Java List 分页的应用

1. PagerUtil

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.Vector;

public class PagerUtil {
	private int pageSize = 10;// 每页大小
	   
    private int nextPage;// 下一页
   
    private int prePage;// 前一页
   
    private int pageCount;// 总页数
   
    private int currentPage;// 当前页
   
    private int listSize = 0;// 记录总数
   
    private ArrayList alist = new ArrayList();
   
    private String url;

   
    /** *//**
     * 初始化记录列表
     * @param it Iterator
     * @return ArrayList
     */
    public ArrayList getAlist(Iterator it) {
        ArrayList al = new ArrayList();
        while (it.hasNext()) {
            al.add(it.next());
        }
        return al;
    }

    /** *//**
     * 构造方法
     * @param list Collection
     */
    public PagerUtil(Collection list) {
        alist = this.getAlist(list.iterator());
        listSize = alist.size();
        nextPage = 1;
        prePage = 0;
        pageCount = listSize / pageSize + 1;
        currentPage = 1;
    }

    /** *//**
     * 构造方法
     * @param list Collection
     * @param pageSize int
     */
    public PagerUtil(Collection list, int pageSize) {
        alist = (ArrayList) list;
        this.pageSize = pageSize;
        listSize = alist.size();
        nextPage = 1;
        prePage = 0;
        pageCount = listSize / pageSize;
        if (listSize % pageSize > 0) {
            pageCount = pageCount + 1;
        }
        currentPage = 1;
    }

    public PagerUtil(Vector v, int pageSize) {
        for (int i = 0; i < v.size(); i++) {
            alist.add(v.get(i));
        }
        this.pageSize = pageSize;
        listSize = alist.size();
        nextPage = 1;
        prePage = 0;
        pageCount = listSize / pageSize;
        if (listSize % pageSize > 0) {
            pageCount = pageCount + 1;
        }
        currentPage = 1;
    }

    /** *//**
     * 下一页
     * @return ArrayList
     */
    public int nextPage() {
        int tempInt = 1;
        if (currentPage < this.getPageCount() && currentPage >= 1) {
            tempInt = currentPage + 1;
        } else
            tempInt = 1;
        return tempInt;
    }

    /** *//**
     * 前一页
     * @return ArrayList
     */
    public int prePage() {
        int tempInt = 1;

        if (currentPage > 1) {
            tempInt = currentPage - 1;
        } else
            tempInt = this.getPageCount();
        return tempInt;
    }

    /** *//**
     * 第一页
     * @return ArrayList
     */
    public int firstPage() {
        nextPage = 1;
        prePage = this.getPageCount();
        currentPage = nextPage;
        return currentPage;
    }

    /** *//**
     * 最后一页
     * @return ArrayList
     */
    public int endPage() {
        nextPage = this.getPageCount();
        prePage = nextPage - 1;
        currentPage = nextPage;
        return currentPage;
    }

    /** *//**
     * 根据当前页得到记录列表
     * @param currentPage int
     * @return ArrayList
     */
    public ArrayList getPageList() {
        ArrayList tempList = new ArrayList();
        for (int i = (currentPage - 1) * pageSize; i < (currentPage - 1)
                * pageSize + pageSize; i++) {
            if (i >= 0 && i < this.alist.size()) {
                tempList.add(alist.get(i));
            } else
                break;
        }
        return tempList;
    }

    public String getPageCtrlString() {
        String strCtrl = "";
        if (this.currentPage == 1) {
            //strCtrl = "首页 ";
        } else {
            strCtrl = "<a href='" + url + "&page=1'>首页</a> ";
        }
        if (this.currentPage == 1) {
            //strCtrl = strCtrl + "上一页 ";
        } else {
            strCtrl = strCtrl + "<a href='" + url + "&page=" + this.prePage() + "'>上页</a> ";
        }
        
        for (int i = 1; i <= this.pageCount; i++) {
       	 	strCtrl = strCtrl + "<a href='" + url + "&page=" + i + "'>[" + i + "]</a> ";
		}
        
        if (this.currentPage == this.pageCount) {
            //strCtrl = strCtrl + "下一页 ";
        } else {
            strCtrl = strCtrl + "<a href='" + url + "&page=" + this.nextPage() + "'>下页</a> ";
        }
        if (this.currentPage == this.pageCount) {
            //strCtrl = strCtrl + "末页 ";
        } else {
            strCtrl = strCtrl + "<a href='" + url + "&page=" + this.getPageCount() + "'>末页</a> ";
        }
//        strCtrl = strCtrl + "\n\r";        //换行
//        strCtrl = strCtrl
//                + "跳到 <select name='toPage' onChange=\"window.location='" + url
//                + "?page='+this.options[this.selectedIndex].value;\">";
        /*
        if (this.currentPage == 1) {
            strCtrl = "首页 ";
        } else {
            strCtrl = "<a href='" + url + "?page=1'>首页</a> ";
        }
        if (this.currentPage == 1) {
            strCtrl = strCtrl + "上一页 ";
        } else {
            strCtrl = strCtrl + "<a href='" + url + "?page=" + this.prePage() + "'>上页</a> ";
        }
        
