建立XML（2/4）--通過SAX方式
阿新 • • 發佈：2018-12-05
注：生成如下內容XML
<?xml version="1.0" encoding="UTF-8"?> <bookStore> <book id="1"> <name>冰與火之歌</name> <author>喬治馬丁</author> <year>2014</year> <price>88</price> </book> <book id="2"> <name>安徒生童話</name> <author>丹麥</author> <year>2004</year> <price>66</price> </book> <book id="3"> <name>java開發</name> <author>美國</author> <year>2000</year> <price>99</price> </book> </bookStore>
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一、準備工作
建立工廠物件 + 設定XML文件格式 + 建立Result物件-
二、生成子節點+節點屬性
//開始新增節點 handler.startElement("", "", "bookStore", attr); //新增子節點bookStores-book以及屬性值 attr.addAttribute("", "", "id", "", "1"); handler.startElement("", "", "book", attr); //結束子節點bookStores-book handler.endElement("", "", "book");
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三、生成帶文字的子節點
//這裡建立的屬性以及值都是從books.xml中獲取到的 if (book.getName() != null && !book.getName().trim().equals("")) { attr.clear(); handler.startElement("", "", "name", attr); //新增name的文字值 handler.characters(book.getName().toCharArray(), 0, book.getName().length()); //結束子節點bookStores-book-name handler.endElement("", "", "name"); }
- 程式碼1、SAXTest.java （建立+解析XML）
package com.test.saxtest; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.util.ArrayList; 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.sax.SAXTransformerFactory; import javax.xml.transform.sax.TransformerHandler; import javax.xml.transform.stream.StreamResult; import org.xml.sax.SAXException; import org.xml.sax.helpers.AttributesImpl; import com.cisau.entity.Book; import com.cisau.handler.SAXParserHandler; public class SAXTest { public static void main(String[] args) { SAXTest saxTest = new SAXTest(); saxTest.createXML(); } /** * 解析XML */ public ArrayList<Book> parseXML() { //1、建立SAXParserFactory物件 SAXParserFactory saxpf = SAXParserFactory.newInstance(); SAXParserHandler saxParserHandler = null; try { //2、通過SAXParserFactory建立SAXParser的例項 SAXParser parser = saxpf.newSAXParser(); //3、建立SAXParserHandler物件 saxParserHandler = new SAXParserHandler(); parser.parse("books.xml", saxParserHandler); //new-start System.out.println("%%%%%%%%%%%共有" + saxParserHandler.getBookList().size() + "本書"); for (Book book : saxParserHandler.getBookList()) { System.out.println(book.getId()); System.out.println(book.getName()); System.out.println(book.getAuthor()); System.out.println(book.getYear()); System.out.println(book.getPrice()); System.out.println("---------finish -------------"); } //new-over }catch (IOException e) { e.printStackTrace(); } catch (ParserConfigurationException e) { e.printStackTrace(); } catch (SAXException e) { e.printStackTrace(); } return saxParserHandler.getBookList(); }//parseXML() /** * 建立XML */ public void createXML() { ArrayList<Book> bookList = parseXML(); //1、建立TransformerFactory物件 SAXTransformerFactory factory = (SAXTransformerFactory) SAXTransformerFactory.newInstance(); try { //2、通過SAXTransformerFactory物件建立一個TransformerHandler物件 TransformerHandler handler = factory.newTransformerHandler(); //3、通過TransformerHandler物件建立一個Transformer Transformer transformer = handler.getTransformer(); //4、通過Transformer物件對生成的XML檔案格式進行設定 //設定編碼格式 transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8"); //設定XML"是否換行" transformer.setOutputProperty(OutputKeys.INDENT, "yes"); //5、建立一個Result物件 File file = new File("src/res/newbooks.xml"); if (!file.exists()) { file.createNewFile(); } //6、建立Result物件，並且使其與handler關聯 Result result = new StreamResult(new FileOutputStream(file)); handler.setResult(result); //7、通過handler進行XML檔案的寫入 //開啟文件 handler.startDocument(); AttributesImpl attr = new AttributesImpl(); //開始新增節點 handler.startElement("", "", "bookStore", attr); /*//新增子節點bookStores-book attr.clear(); attr.addAttribute("", "", "id", "", "1"); handler.startElement("", "", "book", attr); //結束子節點bookStores-book handler.endElement("", "", "book");*/ for (Book book : bookList) { //新增子節點bookStores-book以及他的屬性 attr.clear(); attr.addAttribute("", "", "id", "", book.getId()); handler.startElement("", "", "book", attr); //<1>新增子節點bookStores-book-name //這裡建立的屬性以及值都是從books.xml中獲取到的 if (book.getName() != null && !book.getName().trim().equals("")) { attr.clear(); handler.startElement("", "", "name", attr); //新增name的文字值 handler.characters(book.getName().toCharArray(), 0, book.getName().length()); //結束子節點bookStores-book-name handler.endElement("", "", "name"); } //<2>新增子節點bookStores-book-author if (book.getAuthor() != null && !book.getAuthor().trim().equals("")) { attr.clear(); handler.startElement("", "", "author", attr); //新增author的文字值 