pager.java

数学网

/*
 ---------------------------------------------------------
 Author     : alex
 File       : Pager.java
 作者：杨继往
---------------------------------------------------------
*/

package math.util;

import java.util.*;
public class Pager {

  public static String generate(int offset, int size, int length, String url) {
    if (size > length) {
    	int radius =10/2*length;
      String pref;//连结字符
      if (url.indexOf("?") > -1) {
	pref = "&";
      } else {
	pref = "?";
      }
      int total=size/length;
      String header;
      if(size%length==0)
      { header = "<font face='Helvetica' size='-1'>共 &nbsp"+String.valueOf  (total)+"&nbsp 页: ";}
      else 
    	  { header = "<font face='Helvetica' size='-1'>共 &nbsp"+String.valueOf  (total+1)+"&nbsp 页: ";}
     if(offset==0)
     {header+="首页</a>\n";}
     else{
      header += "&nbsp &nbsp;<a href=\""+url+pref+"pager.offset="+0+"\"> 首页</a>\n";}
      if (offset > 0) {
	     header += "&nbsp &nbsp;<a href=\""+url+pref+"pager.offset="+(offset-length)+"\"> 上一页</a>\n";
      }
      int start;
      
      if (offset < radius) {
	start = 0;
      } else if(offset < size-radius) {
	start = offset - radius;
      } else {
	start = (size/length-9)*length;
      }
      if (start < 0) {
	start = 0;
      }
      for (int i = start; i < size && i < start + 10 * length; i += length) {
	if (i == offset) {
	  header += "<b>"+(i/length+1)+"</b>\n";
	} else {
	  header += "&nbsp &nbsp;<a href=\""+url+pref+"pager.offset="+i+"\">"+(i/length+1)+"</a>\n";
	}
      }
      if(offset < size - length) {
	header += "&nbsp &nbsp;<a href=\""+url+pref+"pager.offset="+((int)offset+(int)length)+"\">下一页 </a>\n";
      }
      int off;
      if(size%length==0){off=size/length*length-length;}
      else{off=size/length*length;}
      if(offset==(size/length*length))
      {header+="&nbsp &nbsp末页</a>\n";}
      else{
      header += "&nbsp &nbsp;<a href=\""+url+pref+"pager.offset="+off+"\">末页 </a>\n";}
      header +=" ";
      return header;
    } 
    /////////////第一个if//////////////////////
    else {
      return "";
    }
  }

}