gRPC Java: High-Performance Spring Boot Microservices

Compare protocol buffers with Json for inter-service communication, highlighting the binary format and faster serialization. Define messages in proto files and generate type-safe client libraries across languages.

Set up a Maven gRPC playground project in IntelliJ, install the protobuf plugin, and configure dependencies and a proto compiler to generate Java sources for learning protobuf and gRPC features.

Create the first proto file in a Maven project using proto3 syntax, defining name and age, then compile to generate Java sources under the generated sources directory.

Learn to configure generated sources in a gRPC Java project, marking protobuf Java as generated source root, and resolve IDE import issues with Maven and IntelliJ for smooth builds.

Create a generated proto instance using the builder pattern and generated source from protobuf. Define a Person with name and age, then build and print it in main.

Learn to organize proto files with java-style packages to avoid name conflicts. The lecture demonstrates using section zero one and section zero two packages and resolving Maven compilation issues.

Enable multiple files for java generated from proto and access the person type and its builder in a maven project while understanding the outer class and generated sources.

Compare two person objects with equals to illustrate value-based equality and double equals as a reference check. Demonstrate immutability with a builder and clear name.

Add comments in proto files using the same approach as Java, including multi-line examples and single-line comments with double slashes.

Explore proto scalar types as building blocks for modeling messages, including int32, int64, float, double, bool, string, and bytes, with signed int32 for negative values used in inter-system messaging.

Demonstrate scalar types in proto by building a person proto, serialize and deserialize, and compare performance against JSON using maven to generate Java sources.

Learn to serialize and deserialize a proto generated person object using writeTo with files or streams and verify equality via byte arrays.

Demonstrate proper management of input and output streams with try-with-resources to ensure automatic closing and prevent resource leaks.

Compare proto and JSON performance by serializing and deserializing a person object to byte arrays and back, using proto generated code versus Jackson, across a million iterations.

This hands-on comparison demonstrates JSON versus protobuf serialization performance in Java, showing protobuf is faster and yields smaller byte sizes after warm-up, highlighting cold-start effects.

Explore how json and proto encoding differ in performance and size, learn how proto uses field numbers and default booleans, and compare json's text encoding with proto's binary serialization.

Explore message composition in proto3 by modeling address within student and school, using builder patterns in Java to create and print nested messages, and understanding build vs build partial.

Model a library as a collection of books in proto using repeated fields, and implement it in Java with a builder pattern, adding books and retrieving via lists.

Explore how proto repeated fields map to lists and sets, why passing a set ensures unique items, and how proto data compares with json types in microservices.

define car and dealer messages in a proto map, populate an inventory map keyed by year, and explore access methods like contains inventory and get inventory.

Model complex data structures in protocol buffers by using map and repeated fields, such as a key with a list of cars, and tailor messages to your needs.

Explore how proto supports enum types by adding a body style enum to a car message, with values like coupe, sedan, suv, and the zero-value first requirement.

Explore default values in proto-generated java classes, including default message instances, primitive defaults, and empty lists or maps, plus has methods and wrappers to avoid nulls.

Explore oneof in protobuf within a gRPC masterclass for Java and Spring Boot, modeling credentials as email or phone data and using Java 17 switch expressions to handle login type.

Organize protobufs into multiple files and import address, car, and person messages across packages to enable reuse, with Java-like package conventions and a Maven clean compile.

Examine google api proto files in the app engine v1 structure to see package naming and how the same proto enables code generation for multiple languages.

Explore well known types in protoc, including google protobuf wrappers and time stamp, and learn to use them in Java with builders and epoch seconds conversion.

Learn how scalar optional fields in proto enable has checks and how adding optional exposes has methods for scalar values in gRPC masterclass with java and spring boot.

See how Protobuf encodes messages using field numbers (tags), defines properties, and serializes data efficiently across services, while ignoring default values like false.

Explore how evolving protobuf message formats affect clients across v1, v2, and v3 in a gRPC Java and Spring Boot setup, including a TV proto example and byte array parsing.

