Java Collection Convert toLimitLengthString(final Collection coll, final int limit)

Description

Creates a string representation according to the java.util.AbstractCollection#toString() method, but with a limited length param.

License

Open Source License

Parameter

Parameter	Description
E	the type of the elements in the collection
coll	the collection to transformed into string
limit	the maximum number of elements to represented in the string

Return

the (limited length) string representation

Declaration

public static <E> String toLimitLengthString(final Collection<E> coll, final int limit) 

Method Source Code

//package com.java2s;
/*/*from   w w w.ja va 2 s  .co  m*/
 * Copyright (c) 2011 Stiftung Deutsches Elektronen-Synchrotron,
 * Member of the Helmholtz Association, (DESY), HAMBURG, GERMANY.
 *
 * THIS SOFTWARE IS PROVIDED UNDER THIS LICENSE ON AN "../AS IS" BASIS.
 * WITHOUT WARRANTY OF ANY KIND, EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED
 * TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR PARTICULAR PURPOSE AND
 * NON-INFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
 * FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. SHOULD THE SOFTWARE PROVE DEFECTIVE
 * IN ANY RESPECT, THE USER ASSUMES THE COST OF ANY NECESSARY SERVICING, REPAIR OR
 * CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS LICENSE.
 * NO USE OF ANY SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER THIS DISCLAIMER.
 * DESY HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
 * OR MODIFICATIONS.
 * THE FULL LICENSE SPECIFYING FOR THE SOFTWARE THE REDISTRIBUTION, MODIFICATION,
 * USAGE AND OTHER RIGHTS AND OBLIGATIONS IS INCLUDED WITH THE DISTRIBUTION OF THIS
 * PROJECT IN THE FILE LICENSE.HTML. IF THE LICENSE IS NOT INCLUDED YOU MAY FIND A COPY
 * AT HTTP://WWW.DESY.DE/LEGAL/LICENSE.HTM
 */

import java.util.Collection;
import java.util.Iterator;

public class Main {
    /**
     * Creates a string representation according to the {@link java.util.AbstractCollection#toString()}
     * method, but with a limited length param.
     * Such that, if limit is >= the collection's size the original representation is returned,
     * otherwise the collection's representation ends after the limit-th element with
     * ",...]".
     *
     * @param <E> the type of the elements in the collection
     * @param coll the collection to transformed into string
     * @param limit the maximum number of elements to represented in the string
     * @return the (limited length) string representation
     */
    public static <E> String toLimitLengthString(final Collection<E> coll, final int limit) {
        if (fallBackToStandardImplementation(coll, limit)) {
            return coll.toString();
        }
        final Iterator<E> iter = coll.iterator();

        final StringBuilder sb = new StringBuilder();
        sb.append('[');

        final int min = Math.min(coll.size(), limit);
        for (int i = 0; i < min; i++) {
            final E e = iter.next();
            sb.append(e == coll ? "(the collection itself)" : e); // recursive check, when an element is the collection itself
            if (!iter.hasNext() || i + 1 >= min) {
                return sb.append(",...]").toString();
            }
            sb.append(", ");
        }
        return "[]";
    }

    private static <E> boolean fallBackToStandardImplementation(final Collection<E> coll, final int limit) {
        return limit >= coll.size() || limit < 0 || coll.isEmpty();
    }
}

Related

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2. toHtml(Collection collection)
3. toIntegerCollection(int[] ints)
4. toJSONString(Collection collection)
5. tokenSetString(Collection tokens)
6. toLowerCase(Collection values)
7. toMap(Collection names, Object[] parameters)
8. toMatrix(Collection collection)
9. toObjectArray(Collection