java - charAt 方法出了什么问题？

Question

程序的这一部分给我带来了麻烦。该文件正在被程序正确接收。没有 charAt 方法程序运行完美。我不太确定问题出在哪里。显然这不是整个程序，只是给我一个错误的部分。

错误:

java.lang.StringIndexOutOfBoundsException: String index out of range: 0 at java.lang.String.charAt(Unknown Source) at GenSeq.main(GenSeq.java:111) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at edu.rice.cs.drjava.model.compiler.JavacCompiler.runCommand(JavacCompiler.java:272)

程序:

do{
   line = inputStream.nextLine();
   line = line.trim();

   if (line.charAt(0) == '>'){
   //Checking to see if it's an information line
   info = info + line;
   count++;
   //Used to count the number of entries
   }
   else{
     seq = seq + line;
     //Concatenating the sequence together
   }
 while (inputStream.hasNextLine());
 inputStream.close();

编辑:我们正在处理 DNA 和 RNA 序列，因此它唯一可以开头的字母是 A、T、C、G 或 U。为了处理空白行，我现在尝试这样做。虽然仍然收到错误。

do{
       line = inputStream.nextLine();
       char first = line.charAt(0);

       if (first == '>'){
       //Checking to see if it's an information line
       info = info + line;
       count++;
       //Used to count the number of entries
       }

       if (first == 'A' || first == 'T' || first == 'G' || first == 'C' || first == 'U'){
         seq = seq + line;
       }
     }
     while (inputStream.hasNextLine());
     inputStream.close();

Answer 1

可能的解决方案是将 line.charAt(0) == '>' 替换为 line.startsWith (">") 至少可以解决数组的问题您可以从那里完成调试。