Thực hành sử dụng XML trong Java Lab 1

Processing XML Using Java Lab 01 Introduction to JAXP Simple API for XML (SAX) Mục tiêu - Sử dụng SAX duyệt file XML - Cách cài đặt Parser (SAXParserFactory, SAXParser) -Sử dụng Parsing Content cách kế thừa ContentHandler, DefaultHandler -Sử dụng XMLReader để đăng ký phân tích file XML -Sử dụng ErrorHandler -Sử dụng FilterHandler Phần I Bài tập step by step Bài 1.1 Phân tích file Employees.xml SAX:  Input:  Employees.xml IT Research Department @BKAP 2015 Trang / 24 Architecting Applications for the Web  Output: In hình theo SAX Parser Step 1: Tạo project java netbean  File  New Project  Java  Java Application  Project Name: Đặt tên project INTXML  Sau tạo ta Project có cấu trúc sau: Step 2: Tạo file Employees.xml  Project  New XML  XML Document IT Research Department @BKAP 2015 Trang / 24 Processing XML Using Java IT Research Department @BKAP 2015 Trang / 24 Architecting Applications for the Web  File Employees.xml sau tạo thành  Tạo nội dung cho Employees.xml Allen Smith Alaska John Davis IT Research Department @BKAP 2015 Trang / 24 Processing XML Using Java California Bob Thomson Kansas Step 3: Tạo lớp xử lý nội dung XML – Content Handler  Intxml  New  Java  Java Class  SaxHandler.java /* * To change this license header, choose License Headers in Project Properties * To change this template file, choose Tools | Templates * and open the template in the editor */ package intxml; IT Research Department @BKAP 2015 Trang / 24 Architecting Applications for the Web import org.xml.sax.Attributes; import org.xml.sax.ContentHandler; import org.xml.sax.Locator; import org.xml.sax.SAXException; /** * * @author DELL */ public class SaxHandler implements ContentHandler{ //Các cờ đánh dấu in characters boolean foundfirstname; boolean foundlastname; boolean foundlocation; //Start Document @Override public void startDocument() throws SAXException { System.out.println("Start document"); } //End Document @Override public void endDocument() throws SAXException { System.out.println("End document"); } //Start Element @Override public void startElement(String uri, String name, String qname, Attributes attributes) throws SAXException { System.out.println("Start element: "+qname); //In attributes element employee if (qname.equals("employee")) { int atts = attributes.getLength(); for (int i = 0; i < atts; i++) { String atrName = attributes.getQName(i); String atrValue = attributes.getValue(i); System.out.println("Attributes: "+atrName+" "+atrValue); } } //Dựng cờ element cần in if (qname.equals("firstname")) { foundfirstname = true; IT Research Department @BKAP 2015 Trang / 24 Processing XML Using Java } if (qname.equals("lastname")) { foundlastname = true; } if (qname.equals("location")) { foundlocation = true; } } //End Element @Override public void endElement(String uri, String name, String qname) throws SAXException { System.out.println("End element: "+qname); } //In Characters với cờ dựng @Override public void characters(char ch[], int start, int length) throws SAXException { if (foundfirstname) { System.out.println("Characters: "+new String(ch,start,length)); foundfirstname=false; } if (foundlastname) { System.out.println("Characters: "+new String(ch,start,length)); foundlastname=false; } if (foundlocation) { System.out.println("Characters: "+new String(ch,start,length)); foundlocation=false; } } @Override public void setDocumentLocator(Locator locator) { } @Override public void startPrefixMapping(String prefix, String uri) throws SAXException { IT Research Department @BKAP 2015 Trang / 24 Architecting Applications for the Web } @Override public void endPrefixMapping(String prefix) throws SAXException { } @Override public void ignorableWhitespace(char[] ch, int start, int length) throws SAXException { } @Override public void processingInstruction(String target, String data) throws SAXException { } @Override public void skippedEntity(String name) throws SAXException { } } Lưu ý:  implements ContentHandler phải implement tất abstract methods  extends