Question

这些是我得到的错误。我知道我的架构存在问题，并且无法找到学生元素。但为什么它不能发现元素超出我。理想情况下，我希望这样做，以便我可以获得学生的姓名，成绩和课程来计算加权平均成绩，并按名称对学生进行排序。我想知道的是我做错了什么。我按照Simple XML serializers website上的教程进行了操作，但我很难理解为什么它不起作用。它给出的行号也不会导致我的代码中出现任何内容。

非常感谢任何帮助。

Exception in thread "main" org.simpleframework.xml.core.ElementException: Element 'students' does not have a match in class Student at line 2
    at org.simpleframework.xml.core.Composite.readElement(Composite.java:527)
    at org.simpleframework.xml.core.Composite.readElements(Composite.java:445)
    at org.simpleframework.xml.core.Composite.access$400(Composite.java:59)
    at org.simpleframework.xml.core.Composite$Injector.read(Composite.java:1433)
    at org.simpleframework.xml.core.Composite.read(Composite.java:201)
    at org.simpleframework.xml.core.Composite.read(Composite.java:148)
    at org.simpleframework.xml.core.Traverser.read(Traverser.java:92)
    at org.simpleframework.xml.core.Persister.read(Persister.java:625)
    at org.simpleframework.xml.core.Persister.read(Persister.java:606)
    at org.simpleframework.xml.core.Persister.read(Persister.java:584)
    at org.simpleframework.xml.core.Persister.read(Persister.java:543)
    at org.simpleframework.xml.core.Persister.read(Persister.java:521)
    at org.simpleframework.xml.core.Persister.read(Persister.java:426)
    at Deserializer.main(Deserializer.java:17)

这是我试图反序列化的XML。

<uni>
<students>

   <student>
    <studentName>Joe</studentName>
        <studentCourses>
            <course name="XML" grade="2" />
            <course name="Java" grade="5" />
        </studentCourses>
   </student>

   <student>
    <studentName>Jane</studentName>
        <studentCourses>
            <course name="XML" grade="3" />
            <course name="Java" grade="5" />
        </studentCourses>
   </student>

</students>
</uni>

我的Java类应该适合XML模式。

Uni class

import org.simpleframework.xml.Element;
import org.simpleframework.xml.Root;

@Root(name="uni")
public class Uni {

    @Element(name="students")
    public Students students;

    public Uni(){}
}

学生班

import java.util.List;

import org.simpleframework.xml.*;


public class Students {

    @ElementList(name="student", entry="students", inline=true)
    public List<Student> student;

    public Students(){}

    public List getProperties(){
        return student;
    }

学生班

import java.util.List;

import org.simpleframework.xml.Element;
import org.simpleframework.xml.ElementList;

//@Element
public class Student {
        @Element(name="studentName")
        public String studentName;

        @ElementList(name="studentCourses")
        public List<StudentCourses> studentCourses;

        //public Student (){}

        public Student(String studentName){
            this.studentName = studentName;
        }

        public String getStudentName(){
            return this.studentName;
        }
    }

学生课程

import java.util.List;

import org.simpleframework.xml.Element;
import org.simpleframework.xml.ElementList;

@Element
public class StudentCourses {

    @ElementList(name="studentCourses")
    public List<Course> course;
}

课程班

import org.simpleframework.xml.Attribute;
import org.simpleframework.xml.Element;


public class Course {
    @Element(name="course", required=false)
    public String course;

    @Attribute(name="name")
    public String courseName;

    @Attribute(name="grade")
    public int grade;

    //default constructor
    public Course () {}

    public  String getCourseName (String courseName){
        return this.courseName = courseName;
    }

    public int getCourseGrade (int courseGrade){
        return this.grade = courseGrade;
    }
}

反序列化程序类

import java.io.File;

import org.simpleframework.xml.Serializer;
import org.simpleframework.xml.core.Persister;





public class Deserializer {

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

        Serializer serializer = new Persister();
        File result = new File("stud.xml");

        Student student = serializer.read(Student.class, result);
        //Students stud = serializer.read(Students.class, result);

            System.out.println(student.getStudentName());
            //System.out.println(stud.getProperties());



    }

}

Answer 1

您的XML文件包含<uni>，但您尝试将其解析为单个Student：

    Student student = serializer.read(Student.class, result);
    System.out.println(student.getStudentName());

您已经定义了与<uni>对应的对象，该对象可能包含许多零或多个学生。解析：

    Uni uni = serializer.read(Uni.class, result);

    for (Student student : uni.students.student) {
        System.out.println(student.getStudentName());
    }

使用Java和Simple XML serializer / deserializer反序列化XML文件

1 个答案: