de.kaiserpfalzEdv.commons.jee.persistence.impl.PageRequestImpl.java Source code

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Here is the source code for de.kaiserpfalzEdv.commons.jee.persistence.impl.PageRequestImpl.java

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/*
 * Copyright 2015 Kaiserpfalz EDV-Service Roland Lichti
 *
 * 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 de.kaiserpfalzEdv.commons.jee.persistence.impl;

import de.kaiserpfalzEdv.commons.jee.persistence.CRUDOrder;
import de.kaiserpfalzEdv.commons.jee.persistence.PageRequest;
import org.apache.commons.lang3.builder.ToStringBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

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

import static com.google.common.base.Preconditions.checkArgument;

/**
 * This is the request for a given page.
 *
 * @author klenkes
 * @since 1.0
 */
public class PageRequestImpl implements PageRequest, Serializable {
    private static final long serialVersionUID = -7739663953536959586L;

    /**
     * Developer's logger.
     */
    private static final Logger LOG = LoggerFactory.getLogger(PageRequestImpl.class);

    /**
     * The start row of the page that should be generated.
     */
    private int startRow;

    /**
     * The size of the page that should be generated.
     */
    private int pageSize;

    private final ArrayList<CRUDOrder> order = new ArrayList<>();

    /**
     * Creates a new page request. Need's a start row and a page size.
     *
     * @param startRow The start row of the result set. Must not be negative.
     * @param pageSize The page size of the result set. Must be a positive long value.
     * @throws IllegalArgumentException if any parameter is negative or the page size is zero.
     */
    public PageRequestImpl(final int startRow, final int pageSize) {
        checkArgument(startRow >= 0, "'%s' is not valid as start row counter.", startRow);
        checkArgument(pageSize > 0, "'%s' is not valid as page size.", pageSize);

        this.startRow = startRow;
        this.pageSize = pageSize;

        LOG.trace("Created: {}", this);
    }

    @Override
    public int getStartRow() {
        return startRow;
    }

    @Override
    public int getPageSize() {
        return pageSize;
    }

    @Override
    public List<CRUDOrder> getOrder() {
        return order;
    }

    @Override
    public PageRequestImpl orderBy(String sortField) {
        return orderBy(sortField, CRUDOrder.ASCENDING);
    }

    @Override
    public PageRequestImpl orderBy(String sortField, CRUDOrder.Direction sortOrder) {
        order.add(new CRUDOrder(sortField, sortOrder));

        return this;
    }

    @Override
    public PageRequestImpl orderBy(CRUDOrder order) {
        this.order.add(order);

        return this;
    }

    @Override
    public PageRequestImpl orderBy(CRUDOrder[] order) {
        Collections.addAll(this.order, order);

        return this;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o)
            return true;
        if (!(o instanceof PageRequestImpl))
            return false;

        PageRequestImpl that = (PageRequestImpl) o;

        return pageSize == that.pageSize && startRow == that.startRow;

    }

    @Override
    public int hashCode() {
        int result = startRow;
        result = 31 * result + pageSize;
        return result;
    }

    @Override
    public String toString() {
        ToStringBuilder sb = new ToStringBuilder(this).append("startRow", startRow).append("pageSize", pageSize);

        if (!order.isEmpty())
            sb.append("ordered", order);

        return sb.toString();
    }
}