1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
/**
*
* Copyright 2005 The Apache Software Foundation or its licensors, as applicable.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.tuscany.core.invocation.jdk;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;
import org.apache.tuscany.core.context.TargetException;
import org.apache.tuscany.core.invocation.Interceptor;
import org.apache.tuscany.core.invocation.InvocationConfiguration;
import org.apache.tuscany.core.invocation.TargetInvoker;
import org.apache.tuscany.core.message.Message;
import org.apache.tuscany.core.message.MessageFactory;
/**
* Receives a request from a JDK proxy and dispatches it to a target invoker or source interceptor stack
*
* @version $Rev$ $Date$
*/
public class JDKInvocationHandler implements InvocationHandler {
private MessageFactory messageFactory;
/*
* an association of an operation to configuration holder. The holder contains the master invocation configuration
* and a locale clone of the master TargetInvoker. TargetInvokers will be cloned by the handler and placed in the
* holder if they are cacheable. This allows optimizations such as avoiding target resolution when a source refers
* to a target of greater scope since the target reference can be maintained by the invoker. When a target invoker
* is not cacheable, the master associated with the invocation configuration will be used.
*/
private Map<Method, ConfigHolder> configuration;
// ----------------------------------
// Constructors
// ----------------------------------
public JDKInvocationHandler(MessageFactory messageFactory, Map<Method, InvocationConfiguration> configuration) {
assert (configuration != null) : "Configuration not specified";
this.configuration = new HashMap(configuration.size());
for (Map.Entry<Method, InvocationConfiguration> entry : configuration.entrySet()) {
this.configuration.put(entry.getKey(), new ConfigHolder(entry.getValue()));
}
// this.configuration = configuration;
this.messageFactory = messageFactory;
}
// ----------------------------------
// Methods
// ----------------------------------
/**
* Dispatches a client request made on a proxy
*/
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
Interceptor headInterceptor = null;
ConfigHolder holder = configuration.get(method);
if (holder == null) {
TargetException e = new TargetException("Operation not configured");
e.setIdentifier(method.getName());
throw e;
}
InvocationConfiguration config = holder.config;
if (config != null) {
headInterceptor = config.getSourceInterceptor();
}
TargetInvoker invoker = null;
if (holder.cachedInvoker == null) {
if(config.getTargetInvoker() == null){
TargetException e= new TargetException("No target invoker configured for operation");
e.setIdentifier(config.getMethod().getName());
throw e;
}
if (config.getTargetInvoker().isCacheable()) {
// clone and store the invoker locally
holder.cachedInvoker = (TargetInvoker) config.getTargetInvoker().clone();
invoker = holder.cachedInvoker;
} else {
invoker = config.getTargetInvoker();
}
} else {
invoker = config.getTargetInvoker();
}
if (headInterceptor == null) {
try {
// short-circuit the dispatch and invoke the target directly
if (config.getTargetInvoker() == null) {
throw new AssertionError("No target invoker [" + method.getName() + "]");
}
return config.getTargetInvoker().invokeTarget(args);
} catch (InvocationTargetException e) {
// the cause was thrown by the target so throw it
throw e.getCause();
}
} else {
Message msg = messageFactory.createMessage();
msg.setTargetInvoker(invoker);// config.getTargetInvoker());
msg.setBody(args);
// dispatch the invocation down the chain and get the response
Message resp = headInterceptor.invoke(msg);
Object body = resp.getBody();
if (body instanceof Throwable) {
throw (Throwable) body;
}
return body;
}
}
/**
* A holder used to associate an invocation configuration with a local copy of a target invoker that was previously
* cloned from the configuration master
*/
private class ConfigHolder {
public ConfigHolder(InvocationConfiguration config) {
this.config = config;
}
InvocationConfiguration config;
TargetInvoker cachedInvoker;
}
}
|
