.size();i++){
            Log.i(TAG,"person info ====");
            Log.i(TAG,"ID = " + mperlist.get(i).getID());  
            Log.i(TAG,"name = "+ mperlist.get(i).getName());
            Log.i(TAG,"age = " + mperlist.get(i).getAge());
            Log.i(TAG,"title = " + mperlist.get(i).getTitle());
        }
    }

相应的打印内容：
10-02 10:47:50.725: I/xmltest(12364): person info ====
10-02 10:47:51.094: I/xmltest(12364): ID = 1
10-02 10:47:51.382: I/xmltest(12364): name = tom
10-02 10:47:51.647: I/xmltest(12364): age = 25
10-02 10:47:51.986: I/xmltest(12364): title = engineer
10-02 10:48:03.057: I/xmltest(12364): person info ====
10-02 10:48:03.057: I/xmltest(12364): ID = 2
10-02 10:48:03.057: I/xmltest(12364): name = kite
10-02 10:48:03.057: I/xmltest(12364): age = 21
10-02 10:48:03.057: I/xmltest(12364): title = tester
10-02 10:48:05.038: I/xmltest(12364): person info ====
10-02 10:48:05.038: I/xmltest(12364): ID = 3
10-02 10:48:05.038: I/xmltest(12364): name = rose
10-02 10:48:05.038: I/xmltest(12364): age = 28
10-02 10:48:05.038: I/xmltest(12364): title = manager

b、直接从内存中读取

/* 直接使用内存测试 */
    private void xml_memory_test(){
        String xml_test = "<foo>Hello World!</foo>";
        try {
            XR.setXML(xml_test);
            int eventType = XR.getEventType();
            Log.i(TAG,"eventType: " + eventType);
            while (eventType != XmlPullParser.END_DOCUMENT) {
                if (eventType == XmlPullParser.START_DOCUMENT) {
                    Log.i(TAG,"Start document");
                } else if (eventType == XmlPullParser.START_TAG) {
                    Log.i(TAG,"Start tag " + XR.getName());
                } else if (eventType == XmlPullParser.END_TAG) {
                    Log.i(TAG,"End tag " + XR.getName());
                } else if (eventType == XmlPullParser.TEXT) {
                    Log.i(TAG,"Text " + XR.getText());
                }
                eventType = XR.getNextEvent();
                Log.i(TAG,"eventType: " + eventType);
            }
            Log.i(TAG,"End document");         
        } catch (Exception e) {
            e.printStackTrace();
        }
        return ;
    }

输出内容：
10-02 10:48:07.975: I/xmltest(12364): eventType: 0
10-02 10:48:07.975: I/xmltest(12364): Start document
10-02 10:48:07.983: I/xmltest(12364): eventType: 2
10-02 10:48:07.983: I/xmltest(12364): Start tag foo
10-02 10:48:07.991: I/xmltest(12364): eventType: 4
10-02 10:48:07.999: I/xmltest(12364): Text Hello World!
10-02 10:48:07.999: I/xmltest(12364): eventType: 3
10-02 10:48:07.999: I/xmltest(12364): End tag foo
10-02 10:48:08.006: I/xmltest(12364): eventType: 1
10-02 10:48:08.006: I/xmltest(12364): End document

c、另外的xml格式用法

/* 另类xml文件写法 */
private void xml_misc_test(){
    String xml_test = "<foo hi=\\"Hello World!\\"/>";
    try {
        XR.setXML(xml_test);
        int eventType = XR.getEventType();
        Log.i(TAG,"eventType: " + eventType);
        while (eventType != XmlPullParser.END_DOCUMENT) {
            if (eventType == XmlPullParser.START_DOCUMENT) {
                Log.i(TAG,"Start document");
            } else if (eventType == XmlPullParser.START_TAG) {
                Log.i(TAG,"Start tag " + XR.getName());
                String name = XR.getAttributeName(0);
                String value = XR.getAttributeValue(name);
                Log.i(TAG,"name:" + name + " value:" + value);
            } else if (eventType == XmlPullParser.END_TAG) {
                Log.i(TAG,"End tag " + XR.getName());
            } else if (eventType == XmlPullParser.TEXT) {
                Log.i(TAG,"Text " + XR.getText());
            }
            eventType = XR.getNextEvent();
            Log.i(TAG,"eventType: " + eventType);
        }
        Log.i(TAG,"End document");         
    } catch (Exception e) {
        e.printStackTrace();
    }
    return ;
}

输出内容:
10-02 10:48:08.014: I/xmltest(12364): eventType: 0
10-02 10:48:08.014: I/xmltest(12364): Start document
10-02 10:48:08.014: I/xmltest(12364): eventType: 2
10-02 10:48:08.014: I/xmltest(12364): Start tag foo
10-02 10:48:08.014: I/xmltest(12364): name:hi value:Hello World!
10-02 10:48:08.014: I/xmltest(12364): eventType: 3
10-02 10:48:08.014: I/xmltest(12364): End tag foo
10-02 10:48:08.014: I/xmltest(12364): eventType: 1
10-02 10:48:08.014: I/xmltest(12364): End document

泡在网上的日子
每天进步一点点
0

粉丝

0

关注

0

获赞

0

访问

推荐文章