Export of my JShell session from the Exploring the last year of Java talk at ConFoo 2020.

confoo-exploring-java.jsh

HttpHandler handler = he -> {
String body = "hello confoo";
he.sendResponseHeaders(200, body.length());

try (OutputStream os = he.getResponseBody()) {
os.write(body.getBytes());
}
}
/l handler
HttpServer hs = HttpServer.create(new InetSocketAddress(8000), 0)
hs.createContext("/hello", handler)
hs.start()
URI uri = URI.create("http://localhost:8000/hello")
HttpURLConnection c = (HttpURLConnection) uri.toURL().openConnection()
c.setRequestMethod("GET")
c.getResponseCode()
new BufferedReader(new InputStreamReader(c.getInputStream())).readLine()
HttpClient client = HttpClient.newHttpClient()
client.version()
HttpRequest request = HttpRequest.newBuilder().uri(uri).GET().build()
HttpResponse<String> response = client.send(request, BodyHandlers.ofString())
response.statusCode()
response.body()
HttpRequest request = HttpRequest.newBuilder()
.uri(uri)
.header("Content-Type", "plain/text")
.POST(BodyPublishers.ofString("hello"))
.build()
HttpResponse<String> response = client.send(request, BodyHandlers.ofString())
response.statusCode()
response.body()
CompletableFuture<HttpResponse<String>> response = client.sendAsync(request, BodyHandlers.ofString())
response.get().statusCode()
response.get().body()
int x = 0
switch (x) { case 0 -> 0; default -> 1; }
switch (x) { case 0,1 -> 0; default -> 1; }
switch (x) { default -> System.out.println("hello"); }
switch (x) { default -> { System.out.println("hello");yield "hello"; }}
switch (x) { default -> { System.out.println("hello");var yield = "hello"; yield yield; }}
Object o = ""
if (o instanceof String) {
String s = (String) o;
s.isEmpty();
}
if (o instanceof String s) {
s.isEmpty();
}
o instanceof String s && s.isEmpty()
if (!(o instanceof String s)) {
s.isEmpty();
}
o instanceof String s || s.isEmpty()
"""
{
  "foo" : "bar"
}
"""
/l
"""
{
  "foo" : "bar"
}
"""
"""
{
  "foo" : "bar"
}"""
""""""
"""
"""
"""
{
  "foo" : "bar"
}
"""
"""
{
  "foo" : "bar"     \s
}
"""
"""
{
  "foo" : "bar"     \
}
"""
"""
  {
    "foo" : "bar"     \
  }
  """
String s = " hello\n "
s.repeat(10)
s.repeat(10).lines().forEach(System.out::println)
s.stripLeading()
s.stripTrailing()
s.strip()
s.isBlank()
Character.isWhitespace(0)
s.repeat(10).indent(4).lines().forEach(System.out::println)
s.repeat(10).indent(-4).lines().forEach(System.out::println)
s.transform(s -> 123)
String s = " hello\n world"
System.out.println(s)
System.out.println(s.stripIndent())
"\n".equals("\\n".translateEscapes())
"hello %s".formatted("world")
record Tuple(int a, int b) {}
Tuple x = new Tuple(1,2)
x.toString()
x.a()
record Tuple(int a, int b) extends Number {}
record Tuple(int a, int b) implements Serializable {}
record Tuple(int a, int b) { int c; }
record Tuple(int a, int b) { static int c; }
abstract record Tuple(int a, int b) { static int c; }
record Tuple(int a, int b) {
void update() {
a = 3;
}
}
record Tuple(int a, int b) {
public Tuple {
System.out.println("validating");
}
}
Tuple x = new Tuple(1,2)
x.getClass().isRecord()
x.getClass().getRecordComponents()
x.getClass().getRecordComponents()[0].getName()
x.getClass().getRecordComponents()[0].getType()
x.getClass().getRecordComponents()[0].getAccessor()
RecordingStream rs = new RecordingStream()
String event = "jdk.CPULoad"
rs.enable(event).withPeriod(Duration.ofSeconds(1))
rs.onEvent(event, System.out::println)
rs.start()
FlightRecorder.getFlightRecorder().getEventTypes().stream().map(e -> e.getName()).forEach(System.out::println)
"""
hello %s
"""
"""
hello %s
"""+"sdfsd"
"""
hello %s
""".formatted("sdfsd")