如何在Java中将浮点数转换为4字节?

I have not been able to convert something like this:

我还没能转化成这样的东西:

byte[] b = new byte[] { 12, 24, 19, 17};

into something like this:

是这样的:

float myfloatvalue = ?;

Could someone please give me an example?

谁能给我举个例子吗?

Also how to turn that float back to bytes?

还有，如何将浮动转换回字节?

3 个解决方案

#1

From byte[] -> float, you could do:

从byte[] ->浮动，你可以做:

byte[] b = new byte[] { 12, 24, 19, 17};
float myfloatvalue = ByteBuffer.wrap(b).getFloat();

Here is an alternative to using ByteBuffer.allocate for converting float -> byte[]:

这里是使用ByteBuffer的一种替代方法。用于转换float ->字节的分配[]:

int bits = Float.floatToIntBits(myFloat);
byte[] bytes = new byte[4];
bytes[0] = (byte)(bits & 0xff);
bytes[1] = (byte)((bits >> 8) & 0xff);
bytes[2] = (byte)((bits >> 16) & 0xff);
bytes[3] = (byte)((bits >> 24) & 0xff);

#2

byte[] -> float

With ByteBuffer:

ByteBuffer:

byte[] b = new byte[]{12, 24, 19, 17};
float f =  ByteBuffer.wrap(b).getFloat();

float -> byte[]

Reverse operation (knowing the result of above):

反向操作(知道以上结果):

float f =  1.1715392E-31f;
byte[] b = ByteBuffer.allocate(4).putFloat(f).array();  //[12, 24, 19, 17]

#3

Convert the bytes to an int and use Float.intBitsToFloat()

将字节转换为int并使用Float.intBitsToFloat()

http://docs.oracle.com/javase/1.5.0/docs/api/java/lang/Float.html#intBitsToFloat(int)

http://docs.oracle.com/javase/1.5.0/docs/api/java/lang/Float.html intBitsToFloat(int)