示例代码：Java 7 新的特性，判断文件的内容类型。

Program to demonstrate Java 7 new feature : Determining the file content type.    package com.hubberspot.nio;    import java.io.IOException;  import java.nio.file.Files;  import java.nio.file.Path;  import java.nio.file.Paths;    public class FileContentType {        public static void main(String[] args) {                    printContentType("D:/Downloads/java.txt");          printContentType("D:/Downloads/java.ppt");          printContentType("D:/Downloads/java.doc");          printContentType("D:/Downloads/java.jar");        }        private static void printContentType(String pathToFile) {                    Path path = Paths.get(pathToFile);          String contentType = null;          try {              contentType = Files.probeContentType(path);          } catch (IOException e) {                     e.printStackTrace();          }          System.out.println("File content type is : " + contentType);                }    }