记录读取xml文件内容
记录下使用document类去读取xml文件内容
xml内容：
1 <?xml version="1.0" encoding = "UTF-8"?> 2 <schools> 3 <school id="1" name="school1"> 4 <class id="11" name="class11"> 5 <student id="111" name="student111"/> 6 <student id="112" name="student112"/> 7 <student id="113" name="student113"/> 8 </class> 9 <class id="12" name="class12"> 10 <student id="121" name="student121"/> 11 <student id="122" name="student122"/> 12 </class> 13 <class id="13" name="class13"> 14 <student id="131" name="student131"/> 15 <student id="132" name="student132"/> 16 </class> 17 </school> 18 <school id="2" name="school2"> 19 <class id="21" name="class21"> 20 <student id="211" name="student211"/> 21 </class> 22 </school> 23 </schools>
使用getElementsByTagName读取文件
定义学校类：
1 public class School { 2 3 private String name; 4 private String id; 5 private List<SClass> sClassList; 6 7 public School(String name, String id) { 8 this.name = name; 9 this.id = id; 10 sClassList = new ArrayList<SClass>(); 11 } 12 13 public String getName() { 14 return name; 15 } 16 17 public String getId() { 18 return id; 19 } 20 21 public List<SClass> getsClassList() { 22 return sClassList; 23 } 24 }
定义班级类：
1 public class SClass { 2 private String id; 3 private String name; 4 private School school; 5 private List<Student> students; 6 7 8 public SClass(String id, String name, School school) { 9 this.id = id; 10 this.name = name; 11 this.school = school; 12 students = new ArrayList<Student>(); 13 school.getsClassList().add(this); 14 } 15 16 public String getId() { 17 return id; 18 } 19 20 21 public String getName() { 22 return name; 23 } 24 25 26 public School getSchool() { 27 return school; 28 } 29 30 31 public List<Student> getStudents() { 32 return students; 33 } 34 }
定义学生类：
1 public class Student { 2 private String id; 3 private String name; 4 private SClass sClass; 5 6 7 public Student(String id, String name, SClass sClass) { 8 this.id = id; 9 this.name = name; 10 this.sClass = sClass; 11 sClass.getStudents().add(this); 12 } 13 14 public String getId() { 15 return id; 16 } 17 18 public String getName() { 19 return name; 20 } 21 22 public SClass getsClass() { 23 return sClass; 24 } 25 }
定义读取xml类：
1 public class SchoolDOM { 2 private Document document; 3 4 public SchoolDOM(File file) { 5 DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); //DOM树的解析器 6 try { 7 DocumentBuilder documentBuilder = factory.newDocumentBuilder(); 8 document = documentBuilder.parse(file); 9 } catch (Exception e) { 10 e.printStackTrace(); 11 } 12 } 13 14 /** 15 * parse school.xml,返回所有学校、班级、学生的信息 16 * 17 * @return 18 */ 19 public List<School> parseSchoolXml() { 20 List<School> schools = null; 21 if (document != null) { 22 schools = new ArrayList<School>(); 23 NodeList schoolList = document.getElementsByTagName(SchoolTag.SCHOOL); //学校的节点 24 for (int i = 0; i < schoolList.getLength(); i++) { 25 Node schoolNode = schoolList.item(i); 26 if (schoolNode.getNodeType() == Node.ELEMENT_NODE) { 27 Element schoolElement = (Element) schoolNode; //把节点（node）强转成元素（element） 28 String schoolID = schoolElement.getAttribute(SchoolTag.ID); 29 String schoolName = schoolElement.getAttribute(SchoolTag.NAME); 30 School school = new School(schoolID, schoolName); 31 schools.add(school); 32 NodeList classList = schoolElement.getChildNodes(); //班级的节点 33 for (int j = 0; j < classList.getLength(); j++) { 34 Node classNode = classList.item(j); 35 if (classNode.getNodeType() == Node.ELEMENT_NODE) { 36 Element classElement = (Element) classNode; 37 String classID = classElement.getAttribute(SchoolTag.ID); 38 String className = classElement.getAttribute(SchoolTag.NAME); 39 SClass sclass = new SClass(classID, className, school); 40 NodeList studentList = classElement.getChildNodes(); //学生的节点 41 for (int k = 0; k < studentList.getLength(); k++) { 42 Node studentNode = studentList.item(k); 43 if (studentNode.getNodeType() == Node.ELEMENT_NODE) { 44 Element studentElement = (Element) studentNode; 45 String studentID = studentElement.getAttribute(SchoolTag.ID); 46 String studentName = studentElement.getAttribute(SchoolTag.NAME); 47 Student student = new Student(studentID, studentName, sclass); 48 } 49 } 50 } 51 } 52 } 53 } 54 } 55 56 return schools; 57 } 58 }
定义Tag常量
1 public class SchoolTag { 2 3 public static final String SCHOOL = "school"; 4 public static final String CLASS = "class"; 5 public static final String STUDENT = "student"; 6 public static final String ID = "id"; 7 public static final String NAME = "name"; 8 9 10 }
测试方法
1 public class TestDom { 2 public static void test() { 3 try { 4 String path = TestDom.class.getResource("/").toURI().getPath(); 5 String pathFileName = path + "\\School.xml"; 6 File file = new File(pathFileName); 7 SchoolDOM schoolDOM = new SchoolDOM(file); 8 List<School> schools = schoolDOM.parseSchoolXml(); 9 for (School school : schools) { 10 System.out.println(school.getId() + "---" + school.getName()); 11 List<SClass> classList = school.getsClassList(); 12 for (SClass sclass : classList) { 13 System.out.println(sclass.getId() + "--" + sclass.getName()); 14 List<Student> students = sclass.getStudents(); 15 for (Student student : students) { 16 StringBuilder stringBuilder = new StringBuilder(); 17 stringBuilder.append(student.getId()); 18 stringBuilder.append("--"); 19 stringBuilder.append(student.getName()); 20 System.out.println(stringBuilder); 21 } 22 } 23 } 24 25 } catch (Exception e) { 26 e.printStackTrace(); 27 } 28 } 29 30 31 public static void main(String[] args) { 32 TestDom.test(); 33 } 34 }
输出结果
school1---1 11--class11 111--student111 112--student112 113--student113 12--class12 121--student121 122--student122 13--class13 131--student131 132--student132 school2---2 21--class21 211--student211
