Arrays.asList分析

詳細
問題1:
コードは次のとおりです.
 

    int [] arr = new int[5];
    arr[0]=1;
    arr[1]=2;
    arr[2]=3;
    arr[3]=4;
    arr[4]=5;
    List list  =  Arrays.asList(arr);
    list.remove(0);

実行後:
 
 

Exception in thread "main" java.lang.UnsupportedOperationException
	at java.util.AbstractList.remove(AbstractList.java:144)
	at test.testArr23.main(testArr23.java:18)

原因分析
 
 

Arrays.asList    List    Arrays         : private static class ArrayList extends AbstractList

最も簡単に実現されるインタフェースと抽象クラスだけで、

AbstractList             UnsupportedOperationException.

    :

 public E set(int index, E element) {
	throw new UnsupportedOperationException();
  }



  public void add(int index, E element) {
	throw new UnsupportedOperationException();
  }
  
    public E remove(int index) {
	throw new UnsupportedOperationException();
  }
  
    :
  
    :
  
int[] arr = new int[5];
    arr[0] = 1;
    arr[1] = 2;
    arr[2] = 3;
    arr[3] = 4;
    arr[4] = 5;
    String[] strArr = new String[3];
    strArr[0] = "11";
    strArr[1] = "22";
    strArr[2] = "33";
     List strlist = Arrays.asList(strArr);
    List arrlist = Arrays.asList(arr);
   
    for (String j : strlist)
    {
      System.out.println(j);
    }


    for (int j : arrlist.get(0))
    {
      System.out.println(j);
    }