001/*
002  GRANITE DATA SERVICES
003  Copyright (C) 2011 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
021package org.granite.logging;
022
023import java.lang.reflect.Array;
024import java.util.ArrayList;
025import java.util.Arrays;
026import java.util.Calendar;
027import java.util.Collection;
028import java.util.Date;
029import java.util.Formattable;
030import java.util.HashMap;
031import java.util.List;
032import java.util.Map;
033
034/**
035 * @author Franck WOLFF
036 */
037public class DefaultLoggingFormatter implements LoggingFormatter {
038
039    private static final int MAX_COLLECTION_ITEMS = 100;
040
041    private final int maxItems;
042
043    public DefaultLoggingFormatter() {
044        this(MAX_COLLECTION_ITEMS);
045    }
046
047    public DefaultLoggingFormatter(int maxItems) {
048        this.maxItems = maxItems;
049    }
050
051    public String format(String message, Object... args) {
052        try {
053            for (int i = 0; i < args.length; i++)
054                args[i] = convert(args[i]);
055
056            return String.format(message, args);
057        } catch (Exception e) {
058            try {
059                return "[FORMATTER ERROR] \"" + message + "\"(" + Arrays.toString(args) + ") - " + e;
060            } catch (Exception f) {
061                return "[FORMATTER ERROR] \"" + message + "\"(" + f + ") - " + e;
062            }
063        }
064    }
065
066    protected Object convert(Object o) {
067        if (o == null ||
068            o instanceof Formattable ||
069            o instanceof Number ||
070            o instanceof Character ||
071            o instanceof Boolean ||
072            o instanceof Date ||
073            o instanceof Calendar)
074            return o;
075
076        try {
077            if (o instanceof String) {
078                o = new StringBuilder().append('"').append(o).append('"').toString();
079            }
080            else if (o.getClass().isArray()) {
081                Class<?> type = o.getClass().getComponentType();
082
083                if (maxItems < 0) {
084                    if (type.isPrimitive()) {
085                        if (type == Byte.TYPE)
086                            return Arrays.toString((byte[])o);
087                        if (type == Character.TYPE)
088                            return Arrays.toString((char[])o);
089                        if (type == Integer.TYPE)
090                             return Arrays.toString((int[])o);
091                        if (type == Double.TYPE)
092                            return Arrays.toString((double[])o);
093                        if (type == Long.TYPE)
094                            return Arrays.toString((long[])o);
095                        if (type == Float.TYPE)
096                            return Arrays.toString((float[])o);
097                        if (type == Short.TYPE)
098                            return Arrays.toString((short[])o);
099                        if (type == Boolean.TYPE)
100                            return Arrays.toString((boolean[])o);
101                        return "[Array of unknown primitive type: " + type + "]"; // Should never append...
102                    }
103                    return Arrays.toString((Object[])o);
104                }
105
106                final int max = Math.min(maxItems, Array.getLength(o));
107                List<Object> list = new ArrayList<Object>(max);
108
109                for (int i = 0; i < max; i++)
110                    list.add(Array.get(o, i));
111                if (max < Array.getLength(o))
112                    list.add("(first " + max + '/' + Array.getLength(o) + " elements only...)");
113
114                o = list;
115            }
116            else if (o instanceof Collection<?> && maxItems >= 0) {
117
118                Collection<?> coll = (Collection<?>)o;
119                final int max = Math.min(maxItems, coll.size());
120                List<Object> list = new ArrayList<Object>(max);
121
122                int i = 0;
123                for (Object item : coll) {
124                    if (i >= max) {
125                        list.add("(first " + max + '/' + coll.size() + " elements only...)");
126                        break;
127                    }
128                    list.add(item);
129                    i++;
130                }
131
132                o = list;
133            }
134            else if (o instanceof Map<?, ?> && maxItems >= 0) {
135                Map<?, ?> map = (Map<?, ?>)o;
136                final int max = Math.min(maxItems, map.size());
137                Map<Object, Object> copy = new HashMap<Object, Object>(max);
138
139                int i = 0;
140                for (Map.Entry<?, ?> item : map.entrySet()) {
141                    if (i >= max) {
142                        copy.put("(first " + max + '/' + map.size() + " elements only...)", "...");
143                        break;
144                    }
145                    copy.put(item.getKey(), item.getValue());
146                    i++;
147                }
148
149                o = copy;
150            }
151            else {
152                o = o.toString();
153            }
154
155            return o;
156        } catch (Exception e) {
157            return o.getClass().getName() + " (exception: " + e.toString() + ")";
158        }
159    }
160}