使用java将新标记附加到现有xml

Question

我的源代码需要在一些现有标签之间追加/添加新标签到我在硬盘上的XML文档。我很困惑我需要使用哪种解析器来完成这项任务。

XML文档我看起来类似于：

<school>
<teacher>
<name>XXXXX</name>
<gender>XXXX</gender>
</teacher>
</school>

需要此XML文档：

 <school>
<teacher>
<name>XXXXX</name>
<gender>XXXX</gender>
</teacher>
<!--need to append student tag-->
<student>
<name>XXXXXX</name>
<gender>XXXXX</name>
</student>
</school>

所以，请帮助我选择高效的xmlparser来完成这项工作。另外，如果你能告诉我样本源代码来完成这项任务，我很感激。

提前致谢..

Answer 1

如果我正确理解了这个问题，我假设您正在尝试使用包含教师的xml文档，对于那些教师，您想要添加相应的生。

我建议使用DOM解析器（底部的链接作为参考）。

我已经创建了一些代码，可以让您使用教师信息获取XML文件，并生成一个包含所需结果的新文件。

为方便起见，我使用了过多的评论！

package com.yourpackage.model;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

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 addStudentsXml {
    public static void main(String[] args) throws Exception {

        //Create the DocumentBuilderFactory
        DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();

        //Parse your XML file
        Document document = documentBuilder.parse("yourFileName.xml"); //Insert your file name here

        //Declare the school that you wish to populate
        School school = new School();

        //Create the list of teachers
        List<Teacher> teachers = new ArrayList<Teacher>();

        //Create the list of nodes from the document
        NodeList nodeList = document.getDocumentElement().getChildNodes();

        //Populate the teacher list with all of the teachers in the XML document
        for (int i = 0; i < nodeList.getLength(); i++) {
            Node node = nodeList.item(i);
            if (node instanceof Element) {
                Teacher newTeacher = new Teacher();
                newTeacher.name = node.getAttributes().getNamedItem("name").getNodeValue();

                NodeList childNodes = node.getChildNodes();
                for (int j = 0; j < childNodes.getLength(); j++) {
                    Node cNode = childNodes.item(j);

                    if (cNode instanceof Element) {
                        String content = cNode.getLastChild().getTextContent().trim();

                        if(cNode.getNodeName().equals("name")) {
                            newTeacher.name = content;
                        } else if(cNode.getNodeName().equals("gender")) {
                            newTeacher.gender = content;
                        }
                    }
                }
                //Add new teachers to the teacher list
                teachers.add(newTeacher);
            }
        }

        //Add your teachers to your school
        school.setTeachers(teachers);

        //Create the list of students
        List<Student> students = new ArrayList<Student>();

        //Populate your students here depending upon how your data is feeding them in

        //Add your students to your school
        school.setStudents(students);

        //Now we will start to create the new xml document to be exported
        Document newDoc = documentBuilder.newDocument();

        //Create the root of the doucment
        Element root = newDoc.getDocumentElement();

        //Create the school element
        Element newSchool = newDoc.createElement("school");

        //Add the school to the root of the document
        root.appendChild(newSchool);

        //For all of the teachers in the teacher list, add their corresponding students
        for (Teacher teacher : teachers) {
            //Create the teacher element
            Element newTeacher = newDoc.createElement("teacher");

            //Add the teacher's name
            Element teacherName = newDoc.createElement("name");
            teacherName.appendChild(newDoc.createTextNode(teacher.getName()));
            newTeacher.appendChild(teacherName);

            //Add the teacher's gender
            Element teacherGender = newDoc.createElement("gender");
            teacherGender.appendChild(newDoc.createTextNode(teacher.getGender()));
            newTeacher.appendChild(teacherGender);

            //Add the teacher to the school
            newSchool.appendChild(newTeacher);
            for (Student student : students) {
                if (student.getTeacherName().trim().equals(teacher.getName().trim())) {
                    //Create the student element
                    Element newStudent = newDoc.createElement("student");

