Question

我正在编写一个程序，从文件中逐行读取代码，并打印出＆＃34; int＆＃34;之后的所有内容。

例如：

int x;
int y;

打印出来：

x
y

这是我到目前为止编写的代码

BufferedReader br = new BufferedReader(new FileReader("C:\\example.txt"));

String line = null;
while((line = br.readLine()) != null)
{
    StringTokenizer token = new StringTokenizer(line);

    while(token.hasMoreTokens())
    {
        String s = null;
        s = token.nextToken();

        if(s.equals("int"))
        {
            System.out.println(token.nextToken());
        }
    }
}

但是，我想要排除要打印的int类型的函数，例如＆＃34; MyFunction＆＃34;在这个例子中

x 
z
MyFunction(int
y)
x,
y

输入文件：

int x = 137;
int z = 42;
int MyFunction(int x, int y) {
   printf("%d,%d,%d\n", x, y, z);
   {
      int x, z;
      z = y;
      x = z;
      {
        int y = x;
        {
          printf("%d,%d,%d\n", x, y, z);
        }
        printf("%d,%d,%d\n", x, y, z);
      }
      printf("%d,%d,%d\n", x, y, z);
    }
 }

我对java很新，所以请耐心等待。

Answer 1

试一试。仅适用于类似上面的输入。

while((line = br.readLine()) != null)
{
   StringTokenizer token = new StringTokenizer(line);

   while(token.hasMoreTokens())
   {
     String s = null;
     String r = null;
     s = token.nextToken();

     if(token.hasMoreTokens()){  //if s was not last token get next one
        r = token.nextToken();
    }
    if(s.equals("int") && r != null && r.length()<3) 
    {
        System.out.println(r.substring(0, 1)); // just to print x instead of x,
    }
}

}

Answer 2

您也可以试试这个。

while((line = br.readLine()) != null){
        String cleaned = line.trim(); //remove leading and trailing white space 
        String [] parts = cleaned.split(" |\\(");// split using white space or opening brace            
        if (line.matches("(\\s*)int(\\s*)(\\w+)(,\\s*\\w+)*(;)")){ // check for multiple variable declariation e.g. int a,b,c;
            for (int k = 1; k <parts.length; k++){
                System.out.println(parts[k]);                            
            }
        }
        else {
            for (int i = 0; i <parts.length-1; i=i+2){
                if((parts[i].equals("int")&&parts[i+1].length()<3) ){ //requires variable name length to be one
                    System.out.println(parts[i+1].substring(0, 1));
                }                            
            }                       
        }                
    }

打印int类型的变量，不包括函数

2 个答案: