01: /*
02: * Licensed to the Apache Software Foundation (ASF) under one
03: * or more contributor license agreements. See the NOTICE file
04: * distributed with this work for additional information
05: * regarding copyright ownership. The ASF licenses this file
06: * to you under the Apache License, Version 2.0 (the
07: * "License"); you may not use this file except in compliance
08: * with the License. You may obtain a copy of the License at
09: *
10: * http://www.apache.org/licenses/LICENSE-2.0
11: *
12: * Unless required by applicable law or agreed to in writing,
13: * software distributed under the License is distributed on an
14: * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15: * KIND, either express or implied. See the License for the
16: * specific language governing permissions and limitations
17: * under the License.
18: *
19: */
20: package org.apache.mina.common;
21:
22: /**
23: * An {@link IoFuture} for {@link IoSession#read() asynchronous read requests}.
24: *
25: * <h3>Example</h3>
26: * <pre>
27: * IoSession session = ...;
28: * // useReadOperation must be enabled to use read operation.
29: * session.getConfig().setUseReadOperation(true);
30: *
31: * ReadFuture future = session.read();
32: * // Wait until a message is received.
33: * future.await();
34: * try {
35: * Object message = future.getMessage();
36: * } catch (Exception e) {
37: * ...
38: * }
39: * </pre>
40: *
41: * @author The Apache MINA Project (dev@mina.apache.org)
42: * @version $Rev: 594477 $, $Date: 2007-11-13 03:42:03 -0700 (Tue, 13 Nov 2007) $
43: */
44: public interface ReadFuture extends IoFuture {
45:
46: /**
47: * Returns the received message. It returns <tt>null</tt> if this
48: * future is not ready or the associated {@link IoSession} has been closed.
49: *
50: * @throws RuntimeException if read or any relevant operation has failed.
51: */
52: Object getMessage();
53:
54: /**
55: * Returns <tt>true</tt> if a message was received successfully.
56: */
57: boolean isRead();
58:
59: /**
60: * Returns <tt>true</tt> if the {@link IoSession} associated with this
61: * future has been closed.
62: */
63: boolean isClosed();
64:
65: /**
66: * Returns the cause of the read failure if and only if the read
67: * operation has failed due to an {@link Exception}. Otherwise,
68: * <tt>null</tt> is returned.
69: */
70: Throwable getException();
71:
72: /**
73: * Sets the message is written, and notifies all threads waiting for
74: * this future. This method is invoked by MINA internally. Please do
75: * not call this method directly.
76: */
77: void setRead(Object message);
78:
79: /**
80: * Sets the associated {@link IoSession} is closed. This method is invoked
81: * by MINA internally. Please do not call this method directly.
82: */
83: void setClosed();
84:
85: /**
86: * Sets the cause of the read failure, and notifies all threads waiting
87: * for this future. This method is invoked by MINA internally. Please
88: * do not call this method directly.
89: */
90: void setException(Throwable cause);
91:
92: ReadFuture await() throws InterruptedException;
93:
94: ReadFuture awaitUninterruptibly();
95:
96: ReadFuture addListener(IoFutureListener<?> listener);
97:
98: ReadFuture removeListener(IoFutureListener<?> listener);
99: }
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