关于android:JAVA-UIHarmonyOSDemo-鸿蒙如何进行xml解析

【鸿蒙】鸿蒙如何进行数据解析

【问题形容】有时候咱们从服务器获取是 xml 格局数据，咱们须要将 xml 转化成 model 对象，该如何应用呢？上面举个例子阐明一下，将分以下几步进行

筹备条件创立 xml 文件，创立 model 对象，构建界面
数据进行解析操作（重点）
运行成果

第一步筹备条件创立 xml 文件，创立 model 对象，构建界面

1.1 在 rawfile 新建 xml 文件，代码如下


<?xml version="1.0" encoding="utf-8"?>

<note>

    <to>George</to>

    <from>John</from>

    <heading>Reminder</heading>

    <body>Don't forget the meeting!</body>

</note>

1.2 新建 class model 代码如下


package com.harmony.alliance.mydemo.model;

 

public class note {

    private  String from;

    private  String heading;

    private String body;

    private  String to;

 

    public String getFrom() {return from;}

 

    public void setFrom(String from) {this.from = from;}

 

    public String getBody() {return body;}

 

    public void setBody(String body) {this.body = body;}

 

    public String getTo() {return to;}

 

    public void setTo(String to) {this.to = to;}

 

    public String getHeading() {return heading;}

 

    public void setHeading(String heading) {this.heading = heading;}

 

    @Override

    public String toString() {

        return "note{" +

                "from='" + from + '\'' +

                ", heading='" + heading + '\'' +

                ", body='" + body + '\'' +

                ", to='" + to + '\'' +

                '}';

    }

}

1.3 新建数据的 abilityslice，xml 如下


<?xml version="1.0" encoding="utf-8"?>

<DirectionalLayout

    xmlns:ohos="http://schemas.huawei.com/res/ohos"

    ohos:height="match_parent"

    ohos:width="match_parent"

    ohos:orientation="vertical">

    <Text

        ohos:id="$+id:mStartParse"

        ohos:height="100vp"

        ohos:width="match_parent"

        ohos:text="开始解析"

        ohos:text_size="20fp"

        ohos:text_color="#ffffff"

        ohos:text_alignment="center"

        ohos:background_element="#ed6262"/>

    <Text

        ohos:id="$+id:mTo"

        ohos:height="100fp"

        ohos:width="match_parent"

        ohos:text_size="20fp"

        ohos:text_color="#ed6262"

        ohos:background_element="#ffffff"/>

    <Text

        ohos:id="$+id:mfrom"

        ohos:height="100fp"

        ohos:width="match_parent"

        ohos:text_size="20fp"

        ohos:text_color="#ed6262"

        ohos:background_element="#ffffff"/>

    <Text

        ohos:id="$+id:mheading"

        ohos:height="100fp"

        ohos:width="match_parent"

        ohos:text_size="20fp"

        ohos:text_color="#ed6262"

        ohos:background_element="#ffffff"/>

 

    <Text

        ohos:id="$+id:mbody"

        ohos:height="100fp"

        ohos:width="match_parent"

        ohos:text_size="20fp"

        ohos:text_color="#ed6262"

        ohos:background_element="#ffffff"/>

 

</DirectionalLayout>

界面成果如下

第二步数据解析
2.1 参考资料如下

SAXParser

https://developer.harmonyos.c…

XMLReader
https://developer.harmonyos.c…
该性能和 Android 的 demo 类似能够参考 Android 的 demo 链接

https://blog.csdn.net/bzlj291…

在上述四个接口中，最重要的就是 ContentHandler 这个接口，上面是对这个接口办法的阐明：

// 设置一个能够定位文档内容事件产生地位的定位器对象

public void setDocumentLocator(Locator locator)

// 用于解决文档解析开始事件

public void startDocument()throws SAXException

// 解决元素开始事件，从参数中能够取得元素所在名称空间的 uri，元素名称，属性类表等信息

public void startElement(String namespacesURI , String localName , String qName , Attributes atts) throws SAXException

// 解决元素完结事件，从参数中能够取得元素所在名称空间的 uri，元素名称等信息

public void endElement(String namespacesURI , String localName , String qName) throws SAXException

// 解决元素的字符内容，从参数中能够取得内容

public void characters(char[] ch , int start , int length) throws SAXException

新建 SaxHelper 代码如下

package com.harmony.alliance.mydemo.model;

 

import ohos.org.xml.sax.Attributes;

import ohos.org.xml.sax.SAXException;

import ohos.org.xml.sax.helpers.DefaultHandler;

 

/**

 * Created by Jay on 2015/9/8 0008.

