Chapter 333. String Template Component Available as of Camel version 1.2 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> 333.1. URI format string-template:templateName[?options] 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&... 333.2. Options The String Template component supports 2 options, which are listed below. Name Description Default Type allowContextMapAll (producer) Sets whether the context map should allow access to all details. By default only the message body and headers can be accessed. This option can be enabled for full access to the current Exchange and CamelContext. Doing so imposes a potential security risk as this opens access to the full power of CamelContext API. false boolean allowTemplateFromHeader (producer) Whether to allow to use resource template from header or not (default false). Enabling this option has security ramifications. For example, if the header contains untrusted or user derived content, this can ultimately impact on the confidentility and integrity of your end application, so use this option with caution. false boolean The String Template endpoint is configured using URI syntax: with the following path and query parameters: 333.2.1. Path Parameters (1 parameters): Name Description Default Type resourceUri Required Path to the resource. You can prefix with: classpath, file, http, ref, or bean. classpath, file and http loads the resource using these protocols (classpath is default). ref will lookup the resource in the registry. bean will call a method on a bean to be used as the resource. For bean you can specify the method name after dot, eg bean:myBean.myMethod. String 333.2.2. Query Parameters (6 parameters): Name Description Default Type allowContextMapAll (producer) Sets whether the context map should allow access to all details. By default only the message body and headers can be accessed. This option can be enabled for full access to the current Exchange and CamelContext. Doing so imposes a potential security risk as this opens access to the full power of CamelContext API. false boolean allowTemplateFromHeader (producer) Whether to allow to use resource template from header or not (default false). Enabling this option has security ramifications. For example, if the header contains untrusted or user derived content, this can ultimately impact on the confidentility and integrity of your end application, so use this option with caution. false boolean contentCache (producer) Sets whether to use resource content cache or not false boolean delimiterStart (producer) The variable start delimiter < char delimiterStop (producer) The variable end delimiter > char synchronous (advanced) Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). false boolean 333.3. Spring Boot Auto-Configuration The component supports 2 options, which are listed below. Name Description Default Type camel.component.string-template.enabled Enable string-template component true Boolean camel.component.string-template.resolve-property-placeholders Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. true Boolean 333.4. Headers 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. 333.5. Hot reloading The string template resource is by default hot-reloadable for both file and classpath resources (expanded jar). If you set contentCache=true , Camel loads the resource only once and hot-reloading is not possible. This scenario can be used in production when the resource never changes. 333.6. StringTemplate Attributes 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); 333.7. Samples 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"); 333.8. The Email Sample 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 USD. Dear <headers.lastName>, <headers.firstName> Thanks for the order of <headers.item>. Regards Camel Riders Bookstore <body> And the java code is as follows: 333.9. See Also Configuring Camel Component Endpoint Getting Started

Commands:
<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>
string-template:templateName[?options]
string-template:resourceUri
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);
from("activemq:My.Queue"). to("string-template:com/acme/MyResponse.tm");
Dear <headers.lastName>, <headers.firstName> Thanks for the order of <headers.item>. Regards Camel Riders Bookstore <body>