DefaultHandler dùng methods cần sử dụng Step 4: Triển khai hàm main chương trình  INTXML.java /* * To change this license header, choose License Headers in Project Properties * To change this template file, choose Tools | Templates * and open the template in the editor */ package intxml; IT Research Department @BKAP 2015 Trang / 24 Processing XML Using Java import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.xml.sax.InputSource; import org.xml.sax.XMLReader; /** * * @author DELL */ public class INTXML { /** * @param args the command line arguments */ public static void main(String[] args) { try { //Tạo SaxHandler xử lý nội dung SaxHandler sax = new SaxHandler(); //Tạo SAX ParserFactory SAXParserFactory parserFactory = SAXParserFactory.newInstance(); //Tạo SAX Parser Factory khai báo SAXParser parser = parserFactory.newSAXParser(); //Khai báo XML Reader dựa SAXParser object XMLReader xmlReader = parser.getXMLReader(); //Xác định đối tượng chịu trách nhiệm xử lý nội dung XML xmlReader.setContentHandler(sax); //Tiến hành phân tích liệu nguồn cung cấp file XML xmlReader.parse(new InputSource("Employees.xml")); } catch (Exception e) { e.printStackTrace(); } } }  Project sau hoàn thành IT Research Department @BKAP 2015 Trang / 24 Architecting Applications for the Web Step 5: Build Run ứng dụng Bài 1.2 Phát triển tiếp 1.1  Sử dụng XML locator để vị trí current parser phân tích  Sử dụng Instruc tions để đọc thị chương trình khác có định dạng:  Thông báo lỗi file XML sai cấu trúc Step 1: Sử dụng XML locator để vị trí current parser  SaxHandler.java IT Research Department @BKAP 2015 Trang 10 / 24 Processing XML Using Java /* * To change this license header, choose License Headers in Project Properties * To change this template file, choose Tools | Templates * and open the template in the editor */ package intxml; import org.xml.sax.Attributes; import org.xml.sax.ContentHandler; import org.xml.sax.Locator; import org.xml.sax.SAXException; /** * * @author DELL */ public class SaxHandler implements ContentHandler{ //Khai báo biến locator private Locator locator; //Các cờ đánh dấu in characters boolean foundfirstname; boolean foundlastname; boolean foundlocation; //Start Document @Override public void startDocument() throws SAXException { System.out.println("Start document"); } //End Document @Override public void endDocument() throws SAXException { System.out.println("End document"); } //Start Element @Override public void startElement(String uri, String name, String qname, Attributes attributes) throws SAXException { System.out.println("Start element: "+qname); //In location cua element dang duyet if (locator!=null) { IT Research Department @BKAP 2015 Trang 11 / 24 Architecting Applications for the Web System.out.println("LOCATOR XML-document name: "+locator.getSystemId()+", column"+locator.getColumnNumber()+", line"+locator.getLineNumber()); } //In attributes element employee if (qname.equals("employee")) { int atts = attributes.getLength(); for (int i = 0; i < atts; i++) { String atrName = attributes.getQName(i); String atrValue = attributes.getValue(i); System.out.println("Attributes: "+atrName+" "+atrValue); } } //Dựng cờ element cần in if (qname.equals("firstname")) { foundfirstname = true; } if (qname.equals("lastname")) { foundlastname = true; } if (qname.equals("location")) { foundlocation = true; } } //End Element @Override public void endElement(String uri, String name, String qname) throws SAXException { System.out.println("End element: "+qname); } //In Characters với cờ dựng @Override public void characters(char ch[], int start, int length) throws SAXException { if (foundfirstname) { System.out.println("Characters: "+new String(ch,start,length)); foundfirstname=false; } if (foundlastname) { System.out.println("Characters: "+new String(ch,start,length)); IT Research Department @BKAP 2015 Trang 12 / 24 Processing XML Using Java foundlastname=false; } if (foundlocation) { System.out.println("Characters: "+new String(ch,start,length)); foundlocation=false; } } @Override