如何在一个对象中合并两种不同的对象类型？

Question

callingmethod(){
File f=new File();  
//...
String s= new String();
//...

method( f + s);    // here is problem (most put f+s in object to send it to method)
}

cant change method args

method(Object o){
//...
//how to split it to file and String here 
}

for any thing not clear ask plz

Answer 1

The cleanest and most idiomatic way is to create a simple class to represent your pair:

static class FileString {
  public final File f;
  public final String s;
  FileString(File f, String s) { 
    this.f = f; this.s = s;
  }
}

then write

method(new FileString(file, string));

inside method:

FileString fs = (FileString)o;
// use fs.f and fs.s

Depending on further details, use a nested class like in my example, or put it into its own file. If you keep it close to the place where you instantiate it, then you can make the constructor private or package-private, like I did. But these are just the finer details.

Answer 2

You can eg put it in an array:

method (new Object[] {f, s});

void method (Object o) {
    final Object[] arr = (Object[]) o;
    File f = (File) arr[0];
    String s = (String) arr[1];
}