1. public interface IList {
   
2.   /**
   
3.    * 往列表的尾部增加一个元素
   
4.    */
   
5.   void add(Object elem);
   
6.   /**
   
7.    * 获取下标所指定的元素。当下标越界时抛出java.lang.IndexOutOfBoundsException
   
8.    */
   
9.   Object get(int index);
   
10.   /**
    
11.    * 获取列表里当前的元素个数
    
12.    */
    
13.   int size();
    
14.   /**
    
15.    * 清空列表，移除列表里所有的元素
    
16.    */
    
17.   void clear();
    
18. }
    
19. 
    
20. public class MyIList implements IList {
    
21. int l;// 存储的长度
    
22. static IList[] list;
    
23. static MyIList ml;
    
24. private static String a;
    
25. private static String b;
    
26. private static String c;
    
27. 
    
28. public MyIList() {
    
29. list = null;
    
30. }
    
31. 
    
32. public static void main(String[] args) {
    
33. // TODO Auto-generated method stub
    
34. ml=new MyIList();
    
35. ml.add(a);
    
36. ml.add(b);
    
37. ml.add(c);
    
38. System.out.println( (String)ml.get(2));
    
39. }
    
40. 
    
41. @Override
    
42. public void add(Object elem) {
    
43. // TODO Auto-generated method stub
    
44. l = ml.size();
    
45. list[l] = (IList) elem;
    
46. }
    
47. 
    
48. @Override
    
49. public Object get(int index) {
    
50. // TODO Auto-generated method stub
    
51. Object elem = null;
    
52. l = ml.size();
    
53. if (index >= l)
    
54. throw new IndexOutOfBoundsException("输入数组下标越界");
    
55. else {
    
56. for (int i = 0; i < l; i++) {
    
57. if (index == i) {
    
58. elem = list[i];
    
59. break;
    
60. }
    
61. i++;
    
62. }
    
63. return elem;
    
64. }
    
65. }
    
66. 
    
67. @Override
    
68. public  int size() {
    
69. // TODO Auto-generated method stub
    
70. l=list.length;
    
71. return l;
    
72. }
    
73. 
    
74. @Override
    
75. public void clear() {
    
76. // TODO Auto-generated method stub
    
77. list=null;
    
78. }
    
79. 
    
80. }

复制代码

请问怎么解决？

1. public interface IList {
   
2.   /**
   
3.    * 往列表的尾部增加一个元素
   
4.    */
   
5.   void add(Object elem);
   
6.   /**
   
7.    * 获取下标所指定的元素。当下标越界时抛出java.lang.IndexOutOfBoundsException
   
8.    */
   
9.   Object get(int index);
   
10.   /**
    
11.    * 获取列表里当前的元素个数
    
12.    */
    
13.   int size();
    
14.   /**
    
15.    * 清空列表，移除列表里所有的元素
    
16.    */
    
17.   void clear();
    
18. }
    
19. 
    
20. public class MyIList implements IList {
    
21. int l;// 存储的长度
    
22. static IList[] list;
    
23. static MyIList ml;
    
24. private static String a;
    
25. private static String b;
    
26. private static String c;
    
27. 
    
28. public MyIList() {
    
29. list = null;
    
30. }
    
31. 
    
32. public static void main(String[] args) {
    
33. // TODO Auto-generated method stub
    
34. ml=new MyIList();
    
35. ml.add(a);
    
36. ml.add(b);
    
37. ml.add(c);
    
38. System.out.println( (String)ml.get(2));
    
39. }
    
40. 
    
41. @Override
    
42. public void add(Object elem) {
    
43. // TODO Auto-generated method stub
    
44. l = ml.size();
    
45. list[l] = (IList) elem;
    
46. }
    
47. 
    
48. @Override
    
49. public Object get(int index) {
    
50. // TODO Auto-generated method stub
    
51. Object elem = null;
    
52. l = ml.size();
    
53. if (index >= l)
    
54. throw new IndexOutOfBoundsException("输入数组下标越界");
    
55. else {
    
56. for (int i = 0; i < l; i++) {
    
57. if (index == i) {
    
58. elem = list[i];
    
59. break;
    
60. }
    
61. i++;
    
62. }
    
63. return elem;
    
64. }
    
65. }
    
66. 
    
67. @Override
    
68. public  int size() {
    
69. // TODO Auto-generated method stub
    
70. l=list.length;
    
71. return l;
    
72. }
    
73. 
    
74. @Override
    
75. public void clear() {
    
76. // TODO Auto-generated method stub
    
77. list=null;
    
78. }
    
79. 
    
80. }

复制代码

请问怎么解决？