public void setDocumentLocator(Locator locator) { this.locator = locator; } @Override public void startPrefixMapping(String prefix, String uri) throws SAXException { } @Override public void endPrefixMapping(String prefix) throws SAXException { } @Override public void ignorableWhitespace(char[] ch, int start, int length) throws SAXException { } @Override public void processingInstruction(String target, String data) throws SAXException { } @Override public void skippedEntity(String name) throws SAXException { } IT Research Department @BKAP 2015 Trang 13 / 24 Architecting Applications for the Web }  Build Run ứng dụng Step 2: Sử dụng Instruc tions để đọc thị chương trình khác có định dạng:  Employees.xml Allen Smith Alaska IT Research Department @BKAP 2015 Trang 14 / 24 Processing XML Using Java John Davis California Bob Thomson Kansas  SaxHandler.java … @Override public void processingInstruction(String target, String data) throws SAXException { System.out.println("processingInstruction - target: "+target+", data: "+data); } …  Build Run ứng dụng IT Research Department @BKAP 2015 Trang 15 / 24 Architecting Applications for the Web Step 3: Thông báo lỗi file XML sai cấu trúc  Tạo lớp ErrorHandler.java để xử lý lỗi sai cấu trúc IntxmlnewOtherJavaJava Classđặt tên ErrorHandler /* * To change this license header, choose License Headers in Project Properties * To change this template file, choose Tools | Templates * and open the template in the editor */ package intxml; import org.xml.sax.SAXException; import org.xml.sax.SAXParseException; /** * * @author DELL */ public class ErrorHandler implements org.xml.sax.ErrorHandler{ @Override public void warning(SAXParseException exception) throws SAXException { showError("Warning", exception); } @Override public void error(SAXParseException exception) throws SAXException { showError("Error", exception); } @Override public void fatalError(SAXParseException exception) throws SAXException { showError("FatalError", exception); } private void showError(String errorType, SAXParseException e) { System.out.println(errorType + ": "+e.getMessage()); System.out.println("Line number: "+e.getLineNumber()+ " - Column: " + e.getColumnNumber()); } IT Research Department @BKAP 2015 Trang 16 / 24 Processing XML Using Java }  Khai báo hàm Main INTXML.java /* * To change this license header, choose License Headers in Project Properties * To change this template file, choose Tools | Templates * and open the template in the editor */ package intxml; import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.xml.sax.InputSource; import org.xml.sax.XMLReader; /** * * @author DELL */ public class INTXML { /** * @param args the command line arguments */ public static void main(String[] args) { try { //Tạo SaxHandler xử lý nội dung SaxHandler sax = new SaxHandler(); //Tạo ErrorHandler thông báo lỗi ErrorHandler err = new ErrorHandler(); //Tạo SAX ParserFactory SAXParserFactory parserFactory = SAXParserFactory.newInstance(); //Tạo SAX Parser Factory khai báo SAXParser parser = parserFactory.newSAXParser(); //Khai báo XML Reader dựa SAXParser object XMLReader xmlReader = parser.getXMLReader(); //Xác định đối tượng chịu trách nhiệm xử lý lỗi phân tích XML xmlReader.setErrorHandler(err); //Xác định đối tượng chịu trách nhiệm xử lý nội dung XML IT Research Department @BKAP 2015 Trang 17 / 24 Architecting Applications for the Web xmlReader.setContentHandler(sax); //Tiến hành phân tích liệu nguồn cung cấp file XML xmlReader.parse(new InputSource("Employees.xml")); } catch (Exception e) { e.printStackTrace(); } } }  Sửa cấu trúc file Employees.xml thành file sai cấu trúc Allen Smith Alaska John Davis California Bob Thomson Kansas  Build and Run ứng dụng IT Research Department @BKAP 2015 Trang 18 / 24 Processing XML Using Java Bài 1.3 Xây dựng ứng dụng SAX:  Duyệt file Personnels.xml  Xây dựng lớp Filter kế thừa interface XMLFilterImpl để thay đổi attributes status = “donotcontact” element có deptid Step 1: Duyệt file Personnels.xml (làm theo step 1.1)  SaxHandler.java