Byte
非可变类 final class
实现对比接口 Comparable
继承于数字类 Number
Member variables
byte MIN_VALUE 最小值
byte MAX_VALUE 最大值
Class<Byte> TYPE 类类型
byte value 初始值
int SIZE bit位数
int BYTES 字节数
Static inner class
static class ByteCache cache class
Byte cache[] -128~128的范围
Static code block
static {
for(int i = 0; i < cache.length; i++)
cache[i] = new Byte((byte)(i - 128)); 循环初始化 -128 ~ 128
}
Construction method
public Byte(String s) throws NumberFormatException {
this.value = parseByte(s, 10);
}
In fact, the internal method is to call Ingeter
Member method
String toString(byte b) Get the string form of the value
public static String toString(byte b) {
return Integer.toString((int)b, 10);
}
Ingeter's toString method is called internally
static Byte valueOf(byte b) returns the wrapper class object
public static Byte valueOf(byte b) {
final int offset = 128;
return ByteCache.cache[(int)b + offset];
}
Return directly from the cache array
byte parseByte(String s, int radix) string value conversion process Byte value
public static byte parseByte(String s, int radix)
throws NumberFormatException {
int i = Integer.parseInt(s, radix);
if (i < MIN_VALUE || i > MAX_VALUE)
throw new NumberFormatException(
"Value out of range. Value:\"" + s + "\" Radix:" + radix);
return (byte)i;
}
radix为可与String转换的最小基数
内部调用Integer的 parseInt方法
判断越界
int hashCode(byte value) Get hash code
public static int hashCode(byte value) {
return (int)value; 数值本身就是hash码
}
int toUnsignedInt(byte x) converted to Int type
public static int toUnsignedInt(byte x) {
return ((int) x) & 0xff;
}
& 0xff is to ensure that the lower eight bits remain unchanged, and the other bits become 0.
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