com.github.hateoas.forms.PropertyUtils Maven / Gradle / Ivy

package com.github.hateoas.forms;

import java.beans.BeanInfo;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

/**
 * Convenience methods to work with Java bean properties.
 * Created by Dietrich on 11.03.2015.
 */
public class PropertyUtils {

	private PropertyUtils() {

	}

	public static Object getPropertyValue(Object currentCallValue, PropertyDescriptor propertyDescriptor) {
		Object propertyValue = null;
		if (currentCallValue != null && propertyDescriptor.getReadMethod() != null) {
			try {
				propertyValue = propertyDescriptor.getReadMethod()
						.invoke(currentCallValue);
			} catch (Exception e) {
				throw new RuntimeException("failed to read property from call value", e);
			}
		}
		return propertyValue;
	}

	public static Map getPropertyDescriptors(Object bean) {
		try {
			PropertyDescriptor[] propertyDescriptors = Introspector.getBeanInfo(bean.getClass())
					.getPropertyDescriptors();
			Map ret = new HashMap();
			for (PropertyDescriptor propertyDescriptor : propertyDescriptors) {
				ret.put(propertyDescriptor.getName(), propertyDescriptor);
			}
			return ret;
		} catch (IntrospectionException e) {
			throw new RuntimeException("failed to get property descriptors of bean " + bean, e);
		}
	}

	public static Constructor findDefaultCtor(Constructor[] constructors) {
		// TODO duplicate on HtmlResourceMessageConverter
		Constructor constructor = null;
		for (Constructor ctor : constructors) {
			if (ctor.getParameterTypes().length == 0) {
				constructor = ctor;
			}
		}
		return constructor;
	}

	public static Constructor findJsonCreator(Constructor[] constructors, Class creatorAnnotation) {
		Constructor constructor = null;
		for (Constructor ctor : constructors) {
			if (AnnotationUtils.findAnnotation(ctor, creatorAnnotation) != null) {
				constructor = ctor;
				break;
			}
		}
		return constructor;
	}

	// TODO move to PropertyUtil and remove current method for propertyDescriptors, cache search results
	public static Object getPropertyOrFieldValue(Object currentCallValue, String propertyOrFieldName) {
		if (currentCallValue == null) {
			return null;
		}
		Object propertyValue = getBeanPropertyValue(currentCallValue, propertyOrFieldName);
		if (propertyValue == null) {
			propertyValue = getFieldValue(currentCallValue, propertyOrFieldName);
		}
		return propertyValue;
	}

	public static Object getFieldValue(Object currentCallValue, String fieldName) {
		try {
			Class beanType = currentCallValue.getClass();
			Object propertyValue = null;
			Field[] fields = beanType.getFields();
			for (Field field : fields) {
				if (fieldName.equals(field.getName())) {
					propertyValue = field.get(currentCallValue);
					break;
				}
			}
			return propertyValue;
		} catch (Exception e) {
			throw new RuntimeException("Failed to read field " + fieldName + " from " + currentCallValue.toString(), e);
		}
	}

	public static Object getBeanPropertyValue(Object currentCallValue, String paramName) {
		if (currentCallValue == null) {
			return null;
		}
		try {
			Object propertyValue = null;
			BeanInfo info = Introspector.getBeanInfo(currentCallValue.getClass());
			PropertyDescriptor[] pds = info.getPropertyDescriptors();
			for (PropertyDescriptor pd : pds) {
				if (paramName.equals(pd.getName())) {
					Method readMethod = pd.getReadMethod();
					if (readMethod != null) {
						propertyValue = readMethod.invoke(currentCallValue);
					}
					break;
				}
			}
			return propertyValue;
		} catch (Exception e) {
			throw new RuntimeException("Failed to read property " + paramName + " from " + currentCallValue.toString
					(), e);
		}
	}
}