Pagination.java

package com.aperture_software.glados_wiki.support;

import org.apache.commons.lang3.builder.EqualsBuilder;
import org.apache.commons.lang3.builder.HashCodeBuilder;
import org.apache.commons.lang3.builder.ToStringBuilder;

import java.io.Serializable;

/**
 * Created by jhyun on 13. 12. 21.
 */
public class Pagination implements Cloneable, Serializable {

    private static final long serialVersionUID = -5717010280390030616L;

    private long totalRows;

    private long currentOffsetRow;

    private long rowsPerPage;

    public Pagination(long totalRows, long currentOffsetRow, long rowsPerPage) {
        this.totalRows = totalRows;
        this.currentOffsetRow = currentOffsetRow;
        this.rowsPerPage = rowsPerPage;
    }

    public long getTotalRows() {
        return totalRows;
    }

    public void setTotalRows(long totalRows) {
        this.totalRows = totalRows;
    }

    public long getCurrentOffsetRow() {
        return currentOffsetRow;
    }

    public void setCurrentOffsetRow(long currentOffsetRow) {
        this.currentOffsetRow = currentOffsetRow;
    }

    public long getRowsPerPage() {
        return rowsPerPage;
    }

    public void setRowsPerPage(long rowsPerPage) {
        this.rowsPerPage = rowsPerPage;
    }

    /**
     * 전체 페이지 갯수.
     *
     * @return 전체 페이지 갯수. 최소 1.
     */
    public long getMaxPage() {
        if (this.totalRows < this.rowsPerPage || this.rowsPerPage < 1) {
            return 1;
        } else {
            return new Double(Math.ceil((float) this.totalRows / (float) this.rowsPerPage)).longValue();
        }
    }

    /**
     * 현재 offset, limit에 따라서 페이지 번호?
     *
     * @return 페이지 값. (0부터 시작.)
     */
    public long getCurrentPage() {
        if (this.totalRows < this.rowsPerPage || this.rowsPerPage < 1) {
            return 0;
        } else {
            return new Double(Math.ceil((float) this.currentOffsetRow / (float) this.rowsPerPage)).longValue();
        }
    }

    public long getNextOffsetRow() {
        if(this.currentOffsetRow >= this.totalRows ||
                this.currentOffsetRow + this.rowsPerPage >= this.totalRows) {
            return -1;
        } else {
            return this.currentOffsetRow + this.rowsPerPage;
        }
    }

    public long getPrevOffsetRow() {
        if(this.currentOffsetRow <= 0) {
            return -1;
        } else {
            return this.currentOffsetRow - this.rowsPerPage;
        }
    }

    public long getMaxOffsetRow() {
        return this.getMaxPage() * this.rowsPerPage;
    }

    @Override
    public int hashCode() {
        return HashCodeBuilder.reflectionHashCode(this);
    }

    @Override
    public boolean equals(Object obj) {
        return EqualsBuilder.reflectionEquals(this, obj);
    }

    @Override
    public Object clone() throws CloneNotSupportedException {
        return super.clone();
    }

    @Override
    public String toString() {
        return ToStringBuilder.reflectionToString(this);
    }
}