/* * [The "BSD license"] * Copyright (c) 2011 Terence Parr * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ package org.stringtemplate.v4.misc; import org.stringtemplate.v4.Interpreter; import org.stringtemplate.v4.ModelAdaptor; import org.stringtemplate.v4.ST; import java.lang.reflect.Field; import java.lang.reflect.Member; import java.lang.reflect.Method; import java.util.HashMap; import java.util.Map; public class ObjectModelAdaptor implements ModelAdaptor { protected static final Member INVALID_MEMBER; static { Member invalidMember; try { invalidMember = ObjectModelAdaptor.class.getDeclaredField("INVALID_MEMBER"); } catch (NoSuchFieldException ex) { invalidMember = null; } catch (SecurityException ex) { invalidMember = null; } INVALID_MEMBER = invalidMember; } protected static final Map<Class<?>, Map<String, Member>> membersCache = new HashMap<Class<?>, Map<String, Member>>(); @Override public synchronized Object getProperty(Interpreter interp, ST self, Object o, Object property, String propertyName) throws STNoSuchPropertyException { if ( o==null ) { throw new NullPointerException("o"); } Class<?> c = o.getClass(); if ( property==null ) { return throwNoSuchProperty(c, propertyName, null); } Member member = findMember(c, propertyName); if ( member!=null ) { try { if ( member instanceof Method ) { return ((Method)member).invoke(o); } else if ( member instanceof Field ) { return ((Field)member).get(o); } } catch (Exception e) { throwNoSuchProperty(c, propertyName, e); } } return throwNoSuchProperty(c, propertyName, null); } protected static Member findMember(Class<?> clazz, String memberName) { if ( clazz==null ) { throw new NullPointerException("clazz"); } if ( memberName==null ) { throw new NullPointerException("memberName"); } synchronized ( membersCache) { Map<String, Member> members = membersCache.get(clazz); Member member; if ( members!=null ) { member = members.get(memberName); if ( member!=null ) { return member != INVALID_MEMBER ?member : null; } } else { members = new HashMap<String, Member>(); membersCache.put(clazz, members); } // try getXXX and isXXX properties, look up using reflection String methodSuffix = Character.toUpperCase(memberName.charAt(0))+ memberName.substring(1, memberName.length()); member = tryGetMethod(clazz, "get"+methodSuffix); if ( member==null ) { member = tryGetMethod(clazz, "is"+methodSuffix); if ( member==null ) { member = tryGetMethod(clazz, "has"+methodSuffix); } } if ( member==null ) { // try for a visible field member = tryGetField(clazz, memberName); } members.put(memberName, member !=null ?member : INVALID_MEMBER); return member; } } protected static Method tryGetMethod(Class<?> clazz, String methodName) { try { Method method = clazz.getMethod(methodName); if ( method!=null ) { method.setAccessible(true); } return method; } catch (NoSuchMethodException ex) { } catch (SecurityException ex) { } return null; } protected static Field tryGetField(Class<?> clazz, String fieldName) { try { Field field = clazz.getField(fieldName); if ( field!=null ) { field.setAccessible(true); } return field; } catch (NoSuchFieldException ex) { } catch (SecurityException ex) { } return null; } protected Object throwNoSuchProperty(Class<?> clazz, String propertyName, Exception cause) { throw new STNoSuchPropertyException(cause, null, clazz.getName()+"."+propertyName); } }