https://github.com/rogervinas/apache-camel-fun
🐫 Fun with Apache Camel
https://github.com/rogervinas/apache-camel-fun
apache-camel
Last synced: 4 months ago
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🐫 Fun with Apache Camel
- Host: GitHub
- URL: https://github.com/rogervinas/apache-camel-fun
- Owner: rogervinas
- Created: 2018-02-13T06:59:18.000Z (over 8 years ago)
- Default Branch: master
- Last Pushed: 2025-03-10T19:25:20.000Z (over 1 year ago)
- Last Synced: 2025-11-05T04:21:46.801Z (8 months ago)
- Topics: apache-camel
- Language: Java
- Homepage:
- Size: 186 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# Fun with Apache Camel
## Before Having Fun
What is Camel? *- Jonathan Anstey at [DZone](https://dzone.com/articles/open-source-integration-apache)*
Apache Camel is an open source Java framework that focuses on making integration easier and more accessible to developers. It does this by providing:
* Concrete implementations of all the widely used EIPs.
* Connectivity to a great variety of transports and APIs.
* Easy to use Domain Specific Languages (DSLs) to wire EIPs and transports together.
All is about Routes, Components and Exchanges:
* Routes:
* A route defines the workflow an Exchange will have to follow.
* A route starts using a Component consumer (the **from**) and then can apply any set of EIP's and invoke any set of Component producers (usually the **to**'s).
* Components:
* A Component may provide two implementations: a Consumer and a Producer.
* A Component consumer is placed at the **from** of a route and generates Exchanges every time its own logic is triggered, usually receiving data from an external source.
* A Component producer is placed at a **to** endpoint and usually sends the Exchange to an external sink.
* Exchanges:
* An Exchange is the data flowing across a route, containing:
* An **in** message: a body (anything) and some headers (list of key+value)
* An **out** message: a body (anything) and some headers (list of key+value)
* Properties: a list of key+value only set/get by us and available along the route.
* At any step of a route the **in** message is transformed to an **out** message which will be the **in** message for the following step.
* Type converters will automatically convert a body to whatever type we want to read it as.
Useful links:
* [What is Camel](http://camel.apache.org/what-is-camel.html)
* [Integration patterns](http://camel.apache.org/enterprise-integration-patterns.html)
* [Components](http://camel.apache.org/components.html)
* [Languages](http://camel.apache.org/languages.html)
* [Type Converters](http://camel.apache.org/type-converter.html)
* [Error handling](http://camel.apache.org/error-handling-in-camel.html)
* [Testing](http://camel.apache.org/testing.html)
* [Examples](https://github.com/apache/camel/tree/master/examples)
* [Source Code](https://github.com/apache/camel/tree/master)
## Fun Use Case #1
* An external system periodically creates files in a local directory.
* The external system sends them ZIP compressed.
* The original content is XML:
```xml
zzzzzz
```
* Generate one JSON for each UserQuote:
```javascript
{ "id" : nnn, "user" : "xxx yyy", "quote" : "zzzzzz" }
```
* Send it both to an FTP server and to a KAFKA topic.
## Fun Use Case #2
* Receive messages published to KAFKA by [Fun Use Case #1](#fun-use-case-1).
* Send them to an AWS-S3 bucket if the id is even.
* Send them to a POSTGRES table if the id is odd.
## Fun Use Case #3
* Poll POSTGRES table rows inserted by [Fun Use Case #2](#fun-use-case-2).
* Aggregate them in groups of 5.
* Convert each group to a CSV file.
* Send the file to an email address.
## Fun Use Case #4
* Poll files uploaded to:
* an FTP server by [Fun Use Case #1](#fun-use-case-1).
* an AWS-S3 bucket by [Fun Use Case #2](#fun-use-case-2).
* Enrich them executing a query to a POSTGRES table.
* Convert to a line of text and append to a file in a local directory.
## Let the Fun Begin
### Code!
Make all the test pass!
```bash
./gradlew test --info
./gradlew integrationTest --info
```
### Run!
Start all servers and applications:
```bash
docker-compose up
cd apache-camel-fun-1 ; ./gradlew bootRun
cd apache-camel-fun-2 ; ./gradlew bootRun
cd apache-camel-fun-3 ; ./gradlew bootRun
cd apache-camel-fun-4 ; ./gradlew bootRun
```
... and test manually:
```bash
cd apache-camel-fun-1/input_samples
zip fun0.zip fun0.xml && mv fun0.zip ../input
zip fun1.zip fun1.xml && mv fun1.zip ../input
zip fun2.zip fun2.xml && mv fun2.zip ../input
zip fun5.zip fun5.xml && mv fun5.zip ../input
zip fun10.zip fun10.xml && mv fun10.zip ../input
```