基于Spring JdbcTemplate 的分页处理

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 {
	private static final int DEFAULT_PAGE_SIZE = 30;

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

	public Page fetchPage(final JdbcTemplate jdbcTemplate, final String countSql, final String dataSql, final Object args[],
			final int pageNo, final int pageSize, final ParameterizedRowMapper rowMapper) {
		// 总记录数据
		final int rowCount = jdbcTemplate.queryForInt(countSql, args);
		// 计算总页数
		int pageCount = rowCount / pageSize;
		if (rowCount > pageSize * pageCount) {
			pageCount++;
		}
		final Page page = new Page();
		page.setPageNo(pageNo);
		page.setTotalCount(pageCount);
		page.setPageSize(pageSize);
		// 根据pageNo取一页数据
		final int startRow = (pageNo - 1) * pageSize;
		jdbcTemplate.query(dataSql, args, new ResultSetExtractor>() {
			public Page extractData(ResultSet rs) throws SQLException, DataAccessException {
				final List 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  Page中记录的类型.
 */
public class Page {
	//-- 公共变量 --//
	public static final String ASC = "asc";
	public static final String DESC = "desc";

	//-- 分页参数 --//
	protected int pageNo = 1;
	protected int pageSize = 1;
	protected String orderBy = null;
	protected String order = null;
	protected boolean autoCount = true;

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

	public Page() {
	}

	public Page(int pageSize) {
		this.pageSize = pageSize;
	}
	/**
	 * 获得当前页的页号,序号从1开始,默认为1.
	 */
	public int getPageNo() {
		return pageNo;
	}

	/**
	 * 设置当前页的页号,序号从1开始,低于1时自动调整为1.
	 */
	public void setPageNo(final int pageNo) {
		this.pageNo = pageNo;

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

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

	/**
	 * 获得每页的记录数量,默认为1.
	 */
	public int getPageSize() {
		return pageSize;
	}

	/**
	 * 设置每页的记录数量,低于1时自动调整为1.
	 */
	public void setPageSize(final int pageSize) {
		this.pageSize = pageSize;

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

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

	/**
	 * 根据pageNo和pageSize计算当前页第一条记录在总结果集中的位置,序号从1开始.
	 */
	public int getFirst() {
		return ((pageNo - 1) * pageSize) + 1;
	}

	/**
	 * 获得排序字段,无默认值.多个排序字段时用','分隔.
	 */
	public String getOrderBy() {
		return orderBy;
	}

	/**
	 * 设置排序字段,多个排序字段时用','分隔.
	 */
	public void setOrderBy(final String orderBy) {
		this.orderBy = orderBy;
	}

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

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

	/**
	 * 设置排序方式向.
	 *
	 * @param order 可选值为desc或asc,多个排序字段时用','分隔.
	 */
	public void setOrder(final String order) {
		//检查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 order(final String theOrder) {
		setOrder(theOrder);
		return this;
	}

	/**
	 * 是否已设置排序字段,无默认值.
	 */
	public boolean isOrderBySetted() {
		return (StringUtils.isNotBlank(orderBy) && StringUtils.isNotBlank(order));
	}

	/**
	 * 查询对象时是否自动另外执行count查询获取总记录数, 默认为false.
	 */
	public boolean isAutoCount() {
		return autoCount;
	}

	/**
	 * 查询对象时是否自动另外执行count查询获取总记录数.
	 */
	public void setAutoCount(final boolean autoCount) {
		this.autoCount = autoCount;
	}

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

	//-- 访问查询结果函数 --//

	/**
	 * 取得页内的记录列表.
	 */
	public List getResult() {
		return result;
	}

	/**
	 * 设置页内的记录列表.
	 */
	public void setResult(final List result) {
		this.result = result;
	}

	/**
	 * 取得总记录数, 默认值为-1.
	 */
	public long getTotalCount() {
		return totalCount;
	}

	/**
	 * 设置总记录数.
	 */
	public void setTotalCount(final long totalCount) {
		this.totalCount = totalCount;
	}

	/**
	 * 根据pageSize与totalCount计算总页数, 默认值为-1.
	 */
	public long getTotalPages() {
		if (totalCount < 0) {
			return -1;
		}

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

	/**
	 * 是否还有下一页.
	 */
	public boolean isHasNext() {
		return (pageNo + 1 <= getTotalPages());
	}

	/**
	 * 取得下页的页号, 序号从1开始.
	 * 当前页为尾页时仍返回尾页序号.
	 */
	public int getNextPage() {
		if (isHasNext()) {
			return pageNo + 1;
		} else {
			return pageNo;
		}
	}

	/**
	 * 是否还有上一页.
	 */
	public boolean isHasPre() {
		return (pageNo - 1 >= 1);
	}

	/**
	 * 取得上页的页号, 序号从1开始.
	 * 当前页为首页时返回首页序号.
	 */
	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 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 JdbcPaginationHelper = new JdbcPaginationHelper();
		return JdbcPaginationHelper.fetchPage(jdbcTemplate, QUERY_TRANS_COUNT_SQL, QUERY_TRANS_DATA_SQL, args, pageNo,
				new TransactionRowMap());
	}

	class TransactionRowMap implements ParameterizedRowMapper {

		@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;
		}

	}
}