Kotlin Android使用SAX解析器解析XML

2025年3月17日 | 阅读 3 分钟

XML文档通常用于在互联网上共享数据。XML格式提供的数据能够经常更新，解析它们是基于网络的应用程序的常见任务。

在Android中，有三种类型的XML解析器来解析XML数据并在android应用程序中读取它们，它们是

在Android中，SAX（XML的简单API）是广泛用于XML解析的API。SAX解析器将逐个字符地检查XML文档，并将其转换为一系列事件，例如startElement()，endElement()和characters()。要使用SAX解析器读取和解析XML数据，我们需要在android应用程序中创建SAXParserFactory、SAXParser和DefaultHandler对象的实例。

使用SAX解析器的XML解析示例

在此示例中，我们将使用SAX解析器解析XML数据，并将它们显示到ListView中。

activity_main.xml

在 activity_main.xml 布局中添加 ListView。

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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="example.javatpoint.com.kotlinxmlparsingusingsaxparser.MainActivity">

   <ListView
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    </ListView>

</android.support.constraint.ConstraintLayout>

empdetail.xml

在assets目录中创建XML文档empdetail.xml以使用SAX解析器解析数据。

<?xml version="1.0" encoding="utf-8"?>
<records>
    <employee>
        <name>Sachin Kumar</name>
        <salary>50000</salary>
        <designation>Developer</designation>
    </employee>
    <employee>
        <name>Rahul Kumar</name>
        <salary>60000</salary>
        <designation>Team Leader</designation>
    </employee>
    <employee>
        <name>John Mike</name>
        <salary>70000</salary>
        <designation>Manager</designation>
    </employee>
    <employee>
        <name>Ajay Kumar</name>
        <salary>45000</salary>
        <designation>Developer</designation>
    </employee>
    <employee>
        <name>Toni Nayer</name>
        <salary>55000</salary>
        <designation>Marketing</designation>
    </employee>
    <employee>
        <name>Mr Bony</name>
        <salary>42000</salary>
        <designation>Sales</designation>
    </employee>
    <employee>
        <name>Raj Kumar</name>
        <salary>30000</salary>
        <designation>Production</designation>
    </employee>
    <employee>
        <name>Rahul Kumar</name>
        <salary>60000</salary>
        <designation>Team Leader</designation>
    </employee>
    <employee>
        <name>John Mike</name>
        <salary>70000</salary>
        <designation>Manager</designation>
    </employee>
    <employee>
        <name>Sachin Kumar</name>
        <salary>50000</salary>
        <designation>Developer</designation>
    </employee>
    <employee>
        <name>Rahul Kumar</name>
        <salary>60000</salary>
        <designation>Team Leader</designation>
    </employee>
    <employee>
        <name>John Mike</name>
        <salary>70000</salary>
        <designation>Manager</designation>
    </employee>
</records>

custom_list.xml

创建一个自定义布局以将数据列表显示到ListView中。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal">
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:orientation="vertical">

            <TextView
                android:id="@+id/name"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="name"
                android:textStyle="bold"
                android:layout_marginLeft="15dp"
                android:layout_marginStart="15dp"
                android:textAppearance="@style/Base.TextAppearance.AppCompat.Medium" />

            <TextView
                android:id="@+id/salary"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="salary"
                android:layout_marginLeft="15dp"
                android:layout_marginStart="15dp"
                android:layout_marginTop="5dp"
                android:textSize="16sp"/>
            <TextView
                android:id="@+id/designation"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="designation"
                android:layout_marginLeft="15dp"
                android:layout_marginStart="15dp"
                android:layout_marginTop="5dp"
                android:textSize="16sp"/>
        </LinearLayout>
</LinearLayout>