 */

public class SaxHelper extends DefaultHandler {

    // 以后解析的元素标签

    private String tagName = null;

    private  note mNote;

 

    /**

     * 当读取到文档开始标记是触发，通常在这里实现一些初始化操作

     */

    @Override

    public void startDocument() throws SAXException {mNote=new note();

    }

 

    /**

     * 读到一个开始标签时调用, 第二个参数为标签名, 最初一个参数为属性数组

     */

    @Override

    public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {System.err.println("####===>>"+localName);

        this.tagName = localName;

    }

 

    /**

     * 读到到内容, 第一个参数为字符串内容, 前面顺次为起始地位与长度

     */

 

    @Override

    public void characters(char[] ch, int start, int length) throws SAXException {

        // 判断以后标签是否无效

        if (this.tagName != null) {String data = new String(ch, start, length);

            // 读取标签中的内容

            if (this.tagName.equals("to")) {mNote.setTo(data);

            } else if (this.tagName.equals("from")) {mNote.setFrom(data);

            }else  if(this.tagName.equals("heading")){mNote.setHeading(data);

            }else  if(this.tagName.equals("body")){mNote.setBody(data);

            }

 

        }

 

    }

 

    /**

     * 解决元素完结时触发, 这里将对象增加到联合中

     */

    @Override

    public void endElement(String uri, String localName, String qName) throws SAXException {this.tagName = null;}

 

    /**

     * 读取到文档结尾时触发，*/

    @Override

    public void endDocument() throws SAXException {super.endDocument();

        System.err.println("#####===>>"+mNote.toString());

//        Log.i("SAX", "读取到文档尾,xml 解析完结");

    }

    public note getmNote() {return mNote;}

 

}

AbilitySlice 代码如下


package com.harmony.alliance.mydemo.slice;

 

import com.harmony.alliance.mydemo.ResourceTable;

import com.harmony.alliance.mydemo.model.SaxHelper;

import com.harmony.alliance.mydemo.model.note;

import ohos.aafwk.ability.AbilitySlice;

import ohos.aafwk.content.Intent;

import ohos.agp.components.Component;

import ohos.agp.components.Text;

import ohos.javax.xml.parsers.SAXParser;

import ohos.javax.xml.parsers.SAXParserFactory;

import ohos.org.xml.sax.InputSource;

import ohos.org.xml.sax.XMLReader;

import java.io.InputStream;

import java.util.Locale;

 

public class myXmlParseAbilitySlice extends AbilitySlice {

    private Text mStartParse,mTo,mfrom,mheading,mbody;

    @Override

    protected void onStart(Intent intent) {super.onStart(intent);

        setUIContent(ResourceTable.Layout_my_xml_parse);

        mStartParse= (Text) findComponentById(ResourceTable.Id_mStartParse);

        mTo= (Text) findComponentById(ResourceTable.Id_mTo);

        mfrom= (Text) findComponentById(ResourceTable.Id_mfrom);

        mheading= (Text) findComponentById(ResourceTable.Id_mheading);

        mbody= (Text) findComponentById(ResourceTable.Id_mbody);

        mStartParse.setClickedListener(new Component.ClickedListener() {

            @Override

            public void onClick(Component component) {

                try {

                    String rawFilePath = "note.xml";

                    String filePath = String.format(Locale.ROOT, "assets/entry/resources/rawfile/%s", rawFilePath);

                    InputStream     is = this.getClass().getClassLoader().getResourceAsStream(filePath);

                    InputSource is2=new InputSource(is);

                    SaxHelper ss = new SaxHelper();

                    SAXParserFactory factory = SAXParserFactory.newInstance();

                    factory.setNamespaceAware(true);

                    SAXParser parser = factory.newSAXParser();

                    XMLReader xmlReader=parser.getXMLReader();

                    xmlReader.setContentHandler(ss);

                    xmlReader.parse(is2);

                    note mNote= ss.getmNote();

                    mTo.setText("to:"+mNote.getTo());

                    mfrom.setText("From:"+mNote.getFrom());

                    mheading.setText("heading:"+mNote.getHeading());

                    mbody.setText("body:"+mNote.getBody());

                    is.close();}catch (Exception e){e.printStackTrace();

                }

            }

        });

    }

}

第三步运行成果如下

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