Android编程实现XML解析与保存的三种方法详解
时间:2019-03-31
本文章向大家介绍Android编程实现XML解析与保存的三种方法详解，主要包括Android编程实现XML解析与保存的三种方法详解使用实例、应用技巧、基本知识点总结和需要注意事项，具有一定的参考价值，需要的朋友可以参考一下。
本文实例讲述了Android编程实现XML解析与保存的三种方法。分享给大家供大家参考，具体如下：
简介
在Android开发中，关于XML解析有三种方式,分别是：
1. SAX 基于事件的解析器，解析速度快，占用内存少。非常适合在Android移动设备中使用。
2. DOM 在内存中以树形结构存放，因此检索和更新效率会更高。但是对于特别大的文档，解析和加载整个文档将会很耗资源
3. PULL 基于事件的解析器，不同于SAX是，PULL是主动请求下一个事件，所以在可控上PULL要比SAX实用。Android系统内部在解析各种XML时也是用PULL解析器。
下面实现各种解析的类以及工程结构
这是我们将要解析的XML文件id.xml以及其对应的Book类
<?xml version="1.0" encoding="UTF-8"?> <books> <book id="1001"> <name>Thinking In Java</name> <price>80.0</price> </book> <book id="1002"> <name>Core Java</name> <price>90.0</price> </book> <book id="1003"> <name>Hello, Andriod</name> <price>100.0</price> </book> </books>
Book.Java
public class Book {
public static final String BOOKS = "books";
public static final String BOOK = "book";
public static final String ID = "id";
public static final String NAME = "name";
public static final String PRICE = "price";
private int id;
private String name;
private float price;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public float getPrice() {
return price;
}
public void setPrice(float price) {
this.price = price;
}
@Override
public String toString() {
return "id:" + id + ",name:" + name + ",price:" + price;
}
}
下面是XML解析类的实现
抽象类用于 XML文件读写的继承
XMLParseFactory.java
import java.io.InputStream;
import java.util.List;
public abstract class XMLParseFactory {
/**
* 读取指定的XML文件
* @param inputStream XML文件输入流
*/
public abstract void readXML(InputStream inputStream);
/**
* 保存XML到指定的文件
* @param filePath 文件的绝对路径
*/
public abstract void writeXML(String filePath);
/**
* 获取Book对象列表
* @return
*/
public abstract List<Book> getBookList();
/**
* 设置Book对象列表
*/
public abstract void setBookList(List<Book> bookList);
}
用SAX实现的方法
SAXParserTool.java
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
import java.util.List;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Result;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.sax.SAXTransformerFactory;
import javax.xml.transform.sax.TransformerHandler;
import javax.xml.transform.stream.StreamResult;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;
import org.xml.sax.helpers.DefaultHandler;
public class SAXParserTool extends XMLParseFactory {
// private static final String TAG = "SAXParserTool";
private SAXHandler mHandler = new SAXHandler();
private List<Book> mBookList;
@Override
public void readXML(InputStream inputStream) {
try {
SAXParserFactory factory = SAXParserFactory.newInstance();
SAXParser parser = factory.newSAXParser();
parser.parse(inputStream, mHandler);
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (inputStream != null) {
try {
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
@Override
public void writeXML(String filePath) {
SAXTransformerFactory factory = (SAXTransformerFactory) TransformerFactory.newInstance();
try {
TransformerHandler handler = factory.newTransformerHandler();
Transformer transformer = handler.getTransformer();
transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "no");
FileOutputStream fos = new FileOutputStream(filePath);
OutputStreamWriter writer = new OutputStreamWriter(fos);
Result result = new StreamResult(writer);
handler.setResult(result);
String uri = "";
String localName = "";
handler.startDocument();
handler.startElement(uri, localName, Book.BOOKS, null);
AttributesImpl attrs = new AttributesImpl();
char[] ch = null;
for (Book book:mBookList) {
attrs.clear();
attrs.addAttribute(uri, localName, Book.ID, "string", String.valueOf(book.getId()));
handler.startElement(uri, localName, Book.BOOK, attrs);
handler.startElement(uri, localName, Book.NAME, null);
ch = book.getName().toCharArray();
handler.characters(ch, 0, ch.length);
