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2  *
3  * Licensed to the Apache Software Foundation (ASF) under one
4  * or more contributor license agreements.  See the NOTICE file
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6  * regarding copyright ownership.  The ASF licenses this file
7  * to you under the Apache License, Version 2.0 (the
8  * "License"); you may not use this file except in compliance
9  * with the License.  You may obtain a copy of the License at
10  *
11  *   http://www.apache.org/licenses/LICENSE-2.0
12  *
13  * Unless required by applicable law or agreed to in writing,
14  * software distributed under the License is distributed on an
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16  * KIND, either express or implied.  See the License for the
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21 
22 
23 
24 package com.sun.star.lib.uno.environments.remote;
25 
26 import com.sun.star.lib.uno.typedesc.TypeDescription;
27 import java.io.IOException;
28 
29 /**
30  * An abstraction of remote bridge protocols.
31  *
32  * <p>A class implementing a given protocol <var>prot</var> must be named
33  * <code>com.sun.star.lib.uno.protocols.<var>prot</var>.<var>prot</var></code>
34  * and must have a public constructor that takes four arguments:  The first
35  * argument of type <code>com.sun.star.uno.IBridge</code> must not be null.  The
36  * second argument of type <code>String</code> represents any attributes; it may
37  * be null if there are no attributes.  The third argument of type
38  * <code>java.io.InputStream</code> must not be null.  The fourth argument of
39  * type <code>java.io.OutputStream</code> must not be null.</p>
40  */
41 public interface IProtocol {
42     /**
43      * Initializes the connection.
44      *
45      * <p>This method must be called exactly once, after the
46      * <code>readMessage</code> loop has already been established.</p>
47      */
init()48     void init() throws IOException;
49 
terminate()50     void terminate();
51 
52     /**
53      * Reads a request or reply message.
54      *
55      * <p>Access to this method from multiple threads must be properly
56      * synchronized.</p>
57      *
58      * @return a non-null message; if the input stream is exhausted, a
59      *     <code>java.io.IOException</code> is thrown instead
60      */
readMessage()61     Message readMessage() throws IOException;
62 
63     /**
64      * Writes a request message.
65      *
66      * @param oid a non-null OID
67      * @param type a non-null UNO type
68      * @param function a non-null function (the name of a UNO interface method
69      *     or attribute compatible with the given <code>type</code>, or either
70      *     <code>"queryInterface"</code> or <code>"release"</code>)
71      * @param threadId a non-null TID
72      * @param arguments a list of UNO arguments compatible with the given
73      *     <code>type</code> and <code>function</code>; may be null to represent
74      *     an empty list
75      * @return <code>true</code> if the request message is sent as a synchronous
76      *     request
77      */
writeRequest( String oid, TypeDescription type, String function, ThreadId tid, Object[] arguments)78     boolean writeRequest(
79         String oid, TypeDescription type, String function, ThreadId tid,
80         Object[] arguments)
81         throws IOException;
82 
83     /**
84      * Writes a reply message.
85      *
86      * @param exception <code>true</code> if the reply corresponds to a raised
87      *     exception
88      * @param tid a non-null TID
89      * @param result if <code>exception</code> is <code>true</code>, a non-null
90      *     UNO exception; otherwise, a UNO return value, which may be null to
91      *     represent a <code>VOID</code> return value
92      */
writeReply(boolean exception, ThreadId tid, Object result)93     void writeReply(boolean exception, ThreadId tid, Object result)
94         throws IOException;
95 }
96