75.Java异常处理机制throws

 package testDate;
 import java.io.FileNotFoundException;
 import java.io.FileReader;
 import java.io.IOException;
 public class TestReadFile {
     public static void main(String[] args) {
         String str = null;
         try {
             str = new TestReadFile().openFile();
         } catch (IOException e){
             e.printStackTrace();
         }
         System.out.println(str);
     }
     String openFile() throws FileNotFoundException,IOException{
         FileReader reader = new FileReader("d:/a.txt");
         char c= (char) reader.read();
         System.out.println(c);
         return "";
     }
 }