com.github.obiteaaron.common.data.FixChunk.java Source code

Introduction

Here is the source code for com.github.obiteaaron.common.data.FixChunk.java

Source

/*
 * Copyright 2014-2015 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.github.obiteaaron.common.data;

import org.springframework.core.convert.converter.Converter;
import org.springframework.data.domain.Pageable;
import org.springframework.data.domain.Slice;
import org.springframework.data.domain.Sort;
import org.springframework.util.Assert;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

/**
 * A chunk of data restricted by the configured {@link Pageable}.
 *
 * @author Oliver Gierke
 * @since 1.8
 */
public abstract class FixChunk<T> implements Slice<T>, Serializable {

    private static final long serialVersionUID = -3557925183561514190L;

    private final List<T> content = new ArrayList<T>();
    private final Pageable pageable;

    /**
     * Creates a new {@link FixChunk} with the given content and the given governing {@link Pageable}.
     *
     * @param content must not be {@literal null}.
     * @param pageable can be {@literal null}.
     */
    public FixChunk(List<T> content, Pageable pageable) {

        Assert.notNull(content, "Content must not be null!");

        this.content.addAll(content);
        this.pageable = pageable;
    }

    public Pageable getPageable() {
        return pageable;
    }

    /*
     * (non-Javadoc)
     * @see org.springframework.data.domain.Slice#getNumber()
     */
    public int getNumber() {
        return pageable == null ? 0 : pageable.getPageNumber();
    }

    /*
     * (non-Javadoc)
     * @see org.springframework.data.domain.Slice#getSize()
     */
    public int getSize() {
        return pageable == null ? 0 : pageable.getPageSize();
    }

    /*
     * (non-Javadoc)
     * @see org.springframework.data.domain.Slice#getNumberOfElements()
     */
    public int getNumberOfElements() {
        return content.size();
    }

    /*
     * (non-Javadoc)
     * @see org.springframework.data.domain.Slice#hasPrevious()
     */
    public boolean hasPrevious() {
        return getNumber() > 0;
    }

    /*
     * (non-Javadoc)
     * @see org.springframework.data.domain.Slice#isFirst()
     */
    public boolean isFirst() {
        return !hasPrevious();
    }

    /*
     * (non-Javadoc)
     * @see org.springframework.data.domain.Slice#isLast()
     */
    public boolean isLast() {
        return !hasNext();
    }

    /*
     * (non-Javadoc)
     * @see org.springframework.data.domain.Slice#nextPageable()
     */
    public Pageable nextPageable() {
        return hasNext() ? pageable.next() : null;
    }

    /*
     * (non-Javadoc)
     * @see org.springframework.data.domain.Slice#previousPageable()
     */
    public Pageable previousPageable() {

        if (hasPrevious()) {
            return pageable.previousOrFirst();
        }

        return null;
    }

    /*
     * (non-Javadoc)
     * @see org.springframework.data.domain.Slice#hasContent()
     */
    public boolean hasContent() {
        return !content.isEmpty();
    }

    /*
     * (non-Javadoc)
     * @see org.springframework.data.domain.Slice#getContent()
     */
    public List<T> getContent() {
        return Collections.unmodifiableList(content);
    }

    /*
     * (non-Javadoc)
     * @see org.springframework.data.domain.Slice#getSort()
     */
    public Sort getSort() {
        return pageable == null ? null : pageable.getSort();
    }

    /*
     * (non-Javadoc)
     * @see java.lang.Iterable#iterator()
     */
    public Iterator<T> iterator() {
        return content.iterator();
    }

    /**
     * Applies the given {@link Converter} to the content of the {@link FixChunk}.
     *
     * @param converter must not be {@literal null}.
     * @return
     */
    protected <S> List<S> getConvertedContent(Converter<? super T, ? extends S> converter) {

        Assert.notNull(converter, "Converter must not be null!");

        List<S> result = new ArrayList<S>(content.size());

        for (T element : this) {
            result.add(converter.convert(element));
        }

        return result;
    }

    /*
     * (non-Javadoc)
     * @see java.lang.Object#equals(java.lang.Object)
     */
    @Override
    public boolean equals(Object obj) {

        if (this == obj) {
            return true;
        }

        if (!(obj instanceof FixChunk<?>)) {
            return false;
        }

        FixChunk<?> that = (FixChunk<?>) obj;

        boolean contentEqual = this.content.equals(that.content);
        boolean pageableEqual = this.pageable == null ? that.pageable == null : this.pageable.equals(that.pageable);

        return contentEqual && pageableEqual;
    }

    /*
     * (non-Javadoc)
     * @see java.lang.Object#hashCode()
     */
    @Override
    public int hashCode() {

        int result = 17;

        result += 31 * (pageable == null ? 0 : pageable.hashCode());
        result += 31 * content.hashCode();

        return result;
    }
}