基於Spring JdbcTemplate 的分頁處理

1.JdbcPaginationHelper.java

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.ResultSetExtractor;
import org.springframework.jdbc.core.simple.ParameterizedRowMapper;
import org.tshark.core.orm.Page;

public class JdbcPaginationHelper<T> {
	private static final int DEFAULT_PAGE_SIZE = 30;

	public Page<T> fetchPage(final JdbcTemplate jdbcTemplate, final String countSql, final String dataSql, final Object args[],
			final int pageNo, final ParameterizedRowMapper<T> rowMapper) {
		return fetchPage(jdbcTemplate, countSql, dataSql, args, pageNo, DEFAULT_PAGE_SIZE, rowMapper);
	}

	public Page<T> fetchPage(final JdbcTemplate jdbcTemplate, final String countSql, final String dataSql, final Object args[],
			final int pageNo, final int pageSize, final ParameterizedRowMapper<T> rowMapper) {
		// 總記錄數據
		final int rowCount = jdbcTemplate.queryForInt(countSql, args);
		// 計算總頁數
		int pageCount = rowCount / pageSize;
		if (rowCount > pageSize * pageCount) {
			pageCount++;
		}
		final Page<T> page = new Page<T>();
		page.setPageNo(pageNo);
		page.setTotalCount(pageCount);
		page.setPageSize(pageSize);
		// 根據pageNo取一頁數據
		final int startRow = (pageNo - 1) * pageSize;
		jdbcTemplate.query(dataSql, args, new ResultSetExtractor<Page<T>>() {
			public Page<T> extractData(ResultSet rs) throws SQLException, DataAccessException {
				final List<T> pageItems = page.getResult();
				int currentRow = 0;
				while (rs.next() && currentRow < startRow + pageSize) {
					if (currentRow >= startRow) {
						pageItems.add(rowMapper.mapRow(rs, currentRow));
					}
					currentRow++;
				}
				return page;
			}
		});
		return page;
	}
}

2.Page.java

import java.util.List;

import org.apache.commons.lang.StringUtils;

import com.google.common.collect.Lists;

/**
 * @param <T> Page中記錄的類型.
 */
public class Page<T> {
	//-- 公共變量 --//
	public static final String ASC = "asc";
	public static final String DESC = "desc";

	//-- 分頁參數 --//
	protected int pageNo = 1;
	protected int pageSize = 1;
	protected String orderBy = null;
	protected String order = null;
	protected boolean autoCount = true;

	protected List<T> result = Lists.newArrayList();
	protected long totalCount = -1;

	public Page() {
	}

	public Page(int pageSize) {
		this.pageSize = pageSize;
	}
	/**
	 * 獲得當前頁的頁號,序號從1開始,默認爲1.
	 */
	public int getPageNo() {
		return pageNo;
	}

	/**
	 * 設置當前頁的頁號,序號從1開始,低於1時自動調整爲1.
	 */
	public void setPageNo(final int pageNo) {
		this.pageNo = pageNo;

		if (pageNo < 1) {
			this.pageNo = 1;
		}
	}

	public Page<T> pageNo(final int thePageNo) {
		setPageNo(thePageNo);
		return this;
	}

	/**
	 * 獲得每頁的記錄數量,默認爲1.
	 */
	public int getPageSize() {
		return pageSize;
	}

	/**
	 * 設置每頁的記錄數量,低於1時自動調整爲1.
	 */
	public void setPageSize(final int pageSize) {
		this.pageSize = pageSize;

		if (pageSize < 1) {
			this.pageSize = 1;
		}
	}

	public Page<T> pageSize(final int thePageSize) {
		setPageSize(thePageSize);
		return this;
	}

	/**
	 * 根據pageNo和pageSize計算當前頁第一條記錄在總結果集中的位置,序號從1開始.
	 */
	public int getFirst() {
		return ((pageNo - 1) * pageSize) + 1;
	}

	/**
	 * 獲得排序字段,無默認值.多個排序字段時用','分隔.
	 */
	public String getOrderBy() {
		return orderBy;
	}

	/**
	 * 設置排序字段,多個排序字段時用','分隔.
	 */
	public void setOrderBy(final String orderBy) {
		this.orderBy = orderBy;
	}

	public Page<T> orderBy(final String theOrderBy) {
		setOrderBy(theOrderBy);
		return this;
	}

	/**
	 * 獲得排序方向.
	 */
	public String getOrder() {
		return order;
	}

	/**
	 * 設置排序方式向.
	 *
	 * @param order 可選值爲desc或asc,多個排序字段時用','分隔.
	 */
	public void setOrder(final String order) {
		//檢查order字符串的合法值
		String[] orders = StringUtils.split(StringUtils.lowerCase(order), ',');
		if(orders != null){
			for (String orderStr : orders) {
				if (!StringUtils.equals(DESC, orderStr) && !StringUtils.equals(ASC, orderStr)) {
					throw new IllegalArgumentException("排序方向" + orderStr + "不是合法值");
				}
			}
		}

		this.order = StringUtils.lowerCase(order);
	}

	public Page<T> order(final String theOrder) {
		setOrder(theOrder);
		return this;
	}

