001 /**
002 * GRANITE DATA SERVICES
003 * Copyright (C) 2006-2013 GRANITE DATA SERVICES S.A.S.
004 *
005 * This file is part of the Granite Data Services Platform.
006 *
007 * Granite Data Services is free software; you can redistribute it and/or
008 * modify it under the terms of the GNU Lesser General Public
009 * License as published by the Free Software Foundation; either
010 * version 2.1 of the License, or (at your option) any later version.
011 *
012 * Granite Data Services is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
015 * General Public License for more details.
016 *
017 * You should have received a copy of the GNU Lesser General Public
018 * License along with this library; if not, write to the Free Software
019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
020 * USA, or see <http://www.gnu.org/licenses/>.
021 */
022 package org.granite.spring.data;
023
024 import java.io.IOException;
025 import java.lang.reflect.Field;
026 import java.lang.reflect.InvocationTargetException;
027 import java.util.ArrayList;
028 import java.util.Arrays;
029 import java.util.List;
030
031 import org.granite.messaging.jmf.ExtendedObjectInput;
032 import org.granite.messaging.jmf.ExtendedObjectOutput;
033 import org.granite.messaging.jmf.codec.ExtendedObjectCodec;
034 import org.springframework.data.domain.Page;
035 import org.springframework.data.domain.PageImpl;
036 import org.springframework.data.domain.Pageable;
037 import org.springframework.data.domain.Sort;
038 import org.springframework.data.domain.Sort.Direction;
039 import org.springframework.data.domain.Sort.Order;
040
041 /**
042 * @author Franck WOLFF
043 */
044 public class PageableCodec implements ExtendedObjectCodec {
045
046 private static final Field pageableField;
047 static {
048 Field pageableFieldTmp = null;
049 try {
050 pageableFieldTmp = PageImpl.class.getDeclaredField("pageable");
051 pageableFieldTmp.setAccessible(true);
052 }
053 catch (NoSuchFieldException e) {
054 // Other exception mean that Spring Data is not present
055 // Don't catch so codec is not installed
056 }
057 pageableField = pageableFieldTmp;
058 }
059
060 public PageableCodec() {
061 }
062
063 public boolean canEncode(ExtendedObjectOutput out, Object v) {
064 return v instanceof Page;
065 }
066
067 public String getEncodedClassName(ExtendedObjectOutput out, Object v) {
068 return org.granite.tide.data.model.Page.class.getName();
069 }
070
071 public void encode(ExtendedObjectOutput out, Object v) throws IOException, IllegalAccessException, InvocationTargetException {
072 @SuppressWarnings("unchecked")
073 Page<Object> springPage = (Page<Object>)v;
074
075 int offset;
076 if (springPage instanceof PageImpl && pageableField != null) {
077 Pageable springPageable = (Pageable)pageableField.get(springPage);
078 offset = springPageable.getOffset();
079 }
080 else
081 offset = springPage.getNumber() * springPage.getSize();
082
083 out.writeObject(Integer.valueOf(offset));
084 out.writeObject(Integer.valueOf(springPage.getSize()));
085 out.writeObject(Integer.valueOf((int)springPage.getTotalElements()));
086 out.writeObject(new ArrayList<Object>(springPage.getContent()));
087 }
088
089 public boolean canDecode(ExtendedObjectInput in, String className) throws ClassNotFoundException {
090 return org.granite.tide.data.model.PageInfo.class.getName().equals(className);
091 }
092
093 public String getDecodedClassName(ExtendedObjectInput in, String className) {
094 return OffsetPageRequest.class.getName();
095 }
096
097 public Object newInstance(ExtendedObjectInput in, String className)
098 throws IOException, ClassNotFoundException, InstantiationException,
099 IllegalAccessException, InvocationTargetException,
100 SecurityException, NoSuchMethodException {
101
102 int firstResult = ((Integer)in.readObject()).intValue();
103 int maxResults = ((Integer)in.readObject()).intValue();
104 String[] orderBys = (String[])in.readObject();
105 boolean[] orderDescs = (boolean[])in.readObject();
106
107 Sort sort = null;
108 if (checkSort(orderBys, orderDescs)) {
109 List<Order> orders = new ArrayList<Order>(orderBys.length);
110 for (int i = 0; i < orderBys.length; i++)
111 orders.add(new Order(orderDescs[i] ? Direction.DESC : Direction.ASC, orderBys[i]));
112 sort = new Sort(orders);
113 }
114
115 return new OffsetPageRequest(firstResult, maxResults, sort);
116 }
117
118 public void decode(ExtendedObjectInput in, Object v) throws IOException,
119 ClassNotFoundException, IllegalAccessException,
120 InvocationTargetException {
121 }
122
123 private boolean checkSort(String[] orderBys, boolean[] orderDescs) {
124 if (orderBys != null) {
125 if (orderDescs == null)
126 throw new IllegalArgumentException("orderBys == " + Arrays.toString(orderBys) + " but sortDescs == null");
127 if (orderDescs.length != orderBys.length)
128 throw new IllegalArgumentException("orderBys == " + Arrays.toString(orderBys) + " but sortDescs == " + Arrays.toString(orderBys));
129 return orderBys.length > 0;
130 }
131 else if (orderDescs != null)
132 throw new IllegalArgumentException("orderBys == null but sortDescs != null");
133 return false;
134 }
135 }