Explore adding a tv type enum in v2, set a default value, and test cross-version gRPC compatibility between v1 and v2 clients using unknown fields.

Remove the model information from the v3 television proto and establish cross-version compatibility with v1 and v2 passers, ensuring brand and type decode correctly with defaults.

Explore how to introduce a new price field in proto v4 while preserving compatibility, using reserved fields, field numbers, and optional wrappers to avoid breaking older clients.

Generate Java, Python, and C# sources from a proto file using protoc plugins, organize outputs, and automate with a proto ci/cd workflow that versions and releases artifacts to a repository.

Explore how protobuf enables efficient inter-service communication with type safety and smaller binary messages compared to json. Master proto concepts—messages, field numbers, repeated, map, enum, oneof, and packaging.

Discover how gRPC enables high-performance client-server communication with protocol buffers, defining both messages and methods in proto files, and generating client libraries for Java.

Explore gRPC communication patterns, including unary, server streaming, client streaming, and bi directional streaming, with examples like a pizza order flow and a ChatGPT like application.

Leverage gRPC's high performance through protocol buffers and http/2, enabling thousands of concurrent requests on a single connection, unlike http/1.1 rest using connection pools.

Explore gRPC unary API by building a simple bank service that defines a balance check request and account balance response using a proto file, with generated client and server code.

Run mvn clean and compile, then check the generated sources protobuf. The gRPC Java directory holds bank service gRPC sources for the server and client; mark the generated source route.

Explore how gRPC stream observer handles unary and streaming responses in Java with Spring Boot, implementing getAccountBalance and emitting results via onNext, onCompleted, and onError.

Implement a unary gRPC service method that receives an account number request and returns a hard-coded balance (account number times ten) via the response observer, focusing on the happy path.

Register a gRPC service on port 6565 and test a unary API with Postman by loading the proto, disabling TLS, and sending account balance requests to validate type-safe protobuf responses.

Explore gRPC communication patterns using an in-memory Java map as a stand-in database, with an account repository that initializes accounts 1–10 with a 100 balance and a get balance method.

Rewrite a gRPC server class and expose start, await, and stop methods to support integration tests, with or without Spring, demonstrating test-friendly server lifecycle and service wiring.

Explore client–server communication in a gRPC setup by wiring a channel and generated stub from a proto RPC to invoke the remote get account balance on the server.

Demonstrate a gRPC client using a managed channel builder to connect to a server with plain text, create a bank service blocking stub, and request an account balance.

Create a private, managed channel at startup and a single thread-safe stub to invoke remote gRPC methods, injecting the bank service for create account, get account, and balance at localhost:6565.

Compare blocking and asynchronous stubs in gRPC with Java and Spring Boot, and learn how Java 21 virtual threads let synchronous code run non-blocking behind the scenes.

Create an asynchronous stub with a channel, attach a stream observer, and invoke get account balance with a balance check request.

Discover listenable futures in gRPC with Java and Spring Boot, comparing blocking, future, and asynchronous stubs. Learn that the asynchronous stub supports all four communication patterns, unlike the others.

Design and run integration tests for gRPC APIs with java by using an abstract channel test, a bank service blocking stub, and a localhost 6565 server with plain text.

Perform an integration test for a unary gRPC API using a blocking stub to send a balance check request, assert the account balance equals 100, and manage server lifecycle.

Expose a new unary api get all accounts in the bank gRPC service using google protobuf empty, returning a list of account balances in an all accounts response.

Practice an integration test for the get all accounts API in a gRPC Java Spring Boot masterclass, including starting and stopping a demo server and asserting account count.

Learn to test gRPC async clients with a unary async bank service, using a countdown latch to synchronize responses, and explore integration testing patterns and pitfalls.

Create a simple test utility named response observer to test async gRPC clients and server streaming, implementing stream observer with a thread-safe list to store items and errors.

