summaryrefslogtreecommitdiffstats
path: root/branches/sca-java-0.90/modules/binding-rmi/src/main/java/org/apache/tuscany/sca/binding/rmi/RMIBindingProvider.java
blob: b22ddd936a70df43dd56bcc68ffd7312ce359ec7 (plain)
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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
/**
 *
 * Copyright 2006 The Apache Software Foundation
 *
 *  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.sca.binding.rmi;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.URI;
import java.rmi.Remote;
import java.rmi.server.UnicastRemoteObject;

import net.sf.cglib.asm.ClassWriter;
import net.sf.cglib.asm.Constants;
import net.sf.cglib.asm.Type;
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;

import org.apache.tuscany.sca.core.invocation.ThreadMessageContext;
import org.apache.tuscany.sca.interfacedef.Interface;
import org.apache.tuscany.sca.interfacedef.InterfaceContract;
import org.apache.tuscany.sca.interfacedef.Operation;
import org.apache.tuscany.sca.interfacedef.java.JavaInterface;
import org.apache.tuscany.sca.interfacedef.java.impl.JavaInterfaceUtil;
import org.apache.tuscany.sca.invocation.Invoker;
import org.apache.tuscany.sca.invocation.Message;
import org.apache.tuscany.sca.invocation.MessageFactory;
import org.apache.tuscany.sca.provider.ReferenceBindingProvider;
import org.apache.tuscany.sca.provider.ServiceBindingProvider;
import org.apache.tuscany.sca.rmi.RMIHost;
import org.apache.tuscany.sca.rmi.RMIHostException;
import org.apache.tuscany.sca.runtime.RuntimeComponent;
import org.apache.tuscany.sca.runtime.RuntimeComponentReference;
import org.apache.tuscany.sca.runtime.RuntimeComponentService;

/**
 * RMIBindingProvider
 */
public class RMIBindingProvider implements ReferenceBindingProvider, ServiceBindingProvider, MethodInterceptor {

    private RuntimeComponent component;
    private RuntimeComponentService service;
    private RuntimeComponentReference reference;
    private RMIBinding binding;
    private MessageFactory messageFactory;
    private RMIHost rmiHost;

    // need this member to morph the service interface to extend from Remote if
    // it does not
    // the base class's member variable interfaze is to be maintained to enable
    // the connection
    // of the service outbound to the component's inbound wire which requires
    // that the service
    // and the component match in their service contracts.
    private Interface serviceInterface;

    public RMIBindingProvider(RuntimeComponent component,
                              RuntimeComponentService service,
                              RMIBinding binding,
                              MessageFactory messageFactory,
                              RMIHost rmiHost) {
        this.component = component;
        this.service = service;
        this.binding = binding;
        this.rmiHost = rmiHost;
        this.messageFactory = messageFactory;
    }

    public RMIBindingProvider(RuntimeComponent component,
                              RuntimeComponentReference reference,
                              RMIBinding binding,
                              RMIHost rmiHost) {
        this.component = component;
        this.reference = reference;
        this.binding = binding;
        this.rmiHost = rmiHost;
    }

    public InterfaceContract getBindingInterfaceContract() {
        if (service != null)
            return service.getInterfaceContract();
        else
            return reference.getInterfaceContract();
    }

    public void start() {
        if (service != null) {
            URI uri = URI.create(component.getURI() + "/" + binding.getName());
            binding.setURI(uri.toString());

            this.serviceInterface = service.getInterfaceContract().getInterface();

            Remote rmiProxy = createRmiService();

            try {
                rmiHost.registerService(binding.getRmiServiceName(), getPort(binding.getRmiPort()), rmiProxy);
            } catch (RMIHostException e) {
                throw new NoRemoteServiceException(e);
            }
        }
    }

    public void stop() {
        if (service != null) {
            try {
                rmiHost.unregisterService(binding.getRmiServiceName(), getPort(binding.getRmiPort()));
            } catch (RMIHostException e) {
                throw new NoRemoteServiceException(e.getMessage());
            }
        }
    }

    public Invoker createInvoker(Operation operation, boolean isCallback) {
        try {
            Method remoteMethod = JavaInterfaceUtil.findMethod(((JavaInterface)reference.getInterfaceContract()
                .getInterface()).getJavaClass(), operation);
            return new RMIBindingInvoker(rmiHost, binding.getRmiHostName(), binding.getRmiPort(), binding
                .getRmiServiceName(), remoteMethod);
        } catch (NoSuchMethodException e) {
            throw new NoRemoteMethodException(operation.toString(), e);
        }
    }

