This document will show you how to build a browser/server application with Vert.x and gRPC Web.
The application involves a client, the browser, and a Vert.x server:
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the user types a name in a text field and clicks the send button
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the browser sends the name to the server using the gRPC Web protocol
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the server replies with a greeting
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the browser displays the greeting
On the server side, you will create a Vert.x gRPC server service that:
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implements a gRPC server stub
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configures an HTTP server replying to both gRPC Web and static file requests
On the client side, you will create a web page that uses the gRPC Web Javascript client.
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A text editor or an IDE
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Java 17 or higher
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The
protocJavascript plugin -
The
protocgRPC Web plugin
The protoc Javascript and gRPC Web plugin files must be installed somewhere on your PATH and be executable.
| Tip | On several Linux-like systems, you can install the plugins like this: mkdir --parents "$HOME/.local/bin" curl -sL https://github.com/protocolbuffers/protobuf-javascript/releases/download/v3.21.4/protobuf-javascript-3.21.4-linux-x86_64.tar.gz | tar xzfO - bin/protoc-gen-js > "$HOME/.local/bin/protoc-gen-js" chmod u+x "$HOME/.local/bin/protoc-gen-js" curl -sL https://github.com/grpc/grpc-web/releases/download/1.5.0/protoc-gen-grpc-web-1.5.0-linux-x86_64 > "$HOME/.local/bin/protoc-gen-grpc-web" chmod u+x "$HOME/.local/bin/protoc-gen-grpc-web" |
You don’t have to install protoc or the Java plugin. They will be managed by a Maven plugin.
The gRPC Greeter service consists in a single SayHello rpc method. The HelloRequest message contains the name sent by the client. The HelloReply message contains the greeting generated by the server.