Question

我想得到一个字符串的前两个字节。例如＆＃34;你好＆＃34;二进制是：

01101000 01101001 00100000 01110100 01101000 01100101 01110010 01100101

我想要二进制的前两个字节，在这种情况下是01101000 01101001。

Answer 1

基本方法。转换为字节数组，然后获取所需的字符，然后根据需要进行格式化。

public class Main { 
    public static void main(String[] args) {        
        StringBuilder result = getBinary("hi there", 2);        
        System.out.println(result.toString());      
        }

    public static StringBuilder getBinary(String str, int numberOfCharactersWanted) {
        StringBuilder result = new StringBuilder();
        byte[] byt = str.getBytes();       
        for (int i = 0; i < numberOfCharactersWanted; i++) {        
            result.append(String.format("%8s", Integer.toBinaryString(byt[i])).replace(' ', '0')).append(' ');
        }
        return  result;
    }
}

Answer 2

此函数接受输入字符串和要转换为位的字节数。像这样称呼它： getBits（“hi there”，2）

public String getBits(String str, int count) {
    String out = ""; //output string
    byte[] content = str.getBytes(); //get the bytes from the input string to convert each byte to bits later
    for(int k=0;k!=count;k++) { //go through the bytes
        String binary = Integer.toBinaryString(content[k]); //convert byte to a bit string
        if(binary.length()<8) { //toBinaryString just outputs necessary bits so we have to add some
            for(int i=0;i<=(8-binary.length());i++) {
                binary = "0"+binary; //add 0 at front
            }
        }
        out = out + binary; //add it to the output string
    }
    return out;
}

如何从java中的字符串中获取前两个字节？

2 个答案: