如何使用Java迭代類及其成員類的對象

Question

我試圖獲取一個類（ objectfactory.java ）的所有數據對象（單獨的變量，而不是它的函數等），並且還調用自身的方法，在同一個包中創建其他類的實例，這樣方法，列出給定包中所有類中的所有對象。 （從透視角度來看，這些是由JAXB創建的類）。

也就是說，我基本上想要做的是，遍歷並列出以下所有數據對象的列表：

Objectfactory, and then,
- Person
- Name
- Url
- Link
- Personnel

類。

這是objectFactory類：

@XmlRegistry
public class ObjectFactory {

    private final static QName _Given_QNAME = new QName("", "given");
    private final static QName _Email_QNAME = new QName("", "email");
    private final static QName _Family_QNAME = new QName("", "family");

    /**
     * Create a new ObjectFactory that can be used to create new instances of schema derived classes for package: schema
     * 
     */
    public ObjectFactory() {
    }
    public Person createPerson() {
        return new Person();
    }

    public Name createName() {
        return new Name();
    }

    public Url createUrl() {
        return new Url();
    }

    public Link createLink() {
        return new Link();
    }

    public Personnel createPersonnel() {
        return new Personnel();
    }

    @XmlElementDecl(namespace = "", name = "given")
    public JAXBElement<String> createGiven(String value) {
        return new JAXBElement<String>(_Given_QNAME, String.class, null, value);
    }
    @XmlElementDecl(namespace = "", name = "email")
    public JAXBElement<String> createEmail(String value) {
        return new JAXBElement<String>(_Email_QNAME, String.class, null, value);
    }

    @XmlElementDecl(namespace = "", name = "family")
    public JAXBElement<String> createFamily(String value) {
        return new JAXBElement<String>(_Family_QNAME, String.class, null, value);
    }

}

我可以直接使用Java Reflection。（getDeclaredFields（））等直到ObjectFactory中的字段和方法。

但是，對於其他類，我只能手動到達他們的對象。 （例如，對於Class Link）

ObjectFactory factory= new ObjectFactory();
Field[] fields = factory.createLink().getClass().getDeclaredFields();

        Field[] fields1 = factory.createPerson().getClass().getDeclaredFields();

        for (Field f1 : fields1) {
            System.out.println("field name = " + f1.getName()); 
        }

但是，我想在運行時為objectfactory中的所有類執行此操作，而不是通過調用“createPerson（）”來手動執行此操作。

我嘗試過做這樣的事情;

ObjectFactory factory= new ObjectFactory();
  Method[] methods = factory.getClass().getDeclaredMethods();
     for (Method m : methods) {
System.out.println("Class name = " + m.getName()); 
        Field[] subfields = m.getClass().getDeclaredFields();


        for (Field sf : subfields) {
            System.out.println("entities = " + sf.getName()); 
        }
        System.out.println("\n\n");

    }

但這不起作用。

我的預期輸出將是這樣的：

Class name = ObjectFactory
    field name = _Given_QNAME
    field name = _Email_QNAME
    field name = _Family_QNAME

Class name = Person
    field name = Name
    field name = Age
    field name = Sex

Class name = Personnel
    field name = address
 ...

等等..

我該怎么做呢？

Answer 1

public void getAllClassAndFields() {
    ObjectFactory objectFactory = new ObjectFactory();
    Method[] methods = objectFactory.getClass().getDeclaredMethods();
    for (Method method : methods) {
        try {
            // Check if method have XmlElementDecl annotation
            XmlElementDecl annotation = method.getAnnotation(XmlElementDecl.java);
            if (annotation == null) {
                // Invoke method only if it is not annoatated with XmlElementDecl 
                Object object = method.invoke(objectFactory, new Object[] {});
                System.out.println("Class Name = " + object.getClass().getName());
                printFileds(object);
            }

        } catch (Exception e) {
          // I used Exception to keep it simple, instead use appropriate exception types here 
        } 
    }
}

public static void printFileds(Object obj) {
    Field[] fields = obj.getClass().getFields();
    for (Field field : fields) {
        System.out.println("Field Name = " + field.getName());
    }
}

Answer 2

不知道你為什么要這樣做？
但請嘗試下面的代碼

public class RelectionTestCases {
public static final String INDENT = "    ";

public static void main(String[] args) throws IllegalArgumentException, IllegalAccessException, InvocationTargetException {
    ObjectFactory factory = new ObjectFactory();

    Field[] fields = ObjectFactory.class.getDeclaredFields();

    // Fields
    System.out.println(ObjectFactory.class.getName());
    for (Field field : fields) {
        System.out.println(INDENT + field.getName());
    }

    // Method
    Method[] methods = ObjectFactory.class.getDeclaredMethods();
    for (Method method : methods) {

        if (method.getReturnType().equals(JAXBElement.class)) {
            continue;
        }

        Object object = method.invoke(factory, null);
        System.out.println(object.getClass().getName());

        Field[] subFields = object.getClass().getDeclaredFields();

        for (Field field : subFields) {
            System.out.println(INDENT + field.getName());
        }
    }
}

}