jsp分页的处理（SSM框架举例）

首先我们需要一个工具类Page类来表达：

import java.util.List;

public class Page
{
  private int everyPage = 10;		//每页显示的条数
  private int totalCount;			//总共需要显示的条数
  private int totalPage;			//总共需要显示的页数
  private int beginPage = 1;		//开始的页数
  private boolean hasPrePage;		//是否有上一页
  private boolean hasNextPage;		//是否有下一页
  private List list;				//用来存储的数据结构（统一为一个list）
  
  /**
   * 初始化：当获得了总共需要显示的条数后即可执行这个方法
   */
  public void init(){
	  int totalPage = totalCount % everyPage == 0 ? totalCount / everyPage : totalCount / everyPage + 1;
	  this.setTotalPage(totalPage);
	  this.setHasNextPage(beginPage >= totalCount);
	  this.setHasPrePage(beginPage <= 1);
  }
  
  public int getEveryPage()
  {
    return this.everyPage;
  }
  
  public void setEveryPage(int everyPage)
  {
    this.everyPage = everyPage;
  }
  
  public int getTotalCount()
  {
    return this.totalCount;
  }
  
  public void setTotalCount(int totalCount)
  {
    this.totalCount = totalCount;
  }
  
  public int getTotalPage()
  {
    return this.totalPage;
  }
  
  public void setTotalPage(int totalPage)
  {
    this.totalPage = totalPage;
  }
  
  public int getBeginPage()
  {
    return this.beginPage;
  }
  
  public void setBeginPage(int beginPage)
  {
    this.beginPage = beginPage;
  }
  
  public boolean isHasPrePage()
  {
    return this.hasPrePage;
  }
  
  public void setHasPrePage(boolean hasPrePage)
  {
    this.hasPrePage = hasPrePage;
  }
  
  public boolean isHasNextPage()
  {
    return this.hasNextPage;
  }
  
  public void setHasNextPage(boolean hasNextPage)
  {
    this.hasNextPage = hasNextPage;
  }
  
  public List getList()
  {
    return this.list;
  }
  
  public void setList(List list)
  {
    this.list = list;
  }
  
}

假设你有这么一个类Microblog，其结构如下：

public class Microblog {
    
    private Integer id;
	
    /**
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database column microblog.userId
     * 这条微博现在属于谁
     * @mbggenerated
     */
    private Integer userid;

    /**
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database column microblog.content
     * 这条微博的内容
     * @mbggenerated
     */
    private String content;

    /**
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database column microblog.time
     * 这条微博现在发布的时间
     * @mbggenerated
     */
    private Date  time;
    
    /**
     * 这条微博是否是转载的，是转载的为true，否则为false
     */
    private Boolean isForward;
    
    private Integer sourceuserid;
    
    /**
     * 这条博客的原创博客的id(原创的话即为0)
     */
    private Integer sourceMicroblogId;
    
    /**
     * 你转发的那条微博（不一定是原创的那一条，原创的话即为0）
     */
    private Integer forwardMicroblogId;
	
	/*接下来就是相应的get和set方法，博主在此省略*/
}

接下来看看底层如何获取这些数据，（假设你此时需要取得一条微博的所有转发微博）xml文件对应的mybatis代码为：

<select id="selectPageByForwardMicroblogId" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
    select 
    <include refid="Base_Column_List" />
    from microblog
    where forwardMicroblogId = #{0,jdbcType=INTEGER} order by time desc limit #{1,jdbcType=INTEGER},#{2,jdbcType=INTEGER}
</select>

其对应接口中的方法声明为：（接口为MicroblogMapper）

/**
	 * 查看当前页面的转发评论
	 * @param forwardMicroblogId
	 * @param beginPage	从第几个开始寻找几个，这个是从0开始的（并不是第几页）
	 * @param everyPage	一页多少条记录
	 * @return
	 */
	List<Microblog> selectPageByForwardMicroblogId(Integer forwardMicroblogId, int beginPage, int everyPage);

