AnyArrayStore


1   package jfun.yan.element;
2   
3   import java.lang.reflect.Array  ;
4   
5   import jfun.util.Misc;
6   import jfun.yan.util.Utils;
7   
8   
9   /**
10   * This class stores component instances into any array.
11   * For a primitive array such as int[], wrapper objects
12   * are automatically unboxed.
13   * <p>
14   * @author Ben Yu
15   * Nov 12, 2005 2:19:48 PM
16   */
17  public class AnyArrayStore<T> implements ElementStore<T> {
18    private final Object   arr;
19    private final int begin;
20    private final int end;
21    private final Class  <?> etype;
22    
23    /**
24     * To create an AnyArrayStore object.
25     * @param arr the array object
26     * @param begin the begin index of the array.
27     * Elements are stored from this index.
28     * @param end the non-inclusive end index.
29     * Elements cannot be stored at or after this index.
30     */
31    public AnyArrayStore(Object   arr, int begin, int end) {
32      if(end > Array.getLength(arr))
33        throw new ArrayIndexOutOfBoundsException  (end);
34      if(!arr.getClass().isArray())
35        throw new IllegalArgumentException  ("array expected, "
36            + Utils.getObjTypeName(arr, null) + " encountered.");
37      this.arr = arr;
38      this.begin = begin;
39      this.end = end;
40      this.etype = arr.getClass().getComponentType();
41    }
42    /**
43     * To create an AnyArrayStore object.
44     * @param arr the array object
45     * @param begin the begin index of the array.
46     * Elements are stored from this index.
47     * 
48     */
49    public AnyArrayStore(Object   arr, int begin){
50      this.arr = arr;
51      this.begin = begin;
52      this.end = Array.getLength(arr);
53      this.etype = arr.getClass().getComponentType();
54    }
55    /**
56     * To create an AnyArrayStore object.
57     * @param arr the array object
58     */
59    public AnyArrayStore(Object   arr){
60      this(arr, 0);
61    }
62    /**
63     * Get the array object that stores the elements.
64     */
65    public Object   getArrayObject() {
66      return arr;
67    }
68  
69    /**
70     * Get the begin index.
71     */
72    public int getBegin() {
73      return begin;
74    }
75  
76    /**
77     * Get the non-inclusive end index.
78     */
79    public int getEnd() {
80      return end;
81    }
82  
83    public void storeElement(int ind, T obj) {
84      Array.set(arr, getIndex(ind), obj);
85    }
86    /*
87    public void checkElement(int ind, Class type) {
88      getIndex(ind);
89      if(type!=null && !ReflectionUtil.isAssignableFrom(etype, type)){
90        throw new TypeMismatchException(etype, type,
91            "type mismatch for #"+ind+" element.");
92      }
93    }*/
94    /**
95     * Map an element to the real index on the array.
96     * @param ind the index.
97     * @return the real index on the physical array.
98     * @throws ArrayIndexOutOfBoundsException if the index is not within the [begin,end) range.
99     */
100   protected final int getIndex(int ind){
101     final int k = ind+begin;
102     if(k >= end){
103       throw new ArrayIndexOutOfBoundsException  (k);
104     }
105     return k;
106   }
107   public boolean equals(Object   obj) {
108     if(obj instanceof AnyArrayStore){
109       final AnyArrayStore other = (AnyArrayStore)obj;
110       return arr==other.arr&&begin==other.begin&&end==other.end;
111     }
112     else return false;
113   }
114   public int hashCode() {
115     return (begin*31+end)*31+System.identityHashCode(arr);
116   }
117   public String   toString() {
118     return Misc.getTypeName(arr.getClass());
119   }
120 }
121
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