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25 
26 package java.nio;
27 
28 /**
29  * A typesafe enumeration for byte orders.
30  *
31  * @author Mark Reinhold
32  * @author JSR-51 Expert Group
33  * @since 1.4
34  */
35 
36 public final class ByteOrder {
37 
38     private String name;
39 
ByteOrder(String name)40     private ByteOrder(String name) {
41         this.name = name;
42     }
43 
44     /**
45      * Constant denoting big-endian byte order.  In this order, the bytes of a
46      * multibyte value are ordered from most significant to least significant.
47      */
48     public static final ByteOrder BIG_ENDIAN
49         = new ByteOrder("BIG_ENDIAN");
50 
51     /**
52      * Constant denoting little-endian byte order.  In this order, the bytes of
53      * a multibyte value are ordered from least significant to most
54      * significant.
55      */
56     public static final ByteOrder LITTLE_ENDIAN
57         = new ByteOrder("LITTLE_ENDIAN");
58 
59     // Retrieve the native byte order. It's used early during bootstrap, and
60     // must be initialized after BIG_ENDIAN and LITTLE_ENDIAN.
61     private static final ByteOrder NATIVE_ORDER
62     // Android-changed: Android is always little-endian.
63     //     = Unsafe.getUnsafe().isBigEndian()
64     //        ? ByteOrder.BIG_ENDIAN : ByteOrder.LITTLE_ENDIAN;
65         = ByteOrder.LITTLE_ENDIAN;
66 
67     /**
68      * Retrieves the native byte order of the underlying platform.
69      *
70      * <p> This method is defined so that performance-sensitive Java code can
71      * allocate direct buffers with the same byte order as the hardware.
72      * Native code libraries are often more efficient when such buffers are
73      * used.  </p>
74      *
75      * @return  The native byte order of the hardware upon which this Java
76      *          virtual machine is running
77      */
nativeOrder()78     public static ByteOrder nativeOrder() {
79         return NATIVE_ORDER;
80     }
81 
82     /**
83      * Constructs a string describing this object.
84      *
85      * <p> This method returns the string
86      * {@code "BIG_ENDIAN"} for {@link #BIG_ENDIAN} and
87      * {@code "LITTLE_ENDIAN"} for {@link #LITTLE_ENDIAN}.
88      *
89      * @return  The specified string
90      */
toString()91     public String toString() {
92         return name;
93     }
94 
95 }
96