com.jk.data.dynamic.paging.DataBasePager Maven / Gradle / Ivy

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/*
 * Copyright 2002-2022 Dr. Jalal Kiswani. 
 * Email: [email protected]
 * Check out https://smart-api.com for more details
 * 
 * All the opensource projects of Dr. Jalal Kiswani are free for personal and academic use only, 
 * for commercial usage and support, please contact the author.
 *
 * 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.jk.data.dynamic.paging;

import javax.sql.rowset.CachedRowSet;

import com.jk.core.util.JKDebugUtil;
import com.jk.data.dataaccess.JKDataAccessFactory;
import com.jk.data.dataaccess.core.JKDataAccessService;
import com.jk.data.datasource.JKDataSource;

// TODO: Auto-generated Javadoc
/**
 * The Class DataBasePager.
 */
public class DataBasePager implements DataPager {

	/**
	 * The main method.
	 *
	 * @param args the arguments
	 */
	// /////////////////////////////////////////////////////
	public static void main(final String[] args) {
		final DataBasePager p = new DataBasePager();
		p.setQuery("SELECT * FROM GEN_NATIONAL_NUMBERS");
		JKDebugUtil.printCurrentTime(1);
		System.out.println(p.getAllRowsCount());
		JKDebugUtil.printCurrentTime(2);
		System.out.println(p.getPagesCount());
		JKDebugUtil.printCurrentTime(3);
		p.moveToFirstPage();
		JKDebugUtil.printCurrentTime(4);
		p.moveToNextPage();
		JKDebugUtil.printCurrentTime(5);
		p.moveToNextPage();
		JKDebugUtil.printCurrentTime(6);
		p.moveToNextPage();
		JKDebugUtil.printCurrentTime(7);
		// p.moveToNextPage();
		// p.moveToNextPage();
		// p.moveToNextPage();
		// p.moveToLastPage();

	}

	/** The query. */
	private String query;

	/** The page rows count. */
	private int pageRowsCount = -1;

	/** The pages count. */
	private int pagesCount;

	/** The current page. */
	private int currentPage;

	/** The all rows count. */
	private int allRowsCount;

	/** The datasource. */
	JKDataSource datasource;

	/** The data access. */
	JKDataAccessService dataAccess = JKDataAccessFactory.getDataAccessService();

	/** The result set. */
	private CachedRowSet resultSet;

	/**
	 * Instantiates a new data base pager.
	 */
	// /////////////////////////////////////////////////////
	public DataBasePager() {
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.jk.db.test.dynamic.paging.DataPager#getAllRowsCount()
	 */
	/**
	 * Gets the all rows count.
	 *
	 * @return the all rows count
	 */
	// /////////////////////////////////////////////////////
	@Override
	public int getAllRowsCount() {
		return this.allRowsCount;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.jk.db.test.dynamic.paging.DataPager#getCurrentPage()
	 */
	/**
	 * Gets the current page.
	 *
	 * @return the current page
	 */
	// /////////////////////////////////////////////////////
	@Override
	public int getCurrentPage() {
		return this.currentPage;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.jk.db.test.dynamic.paging.DataPager#getPageRowsCount()
	 */
	/**
	 * Gets the page rows count.
	 *
	 * @return the page rows count
	 */
	// /////////////////////////////////////////////////////
	@Override
	public int getPageRowsCount() {
		return this.pageRowsCount == -1 ? JKDataAccessFactory.getDefaultDataSource().getRowsLimit() : this.pageRowsCount;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.jk.db.test.dynamic.paging.DataPager#getPagesCount()
	 */
	/**
	 * Gets the pages count.
	 *
	 * @return the pages count
	 */
	// /////////////////////////////////////////////////////
	@Override
	public int getPagesCount() {
		return this.pagesCount;
	}

	/**
	 * Gets the query.
	 *
	 * @return the query
	 */
	// /////////////////////////////////////////////////////
	public String getQuery() {
		return this.query;
	}

	/**
	 * Gets the result set.
	 *
	 * @return the result set
	 */
	public CachedRowSet getResultSet() {
		return this.resultSet;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.jk.db.test.dynamic.paging.DataPager#moveToFirstPage()
	 */
	/**
	 * Move to first page.
	 *
	 * @throws PagingException the paging exception
	 */
	// /////////////////////////////////////////////////////
	@Override
	public void moveToFirstPage() throws PagingException {
		final int currentPage = 0;
		moveToPage(currentPage);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.jk.db.test.dynamic.paging.DataPager#moveToLastPage()
	 */
	/**
	 * Move to last page.
	 *
	 * @throws PagingException the paging exception
	 */
	// /////////////////////////////////////////////////////
	@Override
	public void moveToLastPage() throws PagingException {
		moveToPage(getPagesCount() - 1);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.jk.db.test.dynamic.paging.DataPager#moveToNextPage()
	 */
	/**
	 * Move to next page.
	 *
	 * @throws PagingException the paging exception
	 */
	// /////////////////////////////////////////////////////
	@Override
	public void moveToNextPage() throws PagingException {
		moveToPage(this.currentPage + 1);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.jk.db.test.dynamic.paging.DataPager#moveToPage(int)
	 */
	/**
	 * Move to page.
	 *
	 * @param page the page
	 */
	// /////////////////////////////////////////////////////
	@Override
	public void moveToPage(final int page) {
		if (page >= 0 && page < getPagesCount()) {
			try {
				if (this.pagesCount == 1) {
					this.resultSet = dataAccess.executeQueryAsCachedRowSet(this.query);
				} else {
					this.resultSet = dataAccess.executeQueryAsCachedRowSet(this.query, page * getPageRowsCount(),
							page * getPageRowsCount() + getPageRowsCount());
				}
				this.currentPage = page;
				// dataAccess.printRecordResultSet(resultSet);
			} catch (final Exception e) {
				throw new PagingException(e);
			}
		} else {
			this.resultSet = null;
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.jk.db.test.dynamic.paging.DataPager#moveToPreviousePage()
	 */
	/**
	 * Move to previouse page.
	 *
	 * @throws PagingException the paging exception
	 */
	// /////////////////////////////////////////////////////
	@Override
	public void moveToPreviousePage() throws PagingException {
		moveToPage(this.currentPage - 1);
	}

	/**
	 * Sets the datasource.
	 *
	 * @param datasource the new datasource
	 */
	// /////////////////////////////////////////////////////
	public void setDatasource(final JKDataSource datasource) {
		this.datasource = datasource;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.jk.db.test.dynamic.paging.DataPager#setPageRowsCount(int)
	 */
	/**
	 * Sets the page rows count.
	 *
	 * @param pageRowsCount the new page rows count
	 */
	// /////////////////////////////////////////////////////
	@Override
	public void setPageRowsCount(final int pageRowsCount) {
		this.pageRowsCount = pageRowsCount;
	}

	/**
	 * Sets the query.
	 *
	 * @param query the new query
	 */
	// /////////////////////////////////////////////////////
	public void setQuery(final String query) {
		this.query = query;
		if (getPageRowsCount() == 0) {
			this.pagesCount = 1;
		} else {
			this.allRowsCount = dataAccess.getRowsCount(query);
			if (this.allRowsCount <= getPageRowsCount()) {
				this.pagesCount = 1;
			} else {
				this.pagesCount = this.allRowsCount / getPageRowsCount();
				if (this.allRowsCount % getPageRowsCount() > 0) {
					this.pagesCount++;
				}
			}
		}
		moveToPage(getCurrentPage());
	}
}