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

Question

我想编译和测试我在线看到的代码Expanding an IP add。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是（int，int，String）。我想知道我可以如何运行这个程序。

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

我认为你试图在开始字符和结束字符之间进行替换。在这种情况下，您应该获得这些字符的索引并将其用于替换方法中。否则，你必须将这些字符转换为int以使它们适用于方法。但我想这不是你所感兴趣的东西。

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

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

正如Jobin的答案中所述，您对String使用了不正确的方法。您可以使用String的替换方法而不是StringBuilder。

例如，

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

Answer 3

你试图使用从StringBuilder类上String替代方法..

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

地址是String不是StringBuilder

Answer 4

String.replace方法需要两个CharSequence s或两个char s。我认为你可以通过使用替换字符串本身：

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

看看是否适用于你的例子。祝你好运！