Refactor an async stub integration test using a test utility response observer with a stream observer, awaiting completion and asserting a single account balance of 100.

Contrast gRPC with rest-style CRUD for books by defining rpc methods like get book by id, save book, update book, and delete book.

Explore gRPC, a lightweight high-performance RPC framework from Google, and learn to define services with proto files, generate sources, and implement blocking or async stubs for unary and streaming patterns.

Learn how server streaming in gRPC lets a single client request yield multiple responses from the server, enabling real-time updates, chunked large file transfers, and efficient mobile apps.

Explore how server streaming delivers zero, one, or many updates—stock price updates, bank withdrawals, and order delivery—possibly infinite or ending in errors like bad request or server crash.

Define an RPC method for server streaming withdraw in a gRPC service, modeling a withdraw request with account_number and amount and a streaming money response.

Start the demo server and run the application, then use Postman to send requests and observe streaming responses that show money transfer progress and validation statuses.

Learn to write a server streaming integration test in Java gRPC using the blocking stub, build a withdraw request, and iterate over two money responses.

Experiment with the async client to test a server streaming gRPC API by validating money responses and observer behavior, including asserting two streamed items and a null throwable.

Explore how gRPC server streaming guarantees that messages arrive in the exact order emitted, with no random ordering, and relate this concept to WebSocket and server-sent events.

Choose unary or streaming in gRPC based on response size and time constraints. Use unary for small, fast responses; switch to streaming for large or unknown results to stay responsive.

Understand stream observer thread safety in gRPC with Java and Spring Boot: it is not thread safe and requires synchronization when multiple threads invoke onNext or onCompleted.

Explore client-side processing in a gRPC streaming scenario, comparing sequential execution with optional parallel processing via an executor service to achieve concurrency.

Explore gRPC streaming backpressure in Java and Spring Boot with hands-on lessons, covering four communication patterns, bidirectional communication, and practical fixes for a fast server and slow client.

Master gRPC client streaming by sending messages from client to server, illustrated with Uber location updates, IoT sensor data, and large file uploads, plus a deposit operation returning updated balances.

Explore exposing a client streaming deposit RPC in bank service, defining a deposit request with account number and money, and using a one-off context to send only money, returning balance.

Explore why gRPC client streaming returns a stream observer, enabling the server to receive multiple deposit requests from the client via a dedicated observer while managing streaming behavior.

Implement a streaming deposit handler in a gRPC service, coordinating account number and money chunks via a stream observer and a response observer to update balances and emit the balance.

Demonstrate a gRPC server demo via Postman, showcasing client streaming deposits and error handling for missing account numbers with the updated account balance.

Learn client streaming in gRPC with Java: use async stubs, response observers, and request observers to stream deposits and verify the resulting account balance.

Learn how a client cancels a gRPC streaming call using a stream observer, triggering on error, and how the server handles the cancellation and error propagation.

Explore bidirectional streaming in gRPC with real-world patterns, enabling clients and servers to exchange streams in chat, search autocomplete, and bank transfer scenarios.

Define a gRPC transfer service with a streaming RPC that sends transfer requests (from_account, to_account, amount) and returns responses with a TransferStatus (rejected or completed) and updated balances.

Implement a gRPC bidirectional streaming transfer service in Java, using a transfer request stream and a transfer response observer, validate balances and accounts, and return per-request status.

Demonstrate implementing a gRPC transfer flow with a bidirectional stream in a Java and Spring Boot setup, testing via Postman to validate transfer requests, rejections, and updated account balances.

Explore bi-directional streaming in gRPC with a transfer demo. Observe how the server emits a response only on transfer completion, not after every message.

Explore bidirectional streaming in gRPC using an async stub to test transfer service interactions, configure stream observers, send transfer requests, and validate responses.

Explore bidirectional streaming in gRPC by contrasting independent and interactive streams, and implement a demand-driven, client–server exchange where the client requests items and the server responds accordingly.

Learn bidirectional gRPC streaming with flow control, modeling the server's emission rate to client request size and emitting up to 100 values based on demand.

