Android XML DOM解析SAX解析

声明：内容大部分参考自网友博客。个人只是做了小小的总结


我个人觉得可以用MVC模式去看待解析xml文件的实现：

下面是具体实现：
首先编写一个xml的数据文件存放在res/raw文件目录下：

<?xml version="1.0" encoding="utf-8"?>
<users>
    <beauty>
        <name>范冰冰</name>
        <age>28</age>
    </beauty>
    <beauty>
        <name>杨幂</name>
        <age>23</age>
    </beauty>
</users>

1.编写模型代码：

package com.example.sax;

public class User {
    private String name;
    private String age;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "美女资料 [年龄=" + age + ", 姓名=" + name + "]";
    }

}

package com.example.sax;
import java.util.ArrayList;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class MyHandler extends DefaultHandler {
    //声明一个装载Beauty类型的List
    private ArrayList<User> mList;
    //声明一个Beauty类型的变量
    private User beauty;
    //声明一个字符串变量
    private String content;

    /**
     * MySaxHandler的构造方法
     *
     * @param list 装载返回结果的List对象
     */
    public MyHandler(ArrayList<User> list){
        this.mList = list;
    }

    /**
     * 当SAX解析器解析到XML文档开始时，会调用的方法
     */
    @Override
    public void startDocument() throws SAXException {
        super.startDocument();
    }

    /**
     * 当SAX解析器解析到XML文档结束时，会调用的方法
     */
    @Override
    public void endDocument() throws SAXException {
        super.endDocument();
    }

    /**
     * 当SAX解析器解析到某个属性值时，会调用的方法
     * 其中参数ch记录了这个属性值的内容
     */
    @Override
    public void characters(char[] ch, int start, int length)
            throws SAXException {
        super.characters(ch, start, length);
        content = new String(ch, start, length);
    }

    /**
     * 当SAX解析器解析到某个元素开始时，会调用的方法
     * 其中localName记录的是元素属性名
     */
    @Override
    public void startElement(String uri, String localName, String qName,
                             Attributes attributes) throws SAXException {
        super.startElement(uri, localName, qName, attributes);

        if("beauty".equals(localName)){
            beauty = new User(); //新建Beauty对象
        }
    }

    /**
     * 当SAX解析器解析到某个元素结束时，会调用的方法
     * 其中localName记录的是元素属性名
     */
    @Override
    public void endElement(String uri, String localName, String qName)
            throws SAXException {
        super.endElement(uri, localName, qName);

        if("name".equals(localName)){
            beauty.setName(content);
        }else if("age".equals(localName)){
            beauty.setAge(content);
        }else if("beauty".equals(localName)){
            mList.add(beauty); //将Beauty对象加入到List中
        }
    }

}

2.视图编辑：

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/sax"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

3.控制器代码：

package com.example.sax;

import androidx.appcompat.app.AppCompatActivity;

import android.content.res.AssetManager;
import android.os.Bundle;
import java.io.InputStream;
import java.util.ArrayList;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.InputSource;

import org.xml.sax.XMLReader;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    //声明装载Beauty对象的List
    private ArrayList<User> beautyList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //初始化beautyList链表
        if(beautyList == null){
            beautyList = new ArrayList<User>();
        }

        doMyMission();

        setupViews();
    }

    /**
     * 使用SAX解析器解析XML文件的方法
     */
    private void doMyMission(){
        try {
            //获取AssetManager管理器对象
            AssetManager as = this.getAssets();
            //通过AssetManager的open方法获取到beauties.xml文件的输入流