MainActivity.kt

添加以下代码以使用SAX解析器读取和解析XML数据。创建SAXParserFactory、SAXParser和DefaultHandler对象的实例。

HashMap<String, String>用于从XML文档读取数据，并将它们添加到ArrayList()中。

package example.javatpoint.com.kotlinxmlparsingusingsaxparser

import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import org.xml.sax.helpers.DefaultHandler
import javax.xml.parsers.SAXParserFactory
import android.widget.ListView
import android.widget.SimpleAdapter
import org.xml.sax.SAXException
import java.io.IOException
import java.util.ArrayList
import java.util.HashMap
import javax.xml.parsers.ParserConfigurationException
import javax.xml.parsers.SAXParser

class MainActivity : AppCompatActivity() {
    internal var empList = ArrayList<HashMap<String, String>>()
    internal var empData = HashMap<String, String>()
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        val lv:ListView = findViewById(R.id.listView)
        try {
                        //instancing the SAXParserFactory class
            val parserFactory:SAXParserFactory = SAXParserFactory.newInstance()
            //instancing the SAXParser class
            val saxParser:SAXParser = parserFactory.newSAXParser()
            val defaultHandler= object : DefaultHandler() {
                var currentValue = ""
                var currentElement = false
                //overriding the startElement() method of DefaultHandler
                override fun startElement(uri: String, localName: String, qName: String, attributes: org.xml.sax.Attributes) {
                    currentElement = true
                    currentValue = ""
                    if (localName == "employee") {
                        empData = HashMap()
                    }
                }
                //overriding the endElement() method of DefaultHandler
                override fun endElement(uri: String, localName: String, qName: String) {
                    currentElement = false
                    if (localName.equals("name", ignoreCase = true))
                        empData["name"] = currentValue
                    else if (localName.equals("salary", ignoreCase = true))
                        empData["salary"] = currentValue
                    else if (localName.equals("designation", ignoreCase = true))
                        empData["designation"] = currentValue
                    else if (localName.equals("employee", ignoreCase = true))
                        empList.add(empData)
                }
                //overriding the characters() method of DefaultHandler
                override fun characters(ch: CharArray, start: Int, length: Int) {
                    if (currentElement) {
                        currentValue = currentValue + String(ch, start, length)
                    }
                }
            }
            val istream = assets.open("empdetail.xml")
            saxParser.parse(istream, defaultHandler)
            //creating Adapter class to access the custom list
            val adapter = SimpleAdapter(this@MainActivity, empList, R.layout.custom_list, arrayOf("name", "salary", "designation"), intArrayOf(R.id.name, R.id.salary, R.id.designation))
            lv.adapter = adapter
        } catch (e: IOException) {
            e.printStackTrace()
        } catch (e: ParserConfigurationException) {
            e.printStackTrace()
        } catch (e: SAXException) {
            e.printStackTrace()
        }

    }
}

输出

Kotlin Android XML Parsing using SAX Parser

下一主题#

Kotlin Android使用SAX解析器解析XML

使用SAX解析器的XML解析示例

activity_main.xml

empdetail.xml

custom_list.xml

MainActivity.kt

联系信息

关注我们

教程

面试题

在线编译器

Python

Java

.Net Framework

AI, ML and Data Science

Cloud Technology

B.Tech and MCA

Web Technology

PHP

Software Testing

Technical Interview

Java Interview

Python

Web Interview

Database Interview

B.Tech / MCA

Important Interview

Software Testing Interview

Company Interviews

Online Compilers

Multiple Choice Questions

Kotlin 教程

控制流

函数

Array

String

异常处理

Null 安全

集合

注解

反射

Kotlin OOPs

范围

Java 互操作性

Regex

Android 启动

Kotlin Android

Kotlin Android使用SAX解析器解析XML

使用SAX解析器的XML解析示例

activity_main.xml

empdetail.xml

custom_list.xml

MainActivity.kt

相关帖子

TabLayout with ViewPager

Google Map 当前位置

Android 自定义 Toast

Android Context Menu

Android AlertDialog

Android 自定义 ListView

Android Popup Menu

Android ListView

身份验证 - Google 登录

Android 隐式 Intent

订阅 Tpoint Tech

联系信息

关注我们

教程

面试题

在线编译器