Question

我正在尝试编译和测试我在网上看到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replace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

您正尝试在StringBuilder上使用String课程中的替换方法。

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

地址是String而不是StringBuilder

Answer 2

试试这个：

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

Answer 3

String.replace方法需要两个CharSequence个或两个char个。我认为你可以使用：

替换字符串本身

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

看看它是否适用于您的示例。祝你好运！

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

3 个答案: