SpEL language

Q: Do I need #{...} around the expression?

No. Without #{ the whole text is one expression. Use #{...} to mix literal text and expressions.

Q: Can I call Spring beans?

@name resolves a bean from the Camel registry: plain values and bean methods bound with bind_bean_method. There is no Spring application context.

The spel language evaluates Spring Expression Language expressions and #{...} templates against the exchange.

Name: spel · Crate: cameleer-script · Cargo feature: script · Apache Camel: SpEL

When to use it

Port Spring-based Camel routes that use SpEL.
Build a string with embedded expressions: Hello #{request.body}.

Syntax

Cameleer interprets SpEL itself, without Spring or a JVM. Text with #{...} blocks is a template; a lone #{expr} returns the typed value (a number stays a number); text without #{ is one plain expression. Supported: property and index navigation, method calls, #root, #this and #variables, @bean references from the Camel registry, T(Type) static calls for known JDK types, new for JDK collections, ?., ?:, the ternary operator, list {1, 2} and map {k: v} literals, selection .?[], projection .![], matches, between, instanceof and word operators (eq, div, mod...). Arbitrary Java classes are not available.

The root object has request, response, message, exchange, body, headers and properties.

Examples

yaml example: spel-greeting

- route:
    id: spel-demo
    from:
      uri: direct:spel
      steps:
        - setHeader:
            name: tier
            spel: "#{request.headers.amount > 100 ? 'gold' : 'standard'}"
        - setBody:
            spel: "Hello #{request.body}, you are #{request.headers.tier}"

text

Ada

text

Hello Ada, you are gold

json

{"body": "hello", "headers": {"amount": 250, "name": "Ada"}}

expression	result
`#{request.body.toUpperCase()}`	`HELLO`
`#{request.headers.amount > 100}`	`true`
`Hello #{request.headers.name}`	`Hello Ada`
`#{request.headers['name']}`	`Ada`
`#{headers.missing ?: 'none'}`	`none`
`#{exchange.in.body}`	`hello`
`#{{1, 2, 3, 4}.?[#this > 2]}`	`[3,4]`

Options

option	default	description
`resultType`	(none)	Convert the result to this type.

Rust DSL

rust

b.from("direct:spel-rust")
    .set_body(cameleer_script::spel("Hello #{request.body}"));

Common questions

Do I need `#{...}` around the expression?

No. Without #{ the whole text is one expression. Use #{...} to mix literal text and expressions.

Can I call Spring beans?

@name resolves a bean from the Camel registry: plain values and bean methods bound with bind_bean_method. There is no Spring application context.

Found a problem?

If something on this page doesn't match what Cameleer does, or you hit a bug while building with it, please help fix it, whether you are a person or a coding agent: open an issue that describes what you saw, then fork the repository, fix it, add or update a test, run cargo test --workspace, and open a pull request. CONTRIBUTING.md explains the ground rules.