首次接触XML

准备：在E盘下新建一个.xml文件test.xml

　　　下载jdom-2.0.3.jar文件，放入项目lib目录下，并加入buildpath

package com.slh.common;

import java.io.File;
import java.io.FileWriter;
import java.util.Iterator;

import org.jdom2.Document;
import org.jdom2.Element;
import org.jdom2.input.SAXBuilder;
import org.jdom2.output.Format;
import org.jdom2.output.XMLOutputter;

public class TestXML {
  private File studentListFile;
  private Document doc;
  private Element rootElement;
  private final static XMLOutputter fmt = new XMLOutputter(
      Format.getPrettyFormat());

  public TestXML() throws Exception {
    init();
  }

  private void init() throws Exception {
    SAXBuilder builder = new SAXBuilder();
    studentListFile = new File("e:\\test.xml");
    doc = builder.build(studentListFile);
    rootElement = doc.getRootElement();
    System.out.println("rootElement:" + rootElement.getName());
  }

  public StringBuffer getStudentList() {
    StringBuffer students = new StringBuffer();
    String id, name, age, job, sex, student;

    for (Iterator<Element> it = rootElement.getChildren().iterator(); it.hasNext();) {
      Element child = it.next();
      Element idElement = child.getChild("id");
      Element nameElement = child.getChild("name");
      Element ageElement = child.getChild("age");
      Element jobElement = child.getChild("job");
      Element sexElement = child.getChild("sex");

      id = idElement.getText();
      name = nameElement.getText();
      age = ageElement.getText();
      job = jobElement.getText();
      sex = sexElement.getText();

      student = "    " + child.getName() + ":" + id + " " + name + " " + age + " "
                + job + " " + sex + "\n";
      students.append(student);
    }

    return students;
  }

  public void addStudent(int id, String name, int age, String job, String sex)
      throws Exception {
    Element subElement1 = new Element("student");
    Element idElement = new Element("id");
    Element nameElement = new Element("name");
    Element ageElement = new Element("age");
    Element jobElement = new Element("job");
    Element sexElement = new Element("sex");

    subElement1.addContent(idElement);
    subElement1.addContent(nameElement);
    subElement1.addContent(ageElement);
    subElement1.addContent(jobElement);
    subElement1.addContent(sexElement);

    idElement.setText(Integer.valueOf(id).toString());
    nameElement.setText(name);
    ageElement.setText(Integer.valueOf(age).toString());
    jobElement.setText(job);
    sexElement.setText(sex);

    rootElement.addContent(subElement1);
    fmt.output(doc, new FileWriter(studentListFile));
  }

  public void delStudent(int id) throws Exception {
    for (Iterator<Element> it = rootElement.getChildren().iterator(); it.hasNext();) {
      Element child = it.next();
      String idElement = child.getChild("id").getText();
      if (idElement.equals(Integer.valueOf(id).toString())) {
        it.remove();
      }
    }
    fmt.output(doc, new FileWriter(studentListFile));
  }

  public void updateStudent(int id, String name, int age, String job, String sex)
      throws Exception {
    for (Iterator<Element> it = rootElement.getChildren().iterator(); it.hasNext();) {
      Element child = it.next();
      String idElement = child.getChild("id").getText();
      System.out.println(idElement);
      if (idElement.equals(Integer.valueOf(id).toString())) {
        child.getChild("name").setText(name);
        child.getChild("age").setText(Integer.valueOf(age).toString());
        child.getChild("job").setText(job);
        child.getChild("sex").setText(sex);
        break;
      }
    }
    fmt.output(doc, new FileWriter(studentListFile));
  }

  public static void main(String[] args) throws Exception {
    TestXML testXML = new TestXML();
    // System.out.println(testXML.getStudentList());
    // testXML.addStudent(4, "slh4", 33, "waiter", "f");
    // System.out.println(testXML.getStudentList());
    // testXML.delStudent(4);
    // System.out.println(testXML.getStudentList());
    // testXML.updateStudent(4, "slh44", 33, "actor", "f");
    System.out.println(testXML.getStudentList());
  }
}