public class Test {
 private static String[] aa = { "aa1", "aa2" };
 private static String[] bb = { "bb1", "bb2", "bb3" };
 private static String[] cc = { "cc1", "cc2", "cc3", "cc4" };
 private static String[][] xyz = { aa, bb, cc };
 private static int counterIndex = xyz.length - 1;
 private static int[] counter = { 0, 0, 0 };
 public static void main(String[] args) throws Exception {
  for (int i = 0; i < aa.length * bb.length * cc.length; i++) {
   System.out.print(aa[counter[0]]);
   System.out.print("\t");
   System.out.print(bb[counter[1]]);
   System.out.print("\t");
   System.out.print(cc[counter[2]]);
   System.out.println();
   handle();
  }
 }
 public static void handle() {
  counter[counterIndex]++;
  if (counter[counterIndex] >= xyz[counterIndex].length) {
   counter[counterIndex] = 0;
   counterIndex--;
   if (counterIndex >= 0) {
    handle();
   }
   counterIndex = xyz.length - 1;
  }
 }
}

aa1 bb1 cc1
aa1 bb1 cc2
aa1 bb1 cc3
aa1 bb1 cc4
aa1 bb2 cc1
aa1 bb2 cc2
aa1 bb2 cc3
aa1 bb2 cc4
aa1 bb3 cc1
aa1 bb3 cc2
aa1 bb3 cc3
aa1 bb3 cc4
aa2 bb1 cc1
aa2 bb1 cc2
aa2 bb1 cc3
aa2 bb1 cc4
aa2 bb2 cc1
aa2 bb2 cc2
aa2 bb2 cc3
aa2 bb2 cc4
aa2 bb3 cc1
aa2 bb3 cc2
aa2 bb3 cc3
aa2 bb3 cc4

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class DescartesTest {
 /**
  * 獲取N個(gè)集合的笛卡爾積
  *
  * 說(shuō)明：假如傳入的字符串為："1,2,3==5,6==7,8"
  *  轉(zhuǎn)換成字符串?dāng)?shù)組為：[[1, 2, 3], [5, 6], [7, 8]]
  *  a=[1, 2, 3]
  *  b=[5, 6]
  *  c=[7, 8]
  *  其大小分別為：a_length=3，b_length=2，c_length=2，
  *  目標(biāo)list的總大小為：totalSize=3*2*2 = 12
  *  對(duì)每個(gè)子集a，b，c，進(jìn)行循環(huán)次數(shù)=總記錄數(shù)/(元素個(gè)數(shù)*后續(xù)集合的笛卡爾積個(gè)數(shù))
  *  對(duì)a中的每個(gè)元素循環(huán)次數(shù)=總記錄數(shù)/(元素個(gè)數(shù)*后續(xù)集合的笛卡爾積個(gè)數(shù))=12/(3*4)=1次，每個(gè)元素每次循環(huán)打印次數(shù)：后續(xù)集合的笛卡爾積個(gè)數(shù)=2*2個(gè)
  *  對(duì)b中的每個(gè)元素循環(huán)次數(shù)=總記錄數(shù)/(元素個(gè)數(shù)*后續(xù)集合的笛卡爾積個(gè)數(shù))=12/(2*2)=3次，每個(gè)元素每次循環(huán)打印次數(shù)：后續(xù)集合的笛卡爾積個(gè)數(shù)=2個(gè)
  *  對(duì)c中的每個(gè)元素循環(huán)次數(shù)=總記錄數(shù)/(元素個(gè)數(shù)*后續(xù)集合的笛卡爾積個(gè)數(shù))=12/(2*1)=6次，每個(gè)元素每次循環(huán)打印次數(shù)：后續(xù)集合的笛卡爾積個(gè)數(shù)=1個(gè)
  *
  *  運(yùn)行結(jié)果：
  *  [[1, 2, 3], [5, 6], [7, 8]]
   1,5,7,
   1,5,8,
   1,6,7,
   1,6,8,
   2,5,7,
   2,5,8,
   2,6,7,
   2,6,8,
   3,5,7,
   3,5,8,
   3,6,7,
   3,6,8]
   從結(jié)果中可以看到：
   a中的每個(gè)元素每個(gè)元素循環(huán)1次，每次打印4個(gè)
   b中的每個(gè)元素每個(gè)元素循環(huán)3次，每次打印2個(gè)
   c中的每個(gè)元素每個(gè)元素循環(huán)6次，每次打印1個(gè)
  *
  * @param args
  */
 public static void main(String[] args) {
  // TODO Auto-generated method stub
  String str ="1,3,6,7==4,5,8,9==3,4==43,45,8,9==35,4";
  List<String> result = descartes(str);
  System.out.println(result);
 }
 @SuppressWarnings("rawtypes")
 public static List<String> descartes(String str) {
  String[] list = str.split("==");
  List<List> strs = new ArrayList<List>();
  for(int i=0;i<list.length;i++){
  strs.add(Arrays.asList(list[i].split(",")));
  }
  System.out.println(strs);
  int total = 1;
  for(int i=0;i<strs.size();i++){
   total*=strs.get(i).size();
  }
  String[] mysesult = new String[total];
  int now = 1;
  //每個(gè)元素每次循環(huán)打印個(gè)數(shù)
  int itemLoopNum = 1;
  //每個(gè)元素循環(huán)的總次數(shù)
  int loopPerItem =1;
  for(int i=0;i<strs.size();i++){
   List temp = strs.get(i);
   now = now*temp.size();
   //目標(biāo)數(shù)組的索引值
   int index=0;
   int currentSize = temp.size();
   itemLoopNum = total/now;
   loopPerItem = total/(itemLoopNum*currentSize);
   int myindex = 0;
   for(int j=0;j<temp.size();j++){
    //每個(gè)元素循環(huán)的總次數(shù)
    for(int k=0;k<loopPerItem;k++){
     if(myindex==temp.size())
      myindex=0;
     //每個(gè)元素每次循環(huán)打印個(gè)數(shù)
     for(int m=0;m<itemLoopNum;m++){
      mysesult[index]=(mysesult[index]==null?"":mysesult[index]+",")+((String)temp.get(myindex));
      index++;
     }
     myindex++;
    }
   }
  }
  return Arrays.asList(mysesult);
 }
}

public static void fn(List<String[]> list,String[] arr,String str){
//迭代list
 List<String> li = new ArrayList<String>();
  for(int i=0;i<list.size();i++){
   //取得當(dāng)前的數(shù)組
   if(i==list.indexOf(arr)){
    //迭代數(shù)組
    System.out.println(arr.length);
    for(String st : arr){
     st = str + st;
     if(i<list.size()-1){
      fn(list,list.get(i+1),st);
     }else if(i==list.size()-1){
      li.add(st);
     }
    }
   }
  }
  for(int i = 0 ; i < li.size();i++ )
  {
   System.out.println(li.get(i));
  }
}