从 Vert.x 3 迁移到 4

eventBus.send("the-address", body, ar -> ...);

eventBus.consumer("the-address", message -> {
       message.reply(body, ar -> ...);
});

eventBus.request("the-address", body, ar -> ...);

eventBus.consumer("the-address", message -> {
  message.replyAndRequest(body, ar -> ...);
});

Future<String> fut = getSomeFuture();
fut.setHandler(ar -> ...);

Future<String> fut = getSomeFuture();
fut.onComplete(ar -> ...);

client.request().connectionHandler(conn -> {
  // Connection related code
}).end();

client.connectionHandler(conn -> {
  // Connection related code
});

Verticle createVerticle(String verticleName, ClassLoader classLoader) throws Exception;

void createVerticle(String verticleName, ClassLoader classLoader, Promise<Callable<Verticle>> promise);

return new MyVerticle();

promise.complete(() -> new MyVerticle());

new Thread(() -> {
  assertSame(vertx.getOrCreateContext(), vertx.getOrCreateContext());
}).start();

for (int i = 0;i < n;i++) {
  vertx.executeBlocking(block, handler);
}

for (int i = 0;i < n;i++) {
  vertx.executeBlocking(block, false, handler);
}

switch (options.getClientAuth()) {
case REQUIRED:
// ... behavior same as in releases prior to {VertX} {v4}
break;
default:
// fallback statement...
}

if (options.getClientAuth() == ClientAuth.REQUIRED) {
// behavior in releases prior to {VertX} {v4}

WriteStreamSubscriber<Buffer> subscriber = writeStream.toSubscriber();

subscriber.onComplete(() -> {
    // Called after writeStream.end() is invoked, even if operation has not completed
});

subscriber.onWriteStreamEnd(() -> {
    // Called after writeStream.end() is invoked and completes successfully
});

subscriber.onWriteStreamError(() -> {
    // Called after writeStream.end() is invoked and fails
});

Future<JsonObject> fut = ConfigRetriever. getConfigAsFuture(retriever);

fut = retriever.getConfig();

java -Dvertx.json.base64=legacy ...

public String toBase64(String base64Url) {
  return base64Url
    .replace('+', '-')
    .replace('/', '_');
}

public String toBase64Url(String base64) {
  return base64
    .replace('-', '+')
    .replace('_', '/');
}

String base64url = someJsonObject.getString("base64encodedElement")
String base64 = toBase64(base64url);

// simple deserializer from Base64 to byte[]
class ByteArrayDeserializer extends JsonDeserializer<byte[]> {
  ByteArrayDeserializer() {
  }

  public byte[] deserialize(JsonParser p, DeserializationContext ctxt) {
    String text = p.getText();
    return Base64.getDecoder()
      .decode(text);
  }
}

// ...

ObjectMapper mapper = new ObjectMapper();

// create a custom module to address the Base64 decoding
SimpleModule module = new SimpleModule();
module.addDeserializer(byte[].class, new ByteArrayDeserializer());
mapper.registerModule(module);

// JSON to POJO with custom deserializer
mapper.readValue(json, MyClass.class);

FaviconHandler.create();
ErrorHandler.create();

FaviconHandler.create(vertx);
ErrorHandler.create(vertx);

router
   // protect everything but "/excluded/path"
   .route().handler(JWTAuthHandler(jwtAuth, "/excluded/path")

router
   .route("/excluded/path").handler(/* public access to "/excluded/path" */)
   // protect everything
   .route().handler(JWTAuthHandler(jwtAuth)

Router router = Router.router(vertx);
SockJSHandlerOptions options = new SockJSHandlerOptions()
  .setRegisterWriteHandler(true); // enable the event bus consumer registration
SockJSHandler sockJSHandler = SockJSHandler.create(vertx, options);
router.mountSubRouter("/myapp", sockJSHandler.socketHandler(sockJSSocket -> {
  // Retrieve the writeHandlerID and store it (For example, in a local map)
  String writeHandlerID = sockJSSocket.writeHandlerID();
}));

SockJSHandlerOptions options = new SockJSHandlerOptions()
  .setRegisterWriteHandler(true) // enable the event bus consumer registration
  .setLocalWriteHandler(false) // register a clustered event bus consumer

RouterBuilder.create(vertx, "petstore.yaml").onComplete(ar -> {
  if (ar.succeeded()) {
    // Spec loaded with success
    RouterBuilder routerBuilder = ar.result();
  } else {
    // Something went wrong during router builder initialization
    Throwable exception = ar.cause();
  }
});

