org.springside.modules.orm中的page类自我解读

//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//
import java.util.Collections;
import java.util.List;
import org.apache.commons.lang.StringUtils;

public class Page<T> {

    /*静态变量，用于设置结果是按照正序排列还是反序排列*/
    public static final String ASC = "asc";
    public static final String DESC = "desc";

    /*当前页码*/
    protected int pageNo = 1;
     /*页面容量*/
    protected int pageSize = 1;
    /*orderBy表示通过那个进行排序，比如说：id*/
    protected String orderBy = null;
    /*order是设置以哪种方式进行排序：可以使ASC也可以是DESC*/
    protected String order = null;
    /*只是是否自动计算*/
    protected boolean autoCount = true;

    /*以下2个参数常作为 分页所需的"返回结果"! */
    //result表示当页面存在的实体类集合。
    protected List<T> result = Collections.emptyList();
    //totalCount表示当前页面总条数。
    protected long totalCount = -1L;

    public Page() {
    }

    public Page(int pageSize) {
        this.setPageSize(pageSize);
    }

    public Page(int pageSize, boolean autoCount) {
        this.setPageSize(pageSize);
        this.setAutoCount(autoCount);
    }

    public int getPageNo() {
        return this.pageNo;
    }

    public void setPageNo(int pageNo) {
        this.pageNo = pageNo;
        if(pageNo < 1) {
            this.pageNo = 1;
        }

    }

    public int getPageSize() {
        return this.pageSize;
    }

    public void setPageSize(int pageSize) {
        this.pageSize = pageSize;
        if(pageSize < 0) {
            this.pageSize = 1;
        }

    }

    /**
     * 获得当前页面第一条数据的排列
     * @return
     */
    public int getFirst() {
        return (this.pageNo - 1) * this.pageSize + 1;
    }

    public String getOrderBy() {
        return this.orderBy;
    }

    public void setOrderBy(String orderBy) {
        this.orderBy = orderBy;
    }

    public boolean isOrderBySetted() {
        return StringUtils.isNotBlank(this.orderBy) && StringUtils.isNotBlank(this.order);
    }

    public String getOrder() {
        return this.order;
    }

    public void setOrder(String order) {
        String[] orders = StringUtils.split(StringUtils.lowerCase(order), ',');
        String[] var6 = orders;
        int var5 = orders.length;

        for(int var4 = 0; var4 < var5; ++var4) {
            String orderStr = var6[var4];
            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 boolean isAutoCount() {
        return this.autoCount;
    }

    public void setAutoCount(boolean autoCount) {
        this.autoCount = autoCount;
    }

    public List<T> getResult() {
        return this.result;
    }

    public void setResult(List<T> result) {
        this.result = result;
    }

    public long getTotalCount() {
        return this.totalCount;
    }

    public void setTotalCount(long totalCount) {
        this.totalCount = totalCount;
    }

    /**
     * 获取一共有多少页（设置的是总条数）
     * @return
     */
    public long getTotalPages() {
        if(this.totalCount < 0L) {
            return -1L;
        } else {
            long count = this.totalCount / (long)this.pageSize;
            if(this.totalCount % (long)this.pageSize > 0L) {
                ++count;
            }

            return count;
        }
    }

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

    /**
     * 得到下一页的页码
     * @return
     */
    public int getNextPage() {
        return this.isHasNext()?this.pageNo + 1:this.pageNo;
    }

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

    /**
     * 得到上一页页码
     * @return
     */
    public int getPrePage() {
        return this.isHasPre()?this.pageNo - 1:this.pageNo;
    }
}
 

对于上述代码需要有几点强调的：

1.Page类本质来讲仅仅是一个辅助类，其中包含的是一些争对分页的辅助数据，具体怎么用，还是需要自己进行处理的。

2.XXX随时补充。。。