Apache Camel Developer's Cookbook

coverpage

Apache Camel Developer's Cookbook

Credits

About the Authors

Acknowledgments

About the Reviewers

www.PacktPub.com

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Preface

What is Camel?

Camel Concepts

The Camel DSL

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Chapter 1. Structuring Routes

Introduction

Using Camel in a Java application

Embedding Camel in a Spring application

Using Camel components

Reusing routing logic by connecting routes

Asynchronously connecting routes

Spanning Camel contexts within a single Java process

Using external properties in Camel routes

Reusing endpoints

Reusing routing logic through template routes

Controlling route startup and shutdown

Chapter 2. Message Routing

Introduction

Content Based Routing

Filtering out unwanted messages

Wire Tap – sending a copy of the message elsewhere

Multicast – routing the same message to many endpoints

Recipient List – routing a message to a list of endpoints

Throttler – restricting the number of messages flowing to an endpoint

Request-response route sending a one-way message

One-way route waiting on a request-response endpoint

Dynamic Routing – making routing decisions at runtime

Load balancing across a number of endpoints

Routing Slip – routing a message to a fixed list of endpoints

Chapter 3. Routing to Your Code

Introduction

Routing messages directly to a Java method

Sending messages directly to a Camel endpoint

Using a Java method as a Predicate

Writing a custom Camel Processor

Mapping the message to method parameters

Writing a custom data marshaller

Writing a custom data type converter

Chapter 4. Transformation

Introduction

Transforming using a Simple Expression

Transforming inline with XQuery

Transforming with XSLT

Transforming from Java to XML with JAXB

Transforming from Java to JSON

Transforming from XML to JSON

Parsing comma-separated values (CSV)

Enriching your content with some help from other endpoints

Normalizing messages into a common XML format

Chapter 5. Splitting and Aggregating

Introduction

Splitting a message into fragments

Splitting XML messages

Processing split messages in parallel

Aggregating related messages

Aggregating with timeouts

Aggregating with intervals

Processing aggregated messages in parallel

Splitting a message and processing and gathering responses

Splitting messages and re-aggregating them using different criteria

Chapter 6. Parallel Processing

Introduction

Increasing message consumption through multiple endpoint consumers

Spreading the load within a route using a set of threads

Routing a request asynchronously

Using custom thread pools

Using thread pool profiles

Working with asynchronous APIs

Chapter 7. Error Handling and Compensation

Introduction

Logging errors

Dead Letter Channel – handling errors later

Retrying an operation

Conditional retry

Customizing each redelivery attempt

Catching exceptions

Marking exceptions as handled

Fine-grained error handling using doTry…doCatch

Defining completion actions

Defining completion actions dynamically

Chapter 8. Transactions and Idempotency

Introduction

Preventing duplicate invocation of routing logic

Transactional file consumption

Using transactions with a database

Limiting the scope of a transaction