            InputStream is=this.getResources().openRawResource(R.raw.users);//这个是关键，网上代码不会出现


            //通过获取到的InputStream来得到InputSource实例
            InputSource is2 = new InputSource(is);
            //使用工厂方法初始化SAXParserFactory变量spf
            SAXParserFactory spf = SAXParserFactory.newInstance();
            //通过SAXParserFactory得到SAXParser的实例
            SAXParser sp = spf.newSAXParser();
            //通过SAXParser得到XMLReader的实例
            XMLReader xr = sp.getXMLReader();
            //初始化自定义的类MySaxHandler的变量msh，将beautyList传递给它，以便装载数据
            MyHandler msh = new MyHandler(beautyList);
            //将对象msh传递给xr
            xr.setContentHandler(msh);
            //调用xr的parse方法解析输入流
            xr.parse(is2);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 将解析结果输出到界面的方法
     */
    private void setupViews(){
        String result = "";
        for (User b : beautyList) {
            result += b.toString();
        }

        TextView textView = (TextView) findViewById(R.id.sax);
        textView.setText(result);
    }

}

下面是具体实现：
首先编写一个xml的数据文件存放在res/raw文件目录下：

<?xml version="1.0" encoding="UTF-8"?>
<persons>
    <person id="23">
        <name>liming</name>
        <age>30</age>
    </person>
    <person id="20">
        <name>lixiangmei</name>
        <age>25</age>
    </person>
</persons>

1.编写模型代码：

package com.example.dom;

public class Person {
    int id;
    String name;
    int age;

    public void setId(int id)
    {
        this.id=id;
    }
    public int getId()
    {
        return id;
    }
    public void setName(String name)
    {
        this.name=name;
    }
    public String getName()
    {
        return name;
    }
    public void setAge(int age)
    {
        this.age=age;
    }
    public int getAge()
    {
        return age;
    }
}

package com.example.dom;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

/**
 * Created by zhangmiao on 2016/12/14.
 */
public class AnalyzeDOM {

    public static List<Person> readXML(InputStream inputStream) {
        List<Person> persons = new ArrayList<>();
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        try {
            DocumentBuilder builder = factory.newDocumentBuilder();
            Document dom = builder.parse(inputStream);
            Element root = dom.getDocumentElement();
            NodeList items = root.getElementsByTagName("person");
            for (int i = 0; i < items.getLength(); i++) {
                Person person = new Person();
                Element personNode = (Element) items.item(i);
                person.setId(new Integer(personNode.getAttribute("id")));
                NodeList childNodes = personNode.getChildNodes();
                for (int j = 0; j < childNodes.getLength(); j++) {
                    Node node = childNodes.item(j);
                    if (node.getNodeType() == Node.ELEMENT_NODE) {
                        Element childNode = (Element) node;
                        if ("name".equals(childNode.getNodeName())) {
                            person.setName(childNode.getFirstChild().getNodeValue());
                        } else if ("age".equals(childNode.getNodeName())) {
                            person.setAge(new Short(childNode.getFirstChild().getNodeValue()));
                        }
                    }
                }
                persons.add(person);
            }
            inputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return persons;
    }
}

2.视图编辑：

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
    <Button
        android:id="@+id/dom_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="here"
        android:onClick="onClick"/>

</androidx.constraintlayout.widget.ConstraintLayout>

3.控制器代码：

package com.example.dom;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import java.io.InputStream;
import java.util.List;

public class MainActivity extends AppCompatActivity {

   // private static final String TAG = "AnalyzeXMLDemo";

    private TextView mTextView;

   private Button dom;
    private InputStream inputStream;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mTextView = (TextView) findViewById(R.id.text);
        dom = (Button)findViewById(R.id.dom_button);
    }
    public void onClick(View v) {
        String result = "";
        inputStream = getResources().openRawResource(R.raw.itcase);
        switch (v.getId()) {case R.id.dom_button:
            result += "--------- DOM ---------" + "\n";
            if (inputStream == null) {
                result = "inputStream is null";
            } else {
                List<Person> personList = AnalyzeDOM.readXML(inputStream);
                if (personList != null) {
                    for (int i = 0; i < personList.size(); i++) {
                        String message = "id = " + personList.get(i).getId() + " , name = " + personList.get(i).getName()
                                + " , age = " + personList.get(i).getAge() + ".\n";
                        result += message;
                    }
                }
            }
            mTextView.setText(result);
            break;default:
            break;
        }
    }

}