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ReflectiveProperty.javaAPI DocAndroid 5.1 API7028Thu Mar 12 22:22:10 GMT 2015android.util

ReflectiveProperty

public class ReflectiveProperty extends Property
Internal class to automatically generate a Property for a given class/name pair, given the specification of {@link Property#of(java.lang.Class, java.lang.Class, java.lang.String)}

Fields Summary
private static final String
PREFIX_GET
private static final String
PREFIX_IS
private static final String
PREFIX_SET
private Method
mSetter
private Method
mGetter
private Field
mField
Constructors Summary
public ReflectiveProperty(Class propertyHolder, Class valueType, String name)
For given property name 'name', look for getName/isName method or 'name' field. Also look for setName method (optional - could be readonly). Failing method getters and field results in throwing NoSuchPropertyException.

param
propertyHolder The class on which the methods or field are found
param
name The name of the property, where this name is capitalized and appended to "get" and "is to search for the appropriate methods. If the get/is methods are not found, the constructor will search for a field with that exact name.


                                                                                              
           
         // TODO: cache reflection info for each new class/name pair
        super(valueType, name);
        char firstLetter = Character.toUpperCase(name.charAt(0));
        String theRest = name.substring(1);
        String capitalizedName = firstLetter + theRest;
        String getterName = PREFIX_GET + capitalizedName;
        try {
            mGetter = propertyHolder.getMethod(getterName, (Class<?>[])null);
        } catch (NoSuchMethodException e) {
            // getName() not available - try isName() instead
            getterName = PREFIX_IS + capitalizedName;
            try {
                mGetter = propertyHolder.getMethod(getterName, (Class<?>[])null);
            } catch (NoSuchMethodException e1) {
                // Try public field instead
                try {
                    mField = propertyHolder.getField(name);
                    Class fieldType = mField.getType();
                    if (!typesMatch(valueType, fieldType)) {
                        throw new NoSuchPropertyException("Underlying type (" + fieldType + ") " +
                                "does not match Property type (" + valueType + ")");
                    }
                    return;
                } catch (NoSuchFieldException e2) {
                    // no way to access property - throw appropriate exception
                    throw new NoSuchPropertyException("No accessor method or field found for"
                            + " property with name " + name);
                }
            }
        }
        Class getterType = mGetter.getReturnType();
        // Check to make sure our getter type matches our valueType
        if (!typesMatch(valueType, getterType)) {
            throw new NoSuchPropertyException("Underlying type (" + getterType + ") " +
                    "does not match Property type (" + valueType + ")");
        }
        String setterName = PREFIX_SET + capitalizedName;
        try {
            mSetter = propertyHolder.getMethod(setterName, getterType);
        } catch (NoSuchMethodException ignored) {
            // Okay to not have a setter - just a readonly property
        }
Methods Summary
public Vget(T object)

        if (mGetter != null) {
            try {
                return (V) mGetter.invoke(object, (Object[])null);
            } catch (IllegalAccessException e) {
                throw new AssertionError();
            } catch (InvocationTargetException e) {
                throw new RuntimeException(e.getCause());
            }
        } else if (mField != null) {
            try {
                return (V) mField.get(object);
            } catch (IllegalAccessException e) {
                throw new AssertionError();
            }
        }
        // Should not get here: there should always be a non-null getter or field
        throw new AssertionError();
public booleanisReadOnly()
Returns false if there is no setter or public field underlying this Property.

        return (mSetter == null && mField == null);
public voidset(T object, V value)

        if (mSetter != null) {
            try {
                mSetter.invoke(object, value);
            } catch (IllegalAccessException e) {
                throw new AssertionError();
            } catch (InvocationTargetException e) {
                throw new RuntimeException(e.getCause());
            }
        } else if (mField != null) {
            try {
                mField.set(object, value);
            } catch (IllegalAccessException e) {
                throw new AssertionError();
            }
        } else {
            throw new UnsupportedOperationException("Property " + getName() +" is read-only");
        }
private booleantypesMatch(java.lang.Class valueType, java.lang.Class getterType)
Utility method to check whether the type of the underlying field/method on the target object matches the type of the Property. The extra checks for primitive types are because generics will force the Property type to be a class, whereas the type of the underlying method/field will probably be a primitive type instead. Accept float as matching Float, etc.

        if (getterType != valueType) {
            if (getterType.isPrimitive()) {
                return (getterType == float.class && valueType == Float.class) ||
                        (getterType == int.class && valueType == Integer.class) ||
                        (getterType == boolean.class && valueType == Boolean.class) ||
                        (getterType == long.class && valueType == Long.class) ||
                        (getterType == double.class && valueType == Double.class) ||
                        (getterType == short.class && valueType == Short.class) ||
                        (getterType == byte.class && valueType == Byte.class) ||
                        (getterType == char.class && valueType == Character.class);
            }
            return false;
        }
        return true;