Share a stupid coding case.
Originally, I was in the butt agreement, to put byte hexadecimal string to a byte array,
Because the protocol commands are preceded by 0x, I take it for granted began to bite.
The beginning is written like this.
Is not it foolish? But, after all, is the first time to write, I had to ask of your mother, ask big brother.
Then is this.
I is not no little doubt tell Gangster clear what I want to ask, but are not sure themselves, went to method validation, the result is this.
public static void main(String[] args) {
/**
* 8-0-83-f4-48-11-fe-9d
*/
String sn = "1148f483";
String code3 =sn.substring(0, 2);
String code2 =sn.substring(2, 4);
String code1 =sn.substring(4, 6);
String code0 =sn.substring(6, 8);
System.out.println("11: "+getCode(code3)+"-----48: "+getCode(code2)+"------f4: "+getCode(code1)+"--------83: "+getCode(code0));
//byte[] code = {0x08,0x00,(byte) 0x83,(byte) 0xf4,0x48,0x11,(byte) 0xFE,(byte) 0x9D};
byte[] code = {0x08,0x00,(byte) getCode(code0),(byte) getCode(code1),(byte) getCode(code2),(byte) getCode(code3),(byte) 0xFE,(byte) 0x9D};
if(Integer.toHexString(code[3]&0xff).equals("f4")){
System.out.println("success");
}else{
System.out.println("fail");
}
StringBuilder sb = new StringBuilder();
for(int i=0;i<code.length;i++){
if(i==0){
//java.lang.Integer.toHexString() 方法的参数是int(32位)类型，如果输入一个byte(8位)类型的数字，这个
//方法会把这个数字的高24为也看作有效位，这就必然导致错误，使用& 0XFF操作，可以把高24位置0以避免这样错误的发生。
sb.append(Integer.toHexString(code[i]&0xff)+"");
}else if(i>0){
sb.append("-"+Integer.toHexString(code[i]&0xff));
}
}
System.out.println("sb......"+sb);
}
/**
* 将截取16进制字符串转换为byte类型
* @param str
* @return
*/
public static int getCode(String str){
int h = Integer.parseInt(str.substring(0,1),16);
int l = Integer.parseInt(str.substring(1,2),16);
// byte H = (byte) h;
// byte L = (byte) l;
// int s = H<<4 | L;
byte s = (byte) (((byte)h<<4) + (byte) l);
return s;
}Print Console as follows:
People just do not usually big brother, ha ha
Upgraded version:
The random string to a hexadecimal byte array (two bytes per character string as a byte)
/**
* 将随机16进制字符串转为byte数组（每两个字节字符串作为一byte）
* @param ieee
* @return
*/
public static byte[] hexStrChangeByte(String hexStr){
byte[] codeByte = new byte[hexStr.length()/2];
for(int i=0;i<codeByte.length;i++){
String code = hexStr.substring(2*i, 2*i+2);
codeByte[i] = (byte) getCode(code);
}
System.out.println(Arrays.toString(codeByte));
return codeByte;
}
test:
hexStrChangeByte("1148f483");
hexStrChangeByte("3132302e37382e3134342e3137343a38353939");Test Results:
