简单分页程序

最新推荐文章于 2024-04-21 22:53:27 发布

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本文介绍了一个分页公共类的实现方法，通过设置页大小、当前页并调用initPage方法来获取PageUtil实例，实现了分页功能。该类包含了记录数、总页数等属性，并提供了初始化页面的方法。


/**
 *
 * <p>Title: 分页公共类</p>
 * <p>Description: 使用该函数时需要设置页大小，当前页，然后调用initPage方法，得到一个PageUtil实例</p>
 */
public class Pagination extends ArrayList {
    //首页
    private int firstPage = 1;

    //最后一页
    private int lastPage = 1;

    //下一页
    private int nextPage = 0;

    //前一页
    private int prePage = 0;

    //记录数
    private int recordCount = 0;

    //总页数
    private int pageCount = 0;

    //当前页
    private int currentPage = 1;

    //一页显示条数
    private int pageSize = 0;

    //每页的第一笔数据
    private int startIndex = 1;

    //每页的最后一笔数据
    private int lastIndex = 1;

    //总共记录数
    private int totalRecord = 0;

    public Pagination() {
    }

    public Pagination(int currentPage, int pageSize) {
        if (currentPage > 0) {
            this.currentPage = currentPage;
        }
        this.pageSize = pageSize;
    }

    public int getCurrentPage() {
        return currentPage;
    }

    public void setCurrentPage(int currentPage) {
        this.currentPage = currentPage;
    }

    public int getFirstPage() {
        return firstPage;
    }

    public void setFirstPage(int firstPage) {
        this.firstPage = firstPage;
    }

    public int getLastPage() {
        return lastPage;
    }

    public void setLastPage(int lastPage) {
        this.lastPage = lastPage;
    }

    public int getNextPage() {
        return nextPage;
    }

    public void setNextPage(int nextPage) {
        this.nextPage = nextPage;
    }

    public int getPageCount() {
        return pageCount;
    }

    public void setPageCount(int pageCount) {
        this.pageCount = pageCount;
    }

    public int getPrePage() {
        return prePage;
    }

    public void setPrePage(int prePage) {
        this.prePage = prePage;
    }

    public int getRecordCount() {
        return recordCount;
    }

    public void setRecordCount(int recordCount) {
        this.recordCount = recordCount;
    }

    public void initPage(int total) {
        //得到记录数
        recordCount = total;

        if (pageSize != 0 && recordCount != 0) {
            //得到总页数
            pageCount = (int) Math.ceil( (float) recordCount / pageSize);
        } else {
            pageCount = 1;
        }

        //得到最后一页
        lastPage = pageCount;

        //得到上一页
        if ( (currentPage - 1) >= firstPage) {
            prePage = currentPage - 1;
        } else {
            prePage = currentPage;
        }

        //得到下一页
        if ( (currentPage + 1) <= lastPage) {
            nextPage = currentPage + 1;
        } else {
            nextPage = currentPage;
        }
        //得到每页的第一笔数
        startIndex = (currentPage - 1) * pageSize + 1;
        //得到每页的最后一笔数
        lastIndex = currentPage * pageSize;
        if (lastIndex > recordCount) {
            lastIndex = recordCount;
        }
    }

    public int getPageSize() {
        return pageSize;
    }

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

    public int getTotalRecord() {
        return totalRecord;
    }

    public void setTotalRecord(int totalRecord) {
        //设置总记录数
        this.totalRecord = totalRecord;
        //初始化各种数据
        this.initPage(this.totalRecord);
    }

  public void setLastIndex(int lastIndex) {
    this.lastIndex = lastIndex;
  }

  public void setStartIndex(int startIndex) {
    this.startIndex = startIndex;
  }

  public int getStartIndex() {
        return startIndex;
    }

    public int getLastIndex() {
        return lastIndex;
    }

}

调用的时候：


 public List doFindObjectsBySQL(String sql,
                                         RowCallbackHandler rcHandler,
                                         int pageNum, int pageSize) {
        JdbcTemplate jt = new JdbcTemplate(dataSource);
        Pagination pagination = new Pagination(pageNum, pageSize);

        int total = doCountObjectsBySQL(sql, jt);

        pagination.setTotalRecord(total);

        if (total > 0) {
            StringBuffer paginationSQL = new StringBuffer(" SELECT * FROM ( ");
            paginationSQL.append(" SELECT temp.* ,ROWNUM num FROM ( ");
            paginationSQL.append(sql);
            paginationSQL.append("　) temp where ROWNUM <= " +
                                 pagination.getLastIndex());
            paginationSQL.append(" ) WHERE　num > " + pagination.getStartIndex());
            pagination.addAll(jt.query(paginationSQL.toString(), rcHandler));
        }

        return pagination;
    }