handler.endElement(uri, localName, Book.NAME);
handler.startElement(uri, localName, Book.PRICE, null);
ch = String.valueOf(book.getPrice()).toCharArray();
handler.characters(ch, 0, ch.length);
handler.endElement(uri, localName, Book.PRICE);
handler.endElement(uri, localName, Book.BOOK);
}
handler.endElement(uri, localName, Book.BOOKS);
handler.endDocument();
} catch (TransformerConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* 获取BookList列表
* @return
*/
public List<Book> getBookList() {
if (mHandler == null) {
return null;
}
return mHandler.getBookList();
}
/**
* 设置BookList列表
* @param bookList
*/
public void setBookList(List<Book> bookList) {
mBookList = bookList;
}
class SAXHandler extends DefaultHandler {
private List<Book> mBookList;
private Book mBook;
private String mTargetName;
public List<Book> getBookList() {
return mBookList;
}
@Override
public void startDocument() throws SAXException {
super.startDocument();
mBookList = new ArrayList<Book>();
}
@Override
public void endDocument() throws SAXException {
super.endDocument();
}
@Override
public void startElement(String uri, String localName, String qName,
Attributes attributes) throws SAXException {
super.startElement(uri, localName, qName, attributes);
if (localName.equals(Book.BOOK)) {
mBook = new Book();
mBook.setId(Integer.valueOf(attributes.getValue(Book.ID)));
}
mTargetName = localName;
}
@Override
public void endElement(String uri, String localName, String qName)
throws SAXException {
super.endElement(uri, localName, qName);
if (Book.BOOK.equals(localName)) {
mBookList.add(mBook);
}
mTargetName = null;
}
@Override
public void characters(char[] ch, int start, int length)
throws SAXException {
super.characters(ch, start, length);
if (Book.NAME.equals(mTargetName)) {
mBook.setName(new String(ch, start, length));
} else if (Book.PRICE.equals(mTargetName)) {
mBook.setPrice(Float.valueOf(new String(ch, start, length)));
}
}
}
}
用PULL实现的方法
PULLParserTool.java
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlSerializer;
import android.util.Xml;
public class PULLParserTool extends XMLParseFactory {
// private static final String TAG = "PULLParserTool";
private List<Book> mBookList;
private Book mBook;
@Override
public void readXML(InputStream inputStream) {
try {
XmlPullParser parser = Xml.newPullParser();
parser.setInput(inputStream, "UTF-8");
int eventType = parser.getEventType();
while (eventType != XmlPullParser.END_DOCUMENT) {
String name = parser.getName();
switch (eventType) {
case XmlPullParser.START_DOCUMENT:
mBookList = new ArrayList<Book>();
break;
case XmlPullParser.START_TAG:
// Log.d(TAG, "getName:"+parser.getName()+","+parser.getText());
if (Book.BOOK.equals(name)) {
mBook = new Book();
mBook.setId(Integer.valueOf(parser.getAttributeValue("", Book.ID)));
} else if (Book.NAME.equals(name)) {
mBook.setName(parser.nextText());
} else if (Book.PRICE.equals(name)) {
mBook.setPrice(Float.valueOf(parser.nextText()));
}
break;
case XmlPullParser.END_TAG:
if (Book.BOOK.equals(name)) {
mBookList.add(mBook);
}
break;
default:
break;
}
eventType = parser.next();
}
} catch (XmlPullParserException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (inputStream != null) {
try {
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
@Override
public void writeXML(String filePath) {
XmlSerializer serializer = Xml.newSerializer();
FileOutputStream fos = null;
try {
fos = new FileOutputStream(filePath);
serializer.setOutput(fos, "UTF-8");
serializer.startDocument("UTF-8", true);
serializer.startTag("", Book.BOOKS);
for (Book book:mBookList) {
serializer.startTag("", Book.BOOK);
serializer.attribute("", Book.ID, book.getId()+"");
serializer.startTag("", Book.NAME);
serializer.text(book.getName());
serializer.endTag("", Book.NAME);
