Java string array intersection and set difference set to repeat and set

System method

Package com;

Import java.util.ArrayList;
Import Java.util.Iterator;
Import java.util.List;

public class Test {

public static voidMain (String[] (args) {
List list1 =new ArrayList ();
List1.add ("1111");
List1.add ("2222");
List1.add ("3333");

List list2 =new ArrayList ();
List2.add ("3333");
List2.add ("4444");
List2.add ("5555");

and set
List1.addall (LIST2);
Intersection
List1.retainall (LIST2);
Subtraction
List1.removeall (LIST2);
No duplicate and set
List2.removeall (List1);
List1.addall (LIST2);

Iterator<string> It=list1.iterator ();
while (It.hasnext ()) {
System.out.println (It.next ());

}

System.out.println ("-----------------------------------\ n");
Printstr (List1);

}

public static void Printstr (List list1) {
for (int i = 0; i < list1.size (); i++) {
System.out.println (List1.get (i));
}
}
}

Self simulation

packagecom.array;     importjava.util.ArrayList;  importjava.util.HashMap;  importjava.util.HashSet;   import java.util.Iterator;  importjava.util.List;   importjava.util.Map;   importjava.util.Set;  import java.util.Map.Entry;     publicclassStringArray  {         publicstatic voidmain(String[] args)      {          // 测试union  String[] arr1 = { "abc", "df", "abcd" };          String[] arr2 = { "abc", "cc", "df", "d", "abc"};          String[] result_union = union(arr1, arr2);          System.out.println("求并集的结果如下：");          for(String str : result_union)          {              System.out.println(str);          }          System.out.println("---------------------可爱的分割线------------------------");          // 测试insect  String[] result_insect = intersect(arr1, arr2);          System.out.println("求交集的结果如下：");          for(String str : result_insect)          {              System.out.println(str);          }          System.out.println("---------------------可爱的分割线------------------------");      }         // 求两个字符串数组的并集，利用set的元素唯一性   publicstaticString[] union(String[] arr1, String[] arr2)      {          Set<String> set = newHashSet<String>();          for(String str : arr1)          {              set.add(str);          }          for(String str : arr2)          {              set.add(str);          }          String[] result = {};          returnset.toArray(result);      }         // 求两个数组的交集   publicstaticString[] intersect(String[] arr1, String[] arr2)      {          Map<String, Boolean> map = newHashMap<String, Boolean>();          List<String> list = newArrayList<String>();          for(String str : arr1)          {              if(!map.containsKey(str))              {                  map.put(str, Boolean.FALSE);              }          }          for(String str : arr2)          {              if(map.containsKey(str))              {                  map.put(str, Boolean.TRUE);              }          }              for(Iterator<Entry<String, Boolean>> it = map.entrySet().iterator();it.hasNext();)          {              Entry<String,Boolean> e = (Entry<String,Boolean>)it.next();              if(e.getValue().equals(Boolean.TRUE))              {                  list.add(e.getKey());              }          }          returnlist.toArray(newString[] {});      }         }

Java string array intersection and set difference set to repeat and set