001// Copyright 2010 The Apache Software Foundation 002// 003// Licensed under the Apache License, Version 2.0 (the "License"); 004// you may not use this file except in compliance with the License. 005// You may obtain a copy of the License at 006// 007// http://www.apache.org/licenses/LICENSE-2.0 008// 009// Unless required by applicable law or agreed to in writing, software 010// distributed under the License is distributed on an "AS IS" BASIS, 011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012// See the License for the specific language governing permissions and 013// limitations under the License. 014 015package org.apache.tapestry5.services; 016 017/** 018 * Used when accessing the private instance variables of a component instance. 019 * 020 * @see TransformField#getAccess() 021 * @since 5.2.0 022 */ 023public interface FieldAccess 024{ 025 /** 026 * Reads the value of the field of the provided instance. 027 * 028 * @param instance 029 * object containing field to read 030 */ 031 Object read(Object instance); 032 033 /** 034 * Updates the value of the field within the instance. 035 * 036 * @param instance 037 * object containing field to update 038 * @param value 039 * new value for field 040 */ 041 void write(Object instance, Object value); 042}