        if(this.getPageCount() <= 1) {
           
        } else if(this.getPageCount() <= 5) {
            for (int i = 1; i <= this.getCurrentPage(); i++) {
                if (i == this.getCurrentPage()) {
                    strCtrl = strCtrl + "<b>" + i + "</b> ";
                } else {
                    strCtrl = strCtrl + "<a href='" + url + i + "'>" + i + "</a> ";
                }
            }
        } else if(4 < this.getCurrentPage() && this.getCurrentPage() < (this.getPageCount() - 3)) {
            for (int i = this.getCurrentPage() - 3; i <= this.getCurrentPage() + 3; i++) {
                if (i == this.getCurrentPage()) {
                    strCtrl = strCtrl + "<b>" + i + "</b> ";
                } else {
                    strCtrl = strCtrl + "<a href='" + url + i + "'>" + i + "</a> ";
                }
            }
        } else if(this.getCurrentPage() <= 4) {
            for (int i = 1; i <= 5; i++) {
                if (i == this.getCurrentPage()) {
                    strCtrl = strCtrl + "<b>" + i + "</b> ";
                } else {
                    strCtrl = strCtrl + "<a href='" + url + i + "'>" + i + "</a> ";
                }
            }
        } else if((this.getPageCount() - 6) <= this.getCurrentPage()) {
            for (int i = this.getPageCount() - 6; i <= this.getPageCount(); i++) {
                if (i == this.getCurrentPage()) {
                    strCtrl = strCtrl + "<b>" + i + "</b> ";
                } else {
                    strCtrl = strCtrl + "<a href='" + url + i + "'>" + i + "</a> ";
                }
            }
        } else {
            for (int i = this.getCurrentPage() - 3; i <= this.getCurrentPage() + 3; i++) {
                if (i == this.getCurrentPage()) {
                    strCtrl = strCtrl + "<b>" + i + "</b> ";
                } else {
                    strCtrl = strCtrl + "<a href='" + url + i + "'>" + i + "</a> ";
                }
            }
        }
        
        if (this.currentPage == this.pageCount) {
            //strCtrl = strCtrl + "下一页 ";
        } else {
            strCtrl = strCtrl + "<a href='" + url + "?page=" + this.nextPage() + "'>下页</a> ";
        }
        if (this.currentPage == this.pageCount) {
            //strCtrl = strCtrl + "末页 ";
        } else {
            strCtrl = strCtrl + "<a href='" + url + "?page=" + this.getPageCount() + "'>末页</a> ";
        }
       	  strCtrl = strCtrl + "\n\r";        //换行
        */

//        strCtrl = strCtrl + "当前" + this.getCurrentPage() + "/" + this.getPageCount() + "页 每页"
//            + this.getPageSize() + "条 共" + this.listSize + "条";

        return strCtrl;
    }
   
    public int getCurrentPage() {
        return currentPage;
    }

    public int getNextPage() {
        return nextPage;
    }

    public int getPageCount() {
        return pageCount;
    }

    public int getPageSize() {
        return pageSize;
    }

    public int getPrePage() {
        return prePage;
    }

    public String getUrl() {
        return url;
    }

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

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

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

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

    public void setCurrentPage(int currentPage) {
        if (currentPage > this.getPageCount()) {
            this.currentPage = this.getPageCount();
        } else if (currentPage < 0) {
            this.currentPage = 1;
        } else {
            this.currentPage = currentPage;
        }
    }

    public void setUrl(String url) {
        this.url = url;
    }
    
}

 2. 测试类

import java.util.ArrayList;

public class TestPagrUtil {
    public static void main(String args[]) {
        ArrayList al = new ArrayList();
        al.add("a");
        al.add("b");
        al.add("c");
        al.add("d");
        al.add("e");
        al.add("f");
        al.add("g");
        al.add("h");
        al.add("i");
        al.add("j");
        al.add("k");
        al.add("l");
        al.add("m");
        al.add("n");

        PagerUtil autopage = new PagerUtil(al,1);
        autopage.setCurrentPage(5);
        autopage.setUrl("/page/user/account/isprize.jsp");
        ArrayList currentPageList = autopage.getPageList();       
        String ctrlStr = autopage.getPageCtrlString();
       
        for(Object o: currentPageList) {
            System.out.println(o.toString());
        }
        System.out.println(ctrlStr);
    }
}