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 }