Service层的写法为：

List<Microblog> microblogs = this.microblogMapper.selectPageByForwardMicroblogId(
				microblog.getForwardMicroblogId(), (page.getBeginPage() - 1)*page.getEveryPage(), page.getEveryPage());
int totalCount = this.microblogMapper.countByForwardMicroblogId(microblog.getForwardMicroblogId());
page.setList(microblogs);
page.setTotalCount(totalCount);
page.init();

Controller层的写法：

	@RequestMapping("user/microblog_showForwardMore")
	public String showForwardMore(Microblog microblog, Page page, ModelMap modelMap){
		page = this.microblogService.getTenByForward(microblog,page);
		Microblog mic = this.microblogService.findOne(microblog.getForwardMicroblogId());
		modelMap.addAttribute("microblog", mic);
		modelMap.addAttribute("Page", page);
		modelMap.addAttribute("partSelect",1);
		return "/user/showMore";
	}

接下来，你再将page传给页面，定义为“Page”（博主并没有转化为JSON数据，因为暂时还没有接触，但其实变成JSON更好，因为这样在使用前台的框架时可以更加方便并且可以更加通用，假如你的前台并不是jsp），其使用大致为

<c:forEach var="m" items="${Page.list}">
		<div style="border: 1px solid black">
			<a href="user_scan.action?id=${m.sourceUser.id}">@${m.sourceUser.name}</a>：${m.forwardRemark }
			<c:forEach items="${m.forwardRemarks}" var="r">
				<a href="user_scan.action?id=${r.userId}">@${r.userName }</a>${r.remark }
		   			</c:forEach>
			time:${m.getNTime()}<br /> <a href="#"
				onclick="prom(${m.sourceMicroblogId==0?m.id:m.sourceMicroblogId }, ${m.id})">
				(转发${m.getForwards() }) </a> <br />
		</div>
	</c:forEach>

取数据是比较简单的，因为可以利用各种前台标签（SSM貌似支持最基础的C标签，如果大家知道可以用其他标签的话，请告诉博主，博主将感激不尽），主要说一下首页、上一页、下一页的显示：

<a
			href="microblog_showForwardMore.action?forwardMicroblogId=${Microblog.forwardMicroblogId }&sourceMicroblogId=${Microblog.sourceMicroblogId}&beginPage=1"><input
				type="button" class="className" value=" 首 页  " />   </a>
		<c:choose>
				<c:when test="${Page.beginPage == 1}">
					<input type="button" class="className" style="width: 55px;"
						value="上一页" />
				</c:when>
				<c:otherwise>
					<a
						href="microblog_showForwardMore.action?forwardMicroblogId=${Microblog.forwardMicroblogId }&sourceMicroblogId=${Microblog.sourceMicroblogId}&beginPage=${Page.beginPage-1}"><input
						type="button" class="className" style="width: 55px;" value="上一页" /></a>
				</c:otherwise>
			</c:choose>
		 共
			${Page.totalCount }条记录,
		
		每页
			${Page.getEveryPage() }条
		
		${Page.beginPage }/${Page.totalPage} 
			<c:choose>
				<c:when test="${Page.beginPage >= Page.totalPage}">
					<input type="button" class="className" style="width: 55px;"
						value="下一页" />
				</c:when>
				<c:otherwise>
					<a
					href="microblog_showForwardMore.action?forwardMicroblogId=${Microblog.forwardMicroblogId }&sourceMicroblogId=${Microblog.sourceMicroblogId}&beginPage=${Page.beginPage+1}"><input
					type="button" class="className" style="width: 55px;" value="下一页" /></a>
				</c:otherwise>
			</c:choose>
		 
		<a
			href="microblog_showForwardMore.action?forwardMicroblogId=${Microblog.forwardMicroblogId }&sourceMicroblogId=${Microblog.sourceMicroblogId}&beginPage=${Page.totalPage } ">   <input
				type="button" class="className" value="尾 页" /></a>

点击首页这些按钮时，改变的只有一个beginPage属性而已，请谨记。

总结：博主最开始的分页是在利用struts2写的，当时看了一个晚上，结果写的时候还是磕磕绊绊，但是当你真正实现了一个之后，再看别人写的就不再那么困难了，所以“千里之行始于足下”，希望大家能早日完成自己的功能！