java - 在不重新分配原始字符串值的情况下将 int 的值压入字符串

Question

所以我有一个值作为整数从类中返回，并且根据输入的文本长度重复了几次。我可以打印出每个字符的输出，但我想将输出组合成一个字符串。这是输出示例。

Enter plain-text: hi

The vaule of H is 7

The encrypted value is 721 The decrypted value is 7

The vaule of I is 8

The encrypted value is 330 The decrypted value is 8

我希望它将最终密文打印为 "721330"，以便将其发送到数据库并将该值与数据库中存储的值进行比较。

执行此操作的最佳方法是什么？

@SuppressWarnings("资源") public static void main(String[] args) {

    int p = 29;
    int q = 41;
    int d = 83;
    int n = 0;
    int w = 0;
    int e=27;
    int c =1;
    String plainText;
    String Str = new String("ABCDEFGHIJKLMNOPQRSTUVWXYZ");

    //System.out.println(m);
    n = p*q;
    //System.out.println("The n value equals " + n);
    w = (p-1)*(q-1);
    //System.out.println("The w value equals " + w);

    int qo=0;
    int re=0;

    w = w*1+d*0;
    d = w*0+d*1;


    qo = w/d;
    //System.out.println("quotient value " + qo);
    re = w-qo*d;
    //System.out.println("reminder value " + re);
    qo=d/re;
    //System.out.println("quotient value " + qo);
    re = d-qo*re;
    //System.out.println("reminder value " + re);
    Scanner scn=new Scanner(System.in);

    System.out.println("Enter plain-text:");
    plainText=scn.nextLine();

    plainText=plainText.toUpperCase();
    char[] chars = plainText.toCharArray();

    for (int i=0;i<chars.length;i++)
    { 

    int m= Str.indexOf(chars[i]);

    System.out.println("The value of " +chars[i] + " is " + m +"\n");

    toBin(e);
    //System.out.println("The binary value of e " + toBin(e));
    de_encryption(c,n,m,toBin(e));
    int C = de_encryption(c,n,m,toBin(e));

    //String final_output = String.valueOf(C);

    StringBuilder sb = new StringBuilder(); 
    int part = C;
    sb.append(part);

    String result = sb.toString();
    //I want the final_output value to be appended into a stringbuilder
    System.out.println("The encrypted value is " + result);

    toBin(d);
    //System.out.println("The binary value of d " + toBin(d));

    int D = de_encryption(c,n,C,toBin(d));
    StringBuilder sb1 = new StringBuilder(); 
    int part1 = D;
    sb1.append(part1);

    String result1 = sb1.toString();
    System.out.println("The decrypted value is "+ result1 +"\n");


    }

}

Answer 1

如果我没理解错的话，您是在问我们如何通过连接多个部分来创建一个字符串。

使用 StringBuilder :

StringBuilder sb = new StringBuilder();
for (...) { 
    String part = ...;
    sb.append(part);
} 
String result = sb.toString();