kế thừa DefaultHandler package saxfilter; import org.xml.sax.Attributes; import org.xml.sax.SAXException; import org.xml.sax.helpers.DefaultHandler; /** * * @author DELL */ IT Research Department @BKAP 2015 Trang 19 / 24 Architecting Applications for the Web public class SAXHandler extends DefaultHandler { @Override public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException { if (qName.equals("employee")) { if (attributes.getValue("status").equals("contact")) { System.out.println("Contacting employee " + attributes.getValue("empid")); } } } }  Hàm main lớp SAXFilter.java package saxfilter; import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.xml.sax.InputSource; import org.xml.sax.XMLReader; /** * * @author DELL */ public class SAXFilter { /** * @param args the command line arguments */ public static void main(String[] args) { try { SAXHandler sax = new SAXHandler(); SAXParserFactory parserFactory = SAXParserFactory.newInstance(); SAXParser parser = parserFactory.newSAXParser(); XMLReader xmlReader = parser.getXMLReader(); xmlReader.setContentHandler(sax); xmlReader.parse(new InputSource("Personnels.xml")); IT Research Department @BKAP 2015 Trang 20 / 24 Processing XML Using Java } catch (Exception e) { e.printStackTrace(); } } }  Build and Run ứng dụng Step 2: Xây dựng lớp Filter  Tạo lớp DataFilter.java kế thừa XMLFilterImpl package saxfilter; import org.xml.sax.Attributes; import org.xml.sax.SAXException; import org.xml.sax.helpers.AttributesImpl; import org.xml.sax.helpers.XMLFilterImpl; /** * * @author DELL */ public class DataFilter extends XMLFilterImpl { @Override public void startElement(String uri, String name, String qName, Attributes atts) throws SAXException { AttributesImpl attsImpl = new AttributesImpl(atts); if (qName.equals("employee")) { if (atts.getValue("deptid").equals("3")) { attsImpl.setValue(3, "donotcontact"); } } super.startElement(uri, qName, qName, attsImpl); } IT Research Department @BKAP 2015 Trang 21 / 24 Architecting Applications for the Web }  Sửa hàm main cho phép duyệt nội dung qua lớp DataFilter.java SAXFilter.java package saxfilter; import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.xml.sax.InputSource; import org.xml.sax.XMLReader; /** * * @author DELL */ public class SAXFilter { /** * @param args the command line arguments */ public static void main(String[] args) { try { SAXHandler sax = new SAXHandler(); SAXParserFactory parserFactory = SAXParserFactory.newInstance(); SAXParser parser = parserFactory.newSAXParser(); XMLReader xmlReader = parser.getXMLReader(); DataFilter filter = new DataFilter(); filter.setParent(xmlReader); filter.setContentHandler(sax); filter.parse(new InputSource("Personnels.xml")); // // xmlReader.setContentHandler(sax); xmlReader.parse(new InputSource("Personnels.xml")); } catch (Exception e) { e.printStackTrace(); } } } IT Research Department @BKAP 2015 Trang 22 / 24 Processing XML Using Java  Build and Run ứng dụng PHẦN 2: BÀI TẬP TỰ LÀM Viết chương trình sử dụng SAX để phân tích cấu trúc XML có dạng sau: In hình:  Nội dung file xml  Đầy đủ nội dung file xml với cấu trúc file theo SAX  Sử dụng kế thừa theo ContentHandler DefaultHandler  Vị trí element in IT Research Department @BKAP 2015 Trang 23 / 24 Architecting Applications for the Web  Validate thông báo lỗi có lỗi cấu trúc XML  Filter in hàng hóa có giá bán từ 400USD đến 600USD IT Research Department @BKAP 2015 Trang 24 / 24 ... SaxHandler(); //Tạo SAX ParserFactory SAXParserFactory parserFactory = SAXParserFactory.newInstance(); //Tạo SAX Parser Factory khai báo SAXParser parser = parserFactory.newSAXParser(); //Khai báo... ErrorHandler(); //Tạo SAX ParserFactory SAXParserFactory parserFactory = SAXParserFactory.newInstance(); //Tạo SAX Parser Factory khai báo SAXParser parser = parserFactory.newSAXParser(); //Khai báo... String(ch,start,length)); foundlocation=false; } } @Override public void setDocumentLocator(Locator locator) { this.locator = locator; } @Override public void startPrefixMapping(String prefix, String uri)