001 /*
002 GRANITE DATA SERVICES
003 Copyright (C) 2013 GRANITE DATA SERVICES S.A.S.
004
005 This file is part of Granite Data Services.
006
007 Granite Data Services is free software; you can redistribute it and/or modify
008 it under the terms of the GNU Library General Public License as published by
009 the Free Software Foundation; either version 2 of the License, or (at your
010 option) any later version.
011
012 Granite Data Services is distributed in the hope that it will be useful, but
013 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
014 FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
015 for more details.
016
017 You should have received a copy of the GNU Library General Public License
018 along with this library; if not, see <http://www.gnu.org/licenses/>.
019 */
020
021 package org.granite.spring.data;
022
023 import java.io.IOException;
024 import java.lang.reflect.Field;
025 import java.lang.reflect.InvocationTargetException;
026 import java.util.ArrayList;
027 import java.util.Arrays;
028 import java.util.List;
029
030 import org.granite.messaging.jmf.ExtendedObjectInput;
031 import org.granite.messaging.jmf.ExtendedObjectOutput;
032 import org.granite.messaging.jmf.codec.ExtendedObjectCodec;
033 import org.springframework.data.domain.Page;
034 import org.springframework.data.domain.PageRequest;
035 import org.springframework.data.domain.Pageable;
036 import org.springframework.data.domain.Sort;
037 import org.springframework.data.domain.Sort.Direction;
038 import org.springframework.data.domain.Sort.Order;
039
040 /**
041 * @author Franck WOLFF
042 */
043 public class PageableCodec implements ExtendedObjectCodec {
044
045 private static final Field pageableField;
046 static {
047 Field pageableFieldTmp = null;
048 try {
049 pageableFieldTmp = Page.class.getDeclaredField("pageable");
050 pageableFieldTmp.setAccessible(true);
051 }
052 catch (NoSuchFieldException e) {
053 // Other exception mean that Spring Data is not present
054 // Don't catch so codec is not installed
055 }
056 pageableField = pageableFieldTmp;
057 }
058
059 public PageableCodec() {
060 }
061
062 public boolean canEncode(ExtendedObjectOutput out, Object v) {
063 return v instanceof Page;
064 }
065
066 public String getEncodedClassName(ExtendedObjectOutput out, Object v) {
067 return org.granite.tide.data.model.Page.class.getName();
068 }
069
070 public void encode(ExtendedObjectOutput out, Object v) throws IOException, IllegalAccessException, InvocationTargetException {
071 @SuppressWarnings("unchecked")
072 Page<Object> springPage = (Page<Object>)v;
073
074 int offset;
075 if (pageableField == null)
076 offset = springPage.getNumber() * springPage.getSize();
077 else {
078 Pageable springPageable = (Pageable)pageableField.get(springPage);
079 offset = springPageable.getOffset();
080 }
081
082 out.writeObject(Integer.valueOf(offset));
083 out.writeObject(Integer.valueOf(springPage.getSize()));
084 out.writeObject(Integer.valueOf((int)springPage.getTotalElements()));
085 out.writeObject(new ArrayList<Object>(springPage.getContent()));
086 }
087
088 public boolean canDecode(ExtendedObjectInput in, String className) throws ClassNotFoundException {
089 return org.granite.tide.data.model.PageInfo.class.getName().equals(className);
090 }
091
092 public String getDecodedClassName(ExtendedObjectInput in, String className) {
093 return PageRequest.class.getName();
094 }
095
096 public Object newInstance(ExtendedObjectInput in, String className)
097 throws IOException, ClassNotFoundException, InstantiationException,
098 IllegalAccessException, InvocationTargetException,
099 SecurityException, NoSuchMethodException {
100
101 int firstResult = ((Integer)in.readObject()).intValue();
102 int maxResults = ((Integer)in.readObject()).intValue();
103 String[] orderBys = (String[])in.readObject();
104 boolean[] orderDescs = (boolean[])in.readObject();
105
106 Sort sort = null;
107 if (checkSort(orderBys, orderDescs)) {
108 List<Order> orders = new ArrayList<Order>(orderBys.length);
109 for (int i = 0; i < orderBys.length; i++)
110 orders.add(new Order(orderDescs[i] ? Direction.DESC : Direction.ASC, orderBys[i]));
111 sort = new Sort(orders);
112 }
113
114 return new PageRequest(maxResults > 0 ? firstResult / maxResults : 0, maxResults, sort);
115 }
116
117 public void decode(ExtendedObjectInput in, Object v) throws IOException,
118 ClassNotFoundException, IllegalAccessException,
119 InvocationTargetException {
120 }
121
122 private boolean checkSort(String[] orderBys, boolean[] orderDescs) {
123 if (orderBys != null) {
124 if (orderDescs == null)
125 throw new IllegalArgumentException("orderBys == " + Arrays.toString(orderBys) + " but sortDescs == null");
126 if (orderDescs.length != orderBys.length)
127 throw new IllegalArgumentException("orderBys == " + Arrays.toString(orderBys) + " but sortDescs == " + Arrays.toString(orderBys));
128 return orderBys.length > 0;
129 }
130 else if (orderDescs != null)
131 throw new IllegalArgumentException("orderBys == null but sortDescs != null");
132 return false;
133 }
134 }