hunt.stomp.support.AbstractHeaderMapper source code

1 /*
2  * Copyright 2002-2018 the original author or authors.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 module hunt.stomp.support.AbstractHeaderMapper;
18 
19 import hunt.stomp.MessageHeaders;
20 import hunt.collection.Map;
21 import hunt.logging;
22 
23 
24 /**
25  * A base {@link HeaderMapper} implementation.
26  *
27  * @author Stephane Nicoll
28  * @since 4.1
29  * @param (T) type of the instance to and from which headers will be mapped
30  */
31 abstract class AbstractHeaderMapper(T) : HeaderMapper!(T) {
32 
33 	private string inboundPrefix = "";
34 
35 	private string outboundPrefix = "";
36 
37 
38 	/**
39 	 * Specify a prefix to be appended to the message header name for any
40 	 * user-defined property that is being mapped into the MessageHeaders.
41 	 * The default is an empty string (no prefix).
42 	 */
43 	void setInboundPrefix(string inboundPrefix) {
44 		this.inboundPrefix = (inboundPrefix !is null ? inboundPrefix : "");
45 	}
46 
47 	/**
48 	 * Specify a prefix to be appended to the protocol property name for any
49 	 * user-defined message header that is being mapped into the protocol-specific
50 	 * Message. The default is an empty string (no prefix).
51 	 */
52 	void setOutboundPrefix(string outboundPrefix) {
53 		this.outboundPrefix = (outboundPrefix !is null ? outboundPrefix : "");
54 	}
55 
56 
57 	/**
58 	 * Generate the name to use to set the header defined by the specified
59 	 * {@code headerName} to the protocol specific message.
60 	 * @see #setOutboundPrefix
61 	 */
62 	protected string fromHeaderName(string headerName) {
63 		string propertyName = headerName;
64 		if (StringUtils.hasText(this.outboundPrefix) && !propertyName.startsWith(this.outboundPrefix)) {
65 			propertyName = this.outboundPrefix + headerName;
66 		}
67 		return propertyName;
68 	}
69 
70 	/**
71 	 * Generate the name to use to set the header defined by the specified
72 	 * {@code propertyName} to the {@link MessageHeaders} instance.
73 	 * @see #setInboundPrefix(string)
74 	 */
75 	protected string toHeaderName(string propertyName) {
76 		string headerName = propertyName;
77 		if (StringUtils.hasText(this.inboundPrefix) && !headerName.startsWith(this.inboundPrefix)) {
78 			headerName = this.inboundPrefix + propertyName;
79 		}
80 		return headerName;
81 	}
82 
83 	/**
84 	 * Return the header value, or {@code null} if it does not exist
85 	 * or does not match the requested {@code type}.
86 	 */
87 	
88 	protected V getHeaderIfAvailable(V)(Map!(string, Object) headers, string name) {
89 		Object value = headers.get(name);
90 		if (value is null) {
91 			return V.init;
92 		}
93 
94 		static if(is(T == Nullable!T)) {
95 			Nullable!T o = cast(Nullable!T)value;
96 			return o.value;
97 		} else {
98 			return cast(T) value;
99 		}
100 
101 		// if (!type.isAssignableFrom(value.getClass())) {
102 		// 	version(HUNT_DEBUG) {
103 		// 		trace("Skipping header '" ~ name ~ "': expected type [" ~ type ~ "], but got [" ~
104 		// 				value.getClass() ~ "]");
105 		// 	}
106 		// 	return null;
107 		// }
108 		// else {
109 		// 	return type.cast(value);
110 		// }
111 	}
112 
113 }