Chapter 152. StringTemplate

String Template
링크 복사

The string-template: component allows you to process a message using a String Template. This can be ideal when using Templating to generate responses for requests.

Maven users will need to add the following dependency to their pom.xml for this component:

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-stringtemplate</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-stringtemplate</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>

Copy to Clipboard

Toggle word wrap

URI format
링크 복사

string-template:templateName[?options]

string-template:templateName[?options]

Copy to Clipboard

Toggle word wrap

Where templateName is the classpath-local URI of the template to invoke; or the complete URL of the remote template.

You can append query options to the URI in the following format, ?option=value&option=value&...

Options
링크 복사

Expand

Option	Default	Description
`contentCache`	`false`	Cache for the resource content when its loaded. Note : as of Camel 2.9 cached resource content can be cleared via JMX using the endpoint's `clearContentCache` operation.
`delimiterStart`	`null`	Since Camel 2.11.1, configuring the variable start delimiter
`delimiterStop`	`null`	Since Camel 2.11.1, configuring the variable end delimiter

Headers
링크 복사

Apache Camel will store a reference to the resource in the message header with key, org.apache.camel.stringtemplate.resource. The Resource is an org.springframework.core.io.Resource object.

Hot reloading
링크 복사

The string template resource is by default hot-reloadable for both file and classpath resources (expanded jar). If you set contentCache=true, Apache Camel loads the resource only once and hot-reloading is not possible. This scenario can be used in production when the resource never changes.

StringTemplate Attributes
링크 복사

Apache Camel will provide exchange information as attributes (just a java.util.Map) to the string template. The Exchange is transfered as:

Expand

key	value
`exchange`	The Exchange itself.
`headers`	The headers of the In message.
`camelContext`	The Camel Context.
`request`	The In message.
`in`	The In message.
`body`	The In message body.
`out`	The Out message (only for InOut message exchange pattern).
`response`	The Out message (only for InOut message exchange pattern).

Since Camel 2.14, you can define the custom context map by setting the message header "CamelStringTemplateVariableMap" just like the below code.

Map<String, Object> variableMap = new HashMap<String, Object>();
Map<String, Object> headersMap = new HashMap<String, Object>();
headersMap.put("name", "Willem");
variableMap.put("headers", headersMap);
variableMap.put("body", "Monday");
variableMap.put("exchange", exchange);
exchange.getIn().setHeader("CamelStringTemplateVariableMap", variableMap);

Map<String, Object> variableMap = new HashMap<String, Object>();
Map<String, Object> headersMap = new HashMap<String, Object>();
headersMap.put("name", "Willem");
variableMap.put("headers", headersMap);
variableMap.put("body", "Monday");
variableMap.put("exchange", exchange);
exchange.getIn().setHeader("CamelStringTemplateVariableMap", variableMap);

Copy to Clipboard

Toggle word wrap

Samples
링크 복사

For example you could use a string template as follows in order to formulate a response to a message:

from("activemq:My.Queue").
  to("string-template:com/acme/MyResponse.tm");

from("activemq:My.Queue").
  to("string-template:com/acme/MyResponse.tm");

Copy to Clipboard

Toggle word wrap

The Email Sample
링크 복사

In this sample we want to use a string template to send an order confirmation email. The email template is laid out in StringTemplate as: This example works for camel 2.11.0. If your camel version is less than 2.11.0, the variables should be started and ended with $.

Dear <headers.lastName>, <headers.firstName>

Thanks for the order of <headers.item>.

Regards Camel Riders Bookstore
<body>

Dear <headers.lastName>, <headers.firstName>

Thanks for the order of <headers.item>.

Regards Camel Riders Bookstore
<body>

Copy to Clipboard

Toggle word wrap

And the java code is as follows:

private Exchange createLetter() {
    Exchange exchange = context.getEndpoint("direct:a").createExchange();
    Message msg = exchange.getIn();
    msg.setHeader("firstName", "Claus");
    msg.setHeader("lastName", "Ibsen");
    msg.setHeader("item", "Camel in Action");
    msg.setBody("PS: Next beer is on me, James");
    return exchange;
}

@Test
public void testVelocityLetter() throws Exception {
    MockEndpoint mock = getMockEndpoint("mock:result");
    mock.expectedMessageCount(1);
    mock.expectedBodiesReceived("Dear Ibsen, Claus! Thanks for the order of Camel in Action. Regards Camel Riders Bookstore PS: Next beer is on me, James");

    template.send("direct:a", createLetter());

    mock.assertIsSatisfied();
}

protected RouteBuilder createRouteBuilder() throws Exception {
    return new RouteBuilder() {
        public void configure() throws Exception {
            from("direct:a").to("string-template:org/apache/camel/component/stringtemplate/letter.tm").to("mock:result");
        }
    };
}

private Exchange createLetter() {
    Exchange exchange = context.getEndpoint("direct:a").createExchange();
    Message msg = exchange.getIn();
    msg.setHeader("firstName", "Claus");
    msg.setHeader("lastName", "Ibsen");
    msg.setHeader("item", "Camel in Action");
    msg.setBody("PS: Next beer is on me, James");
    return exchange;
}

@Test
public void testVelocityLetter() throws Exception {
    MockEndpoint mock = getMockEndpoint("mock:result");
    mock.expectedMessageCount(1);
    mock.expectedBodiesReceived("Dear Ibsen, Claus! Thanks for the order of Camel in Action. Regards Camel Riders Bookstore PS: Next beer is on me, James");

    template.send("direct:a", createLetter());

    mock.assertIsSatisfied();
}

protected RouteBuilder createRouteBuilder() throws Exception {
    return new RouteBuilder() {
        public void configure() throws Exception {
            from("direct:a").to("string-template:org/apache/camel/component/stringtemplate/letter.tm").to("mock:result");
        }
    };
}

Copy to Clipboard

Toggle word wrap

이 콘텐츠는 선택한 언어로 제공되지 않습니다.

String Template
링크 복사

URI format
링크 복사

Options
링크 복사

Headers
링크 복사

Hot reloading
링크 복사

StringTemplate Attributes
링크 복사

Samples
링크 복사

The Email Sample
링크 복사

자세한 정보

평가판, 구매 및 판매

커뮤니티

Red Hat 문서 정보

보다 포괄적 수용을 위한 오픈 소스 용어 교체

Red Hat 소개

Theme

Red Hat legal and privacy links

Red Hat legal and privacy links

이 콘텐츠는 선택한 언어로 제공되지 않습니다.

Chapter 152. StringTemplate

String Template링크 복사링크가 클립보드에 복사되었습니다!

URI format링크 복사링크가 클립보드에 복사되었습니다!

Options링크 복사링크가 클립보드에 복사되었습니다!

Headers링크 복사링크가 클립보드에 복사되었습니다!

Hot reloading링크 복사링크가 클립보드에 복사되었습니다!

StringTemplate Attributes링크 복사링크가 클립보드에 복사되었습니다!

Samples링크 복사링크가 클립보드에 복사되었습니다!

The Email Sample링크 복사링크가 클립보드에 복사되었습니다!

자세한 정보

평가판, 구매 및 판매

커뮤니티

Red Hat 문서 정보

보다 포괄적 수용을 위한 오픈 소스 용어 교체

Red Hat 소개

Theme

Red Hat legal and privacy links

Red Hat legal and privacy links

String Template
링크 복사

URI format
링크 복사

Options
링크 복사

Headers
링크 복사

Hot reloading
링크 복사

StringTemplate Attributes
링크 복사

Samples
링크 복사

The Email Sample
링크 복사