JAVA实现二进制和16进制之间的互相转换，8进制同理，附带异或操作实现

public static String bin2Hex(String binStr) {
int deci = Integer.valueOf(binStr,2);
return Integer.toHexString(deci);
}

public static String hex2Bin(String hexStr) {
int deci = Integer.valueOf(hexStr,16);
return Integer.toBinaryString(deci);
}

public static void main(String args[]) {
String str = "f012";
System.out.println(hex2Bin(str));
System.out.println(bin2Hex("01011011"));
}

执行结果：

1111000000010010

5b

非常简单

8进制同理，转换

但是以上方法的缺陷是，16进制或2进制串很大时就转换失败，下面给出通用方法：

public static String bin2Hex(String binStr) {
StringBuffer temp = null;
while (binStr.length() % 4 != 0) {
temp = new StringBuffer(binStr);
temp.insert(0, "0");
binStr = temp.toString();
}
StringBuffer sb = new StringBuffer();
int deci = 0;
for (int i = 0; i <= binStr.length() - 4; i += 4) {
deci = Integer.valueOf(binStr.substring(i, i + 4), 2);
sb.append(Integer.toHexString(deci));
}
return sb.toString();
}

public static String hex2Bin(String hexStr) {
StringBuffer sb = new StringBuffer();
int deci = 0;
StringBuffer temp = null;
for (int i = 0; i < hexStr.length(); i++) {
deci = Integer.valueOf(hexStr.charAt(i) + "", 16);
temp = new StringBuffer(Integer.toBinaryString(deci));
while (temp.length() < 4) {
temp.insert(0, "0");
}
sb.append(temp);
}
return sb.toString();
}

顺带来个异或操作：
public static String xor(String binStr1, String binStr2) {
int len1 = binStr1.length();
int len2 = binStr2.length();
StringBuffer sb = new StringBuffer();
if (len1 != len2) {
return null;
}
for (int i = 0; i < len1; i++) {
if (binStr1.charAt(i) == binStr2.charAt(i)) {
sb.append("0");
} else {
sb.append("1");
}
}
return sb.toString();
}

public static void main(String args[]) {

String str = "89451211512131";
String str2 = "fd589213165131";
String bin1 = hex2Bin(str);
String bin2 = hex2Bin(str2);

System.out.println(bin1.length() + "==" + bin2.length());
System.out.println(bin2Hex(bin1));
System.out.println(bin2Hex(bin2));
String bin = xor(bin1,bin2);
System.out.println(bin2Hex(bin));
}

运行结果如下：
56==56

89451211512131

fd589213165131

741d8002477000

上述原理仍然是使用Integer.valueOf方法来实现的，只不过是分段转换