Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
import java.util.Collection;
import java.util.List;
import com.google.common.collect.ForwardingList;

public class Main {
    /**
     * Returns a decorated list with a limited amount of elements.
     * @param decorated the decorated list to be limited
     * @param maxSize the maximum size of the list
     * @param silent if true, when an element is added, and the maximum size has been reached, 
     * it silently ignores the operation, otherwise it throws an exception
     * @return the newly decorated list
     * @throws IllegalArgumentException if the decorated list has already more elements than maxSize
     */
    public static <T> List<T> maxSizeLimit(final List<T> decorated, final int maxSize, final boolean silent) {
        if (decorated.size() > maxSize) {
            throw new IllegalArgumentException("The list contains already more elements than " + maxSize);
        }
        return new ForwardingList<T>() {
            @Override
            public boolean addAll(Collection<? extends T> collection) {
                return standardAddAll(collection);
            }

            @Override
            public boolean addAll(int index, Collection<? extends T> elements) {
                return standardAddAll(index, elements);
            }

            public boolean add(T e) {
                if (!checkMaxSize())
                    return false;
                return delegate().add(e);
            }

            @Override
            public void add(final int index, final T e) {
                if (!checkMaxSize())
                    return;
                delegate().add(index, e);
            }

            private boolean checkMaxSize() {
                if (size() >= maxSize) {
                    if (silent) {
                        return false;
                    }
                    throw new UnsupportedOperationException("Maximum Size " + maxSize + " reached");
                }
                return true;
            }

            @Override
            protected List<T> delegate() {
                return decorated;
            }
        };
    }
}