Java 中String转化为byte数组

public static byte[] string2Bytes(String buffer) {

String temp = buffer.replace(" ", ""); 

int len = temp.length();

byte[] b = new byte[len/2];

int j=0;

for(int i=0;i<len;i+=2) {

StringBuilder builder = new StringBuilder();

builder.insert(0, temp.charAt(i));

builder.insert(1, temp.charAt(i+1));

int t = Integer.valueOf(builder.toString(),16);

b[j] = (byte)t;

j++;

}

return b;

}