handler.characters(book.getAuthor().toCharArray(), 0, book.getAuthor().length()); //結束子節點bookStores-book-author handler.endElement("", "", "author"); } //<3>新增子節點bookStores-book-year if (book.getYear() != null && !book.getYear().trim().equals("")) { attr.clear(); handler.startElement("", "", "year", attr); //新增year的文字值 handler.characters(book.getYear().toCharArray(), 0, book.getYear().length()); //結束子節點bookStores-book-year handler.endElement("", "", "year"); } //<4>新增子節點bookStores-book-price if (book.getPrice() != null && !book.getPrice().trim().equals("")) { attr.clear(); handler.startElement("", "", "price", attr); //新增price的文字值 handler.characters(book.getPrice().toCharArray(), 0, book.getPrice().length()); //結束子節點bookStores-book-price handler.endElement("", "", "price"); } //結束子節點bookStores-book handler.endElement("", "", "book"); } //結束新增節點 handler.endElement("", "", "bookStore"); //結束文件 handler.endDocument(); System.out.println("生成完畢..."); } catch (TransformerConfigurationException e) { e.printStackTrace(); }catch (FileNotFoundException e) { e.printStackTrace(); }catch (IOException e) { e.printStackTrace(); }catch (SAXException e) { e.printStackTrace(); } } } - SAXParserHandler.java
package com.cisau.handler; import java.util.ArrayList; import org.xml.sax.Attributes; import org.xml.sax.SAXException; import org.xml.sax.helpers.DefaultHandler; import com.cisau.entity.Book; public class SAXParserHandler extends DefaultHandler { int bookIndex = 0; String value = null; Book book = null; private ArrayList<Book> bookList = new ArrayList<Book>(); public ArrayList<Book> getBookList() { return bookList; } //****************************************************************************************** /** * 遍歷XML檔案的--開始--標籤 * 解析XML元素 */ @Override public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException { //呼叫DefaultHandler的startElement方法 super.startElement(uri, localName, qName, attributes); if (qName.equals("book")) { //建立一個bookd物件 book = new Book(); bookIndex ++ ; System.out.println("=============開始遍歷" + bookIndex + "本書的內容============"); //已知book標籤中只有一個ID屬性，根據屬性名獲取屬性值 /* String value = attributes.getValue("id"); System.out.println("book標籤中的屬性值是：" + value);*/ //不知道book標籤中的屬性名和個數 int length = attributes.getLength(); for (int i = 0; i < length; i++) { System.out.print("book元素的第" + (i+1) + "個屬性名是：" + attributes.getQName(i)); System.out.println("-----屬性值是：" + attributes.getValue(i)); if (attributes.getQName(i).equals("id")) { book.setId(attributes.getValue(i)); } } } else if(!qName.equals("bookstore")){ System.out.print("節點名是：" + qName + "--------"); } } /** * 遍歷XML檔案的--結束--標籤 */ @Override public void endElement(String uri, String localName, String qName) throws SAXException { //呼叫DefaultHandler的startElement方法 super.endElement(uri, localName, qName); if (qName.equals("book")) { bookList.add(book); book = null; System.out.println("=============結束遍歷" + bookIndex + "本書的內容============"); }else if (qName.equals("name")) { book.setName(value); }else if (qName.equals("author")) { book.setAuthor(value); }else if (qName.equals("year")) { book.setYear(value); }else if (qName.equals("price")) { book.setPrice(value); } } //***************************************標識開始解析*************************************************** /** * 標識XML解析--開始 */ @Override public void startDocument() throws SAXException { super.startDocument(); System.out.println("解析:開始--"); } /** * 標識XML解析--結束 */ @Override public void endDocument() throws SAXException { super.endDocument(); System.out.println("解析:--結束"); } //****************************************開始獲取節點資訊************************************************** /** * 獲取整個文件中的所有內容---解析節點名+節點間文字 */ @Override public void characters(char[] ch, int start, int length) throws SAXException { super.characters(ch, start, length); value = new String(ch, start, length); if (!value.trim().equals("")) { System.out.println("節點值是：" + value); } } } - Book.java
package com.cisau.entity; public class Book { private String id; private String name; private String author; private String year; private String price; private String language; ---------------------------------------- get()+set()方法 } -
books.xml
<?xml version="1.0" encoding="UTF-8"?> <bookstore> <book id="1"> <name>冰與火之歌</name> <author>喬治馬丁</author> <year>2014</year> <price>88</price> </book> <book id ="2"> <name>安徒生童話</name> <author>丹麥</author> <year>2004</year> <price>66</price> </book> <book id="3"> <name>java開發</name> <author>美國</author> <year>2000</year> <price>99</price> </book> </bookstore>