serializer.startTag("", Book.PRICE);
serializer.text(String.valueOf(book.getPrice()));
serializer.endTag("", Book.PRICE);
serializer.endTag("", Book.BOOK);
}
serializer.endTag("", Book.BOOKS);
serializer.endDocument();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (fos != null) {
try {
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
public List<Book> getBookList() {
return mBookList;
}
public void setBookList(List<Book> bookList) {
mBookList = bookList;
}
}
用DOM实现的方法
DOMParserTool.java
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
import android.util.Log;
public class DOMParserTool extends XMLParseFactory {
private static final String TAG = "DOMParserTool";
private List<Book> mBookList;
@Override
public void readXML(InputStream inputStream) {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder builder = factory.newDocumentBuilder();
Document parse = builder.parse(inputStream);
Element root = parse.getDocumentElement();
NodeList nodeList = root.getElementsByTagName(Book.BOOK);
mBookList = new ArrayList<Book>();
Log.d(TAG,"length:"+nodeList.getLength());
for (int i = 0; i < nodeList.getLength(); i++) {
Book book = new Book();
Element item = (Element) nodeList.item(i);
book.setId(Integer.valueOf(item.getAttribute(Book.ID)));
NodeList nodes = item.getChildNodes();
for (int j = 0; j < nodes.getLength(); j++) {
Node node = nodes.item(j);
if (node.getNodeType() == Node.ELEMENT_NODE) {
if (Book.NAME.equals(node.getNodeName())) {
String content = node.getTextContent();
book.setName(content);
} else if (Book.PRICE.equals(node.getNodeName())) {
String content = node.getTextContent();
book.setPrice(Float.valueOf(content));
}
}
Log.d(TAG, "readXML:"+node.getLocalName()+","+node.getNodeName()
+","+node.getNodeType()+","+node.getNodeValue()
+","+node.getTextContent()
+","+node.toString());
}
mBookList.add(book);
}
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (inputStream != null) {
try {
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
@Override
public void writeXML(String filePath) {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder builder = factory.newDocumentBuilder();
Document document = builder.newDocument();
Element rootElement = document.createElement("books");
for (Book book:mBookList) {
Element bookElement = document.createElement("book");
bookElement.setAttribute(Book.ID, book.getId()+"");
Element nameElement = document.createElement(Book.NAME);
nameElement.setTextContent(book.getName());
bookElement.appendChild(nameElement);
Element priceElement = document.createElement(Book.PRICE);
priceElement.setTextContent(String.valueOf(book.getPrice()));
bookElement.appendChild(priceElement);
rootElement.appendChild(bookElement);
}
document.appendChild(rootElement);
TransformerFactory transfactory = TransformerFactory.newInstance();
Transformer transformer = transfactory.newTransformer();
transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");// 设置输出采用的编码方式
transformer.setOutputProperty(OutputKeys.INDENT, "yes");// 是否自动添加额外的空白
transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "no");// 是否忽略XML声明
FileOutputStream fos = new FileOutputStream(filePath);
Source source = new DOMSource(document);
Result result = new StreamResult(fos);
transformer.transform(source, result);
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (TransformerConfigurationException e) {
e.printStackTrace();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (TransformerException e) {
e.printStackTrace();
}
}
public List<Book> getBookList() {
return mBookList;
}
public void setBookList(List<Book> bookList) {
mBookList = bookList;
}
}
这是调用各种解析类的实现
MainActivity.java
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
import com.example.xmlparsedemo.xmlparser.Book;
import com.example.xmlparsedemo.xmlparser.DOMParserTool;
