Cas d'analyse XML-DOM

[Titre] : Implémentez un programme console simple basé sur des fichiers XML, qui peut vérifier les scores des étudiants, ajouter des étudiants, supprimer des étudiants, etc.

Le fichier xml est enregistré dans le dossier src/com/dom/exercise :

<?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>

On peut dire que c'est le. programme le plus simple. , la chose légèrement plus compliquée est qu'il est implémenté sur la base de fichiers XML, donc l'analyse DOM doit être utilisée ici. SAX ne peut pas être utilisé car l'analyse SAX ne peut lire que les fichiers XML et ne peut pas les mettre à jour.

---

1. Écrivez d'abord StudentBean, comme suit :

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. Écrivez la classe StudentService la plus critique, qui est. très utile pour les documents XML pour diverses opérations

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 Écrivez le programme de test principal
pour implémenter une interface simple :

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. Exécution des résultats

---

La clé du problème est toujours l'analyse du XML par le DOM et l'exécution d'opérations brutes sur XML.

[Titre] : Implémentez un programme de console simple basé sur des fichiers XML, qui peut vérifier les scores des étudiants, ajouter des étudiants, supprimer des étudiants, etc.

Le fichier XML est enregistré dans le dossier src/com/dom/exercise :

<?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>

Cela peut être considéré comme le programme le plus simple, un peu plus compliqué. Le point clé est qu'il doit être implémenté sur la base de fichiers XML, donc l'analyse DOM doit être utilisée ici. SAX ne peut pas être utilisé car l'analyse SAX ne peut lire que les fichiers XML et ne peut pas les mettre à jour.

---

1. Écrivez d'abord StudentBean, comme suit :

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. Écrivez la classe StudentService la plus critique, qui est. très utile pour les documents XML pour diverses opérations

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 Écrivez le programme de test principal pour implémenter une interface simple :

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. Exécution des résultats

---

La clé du problème est toujours l'analyse du XML par le DOM et l'exécution d'opérations brutes sur XML.

Ce qui précède est le contenu du cas d'analyse XML-DOM. Pour plus de contenu connexe, veuillez faire attention au site Web PHP chinois (www.php.cn) !