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最新推荐文章于 2025-09-06 09:33:29 发布

转载最新推荐文章于 2025-09-06 09:33:29 发布 · 52 阅读

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原文链接：http://www.cnblogs.com/wzz1020/p/4859628.html

文章标签：

#java

本文详细介绍了一种基于Java的分页查询实现方法，通过自定义PageParam类管理分页参数，利用MyBatis进行数据库操作，实现了动态SQL查询及条件筛选。同时，通过Spring框架整合业务逻辑，最终在Web页面上展示分页后的数据。

entiy

public class PageParam {

	private int currPage ; // 当前页
	
	private int totalPage ; // 总页
	
	private int rowCount ; // 总记录数
	
	public static int pageSize = 10; // 页大小
	
	private List<TableIp> data ; // 数据

	public int getCurrPage() {
		return currPage;
	}

	public void setCurrPage(int currPage) {
		this.currPage = currPage;
	}

	public int getTotalPage() {
		return totalPage;
	}

	public void setTotalPage(int totalPage) {
		this.totalPage = totalPage;
	}

	public int getRowCount() {
		return rowCount;
	}

	public void setRowCount(int rowCount) {
		int totalPage = rowCount / pageSize;
		if (rowCount % pageSize > 0) {
			totalPage += 1;
		}
		setTotalPage(totalPage);
		this.rowCount = rowCount;
	}

	public int getPageSize() {
		return pageSize;
	}

	public void setPageSize(int pageSize) {
		this.pageSize = pageSize;
	}

	public List<TableIp> getData() {
		return data;
	}

	public void setData(List<TableIp> data) {
		this.data = data;
	}
	
	
}

　　Dao Interface

@Repository
public interface ITableIpDao {

	int getRowCount();

	List<TableIp> selectByParams(Map<String, Object> params);

	List<TableIp> fetchByParams(Map<String, Object> params);

}

　　mybatis.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!-- namespace必须指向Dao接口 -->
<mapper namespace="com.jikexueyuan.demo.dao.ITableIpDao">

	<select id="getRowCount" resultType="int">
		select count(*) from table_ip
	</select>
	
	<select id="selectByParams" resultType="com.jikexueyuan.demo.entity.TableIp" parameterType="map">
		select * from table_ip
		order by findTime desc
		limit ${offset}, ${size}
	</select>
	
	<select id="fetchByParams" resultType="com.jikexueyuan.demo.entity.TableIp" parameterType="map">
		select * from table_ip
		where 1=1
		<if test="country != null and country != ''">
			and country = '${country}'
		</if>
		<if test="isp != null and isp != ''">
			and isp = '${isp}'
		</if>
		limit ${size}
	</select>
	
</mapper>

service

@Service
public class TableIpService {

	@Resource
	ITableIpDao dao ;
	
	public int getRowCount() {
		return dao.getRowCount();
	}

	public PageParam getIpListByPage(PageParam pageParam) {
		int currPage = pageParam.getCurrPage();
		// limit offset, size
		int offset = (currPage - 1) * PageParam.pageSize ;
		int size = PageParam.pageSize;
		Map<String, Object> params = new HashMap<String, Object>();
		params.put("offset", offset);
		params.put("size", size);
		
		List<TableIp> ipList = dao.selectByParams(params);
		pageParam.setData(ipList);
		
		return pageParam;
	}

	public String printIp(String number, String country, String isp) {
		int size = 100;
		try {
			size = Integer.parseInt(number);
		} catch (Exception e) {
		}
		Map<String, Object> params = new HashMap<String, Object>();
		params.put("size", size);
		params.put("country", country);
		params.put("isp", isp);
		
		List<TableIp> ipList = dao.fetchByParams(params);
		StringBuilder sBuilder = new StringBuilder();
		for (TableIp tableIp : ipList) {
			sBuilder.append(tableIp.getIp()).append(":").append(tableIp.getPort()).append(",").append(tableIp.getCountry()).append(",").append(tableIp.getIsp());
			sBuilder.append("\r\n");
		}
		
		return sBuilder.toString();
	}


}

controller

@Controller
public class IndexController {

	@Resource
	TableIpService service;
	
	@RequestMapping(value = "index")
	public String helloWorld(HttpServletRequest request){
		String currPageStr = request.getParameter("page");
		int currPage = 1;
		try {
			currPage = Integer.parseInt(currPageStr);
		} catch (Exception e) {
		}
		
		// 获取总记录数
		int rowCount = service.getRowCount();
		PageParam pageParam = new PageParam();
		pageParam.setRowCount(rowCount);
		if (pageParam.getTotalPage() < currPage) {
			currPage = pageParam.getTotalPage();
		}
		pageParam.setCurrPage(currPage);
		pageParam = service.getIpListByPage(pageParam);
		
		request.setAttribute("pageParam", pageParam);
		
		return "index";
	}
	
}

　　jsp

<tbody>
							
							<c:forEach items="${pageParam.data }" var="item">
							<tr>
								<td>${item.ip }</td>
								<td>${item.port }</td>
								<td>${item.country }</td>
								<td>${item.province } ${item.city }</td>
								<td>${item.isp }</td>
								<td>${item.findTime }</td>
							</tr>							
							</c:forEach>

</tbody>


<div>
						<span>第</span>
						<%
						
							PageParam pageParam = (PageParam)request.getAttribute("pageParam");
							int currPage = pageParam.getCurrPage();
							int totalPage = pageParam.getTotalPage();
							for(int i = 1; i <= totalPage; i ++){
								if(i == currPage){
									%><span class="current"><%=currPage %></span><%
								}else{
									%><a href="index.html?page=<%=i %>"><%=i %></a><%
								}
							}
						%>
						<span>页</span>
</div>

转载于:https://www.cnblogs.com/wzz1020/p/4859628.html