                    //Add the student's name
                    Element studentName = newDoc.createElement("name");
                    studentName.appendChild(newDoc.createTextNode(student.getName()));
                    newStudent.appendChild(studentName);

                    //Add the student's gender
                    Element studentGender = newDoc.createElement("gender");
                    studentGender.appendChild(newDoc.createTextNode(student.getGender()));
                    newStudent.appendChild(studentGender);

                    //Add the student to the school
                    newSchool.appendChild(newStudent);
                }       
            }
        }

        //Create the transformerFactory, transformer, and the result to be saved to a new file "schoolinfo.xml"
        TransformerFactory transformerFactory = TransformerFactory.newInstance();
        Transformer transformer = transformerFactory.newTransformer();
        DOMSource source = new DOMSource(newDoc);
        StreamResult result = new StreamResult(new File("C://schoolinfo.xml"));

        transformer.transform(source, result);

        System.out.println("File saved!");

    }

    public static class School {
        private List<Teacher> teachers;
        private List<Student> students;

        public void setTeachers(List<Teacher> teachers) {
            this.teachers = teachers;
        }

        public void setStudents(List<Student> students) {
            this.students = students;
        }

        public List<Teacher> getTeachers() {
            return teachers;
        }

        public List<Student> getStudents() {
            return students;
        }
    }

    public static class Teacher {
        private String name = "";
        private String gender =  "";

        public String getName() {
            return name;
        }
        public String getGender() {
            return gender;
        }
    }

    public static class Student {
        private String studentName = "";
        private String studentGender = "";
        private String teacherName = "";

        public String getName() {
            return studentName;
        }
        public String getGender() {
            return studentGender;
        }
        public String getTeacherName() {
            return teacherName;
        }
    }
}

这应该在您的XML文件中读取（您必须用您的实际文件名替换文件名）并填充教师列表。就学生信息而言，您必须从您从中检索数据的任何位置填充该列表。

一旦该数据可用并正确存储，将创建一个新文档，并且XML应以您希望的形式附加到该文档。此文档将存储到您的C：驱动器中，但您可以更改该路径以将其存储在您喜欢的任何位置。

我使用这些链接作为参考：
MKYong（导出XML文件）：here
Stackoverflow（追加节点）：here
Java Code Geeks（DOM Parsers）：here

如果我的解决方案中有任何需要澄清的内容，请告诉我，我是stackoverflow的新手！

Answer 2

XOM是最简单的Java XML系统。通过操作XOM树本身可以避免很多混乱。

public void test() throws ParsingException, ValidityException, IOException {
    String xml = "<school><teacher><name>XXXXX</name><gender>XXXX</gender></teacher></school>";
    String add = "<student><name>XXXXXX</name><gender>XXXXX</gender></student>";
    Builder parser = new Builder();
    // Parse them.
    Document school = parser.build(new ByteArrayInputStream(xml.getBytes()));
    Document student = parser.build(new ByteArrayInputStream(add.getBytes()));
    // Manipulate - remember to copy.
    school.getRootElement().appendChild(student.getRootElement().copy());
    // To XML.
    System.out.println(school.getRootElement().toXML());
}

打印：

<school><teacher><name>XXXXX</name><gender>XXXX</gender></teacher><student><name>XXXXXX</name><gender>XXXXX</gender></student></school>

即

    <school>
        <teacher>
            <name>XXXXX</name>
            <gender>XXXX</gender>
        </teacher>
        <student>
            <name>XXXXXX</name>
            <gender>XXXXX</gender>
        </student>
    </school>

对于重要的项目，它可能是一个更好的解决方案，可以将XML编组到对象中，操作对象并将它们解组回xml（如@KyleStoflet所建议的那样）。

或者 - 您可以使用暴力并直接操纵字符串。这是非常不满意的。

public void test() {
    String xml = "<school><teacher><name>XXXXX</name><gender>XXXX</gender></teacher></school>";
    String add = "<student><name>XXXXXX</name><gender>XXXXX</gender></student>";
    StringBuilder both = new StringBuilder(xml)
            .insert(xml.indexOf("</school>"), add);
    System.out.println(both);
}