解析XML数据

1 原始数据

assets包下的 Book.xml文件

<?xml version="1.0" encoding="utf-8"?><books>    <book>        <id>1001</id>        <name>Thinking In Java</name>        <price>80.00</price>    </book>    <book>        <id>1002</id>        <name>Core Java</name>        <price>90.00</price>    </book>    <book>        <id>1003</id>        <name>Hello, Andriod</name>        <price>100.00</price>    </book></books>  

Book的Bean类

public class Book {  private int id;  private String name;  private float price;  //get、set  ...}

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2 定义解析接口

public interface BooksParser {  /**   * 解析输入流，得到Book对象集合--解析   *    * @param is   * @return   * @throws Exception   */  List<Book> parse(InputStream is) throws Exception;  /**   * 序列化Book对象集合，得到XML形式的字符串--保存   * 不用Parcelable是因为此时用于本地数据的保存，而不是用于内存的持久化   * @param books   * @return   * @throws Exception   */   String serialize(List<Book> books) throws Exception;}

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3 编写解析类

1 DOM解析

package com.example.xml.parser;import com.example.xml.model.Book;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.io.StringWriter;import java.util.ArrayList;import java.util.List;import javax.xml.parsers.DocumentBuilder;import javax.xml.parsers.DocumentBuilderFactory;import javax.xml.transform.OutputKeys;import javax.xml.transform.Result;import javax.xml.transform.Source;import javax.xml.transform.Transformer;import javax.xml.transform.TransformerFactory;import javax.xml.transform.dom.DOMSource;import javax.xml.transform.stream.StreamResult;/** * DOM 解析 */public class DomBookParser implements BooksParser {  @Override  public List<Book> parse(InputStream is) throws Exception {    List<Book> books = new ArrayList<Book>();    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();// 获取DocumentBuilderFactory实例    DocumentBuilder builder = factory.newDocumentBuilder();// 从factory获取DocumentBuilder实例    Document doc = builder.parse(is);// 解析输入流，得到Document实例    Element rootElement = doc.getDocumentElement();    NodeList items = rootElement.getElementsByTagName("book");//所有Book节点    for (int i = 0; i < items.getLength(); i++) {      Book book = new Book();      Node item = items.item(i);// 获取book节点集合(单个Book实例)      NodeList properties = item.getChildNodes();// 获取子节点集合(各个属性)      for (int j = 0; j < properties.getLength(); j++) {        Node property = properties.item(j);        String nodeName = property.getNodeName();        if ("id".equals(nodeName)) {          book.setId(Integer.parseInt(property.getFirstChild().getNodeValue()));        } else if ("name".equals(nodeName)) {          book.setName(property.getFirstChild().getNodeValue());        } else if ("price".equals(nodeName)) {          book.setPrice(Float.parseFloat(property.getFirstChild().getNodeValue()));        }      }      books.add(book);    }    return books;  }  @Override  public String serialize(List<Book> books) throws Exception {    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();    DocumentBuilder builder = factory.newDocumentBuilder();    Document doc = builder.newDocument(); // 由builder创建新文档    Element rootElement = doc.createElement("books");    for (Book book : books) {      Element bookElement = doc.createElement("book");      bookElement.setAttribute("id", book.getId() + "");      Element nameElement = doc.createElement("name");      nameElement.setTextContent(book.getName());      bookElement.appendChild(nameElement);      Element priceElement = doc.createElement("price");      priceElement.setTextContent(book.getPrice() + "");      bookElement.appendChild(priceElement);      rootElement.appendChild(bookElement);    }    doc.appendChild(rootElement);    TransformerFactory transFactory = TransformerFactory.newInstance();// 取得TransformerFactory实例    Transformer transformer = transFactory.newTransformer(); // 从transFactory获取Transformer实例    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    StringWriter writer = new StringWriter();    Source source = new DOMSource(doc); // 表明文档来源是doc    Result result = new StreamResult(writer);// 表明目标结果为writer    transformer.transform(source, result); // 开始转换    return writer.toString();  }}

2 Pull解析

package com.example.xml.parser;import java.io.InputStream;import java.io.StringWriter;import java.util.ArrayList;import java.util.List;import org.xmlpull.v1.XmlPullParser;import org.xmlpull.v1.XmlSerializer;import android.util.Xml;import com.example.xml.model.Book;/** * Pull 解析 * 轻巧灵活，速度快，占用内存小 */public class PullBookParser implements BooksParser {  private List<Book> books = null;  private Book book = null;  @Override  public List<Book> parse(InputStream is) throws Exception {    XmlPullParser parser = Xml.newPullParser(); // 由android.util.Xml创建一个XmlPullParser实例    parser.setInput(is, "UTF-8"); // 设置输入流 并指明编码方式    int eventType = parser.getEventType();    while (eventType != XmlPullParser.END_DOCUMENT) {      switch (eventType) {        case XmlPullParser.START_DOCUMENT:          books = new ArrayList<Book>();          break;        case XmlPullParser.START_TAG:          if (parser.getName().equals("book")) {            book = new Book();          } else if (parser.getName().equals("id")) {            eventType = parser.next();            book.setId(Integer.parseInt(parser.getText()));          } else if (parser.getName().equals("name")) {            eventType = parser.next();            book.setName(parser.getText());          } else if (parser.getName().equals("price")) {            eventType = parser.next();            book.setPrice(Float.parseFloat(parser.getText()));          }          break;        case XmlPullParser.END_TAG:          if (parser.getName().equals("book")) {            books.add(book);            book = null;          }          break;      }      eventType = parser.next();    }    return books;  }  @Override  public String serialize(List<Book> books) throws Exception {    XmlSerializer serializer = Xml.newSerializer(); // 由android.util.Xml创建一个XmlSerializer实例    StringWriter writer = new StringWriter();    serializer.setOutput(writer); // 设置输出方向为writer    serializer.startDocument("UTF-8", true);    serializer.startTag("", "books");    for (Book book : books) {      serializer.startTag("", "book");      serializer.attribute("", "id", book.getId() + "");      serializer.startTag("", "name");      serializer.text(book.getName());      serializer.endTag("", "name");      serializer.startTag("", "price");      serializer.text(book.getPrice() + "");      serializer.endTag("", "price");      serializer.endTag("", "book");    }    serializer.endTag("", "books");    serializer.endDocument();    return writer.toString();  }}

