我如何在 spring jdbcTemplate 中实现分页 [英] how can i implement a pagination in spring jdbcTemplate

问题描述

这是我的以下 dao 实现

here is my following dao implementaion

@Override
    public List<UserAddress> getAddresses(int pageid,int total) {

        String sql = "select * FROM user_addresses order by id desc limit "+(pageid-1)+","+total;
        List<UserAddress> userAddresses  = jdbcTemplate.query(sql, new RowMapper<UserAddress>() {
            @Override
            public UserSessionLog mapRow(ResultSet rs, int rowNum) throws SQLException {
                UserAddress userAdd = new UserAddress();
                userAdd.setId(rs.getInt("id"));
                userAdd.setId(rs.getString("city"));
                return userSession;
            }
        });
        return userAddresses;
    }

在上面的dao实现中，我列出了所有的用户地址，尝试限制列出

in the above dao implementaion, i list all the user addresses, trying to list with limit

@RequestMapping("/userAddresses/{pageid}")
       public ModelAndView userAddresses(@PathVariable int pageid) {
        int total=5;  
        if(pageid==1){}  
        else{  
            pageid=(pageid-1)*total+1;  
        }  
         List<UserAddress> listAddresses = userAddressFacade.getAddresses(pageid,total);
         return new ModelAndView("userAddresses", "listAddresses", listAddresses);
    }

这是我的观点部分，

<table class="table table-condensed">
        <thead>
            <tr>
                <th>Address1</th>
                <th>City</th>
            </tr>
        </thead>
        <tbody>
            <c:if test="${not empty addresses}">
                <c:forEach var="address" items="${addresses}">
                    <tr>
                        <td>${address.address1}</td>
                        <td>${address.city}</td>
                    </tr>
                </c:forEach>
            </c:if>
        </tbody>
    </table>

     <br/>  
   <a href="/pro/userAddress/1">1</a>   
   <a href="/pro/userAddress/2">2</a>   
   <a href="/pro/userAddress/3">3</a>  

我已经对分页部分进行了硬编码，有没有人有想法，如何进行分页.我是 java jdbcTemplate 的新手，

I have hardcoded the pagination part, do any one have idea, how to do pagination. i am newbie to java jdbcTemplate,

推荐答案

只要您的数据库支持 LIMIT 和 OFFSET，就可以这样做.

This can be done as long as your database supports LIMIT and OFFSET.

在此处给出了一个示例.关键代码如下所示(你可以忽略 fluent builder 子句):

An example is given here. The critical code is shown below (you can ignore the fluent builder clauses):

import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageImpl;
import org.springframework.data.domain.Pageable;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

@Repository
public class DemoRepository {
    private JdbcTemplate jdbcTemplate;

    @Autowired
    public DemoRepository(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }

    public List<Demo> findDemo() {
        String querySql = "SELECT name, action, operator, operated_at " +
                "FROM auditing " +
                "WHERE module = ?";
        return jdbcTemplate.query(querySql, new Object[]{Module.ADMIN_OPERATOR.getModule()}, (rs, rowNum) ->
                Demo.builder()
                        .rowNum(rowNum)
                        .operatedAt(rs.getTimestamp("operated_at").toLocalDateTime())
                        .operator(rs.getString("operator"))
                        .action(rs.getString("action"))
                        .name(rs.getString("name"))
                        .build()
        );
    }

    public Page<Demo> findDemoByPage(Pageable pageable) {
        String rowCountSql = "SELECT count(1) AS row_count " +
                "FROM auditing " +
                "WHERE module = ? ";
        int total =
                jdbcTemplate.queryForObject(
                        rowCountSql,
                        new Object[]{Module.ADMIN_OPERATOR.getModule()}, (rs, rowNum) -> rs.getInt(1)
                );

        String querySql = "SELECT name, action, operator, operated_at " +
                "FROM auditing " +
                "WHERE module = ? " +
                "LIMIT " + pageable.getPageSize() + " " +
                "OFFSET " + pageable.getOffset();
        List<Demo> demos = jdbcTemplate.query(
                querySql,
                new Object[]{Module.ADMIN_OPERATOR.getModule()}, (rs, rowNum) -> Demo.builder()
                        .rowNum(rowNum)
                        .operatedAt(rs.getTimestamp("operated_at").toLocalDateTime())
                        .operator(rs.getString("operator"))
                        .action(rs.getString("action"))
                        .name(rs.getString("name"))
                        .build()
        );

        return new PageImpl<>(demos, pageable, total);
    }
}

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