public static void main (String [] args) throws IOException {Stream<Path> files = Files.walk(Paths.get(System.getProperty("user.home")));files.forEach (fName -> { //line n1try {Path aPath = fName.toAbsolutePath(); //line n2System.out.println(fName + ":"+ Files.readAttributes(aPath,BasicFileAttributes.class).creationTime());} catch (IOException ex) {ex.printStackTrace();}});}

class Vehicle {
int vno;
String name;
public Vehicle (int vno, String name) {
this.vno = vno;
this.name = name;
}
public String toString () {
return vno + ":" + name;
}
}

Set<Vehicle> vehicles = new TreeSet <> ();vehicles.add(new Vehicle (10123, "Ford"));vehicles.add(new Vehicle (10124, "BMW"));System.out.println(vehicles);

What is the result?

public static void main (String[ ] args) {
int i;
char c;
try (FileInputStream fis = new FileInputStream (“course.txt”);
InputStreamReader isr = new InputStreamReader(fis);) {
while (isr.ready()) { //line n1
isr.skip(2);
i = isr.read ();
c = (char) i;
System.out.print(c);
}
} catch (Exception e) {
e.printStackTrace();
}
}

Part two 涉及到的FileInputStream类的使用：https://blog.csdn.net/chentiefeng521/article/details/51776218

public class Test<T> {
private T t;
public T get () {
return t;
}
public void set (T t) { this.t = t;
}
public static void main (String args [ ] ) {
Test<String> type = new Test<>();
Test type1 = new Test (); //line n1
type.set("Java");
type1.set(100); //line n2
System.out.print(type.get() + " " + type1.get());
}
}

class Vehicle {
String name;
void setName (String name) {
this.name = name;
}
String getName() {
return name;
}
}

public class Product {
int id; int price;
public  Product(int id,int price) {
this.id = id;
this.price = price;
}
public String toString() { return id + ":" + price; }
}

List<Product> products = Arrays.asList(new Product(1, 10),
new Product (2, 30),
new Product (2, 30));
Product p = products.stream().reduce(new Product (4, 0), (p1, p2) -> {
p1.price+=p2.price;
return new Product (p1.id, p1.price);});
products.add(p);
products.stream().parallel()
.reduce((p1, p2) - > p1.price > p2.price ? p1 : p2)
.ifPresent(System.out: :println);

public class Book implements Comparator<Book> {
String name;
double price;
public Book () {}
public Book(String name, double price) {
this.name = name;
this.price = price;
}
public int compare(Book b1, Book b2) {
return b1.name.compareTo(b2.name);
}
public String toString() {
return name + “:” + price;
}
}

List<Book>books = Arrays.asList (new Book (“Beginning with Java”, 2), new book
(“A
Guide to Java Tour”, 3));
Collections.sort(books, new Book());
System.out.print(books);

List<String> listVal = Arrays.asList(“Joe”, “Paul”, “Alice”, “Tom”);
System.out.println (
// line n1
);

class Caller implements Callable<String> {
String str;
public Caller (String s) {this.str=s;}
public String call()throws Exception { return str.concat (“Caller”);}
}
class Runner implements Runnable {
String str;
public Runner (String s) {this.str=s;}
public void run () { System.out.println (str.concat (“Runner”));}
}

public static void main (String[] args) throws InterruptedException,ExecutionException {ExecutorService es = Executors.newFixedThreadPool(2);Future f1 = es.submit (new Caller ("Call"));Future f2 = es.submit (new Runner ("Run"));String str1 = (String) f1.get();String str2 = (String) f2.get(); //line n1System.out.println(str1+ ":" + str2);}

Explanation/Reference:

InterruptedException 异常:https://blog.csdn.net/derekjiang/article/details/4845757

Callable和Future:https://blog.csdn.net/ghsau/article/details/7451464

ExecutorService详解:https://blog.csdn.net/fwt336/article/details/81530581

public class Canvas implements Drawable {
public void draw () { }
}
public abstract class Board extends Canvas { }
public class Paper extends Canvas {
protected void draw (int color) { }
}
public class Frame extends Canvas implements Drawable {
public void resize () { }
}
public interface Drawable {
public abstract void draw ();
}