Java - StringBuilder replace() 显示错误：方法 String.replace(char,char) 不适用

Question

我正在尝试编译和测试我在网上看到的Expanding an IP add 的代码。但是，当我尝试编译它时，我收到有关 StringBuilder 替换方法的错误。它说：

IPadd.java:52: error: no suitable method found for replace(int,int,String)
                    address.replace(tempCompressLocation,tempCompressLocation+2,":");
                           ^
method String.replace(char,char) is not applicable
  (actual and formal argument lists differ in length)

我检查了代码的替换方法，它显示了正确的数据类型，即 (int,int,String)。我想知道如何运行这个程序。

import java.util.*;

public class IPadd {

    public static void main (String[] args){

        Scanner sc = new Scanner(System.in);

        System.out.print("Input address: ");
        String address = sc.nextLine();

        // Store the location where you need add zeroes that were removed during uncompression

        int tempCompressLocation=address.indexOf("::");

        //if address was compressed and zeroes were removed, remove that marker i.e "::"
        if(tempCompressLocation!=-1){
            address.replace(tempCompressLocation,tempCompressLocation+2,":");
        }

        //extract rest of the components by splitting them using ":"
        String[] addressComponents=address.toString().split(":");

        for(int i=0;i<addressComponents.length;i++){
            StringBuilder uncompressedComponent=new StringBuilder("");
            for(int j=0;j<4-addressComponents[i].length();j++){

                //add a padding of the ignored zeroes during compression if required
                uncompressedComponent.append("0");

            }
            uncompressedComponent.append(addressComponents[i]);

            //replace the compressed component with the uncompressed one
            addressComponents[i]=uncompressedComponent.toString();
        }


        //Iterate over the uncompressed address components to add the ignored "0000" components depending on position of "::"
        ArrayList<String> uncompressedAddressComponents=new ArrayList<String>();

        for(int i=0;i<addressComponents.length;i++){
            if(i==tempCompressLocation/4){
                for(int j=0;j<8-addressComponents.length;j++){
                    uncompressedAddressComponents.add("0000");
                }
            }
            uncompressedAddressComponents.add(addressComponents[i]);

        }

        //iterate over the uncomopressed components to append and produce a full address
        StringBuilder uncompressedAddress=new StringBuilder("");
        Iterator it=uncompressedAddressComponents.iterator();
        while (it.hasNext()) {
            uncompressedAddress.append(it.next().toString());
            uncompressedAddress.append(":");
        }
        uncompressedAddress.replace(uncompressedAddress.length()-1, uncompressedAddress.length(), "");
        return uncompressedAddress.toString();
        }

}

Answer 1

试试这个：

StringBuilder address = new StringBuilder(sc.nextLine());

Answer 2

您正在尝试在String 上使用StringBuilder 类中的替换方法..

address.replace(tempCompressLocation, tempCompressLocation + 2, ":");

地址是String 不是StringBuilder

Answer 3

String.replace 方法采用两个 CharSequences 或两个 chars。我认为您可以使用以下方法替换字符串本身：

if (tempCompressLocation != -1) {
  address.replace("::", ":");
}

看看这是否适用于您的示例。祝你好运！

Answer 4

我认为您正在尝试在开始字符和结束字符之间进行替换。在这种情况下，您应该获取这些字符的索引并在替换方法中使用它们。否则，您必须将字符转换为 int 以使其适用于方法。但我想这不是你感兴趣的。

int index = stringbuilder.indexOf(String.valueOf(tempCompressLocation));
stringbuilder.replace(index, index + 2, ":");

您可以简单地使用Stringbuilder#setCharAt 在特定位置设置字符。但不确定它是否能满足您的要求。

正如 Jobin 的 回答中所述，您对字符串使用了不正确的方法。您可以使用 String 的 replace 方法而不是 StringBuilder。

例如，

address = address.replace("::", ":");//Replace all :: with :
address = address.replaceFirst("::", ":");//Replace first occurrence of :: with :