Test and interact with a flow control gRPC service via Postman, sending request sizes to trigger streaming responses and observe emitted values, limits, and completion.

Set up a gRPC server and an interactive bidirectional streaming client using the flow control service, wait for two server messages, print results, then send the next request.

Introduces a response handler class that implements a stream observer for server output, uses a request observer to control message flow, and simulates processing delays with random sleep.

In this hands on gRPC masterclass segment, wire a response observer and a request observer to enable flow control, perform streaming, and handle randomized requests until the server completes.

Explore input validation and error handling in gRPC, using stream observer on error to convey status codes. Choose appropriate not found or invalid argument codes based on your team's judgment.

Set up a gRPC bank service in section zero nine using java and spring boot, implementing input validation and error handling for unary and server streaming RPCs.

Apply a request validator utility to validate account numbers 1 to 10 and emit io gRPC status codes such as invalid argument and not found.

Implement input validation in gRPC and return errors as runtime exceptions via the response observer, while sending the account balance or money when validation passes with a functional optional flow.

Perform a Postman demo on a gRPC bank service, importing the input validation proto, validating account numbers 1–10, and validating withdraw preconditions such as multiples of ten and sufficient balance.

Explore unary error handling in gRPC with Java and Spring Boot by validating input in tests for blocking and async clients, expecting a status runtime exception with an invalid argument.

Learn to test server streaming withdraw requests by implementing an input validation test with blocking and async stubs, using JUnit parameterized tests to validate invalid argument and failed precondition errors.

Explore how gRPC handles server errors versus client errors, simulate a runtime exception in a bank withdraw method, and return an internal error via response observer with a descriptive message.

Apply input validation across all gRPC patterns using the response observer to emit errors when prerequisites, such as the account number and money, are missing.

Learn how gRPC uses metadata and trailers to deliver type-safe status information at the end of an RPC. Understand trailer metadata, content type application gRPC, and streaming patterns.

Define a gRPC service with protobuf, create a domain-specific validation enum, and return type-safe error messages to the client, such as invalid account, invalid amount, and insufficient balance.

Set up the gRPC project by running mvn clean and mvn compile for the proto file, create section ten under src/main/java, copy from section nine, and update references.

Explains trailer metadata in a gRPC flow by building a metadata object with a key of type T, attaching error messages to status via a status runtime exception.

Update the package name and import the correct proto file, start the gRPC server, and test via Postman to explore invalid arguments, trailers, and binary-encoded error messages in withdraw flows.

Learn to send string metadata in gRPC by creating a string metadata key with the factory method, naming it description, attaching a value, and testing with postman.

Access trailer metadata from a status runtime exception in a Java gRPC client, using trailers from throwable to extract the error message and validate codes like invalid account.

Execute a server streaming input validation test using custom error codes, validating scenarios like invalid account, invalid amount, and insufficient balance, and implement responses with a Java switch expression.

Explore flexible gRPC error handling with oneof to deliver either a success or domain-specific error, enabling continued streaming, illustrated by a calculator example.

Explore gRPC error handling by selecting appropriate status codes, returning meaningful descriptions via stream observer, and using trailers or metadata with a documented key, including one-offs for streaming.

Explore deadline as a timeout configuration to fail fast and build resilient gRPC apps, demonstrating with unary and server streaming calls and a deliberate three-second delay.

Develop and test gRPC deadline handling in a Java and Spring Boot project, using blocking and async clients, deadlines, and status from throwable utilities.

Explore how the managed channel keeps the connection alive, reestablishing it on next RPC call, with 5–10 minute pings not below 10 seconds and a go away signal after inactivity.

Learn how Kubernetes cluster IP services fail to balance gRPC requests and how LinkedIn service mesh (or Istio) enables load balancing across multiple pods.

Understand that a gRPC channel in Java abstracts a connection, with host and port, lazily initialized on the first RPC as gRPC handles the rest, and is thread-safe for reuse.