public class JDK7GenericTest {
   public static void main(String[] args) {
      // Pre-JDK 7
      List<String> lst1 = new ArrayList<String>();
      // JDK 7 supports limited type inference for generic instance creation
      List<String> lst2 = new ArrayList<>();
  
      lst1.add("Mon");
      lst1.add("Tue");
      lst2.add("Wed");
      lst2.add("Thu");
  
      for (String item: lst1) {
         System.out.println(item);
      }
  
      for (String item: lst2) {
         System.out.println(item);
      }
   }
}

/**
 * A resource that must be closed when it is no longer needed.
 *
 * @author Josh Bloch
 * @since 1.7
 */
public interface AutoCloseable {
    /**
     * Closes this resource, relinquishing any underlying resources.
     * This method is invoked automatically on objects managed by the
     * {@code try}-with-resources statement.
     *
     */
    void close() throws Exception;
}

class TryClose implements AutoCloseable {

 @Override
 public void close() throw Exception {
  System.out.println(" Custom close method …
                                         close resources ");
 }
}
//请看jdk自带类BufferedReader如何实现close方法（当然还有很多类似类型的类）

  public void close() throws IOException {
        synchronized (lock) {
            if (in == null)
                return;
            in.close();
            in = null;
            cb = null;
        }
    }