Android中XML解析，保存的三种方法

简介

在Android开发中，关于XML解析有三种方式,分别是：

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。

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

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

/article/7553406.html

/article/4783901.html

http://www.cnblogs.com/weixing/archive/2013/08/07/3243366.html