3 SAX解析

package com.example.xml.parser;import com.example.xml.model.Book;import org.xml.sax.Attributes;import org.xml.sax.SAXException;import org.xml.sax.helpers.AttributesImpl;import org.xml.sax.helpers.DefaultHandler;import java.io.InputStream;import java.io.StringWriter;import java.util.ArrayList;import java.util.List;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.TransformerFactory;import javax.xml.transform.sax.SAXTransformerFactory;import javax.xml.transform.sax.TransformerHandler;import javax.xml.transform.stream.StreamResult;/** * SAX解析 * @author Administrator * */public class SaxBookParser implements BooksParser {  @Override  public List<Book> parse(InputStream is) throws Exception {    SAXParserFactory factory = SAXParserFactory.newInstance(); // 取得SAXParserFactory实例    SAXParser parser = factory.newSAXParser(); // 从factory获取SAXParser实例    MyHandler handler = new MyHandler(); // 实例化自定义Handler    parser.parse(is, handler); // 根据自定义Handler规则解析输入流    return handler.getBooks();  }  @Override  public String serialize(List<Book> books) throws Exception {    SAXTransformerFactory factory = (SAXTransformerFactory) TransformerFactory.newInstance();// 取得SAXTransformerFactory实例    TransformerHandler handler = factory.newTransformerHandler(); // 从factory获取TransformerHandler实例    Transformer transformer = handler.getTransformer(); // 从handler获取Transformer实例    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    StringWriter writer = new StringWriter();    Result result = new StreamResult(writer);    handler.setResult(result);    String uri = ""; // 代表命名空间的URI 当URI无值时 须置为空字符串    String localName = ""; // 命名空间的本地名称(不包含前缀) 当没有进行命名空间处理时 须置为空字符串    handler.startDocument();    handler.startElement(uri, localName, "books", null);    AttributesImpl attrs = new AttributesImpl(); // 负责存放元素的属性信息    char[] ch = null;    for (Book book : books) {      attrs.clear(); // 清空属性列表      attrs.addAttribute(uri, localName, "id", "string", String.valueOf(book.getId()));// 添加一个名为id的属性(type影响不大,这里设为string)      handler.startElement(uri, localName, "book", attrs); // 开始一个book元素 关联上面设定的id属性      handler.startElement(uri, localName, "name", null); // 开始一个name元素 没有属性      ch = String.valueOf(book.getName()).toCharArray();      handler.characters(ch, 0, ch.length); // 设置name元素的文本节点      handler.endElement(uri, localName, "name");      handler.startElement(uri, localName, "price", null);// 开始一个price元素 没有属性      ch = String.valueOf(book.getPrice()).toCharArray();      handler.characters(ch, 0, ch.length); // 设置price元素的文本节点      handler.endElement(uri, localName, "price");      handler.endElement(uri, localName, "book");    }    handler.endElement(uri, localName, "books");    handler.endDocument();    return writer.toString();  }  // 需要重写DefaultHandler的方法  private class MyHandler extends DefaultHandler {    private List<Book> books;    private Book book;    private StringBuilder builder;    // 返回解析后得到的Book对象集合    public List<Book> getBooks() {      return books;    }    @Override    public void startDocument() throws SAXException {      super.startDocument();      books = new ArrayList<Book>();      builder = new StringBuilder();    }    @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 = new Book();      }      builder.setLength(0); // 将字符长度设置为0 以便重新开始读取元素内的字符节点    }    @Override    public void characters(char[] ch, int start, int length) throws SAXException {      super.characters(ch, start, length);      builder.append(ch, start, length); // 将读取的字符数组追加到builder中    }    @Override    public void endElement(String uri, String localName, String qName) throws SAXException {      super.endElement(uri, localName, qName);      if (localName.equals("id")) {        book.setId(Integer.parseInt(builder.toString()));      } else if (localName.equals("name")) {        book.setName(builder.toString());      } else if (localName.equals("price")) {        book.setPrice(Float.parseFloat(builder.toString()));      } else if (localName.equals("book")) {        books.add(book);      }    }  }}

解析只要看第一个方法就行了。

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4 解析类的使用

1 实例化解析类

DomBookParser parser=new DomBookParser();//PullBookParser parser=new PullBookParser();//SaxBookParser parser = new SaxBookParser();

2 解析xml文件

 InputStream is = getAssets().open("books.xml");      books = parser.parse(is);      for (Book book : books) {        Log.i(TAG, book.toString());      }

5 代码地址

http://download.csdn.net/detail/cherish20151011/9509352