RouterBuilder.create(vertx, "petstore.yaml")
  .onSuccess(routerBuilder -> {
    // Spec loaded with success
  })
  .onFailure(exception -> {
    // Something went wrong during router builder initialization
  });

RequestParameters parameters = routingContext.get(io.vertx.ext.web.validation.ValidationHandler.REQUEST_CONTEXT_KEY);
int aParam = parameters.queryParameter("aParam").getInteger();

JsonObject model = routerBuilder.operation("getPets").getOperationModel();

JsonObject contract = routerBuilder.getOpenAPI().getOpenAPI();

JsonObject petModel = routerBuilder.getOpenAPI().getCached(JsonPointer.from("/components/schemas/Pet"));

router.get("/api/transactions")
  .handler(
    ValidationHandlerBuilder.create(schemaParser)
      .queryParameter(optionalParam("from", stringSchema()))
      .queryParameter(optionalParam("to", stringSchema()))
      .build()
  ).handler(
    RouteToEBServiceHandler.build(eventBus, "transactions.myapplication", "getTransactionsList")
  );

JsonObject defaultConf = new JsonObject();
serviceDiscovery.registerServiceImporter(new KubernetesServiceImporter(), defaultConf);

new SecretOptions()
    .setType("HS256")
    .setSecret("password")

new PubSecKeyOptions()
    .setAlgorithm("HS256")
    .setBuffer("password")

new PubSecKeyOptions()
  .setPublicKey(
    // remove the PEM boundaries
    pubPemString
      .replaceAll("-----BEGIN PUBLIC KEY----")
      .replaceAll("-----END PUBLIC KEY----"))
  .setSecretKey(
    // remove the PEM boundaries
    secPemString
      .replaceAll("-----BEGIN PUBLIC KEY----")
      .replaceAll("-----END PUBLIC KEY----"));

PubSecKeyOptions pubKey =
  new PubSecKeyOptions()
    // the buffer is the exact contents of the PEM file and had boundaries included in it
    .setBuffer(pubPemString);

PubSecKeyOptions secKey =
  new PubSecKeyOptions()
    // the buffer is the exact contents of the PEM file and had boundaries included in it
    .setBuffer(secPemString);

PubSecKeyOptions x509Certificate =
  new PubSecKeyOptions()
    // the buffer is the exact contents of the PEM file and had boundaries included in it
    .setBuffer(x509PemString);

new KeyStoreOptions()
  .setPath("path/to/keystore.jks")
  .setPassword("keystore-password");

new KeyStoreOptions()
  .setPath("path/to/keystore.jks")
  // Modern JDKs use `jceks` keystore. But this type is not the default
  // If the type is not set to `jceks` then probably `pkcs12` will be used
  .setType("jceks")
  .setPassword("keystore-password")
  // optionally if your keys have different passwords
  // and if a key specific id is not provided it defaults to
  // the keystore password
  .putPasswordProtection("key-id", "key-specific-password");

<!-- Vert.x 3.x -->
<plugin>
  <groupId>org.xolstice.maven.plugins</groupId>
  <artifactId>protobuf-maven-plugin</artifactId>
  <configuration>
    <protocArtifact>com.google.protobuf:protoc:3.2.0:exe:${os.detected.classifier}</protocArtifact>
    <pluginId>grpc-java</pluginId>
    <!-- NOTE: the gav coordinates point to the 3.x only compiler fork -->
    <pluginArtifact>io.vertx:protoc-gen-grpc-java:${vertx.grpc.version}:exe:${os.detected.classifier}</pluginArtifact>
  </configuration>
  ...
</plugin>

<!-- Vert.x 4.0 -->
<plugin>
  <groupId>org.xolstice.maven.plugins</groupId>
  <artifactId>protobuf-maven-plugin</artifactId>
  <configuration>
    <protocArtifact>com.google.protobuf:protoc:3.2.0:exe:${os.detected.classifier}</protocArtifact>
    <pluginId>grpc-java</pluginId>
    <!-- NOTE: the gav coordinates point to the official compiler -->
    <pluginArtifact>io.grpc:protoc-gen-grpc-java:${vertx.grpc.version}:exe:${os.detected.classifier}</pluginArtifact>
    <protocPlugins>
      <!-- NEW: a plugin is added to generate the Vert.x specific code -->
      <protocPlugin>
        <id>vertx-grpc-protoc-plugin</id>
        <groupId>io.vertx</groupId>
        <artifactId>vertx-grpc-protoc-plugin</artifactId>
        <version>${vertx.version}</version>
        <mainClass>io.vertx.grpc.protoc.plugin.VertxGrpcGenerator</mainClass>
      </protocPlugin>
    </protocPlugins>
  </configuration>
  ...
</plugin>

service Greeter {
  rpc SayHello (HelloRequest) returns (HelloReply) {}
}

// 3.x
GreeterGrpc.GreeterVertxImplBase service =
  new GreeterGrpc.GreeterVertxImplBase() {
      ...
  }

// 4.x
VertxGreeterGrpc.GreeterVertxImplBase service =
  new VertxGreeterGrpc.GreeterVertxImplBase() {
      ...
  }

// 3.x
GreeterGrpc.GreeterVertxImplBase service =
  new GreeterGrpc.GreeterVertxImplBase() {
        @Override
        public void sayHello(HelloRequest request, Promise<HelloReply> future) {
          future.complete(
              HelloReply.newBuilder().setMessage(request.getName()).build());
        }
  }

// 4.x
VertxGreeterGrpc.GreeterVertxImplBase service =
  new VertxGreeterGrpc.GreeterVertxImplBase() {
      @Override
      public Future<HelloReply> sayHello(HelloRequest request) {
        return Future.succeededFuture(
          HelloReply.newBuilder()
            .setMessage(request.getName())
            .build());
      }
  }

client
   .publish("hello", Buffer.buffer("hello"), MqttQoS.EXACTLY_ONCE, false, false)
   .publish("hello", Buffer.buffer("hello"), MqttQoS.AT_LEAST_ONCE, false, false);

client.publish("hello", Buffer.buffer("hello"), MqttQoS.EXACTLY_ONCE, false, false);
client.publish("hello", Buffer.buffer("hello"), MqttQoS.AT_LEAST_ONCE, false, false);

<dependencies>
  <dependency>
    <groupId>io.vertx</groupId>
    <artifactId>vertx-codegen</artifactId>
    <classifier>processor</classifier>
  </dependency>
  <dependency>
    <groupId>io.vertx</groupId>
    <artifactId>vertx-service-proxy</artifactId>
  </dependency>
</dependencies>

// 3.x
SQLClient client = JDBCClient.create(vertx, jsonConfig);

// 4.x
JDBCPool pool = JDBCPool.pool(vertx, jsonConfig);

// 3.x
client.getConnection(res -> {
  if (res.succeeded()) {
    SQLConnection connection = res.result();
    // Important, do not forget to return the connection
    connection.close();
  } else {
    // Failed to get connection
  }
});

// 4.x
pool
  .getConnection()
  .onFailure(e -> {
    // Failed to get a connection
  })
  .onSuccess(conn -> {
    // Important, do not forget to return the connection
    conn.close();
  });

// 4.x ONLY!!!
JDBCPool pool = JDBCPool.pool(
      vertx,
      // configure the connection
      new JDBCConnectOptions()
        // H2 connection string
        .setJdbcUrl("jdbc:h2:~/test")
        // username
        .setUser("sa")
        // password
        .setPassword(""),
      // configure the pool
      new PoolOptions()
        .setMaxSize(16)
    );

// 3.x
connection.callWithParams(
  "{ call new_customer(?, ?) }",
  new JsonArray().add("John").add("Doe"),
  null,
  res -> {
    if (res.succeeded()) {
      // Success!
    } else {
      // Failed!
    }
  });

// 4.0
client
  .preparedQuery("{call new_customer(?, ?)}")
  .execute(Tuple.of("Paulo", "Lopes"))
  .onSuccess(rows -> {
    ...
  });

// 3.x
connection.callWithParams(
  "{ call customer_lastname(?, ?) }",
  new JsonArray().add("John"),
  new JsonArray().addNull().add("VARCHAR"),
  res -> {
    if (res.succeeded()) {
      ResultSet result = res.result();
    } else {
      // Failed!
    }
});

// 4.x
client
  .preparedQuery("{call customer_lastname(?, ?)}")
  .execute(Tuple.of("John", SqlOutParam.OUT(JDBCType.VARCHAR)))
  .onSuccess(rows -> {
    ...
  });