Question

基本上我需要以递归方式以名称值对格式打印所有实例变量名称及其值。说我的班级结构如下

public class SomeClass{

private String classDescription;
private Animals animals;
private Birds birds;
private List<Insects> insects;
private Map<String, Reptiles> others;

}

public class Animals{

private Dogs dogs;
private Cats cats;
private List<Mammals> mammalsList;

}

public class Dogs{
private String variable1;
private long variable2;
}

对于我有对象引用链的上述类结构，我需要打印实例变量名称和递归的相应值。代码会有所帮助。

Answer 1

我想这段代码可能有所帮助。我没有添加处理Map的功能，但它适用于List：

public static void main(String[] args) throws ClassNotFoundException 
{
    SomeClass s = new SomeClass();
    Class c = s.getClass();
    getMembers(c);
}

public static void getMembers(Class c) throws ClassNotFoundException 
{
    Field[] fields = c.getDeclaredFields();

    for (Field f : fields) 
    {
        if (f.getType().isPrimitive() || f.getType().equals(String.class))
        {
            System.out.println(c.getSimpleName() + ": " + f.getName() + " is a "+ f.getType().getSimpleName());
        }
        else 
        {
            if (Collection.class.isAssignableFrom(f.getType())) 
            {
                String s = f.toGenericString();
                String type = s.split("\\<")[1].split("\\>")[0];
                Class clazz = Class.forName(type);
                System.out.println(c.getSimpleName()+ ": "+ f.getName()+ " is a collection of "+ clazz.getSimpleName());
                getMembers(clazz);
            }
            else
            {
                System.out.println(c.getSimpleName() + ": " + f.getName() + " is a "+ f.getType().getSimpleName());
                getMembers(f.getType());
            }
        }
    }
}

希望有所帮助。

Answer 2

使用反射获取名称值的另一个简单示例：

public void getNameValue() {
    try {
        RingtoneManager ringtoneManager = new RingtoneManager(this);
        Field field = RingtoneManager.class.getField("ACTION_RINGTONE_PICKER");
        String type = field.getType().getSimpleName();
        String name = field.getName();
        String value = (String)field.get(ringtoneManager);
        Log.e(TAG,type + " " + name + " = " + value);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

如何使用java中的反射递归获取所有实例变量名称和值

2 个答案: