Heim >Backend-Entwicklung >XML/RSS-Tutorial >XML-DOM-Parsing-Fall
[Titel]: Implementieren Sie ein einfaches Konsolenprogramm basierend auf XML-Dateien, das die Ergebnisse der Schüler überprüfen, Schüler hinzufügen, Schüler löschen usw. kann.
Die XML-Datei wird im Ordner src/com/dom/exercise gespeichert. Ihr Format ist wie folgt:
<?xml version="1.0" encoding="utf-8" standalone="no"?><students> <student sid="001"> <name>小明</name> <course> <java>90</java> <oracle>90</oracle> <vb>93</vb> </course> </student> <student sid="002"> <name>小李</name> <course> <java>78</java> <oracle>86</oracle> <vb>98</vb> </course> </student> <student sid="003"> <name>小王</name> <course> <java>89</java> <oracle>83</oracle> <vb>95</vb> </course> </student></students>
Dies kann man sagen Das einfachste Programm ist, dass es auf der Grundlage von XML-Dateien implementiert ist. Daher kann SAX nicht verwendet werden, da SAX-Parsing nur XML-Dateien lesen und nicht aktualisieren kann.
1. Schreiben Sie zuerst StudentBean wie folgt:
package com.dom.exercise;public class Student { private String id = null; private String name = null; private int score_java; private int score_oracle; private int score_vb; public Student() { } public Student(String id, String name, int score_java, int score_oracle, int score_vb) { super(); this.id = id; this.name = name; this.score_java = score_java; this.score_oracle = score_oracle; this.score_vb = score_vb; } public String getId() { return id; } public void setId(String id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getScore_java() { return score_java; } public void setScore_java(int score_java) { this.score_java = score_java; } public int getScore_oracle() { return score_oracle; } public void setScore_oracle(int score_oracle) { this.score_oracle = score_oracle; } public int getScore_vb() { return score_vb; } public void setScore_vb(int score_vb) { this.score_vb = score_vb; } }
2. Schreiben Sie die kritischste StudentService-Klasse Sehr nützlich für XML-Dokumente, um verschiedene Operationen auszuführen
import java.util.ArrayList; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.transform.Transformer; 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; public class StudentService { private static Document document = null; private static String path = "src/com/dom/exercise/student.xml"; static{ try{ DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance(); DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder(); document = documentBuilder.parse(path); }catch(Exception e){ System.out.println("初始化失败..."); e.printStackTrace(); } } /** * 获取所有学生信息 * @return */ public static ArrayList<Student> readAll(){ ArrayList<Student> array = new ArrayList<Student>(); NodeList students = document.getElementsByTagName("student"); for (int i = 0; i < students.getLength(); i++) { Element node_student = (Element)students.item(i); String id = node_student.getAttribute("sid"); Node node_name = node_student.getElementsByTagName("name").item(0); String name = node_name.getTextContent(); Element node_course = (Element)node_student.getElementsByTagName("course").item(0); Node course_java = node_course.getElementsByTagName("java").item(0); Node course_oracle = node_course.getElementsByTagName("oracle").item(0); Node course_vb = node_course.getElementsByTagName("vb").item(0); int score_java = Integer.parseInt(course_java.getTextContent()); int score_oracle = Integer.parseInt(course_oracle.getTextContent()); int score_vb = Integer.parseInt(course_vb.getTextContent()); Student student = new Student(id, name, score_java, score_oracle, score_vb); array.add(student); } return array; } /** * 根据ID获取一个学生的信息 * @param sid * @return */ public static Student getStudentById(String sid){ NodeList students = document.getElementsByTagName("student"); for (int i = 0; i < students.getLength(); i++) { Element node_student = (Element)students.item(i); String id = node_student.getAttribute("sid"); if(!id.equals(sid)){ continue; } Node node_name = node_student.getElementsByTagName("name").item(0); String name = node_name.getTextContent(); Element node_course = (Element)node_student.getElementsByTagName("course").item(0); Node course_java = node_course.getElementsByTagName("java").item(0); Node course_oracle = node_course.getElementsByTagName("oracle").item(0); Node course_vb = node_course.getElementsByTagName("vb").item(0); int