	/**
	 * 是否已設置排序字段,無默認值.
	 */
	public boolean isOrderBySetted() {
		return (StringUtils.isNotBlank(orderBy) && StringUtils.isNotBlank(order));
	}

	/**
	 * 查詢對象時是否自動另外執行count查詢獲取總記錄數, 默認爲false.
	 */
	public boolean isAutoCount() {
		return autoCount;
	}

	/**
	 * 查詢對象時是否自動另外執行count查詢獲取總記錄數.
	 */
	public void setAutoCount(final boolean autoCount) {
		this.autoCount = autoCount;
	}

	public Page<T> autoCount(final boolean theAutoCount) {
		setAutoCount(theAutoCount);
		return this;
	}

	//-- 訪問查詢結果函數 --//

	/**
	 * 取得頁內的記錄列表.
	 */
	public List<T> getResult() {
		return result;
	}

	/**
	 * 設置頁內的記錄列表.
	 */
	public void setResult(final List<T> result) {
		this.result = result;
	}

	/**
	 * 取得總記錄數, 默認值爲-1.
	 */
	public long getTotalCount() {
		return totalCount;
	}

	/**
	 * 設置總記錄數.
	 */
	public void setTotalCount(final long totalCount) {
		this.totalCount = totalCount;
	}

	/**
	 * 根據pageSize與totalCount計算總頁數, 默認值爲-1.
	 */
	public long getTotalPages() {
		if (totalCount < 0) {
			return -1;
		}

		long count = totalCount / pageSize;
		if (totalCount % pageSize > 0) {
			count++;
		}
		return count;
	}

	/**
	 * 是否還有下一頁.
	 */
	public boolean isHasNext() {
		return (pageNo + 1 <= getTotalPages());
	}

	/**
	 * 取得下頁的頁號, 序號從1開始.
	 * 當前頁爲尾頁時仍返回尾頁序號.
	 */
	public int getNextPage() {
		if (isHasNext()) {
			return pageNo + 1;
		} else {
			return pageNo;
		}
	}

	/**
	 * 是否還有上一頁.
	 */
	public boolean isHasPre() {
		return (pageNo - 1 >= 1);
	}

	/**
	 * 取得上頁的頁號, 序號從1開始.
	 * 當前頁爲首頁時返回首頁序號.
	 */
	public int getPrePage() {
		if (isHasPre()) {
			return pageNo - 1;
		} else {
			return pageNo;
		}
	}
}

3.TransactionJdbcService.java

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import org.springframework.jdbc.core.PreparedStatementSetter;
import org.springframework.jdbc.core.simple.ParameterizedRowMapper;
import org.springframework.stereotype.Service;
import org.tshark.core.orm.Page;
import org.tshark.core.service.AbstractJdbcService;
import org.tshark.core.service.JdbcPaginationHelper;
import org.tshark.framework.model.TransactionModel;

@Service
public class TransactionJdbcService extends AbstractJdbcService {
	private static String QUERY_TRANS_COUNT_SQL = "select count(*) from sys_transaction  ";
	private static String QUERY_TRANS_DATA_SQL = "select * from sys_transaction ";
	private static String INSERT_TRANS_SQL = "insert into `sys_transaction` (`amount`,`month`,`region`) values(?,?,?) ";
	@Transient
	protected JdbcTemplate jdbcTemplate;


	@Resource
	public void setDataSource(DataSource dataSource) {
		jdbcTemplate = new JdbcTemplate(dataSource);
	}
	public void insertTransaction(final TransactionModel transaction) {
		jdbcTemplate.update(INSERT_TRANS_SQL, new PreparedStatementSetter() {
			@Override
			public void setValues(PreparedStatement ps) throws SQLException {
				ps.setDouble(1, transaction.getAmount());
				ps.setInt(2, transaction.getMonth());
				ps.setString(3, transaction.getRegion());
			}
		});
	}

	public Page<TransactionModel> findTransactionList(int pageNo, int month) {
		Object[] args = null;
		if (month != 0) {
			QUERY_TRANS_COUNT_SQL += "where month=?";
			QUERY_TRANS_DATA_SQL += "where month=?";
			args = new Object[] { month };
		}
		JdbcPaginationHelper<TransactionModel> JdbcPaginationHelper = new JdbcPaginationHelper<TransactionModel>();
		return JdbcPaginationHelper.fetchPage(jdbcTemplate, QUERY_TRANS_COUNT_SQL, QUERY_TRANS_DATA_SQL, args, pageNo,
				new TransactionRowMap());
	}

	class TransactionRowMap implements ParameterizedRowMapper<TransactionModel> {

		@Override
		public TransactionModel mapRow(ResultSet rs, int rowNum) throws SQLException {
			TransactionModel transaction = new TransactionModel();
			transaction.setId(rs.getLong("id"));
			transaction.setAmount(rs.getDouble("amount"));
			transaction.setMonth(rs.getInt("month"));
			transaction.setRegion(rs.getString("region"));
			return transaction;
		}

	}
}