    protected Remote createRmiService() {
        Enhancer enhancer = new Enhancer();
        enhancer.setSuperclass(UnicastRemoteObject.class);
        enhancer.setCallback(this);
        Class targetJavaInterface = getTargetJavaClass(serviceInterface);
        if (!Remote.class.isAssignableFrom(targetJavaInterface)) {
            RMIServiceClassLoader classloader = new RMIServiceClassLoader(getClass().getClassLoader());
            final byte[] byteCode = generateRemoteInterface(targetJavaInterface);
            targetJavaInterface = classloader.defineClass(byteCode);
            enhancer.setClassLoader(classloader);
        }
        enhancer.setInterfaces(new Class[] {targetJavaInterface});
        return (Remote)enhancer.create();
    }

    // if the interface of the component whose serviceBindings must be exposed
    // as RMI Service, does not
    // implement java.rmi.Remote, then generate such an interface. This method
    // will stop with
    // just generating the bytecode. Defining the class from the byte code must
    // tbe the responsibility
    // of the caller of this method, since it requires a classloader to be
    // created to define and load
    // this interface.
    protected byte[] generateRemoteInterface(Class serviceInterface) {
        String interfazeName = serviceInterface.getCanonicalName();
        ClassWriter cw = new ClassWriter(false);

        String simpleName = serviceInterface.getSimpleName();
        cw.visit(Constants.V1_5, Constants.ACC_PUBLIC + Constants.ACC_ABSTRACT + Constants.ACC_INTERFACE, interfazeName
            .replace('.', '/'), "java/lang/Object", new String[] {"java/rmi/Remote"}, simpleName + ".java");

        StringBuffer argsAndReturn = null;
        Method[] methods = serviceInterface.getMethods();
        for (Method method : methods) {
            argsAndReturn = new StringBuffer("(");
            Class[] paramTypes = method.getParameterTypes();
            Class returnType = method.getReturnType();

            for (Class paramType : paramTypes) {
                argsAndReturn.append(Type.getType(paramType));
            }
            argsAndReturn.append(")");
            argsAndReturn.append(Type.getType(returnType));

            cw.visitMethod(Constants.ACC_PUBLIC + Constants.ACC_ABSTRACT,
                           method.getName(),
                           argsAndReturn.toString(),
                           new String[] {"java/rmi/RemoteException"},
                           null);
        }
        cw.visitEnd();
        return cw.toByteArray();
    }

    public Object intercept(Object object, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
        // since incoming method signatures have 'remotemethod invocation' it
        // will not match with the
        // wired component's method signatures. Hence need to pull in the
        // corresponding method from the
        // component's service contract interface to make this invocation.

        return invokeTarget(JavaInterfaceUtil.findOperation(method, serviceInterface.getOperations()), args);
    }

    public Object invokeTarget(Operation op, Object[] args) throws InvocationTargetException {
        
        Message requestMsg = messageFactory.createMessage();
        ThreadMessageContext.setMessageContext(requestMsg);
        requestMsg.setBody(args);

        Message responseMsg = service.getInvoker(binding, op).invoke(requestMsg);

        if (responseMsg.isFault()) {
            throw new InvocationTargetException((Throwable)responseMsg.getBody());
        }
        return responseMsg.getBody();
    }

    protected int getPort(String port) {
        int portNumber = RMIHost.RMI_DEFAULT_PORT;
        if (port != null && port.length() > 0) {
            portNumber = Integer.decode(port);
        }

        return portNumber;
    }

    private Class<?> getTargetJavaClass(Interface targetInterface) {
        // TODO: right now assume that the target is always a Java
        // Implementation. Need to figure out
        // how to generate Java Interface in cases where the target is not a
        // Java Implementation
        return ((JavaInterface)targetInterface).getJavaClass();
    }

    private class RMIServiceClassLoader extends ClassLoader {
        public RMIServiceClassLoader(ClassLoader parent) {
            super(parent);
        }

        public Class defineClass(byte[] byteArray) {
            return defineClass(null, byteArray, 0, byteArray.length);
        }
    }

}