View Javadoc
1   /*
2    * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
3    * The software in this package is published under the terms of the CPAL v1.0
4    * license, a copy of which has been included with this distribution in the
5    * LICENSE.txt file.
6    */
7   package org.mule.api.annotations.param;
8   
9   import org.mule.api.annotations.meta.Evaluator;
10  
11  import java.lang.annotation.Documented;
12  import java.lang.annotation.ElementType;
13  import java.lang.annotation.Retention;
14  import java.lang.annotation.RetentionPolicy;
15  import java.lang.annotation.Target;
16  
17  /**
18   * Used on component methods, this annotation marks the method parameter that will be used to pass in one or more of the headers received.
19   * This annotation value can define a single header, a comma-separated list of header names, '*' to denote all headers, or a comma-separated list
20   * of wildcard expressions such as 'MULE_*, X-*'. By default, if a named header is not present on the current message, an exception will be thrown.
21   * However, if the header name is defined with the '?' post fix, it will be marked as optional.
22   * <p/>
23   * When defining multiple header names or using wildcards, the parameter can be a {@link java.util.Map} or {@link java.util.List}. If a
24   * {@link java.util.Map} is used, the header name and value is passed in. If {@link java.util.List} is used, just the header values are used.
25   * If a single header name is defined, the header type can be used as the parameter type, though {@link java.util.List} or {@link java.util.Map}
26   * can be used too.
27   *
28   * The Inbound headers collection is immutable, so the headers Map or List passed in will be immutable too. Attempting to write to the Map or List will result in an {@link UnsupportedOperationException}.
29   */
30  @Target(ElementType.PARAMETER)
31  @Retention(RetentionPolicy.RUNTIME)
32  @Documented
33  @Evaluator("messageProperty")
34  public @interface InboundHeaders
35  {
36      /**
37       * Defines the headers that should be injected into the parameter. This can be a single header, a comma-separated
38       * list of header names,'*' to denote all headers or a comma-separated list of wildcard expressions. By default,
39       * if a named header is not present, an exception will be thrown. However, if the header name is defined with the
40       * '?' post fix, it will be marked as optional.
41       * The optional '?' post fix is not supported when using wildcard expressions
42       *
43       * @return the header expression used to query the message for headers
44       */
45       String value();
46  }