page.java

负责公文的传输及一些处理功能

package com.example.businessmodel;
import java.util.*;

import javax.servlet.http.HttpServletRequest;

import org.hibernate.Session;

public class Page {

    private List elements;
    private int StartPosition;
    private int TotalRecords;
    private int PageSize;
    private String nextLabel = "下一页>>";
    private String previousLabel = "<<上一页";
    private String totalRecordsLabel = "?条记录";
    private String totalLabel = "共?页&nbsp;";
    private String currentLabel = "当前第?页&nbsp;";
    private String form = "thisForm";
    private String titleColor = "#dfe1ee";
    private String listTitleColor = "#9499C6";
    private String oddRowColor = "#FFFFFF";
    private String evenRowColor = "#ECEDF5";
    private final String jumpTo = "\n<script language=\"javascript\">"  +
                            "\n\tfunction jumpto(start, form){"  +
                            "\n\t\tvar oForm = document.all(form);" +
                            "\n\t\tif(oForm==null) return;" +
                            "\n\t\toForm.start.value=start;" +
                            "\n\t\toForm.submit();" +
                            "\n\t}\n" +
                            "\nfunction jumptoPage(pageSize, form){" +
                            "\n\tif(event.keyCode != 13)	return;" +
                            "\n\t\tvar pageValue = parseInt(event.srcElement.value);" +
                            "\n\t\tif(isNaN(pageValue) || pageValue<=0) {" +
                            "\n\t\t\tevent.srcElement.value=\"\";" +
                            "\n\t\t\treturn;" +
                            "\n\t\t}" +
                            "\n\t\tjumpto((pageValue-1)*pageSize + 1, form);" +
                            "\n\t}" +
                            "\n</script>";

    public Page(){
    }

    public Page(int ps) {
        if(ps <= 0) {
            throw new RuntimeException("PageSize必须大于零。");
        } else {
            elements = Collections.EMPTY_LIST;
            StartPosition = 1;
            TotalRecords = 0;
            PageSize = ps;
            return;
        }
    }

    public Page(List l, int s, int t, int ps) {
        StartPosition = getValidStart(s, t, ps);
        elements = new Vector(l);
        TotalRecords = t;
        PageSize = ps;
    }

    public List getList() {
        return elements;
    }

    private boolean hasNextPage() {
        return (StartPosition + elements.size()) - 1 < TotalRecords;
    }

    private boolean hasPreviousPage() {
        return StartPosition > 1;
    }

    private int getStartOfNextPage() {
        return getValidStart(StartPosition + elements.size(), TotalRecords, PageSize);
    }

    private int getStartOfPreviousPage() {
        return getValidStart(StartPosition - PageSize, TotalRecords, PageSize);
    }

    public int getSize() {
        return elements.size();
    }

    public int getPageCount() {
        return (TotalRecords - 1) / PageSize + 1;
    }

    public int getPageNumber() {
        return (StartPosition - 1) / PageSize + 1;
    }

    public int getPageNum(){
    	return StartPosition;
    }

    private int getPageSize() {
        return PageSize;
    }

    public int getTotalRecords() {
        return TotalRecords;
    }

    private static int getValidStart(int s, int t, int ps) {
        if(ps <= 0)
            throw new RuntimeException("PageSize必须大于零。");
        if(t < 0)
            throw new RuntimeException("记录总数不能小于零。");
        if(s > t)
            return ((t - 1) / ps) * ps + 1;
        if(s < 1)
            return 1;
        else
            return s;
    }

    public String getPageHeader() throws Exception{
    	String retVal="";
    	try {
    		StringBuffer html = new StringBuffer();
            if(hasPreviousPage()) {
                html.append(appendPageLabel(getStartOfPreviousPage(), previousLabel));
            }
            if(hasNextPage()) {
                html.append(appendPageLabel(getStartOfNextPage(), nextLabel));
            }
            currentLabel = (appendReplace(currentLabel, "&nbsp;<input type=\"text\" size=\"5\" maxlength=\"5\" value=\"?\" style=\"text-align:right\" onkeyup=\"jumptoPage(" + getPageSize() +",'" + form + "')\">")).toString();
            html.append(appendReplace(currentLabel,(new Integer(getPageNumber())).toString()));
            html.append(appendReplace(totalLabel,(new Integer(getPageCount())).toString()));
            html.append(appendReplace(totalRecordsLabel,(new Integer(getTotalRecords())).toString()));
            html.append(jumpTo);
            retVal=new String(html);
        }
        catch(Exception e){
            e.printStackTrace();
        }
        finally{
        	return retVal;
        }

    }

    private String appendPageLabel(int page, String content) {
        return "<a href=\"javascript:jumpto(" + page + ",'" + form + "')\">" + content + "</a>&nbsp;";
    }

    private StringBuffer appendReplace(String source, String info){
        int index = source.indexOf("?");
        StringBuffer ret = new StringBuffer(source);
        ret.replace(index, index+1, info);
        return ret;
    }

	public String getTitleColor() {
		return titleColor;
	}

	public void setTitleColor(String titleColor) {
		this.titleColor = titleColor;
	}

	public String getEvenRowColor() {
		return evenRowColor;
	}

	public void setEvenRowColor(String evenRowColor) {
		this.evenRowColor = evenRowColor;
	}

	public String getOddRowColor() {
		return oddRowColor;
	}

	public void setOddRowColor(String oddRowColor) {
		this.oddRowColor = oddRowColor;
	}

	public String getListTitleColor() {
		return listTitleColor;
	}

	public void setListTitleColor(String listTitleColor) {
		this.listTitleColor = listTitleColor;
	}
}