import com.example.xmlparsedemo.xmlparser.PULLParserTool;
import com.example.xmlparsedemo.xmlparser.SAXParserTool;
import com.example.xmlparsedemo.xmlparser.XMLParseFactory;
import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends Activity implements OnClickListener {
private TextView mText;
private XMLParseFactory parseFactory;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
init();
}
private void init() {
Button saxReadBtn = (Button) findViewById(R.id.id_saxread);
Button saxWriteBtn = (Button) findViewById(R.id.id_saxwrite);
Button domReadBtn = (Button) findViewById(R.id.id_domread);
Button domWriteBtn = (Button) findViewById(R.id.id_domwrite);
Button pullReadBtn = (Button) findViewById(R.id.id_pullread);
Button pullWriteBtn = (Button) findViewById(R.id.id_pullwrite);
mText = (TextView) findViewById(R.id.id_text);
saxReadBtn.setOnClickListener(this);
saxWriteBtn.setOnClickListener(this);
domReadBtn.setOnClickListener(this);
domWriteBtn.setOnClickListener(this);
pullReadBtn.setOnClickListener(this);
pullWriteBtn.setOnClickListener(this);
}
@Override
public void onClick(View v) {
InputStream inputStream;
try {
inputStream = getAssets().open("id.xml");
switch (v.getId()) {
case R.id.id_saxread:
parseFactory = new SAXParserTool();
parseFactory.readXML(inputStream);
showBookList(parseFactory.getBookList());
break;
case R.id.id_saxwrite:
parseFactory.setBookList(parseFactory.getBookList());
parseFactory.writeXML(Environment.getExternalStorageDirectory().getPath()+"/id.xml");
break;
case R.id.id_domread:
parseFactory = new DOMParserTool();
parseFactory.readXML(inputStream);
showBookList(parseFactory.getBookList());
break;
case R.id.id_domwrite:
parseFactory.writeXML(Environment.getExternalStorageDirectory().getPath()+"/id2.xml");
break;
case R.id.id_pullread:
parseFactory = new PULLParserTool();
parseFactory.readXML(inputStream);
showBookList(parseFactory.getBookList());
break;
case R.id.id_pullwrite:
parseFactory.writeXML(Environment.getExternalStorageDirectory().getPath()+"/id3.xml");
break;
default:
break;
}
} catch (IOException e1) {
e1.printStackTrace();
}
}
private void showBookList(List<Book> bookList) {
StringBuilder builder = new StringBuilder();
for (Book book:bookList) {
builder.append(book.toString());
builder.append("\n");
}
mText.setText(builder.toString());
}
}
解析实现的主布局
activity_main.xml
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<Button
android:id="@+id/id_saxread"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SAXParserRead" />
<Button
android:id="@+id/id_saxwrite"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SAXParserWrite" />
<Button
android:id="@+id/id_domread"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="DOMParserRead" />
<Button
android:id="@+id/id_domwrite"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="DOMParserWrite" />
<Button
android:id="@+id/id_pullread"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="PULLParserRead" />
<Button
android:id="@+id/id_pullwrite"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="PULLParserWrite" />
<TextView
android:id="@+id/id_text"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
</ScrollView>
效果图
参考文章
//www.jb51.net/article/97247.htm
//www.jb51.net/article/97376.htm
PS：这里再为大家提供几款关于xml操作的在线工具供大家参考使用：
在线XML/JSON互相转换工具：
http://tools.jb51.net/code/xmljson
在线格式化XML/在线压缩XML：
http://tools.jb51.net/code/xmlformat
XML在线压缩/格式化工具：
http://tools.jb51.net/code/xml_format_compress
XML代码在线格式化美化工具：
http://tools.jb51.net/code/xmlcodeformat
更多关于Android相关内容感兴趣的读者可查看本站专题：《Android操作XML数据技巧总结》、《Android编程之activity操作技巧总结》、《Android资源操作技巧汇总》、《Android文件操作技巧汇总》、《Android开发入门与进阶教程》、《Android视图View技巧总结》及《Android控件用法总结》
希望本文所述对大家Android程序设计有所帮助。
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