score_java = Integer.parseInt(course_java.getTextContent()); int score_oracle = Integer.parseInt(course_oracle.getTextContent()); int score_vb = Integer.parseInt(course_vb.getTextContent()); Student student = new Student(id, name, score_java, score_oracle, score_vb); return student; } return null; } /** * 添加学生 * @param student */ public static void addStudent(Student student){ Element stu = document.createElement("student"); stu.setAttribute("sid", student.getId()); Element name = document.createElement("name"); name.setTextContent(student.getName()); Element course = document.createElement("course"); Element score_java = document.createElement("java"); Element score_oracle = document.createElement("oracle"); Element score_vb = document.createElement("vb"); score_java.setTextContent(String.valueOf(student.getScore_java())); score_oracle.setTextContent(String.valueOf(student.getScore_oracle())); score_vb.setTextContent(String.valueOf(student.getScore_vb())); course.appendChild(score_java); course.appendChild(score_oracle); course.appendChild(score_vb); stu.appendChild(name); stu.appendChild(course); document.getDocumentElement().appendChild(stu); update(document, path); } /** * 根据ID删除一个学生 * @param sid */ public static void deleteStudentById(String sid){ NodeList students = document.getElementsByTagName("student"); for (int i = 0; i < students.getLength(); i++) { Element student = (Element)students.item(i); if(student.getAttribute("sid").equals(sid)){ student.getParentNode().removeChild(student); } } update(document,path); } /** * 更新到文件 * @param document * @param path */ public static void update(Document document,String path){ try{ TransformerFactory transformerFactory = TransformerFactory.newInstance(); Transformer transformer = transformerFactory.newTransformer(); transformer.transform(new DOMSource(document), new StreamResult(new File(path))); }catch(Exception e){ e.printStackTrace(); } } }
3. Schreiben Sie das Haupttestprogramm
, um eine einfache Schnittstelle zu implementieren:
package com.dom.exercise; import java.util.ArrayList; import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); boolean flag = true; while(flag){ // 显示操作界面 System.console(); System.out.println("*********************操作界面*********************"); System.out.println("\t\t1.查询所有学生的成绩"); System.out.println("\t\t2.按照ID查询学生成绩 "); System.out.println("\t\t3.添加一个学生"); System.out.println("\t\t4.按照ID删除一个学生"); System.out.println("\t\t0.退出系统"); System.out.println("************************************************"); // 获取用户的操作 String operate = scanner.next(); if ("1".equals(operate)) { ArrayList<Student> students = StudentService.readAll(); System.out.println("所有的学生信息如下:"); System.out.println("Name\tID\tJava\tOracle\tVB"); for (Student student : students) { System.out.println(student.getName() + "\t" + student.getId() + "\t" + student.getScore_java() + "\t" + student.getScore_oracle() + "\t" + student.getScore_vb()); } }else if("2".equals(operate)){ System.out.println("请输入要查询的学生ID:"); String sid = scanner.next(); Student student = StudentService.getStudentById(sid); System.out.println("学号为"+sid+"的学生的信息如下:"); System.out.println("Name\tID\tJava\tOracle\tVB"); System.out.println(student.getName() + "\t" + student.getId() + "\t" + student.getScore_java() + "\t" + student.getScore_oracle() + "\t" + student.getScore_vb()); }else if("3".equals(operate)){ System.out.println("请输入要添加的学生ID:"); String sid = scanner.next(); System.out.println("请输入要添加的学生姓名:"); String name = scanner.next(); System.out.println("请输入要添加的学生Java成绩:"); int score_java = Integer.parseInt(scanner.next()); System.out.println("请输入要添加的学生Oracle成绩:"); int score_oracle = Integer.parseInt(scanner.next()); System.out.println("请输入要添加的学生VB成绩:"); int score_vb = Integer.parseInt(scanner.next()); Student student = new Student(sid, name, score_java, score_oracle, score_vb); StudentService.addStudent(student); System.out.println("添加成功!"); }else if("4".equals(operate)){ System.out.println("请输入要删除的学生的ID:"); String sid = scanner.next(); StudentService.deleteStudentById(sid); System.out.println("删除成功!"); } System.out.println("是否继续?(Y/N)"); flag = scanner.next().trim().toLowerCase().equals("y")?true:false; } scanner.close(); } }
4. Ergebnisse ausführen
Der Schlüssel zum Problem liegt immer noch in der DOM-Analyse von XML und der Durchführung grober Operationen auf XML.
[Titel]: Implementieren Sie ein einfaches Konsolenprogramm basierend auf XML-Dateien, das Schülerergebnisse überprüfen, Schüler hinzufügen, Schüler löschen usw. kann.
Die XML-Datei wird im Ordner src/com/dom/exercise gespeichert. Ihr Format ist wie folgt:
<?xml version="1.0" encoding="utf-8" standalone="no"?><students> <student sid="001"> <name>小明</name> <course> <java>90</java> <oracle>90</oracle> <vb>93</vb> </course> </student> <student sid="002"> <name>小李</name> <course> <java>78</java> <oracle>86</oracle> <vb>98</vb> </course> </student> <student sid="003"> <name>小王</name> <course> <java>89</java> <oracle>83</oracle> <vb>95</vb> </course> </student></students>
Dies kann als das einfachste Programm bezeichnet werden. Der entscheidende Punkt ist, dass es auf der Grundlage von XML-Dateien implementiert werden muss. Daher kann SAX nicht verwendet werden, da SAX-Parsing nur XML-Dateien lesen und nicht aktualisieren kann.
1. Schreiben Sie zuerst StudentBean wie folgt:
package com.dom.exercise;public class Student { private String id = null; private String name = null; private int score_java; private int score_oracle; private int score_vb; public Student() { } public Student(String id, String name, int score_java, int score_oracle, int score_vb) { super(); this.id = id; this.name = name; this.score_java = score_java; this.score_oracle = score_oracle; this.score_vb = score_vb; } public String getId() { return id; } public void setId(String id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getScore_java() { return score_java; } public void setScore_java(int score_java) { this.score_java = score_java; } public int getScore_oracle() { return score_oracle; } public void setScore_oracle(int score_oracle) { this.score_oracle = score_oracle; } public int getScore_vb() { return score_vb; } public void setScore_vb(int score_vb) { this.score_vb = score_vb; } }
2. Schreiben Sie die kritischste StudentService-Klasse Sehr nützlich für XML-Dokumente, um verschiedene Operationen auszuführen
import java.util.ArrayList; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.transform.Transformer; 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; public class StudentService { private static Document document = null; private static String path = "src/com/dom/exercise/student.xml"; static{ try{ DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance(); DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder(); document = documentBuilder.parse(path); }catch(Exception e){ System.out.println("初始化失败..."); e.printStackTrace(); } } /** * 获取所有学生信息 * @return */ public static ArrayList<Student> readAll(){ ArrayList<Student> array = new ArrayList<Student>(); NodeList students = document.getElementsByTagName("student"); for (int i = 0; i < students.getLength(); i++) { Element node_student = (Element)students.item(i); String id = node_student.getAttribute("sid"); Node node_name = node_student.getElementsByTagName("name").item(0); String name = node_name.getTextContent(); Element node_course = (Element)node_student.getElementsByTagName("course").item(0); Node course_java = node_course.getElementsByTagName("java").item(0); Node course_oracle = node_course.getElementsByTagName("oracle").item(0); Node course_vb = node_course.getElementsByTagName("vb").item(0); int score_java = Integer.parseInt(course_java.getTextContent()); int score_oracle = Integer.parseInt(course_oracle.getTextContent()); int score_vb = Integer.parseInt(course_vb.getTextContent()); Student student = new Student(id, name, score_java, score_oracle, score_vb); array.add(student); } return array; } /** * 根据ID获取一个学生的信息 * @param sid * @return */ public static Student getStudentById(String sid){ NodeList students = document.getElementsByTagName("student"); for (int i = 0; i < students.getLength(); i++) { Element node_student = (Element)students.item(i); String id = node_student.getAttribute("sid"); if(!id.equals(sid)){ continue; } Node node_name = node_student.getElementsByTagName("name").item(0); String name = node_name.getTextContent(); Element node_course = (Element)node_student.getElementsByTagName("course").item(0); Node course_java = node_course.getElementsByTagName("java").item(0); Node course_oracle = node_course.getElementsByTagName("oracle").item(0); Node course_vb = node_course.getElementsByTagName("vb").item(0); int score_java = Integer.parseInt(course_java.getTextContent()); int score_oracle = Integer.parseInt(course_oracle.getTextContent()); int score_vb = Integer.parseInt(course_vb.getTextContent()); Student student = new Student(id, name, score_java, score_oracle, score_vb); return student; } return null; } /** * 添加学生 * @param student */ public static void addStudent(Student student){ Element stu = document.createElement("student"); stu.setAttribute("sid", student.getId()); Element name = document.createElement("name"); name.setTextContent(student.getName()); Element course = document.createElement("course"); Element score_java = document.createElement("java"); Element score_oracle = document.createElement("oracle"); Element score_vb = document.createElement("vb"); score_java.setTextContent(String.valueOf(student.getScore_java())); score_oracle.setTextContent(String.valueOf(student.getScore_oracle())); score_vb.setTextContent(String.valueOf(student.getScore_vb())); course.appendChild(score_java); course.appendChild(score_oracle); course.appendChild(score_vb); stu.appendChild(name); stu.appendChild(course); document.getDocumentElement().appendChild(stu); update(document, path); } /** * 根据ID删除一个学生 * @param sid */ public static void deleteStudentById(String sid){ NodeList students = document.getElementsByTagName("student"); for (int i = 0; i < students.getLength(); i++) { Element student = (Element)students.item(i); if(student.getAttribute("sid").equals(sid)){ student.getParentNode().removeChild(student); } } update(document,path); } /** * 更新到文件 * @param document * @param path */ public static void update(Document document,String path){ try{ TransformerFactory transformerFactory = TransformerFactory.newInstance(); Transformer transformer = transformerFactory.newTransformer(); transformer.transform(new DOMSource(document), new StreamResult(new File(path))); }catch(Exception e){ e.printStackTrace(); } } }
3. Schreiben Sie das Haupttestprogramm
, um eine einfache Schnittstelle zu implementieren:
package com.dom.exercise;import java.util.ArrayList;import java.util.Scanner;public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); boolean flag = true; while(flag){ // 显示操作界面 System.console(); System.out.println("*********************操作界面*********************"); System.out.println("\t\t1.查询所有学生的成绩"); System.out.println("\t\t2.按照ID查询学生成绩 "); System.out.println("\t\t3.添加一个学生"); System.out.println("\t\t4.按照ID删除一个学生"); System.out.println("\t\t0.退出系统"); System.out.println("************************************************"); // 获取用户的操作 String operate = scanner.next(); if ("1".equals(operate)) { ArrayList<Student> students = StudentService.readAll(); System.out.println("所有的学生信息如下:"); System.out.println("Name\tID\tJava\tOracle\tVB"); for (Student student : students) { System.out.println(student.getName() + "\t" + student.getId() + "\t" + student.getScore_java() + "\t" + student.getScore_oracle() + "\t" + student.getScore_vb()); } }else if("2".equals(operate)){ System.out.println("请输入要查询的学生ID:"); String sid = scanner.next(); Student student = StudentService.getStudentById(sid); System.out.println("学号为"+sid+"的学生的信息如下:"); System.out.println("Name\tID\tJava\tOracle\tVB"); System.out.println(student.getName() + "\t" + student.getId() + "\t" + student.getScore_java() + "\t" + student.getScore_oracle() + "\t" + student.getScore_vb()); }else if("3".equals(operate)){ System.out.println("请输入要添加的学生ID:"); String sid = scanner.next(); System.out.println("请输入要添加的学生姓名:"); String name = scanner.next(); System.out.println("请输入要添加的学生Java成绩:"); int score_java = Integer.parseInt(scanner.next()); System.out.println("请输入要添加的学生Oracle成绩:"); int score_oracle = Integer.parseInt(scanner.next()); System.out.println("请输入要添加的学生VB成绩:"); int score_vb = Integer.parseInt(scanner.next()); Student student = new Student(sid, name, score_java, score_oracle, score_vb); StudentService.addStudent(student); System.out.println("添加成功!"); }else if("4".equals(operate)){ System.out.println("请输入要删除的学生的ID:"); String sid = scanner.next(); StudentService.deleteStudentById(sid); System.out.println("删除成功!"); } System.out.println("是否继续?(Y/N)"); flag = scanner.next().trim().toLowerCase().equals("y")?true:false; } scanner.close(); } }
4. Ergebnisse ausführen
Der Schlüssel zum Problem liegt immer noch in der DOM-Analyse von XML und der Durchführung grober Operationen auf XML.
Das Obige ist der Inhalt des XML-DOM-Analysefalls. Weitere verwandte Inhalte finden Sie auf der chinesischen PHP-Website (www.php.cn)!