Java Collection Max format(String theLabel, Collection coll, int maxNumberReported, String theClassName)

Here you can find the source of format(String theLabel, Collection coll, int maxNumberReported, String theClassName)

Description

Format a collection, array, or map (internal method).

License

Open Source License

Parameter

Parameter Description
theLabel a parameter
coll a parameter
maxNumberReported a parameter
theClassName a parameter

Return

The formatted collection, spans multiple lines.

Declaration

private static String format(String theLabel, Collection<?> coll, int maxNumberReported, String theClassName) 

Method Source Code


//package com.java2s;
/*/* w  w  w.ja v  a 2  s . co m*/
 * logic2j - "Bring Logic to your Java" - Copyright (C) 2011 Laurent.Tettoni@gmail.com
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

import java.util.*;
import java.util.Map.Entry;

public class Main {
    /**
     * Format a collection, array, or map (internal method).
     *
     * @param theLabel
     * @param coll
     * @param maxNumberReported
     * @param theClassName
     * @return The formatted collection, spans multiple lines.
     */
    private static String format(String theLabel, Collection<?> coll, int maxNumberReported, String theClassName) {
        final boolean showCollectionIndexes = false;
        final int half = (maxNumberReported == 0) ? 10000 : ((maxNumberReported - 1) / 2) + 1;

        String label = theLabel;
        if (label == null) {
            label = "";
        }

        final Map<Class<?>, Integer> instancesByClass = new HashMap<Class<?>, Integer>();
        final StringBuilder sb = new StringBuilder(label);

        if (label.length() > 0) {
            sb.append(' ');
        }

        final int size = (coll != null) ? coll.size() : 0;

        if (size > 0) {
            sb.append('\n');
        }

        int counter = 0;
        boolean shownEllipsis = false;

        if (coll == null) {
            sb.append("null Collection or Map");
            return sb.toString();
        }

        for (final Object element : coll) {
            // Statistics
            final Class<?> theElementClass = (element != null) ? element.getClass() : null;
            Integer nbrOfThisClass = instancesByClass.get(theElementClass);

            if (nbrOfThisClass == null) {
                nbrOfThisClass = 0;
            }
            nbrOfThisClass = nbrOfThisClass.intValue() + 1;
            instancesByClass.put(theElementClass, nbrOfThisClass);

            // Report
            if (counter < half || counter >= size - half) {
                if (element instanceof Entry<?, ?>) {
                    final Entry<?, ?> entry = (Entry<?, ?>) element;
                    if (entry.getValue() instanceof Collection<?>) {
                        final int colLSize = ((Collection<?>) entry.getValue()).size();
                        sb.append(" ").append(entry.getKey()).append('[').append(colLSize).append("]=")
                                .append(entry.getValue()).append('\n');
                    } else {
                        sb.append(" ").append(entry.getKey()).append('=').append(entry.getValue()).append('\n');
                    }
                } else {
                    sb.append(' ');
                    if (showCollectionIndexes) {
                        sb.append('[');
                        sb.append(counter);
                        sb.append("]=");
                    }
                    sb.append(String.valueOf(element));
                    sb.append('\n');
                }
            } else {
                if (!shownEllipsis) {
                    sb.append(" [").append(half).append('-').append(size - half - 1).append("]=(")
                            .append(size - half - half).append(" skipped)\n");
                }
                shownEllipsis = true;
            }
            counter++;
        }

        // Special case for Arrays$ArrayList
        String className = theClassName;
        if ("Arrays$ArrayList".equals(className)) {
            className = "Object[]";
        }
        sb.append(className);
        sb.append(" size=");
        sb.append(size);

        if (!className.endsWith("Map")) {
            // Report number of classes
            for (final Entry<Class<?>, Integer> entry : instancesByClass.entrySet()) {
                final Class<?> key = entry.getKey();
                final Integer value = entry.getValue();
                sb.append(", ");
                sb.append(value);
                sb.append(' ');
                sb.append(key.getSimpleName());
            }
        }
        sb.append('.');
        return sb.toString();
    }

    /**
     * Generate a usually multiline String reporting a collection's elements. If the collection is a Map.entrySet(), actually if elements
     * are instances of Map.Entry then their key is reported instead of the element's index.
     *
     * @param theLabel A label to display first, as is without change. If null, "" is used.
     * @param coll A collection whose elements will be listed (if not too large)
     * @param maxNumberReported The maximum number of elements to report in case of large collections, or 0 to report all whatever the size.
     * @return A usually multiline String describing the collection. This can be logged, or output to System.out, for instance. If the
     *         collection is empty, one line is output. If the collection is large, only the first and last elements are output, while "..."
     *         is shown in the middle.
     */
    public static String format(String theLabel, Collection<?> coll, int maxNumberReported) {
        String label = theLabel;
        if (coll == null) {
            if (label == null) {
                label = "";
            }
            return label + " null Collection";
        }
        return format(label, coll, maxNumberReported, coll.getClass().getSimpleName());
    }

    /**
     * Generate a usually multiline String reporting an array's elements.
     *
     * @param theLabel See related function.
     * @param array See related function.
     * @param maxNumberReported See related function.
     * @return See related function.
     * @see #format(String, java.util.Collection, int)
     */
    public static String format(String theLabel, Object[] array, int maxNumberReported) {
        String label = theLabel;
        if (array == null) {
            if (label == null) {
                label = "";
            }
            return label + " null Object[]";
        }
        return format(label, Arrays.asList(array), maxNumberReported, "Object[]");
    }

    /**
     * Generate a usually multiline String reporting a Map's entries.
     *
     * @param theLabel See related function.
     * @param map See related function.
     * @param maxNumberReported See related function.
     * @return See related function.
     * @see #format(String, java.util.Collection, int)
     */
    public static String format(String theLabel, Map<?, ?> map, int maxNumberReported) {
        String label = theLabel;
        if (map == null) {
            if (label == null) {
                label = "";
            }
            return label + " null Map";
        }
        return format(label, map.entrySet(), maxNumberReported, map.getClass().getSimpleName());
    }
}

Related

  1. calculateMaxTime(Collection times)
  2. getMaximumElementLength(final Collection collection)
  3. max(Collection coll)
  4. max(Collection data)
  5. max(Collection doubles)