DatagramSocketImpl这个类是由哪些子类实现的，怎么在jdk源码库中找不到

难道这个抽象类，在哪个类中使用了匿名的形式实现？

1. /**
   
2. * @(#)DatagramSocketImpl.java        1.34 06/04/26
   
3. *
   
4. * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
   
5. * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
   
6. */
   
7. 
   
8. package java.net;
   
9. 
   
10. import java.io.FileDescriptor;
    
11. import java.io.IOException;
    
12. import java.io.InterruptedIOException;
    
13. 
    
14. /***
    
15. * Abstract datagram and multicast socket implementation base class.
    
16. * @author Pavani Diwanji
    
17. * @since  JDK1.1
    
18. */
    
19. 
    
20. public abstract class DatagramSocketImpl implements SocketOptions {
    
21. 
    
22.     /***
    
23.      * The local port number.
    
24.      */   
    
25.     protected int localPort;
    
26. 
    
27.     /***
    
28.      * The file descriptor object.
    
29.      */
    
30.     protected FileDescriptor fd;
    
31. 
    
32.     /***
    
33.      * Creates a datagram socket.
    
34.      * @exception SocketException if there is an error in the
    
35.      * underlying protocol, such as a TCP error.
    
36.      */
    
37.     protected abstract void create() throws SocketException;
    
38. 
    
39.     /***
    
40.      * Binds a datagram socket to a local port and address.
    
41.      * @param lport the local port
    
42.      * @param laddr the local address
    
43.      * @exception SocketException if there is an error in the
    
44.      * underlying protocol, such as a TCP error.
    
45.      */
    
46.     protected abstract void bind(int lport, InetAddress laddr) throws SocketException;
    
47. 
    
48.     /***
    
49.      * Sends a datagram packet. The packet contains the data and the
    
50.      * destination address to send the packet to.
    
51.      * @param p the packet to be sent.
    
52.      * @exception IOException if an I/O exception occurs while sending the
    
53.      * datagram packet.
    
54.      * @exception  PortUnreachableException may be thrown if the socket is connected
    
55.      * to a currently unreachable destination. Note, there is no guarantee that
    
56.      * the exception will be thrown.
    
57.      */
    
58.     protected abstract void send(DatagramPacket p) throws IOException;
    
59. 
    
60.     /***
    
61.      * Connects a datagram socket to a remote destination. This associates the remote
    
62.      * address with the local socket so that datagrams may only be sent to this destination
    
63.      * and received from this destination. This may be overridden to call a native
    
64.      * system connect.
    
65.      *
    
66.      * <p>If the remote destination to which the socket is connected does not
    
67.      * exist, or is otherwise unreachable, and if an ICMP destination unreachable
    
68.      * packet has been received for that address, then a subsequent call to
    
69.      * send or receive may throw a PortUnreachableException.
    
70.      * Note, there is no guarantee that the exception will be thrown.
    
71.      * @param address the remote InetAddress to connect to
    
72.      * @param port the remote port number
    
73.      * @exception   SocketException may be thrown if the socket cannot be
    
74.      * connected to the remote destination
    
75.      * @since 1.4
    
76.      */
    
77.     protected void connect(InetAddress address, int port) throws SocketException {}
    
78. 
    
79.     /***
    
80.      * Disconnects a datagram socket from its remote destination.
    
81.      * @since 1.4
    
82.      */
    
83.     protected void disconnect() {}
    
84. 
    
85.     /***
    
86.      * Peek at the packet to see who it is from. Updates the specified <code>InetAddress</code>
    
87.      * to the address which the packet came from.
    
88.      * @param i an InetAddress object
    
89.      * @return the port number which the packet came from.
    
90.      * @exception IOException if an I/O exception occurs
    
91.      * @exception  PortUnreachableException may be thrown if the socket is connected
    
92.      *       to a currently unreachable destination. Note, there is no guarantee that the
    
93.      *       exception will be thrown.
    
94.      */
    
95.     protected abstract int peek(InetAddress i) throws IOException;
    
96. 
    
97.     /***
    
98.      * Peek at the packet to see who it is from. The data is copied into the specified
    
99.      * <code>DatagramPacket</code>. The data is returned,
    
100.      * but not consumed, so that a subsequent peekData/receive operation
     
101.      * will see the same data.
     
102.      * @param p the Packet Received.
     
103.      * @return the port number which the packet came from.
     
104.      * @exception IOException if an I/O exception occurs
     
105.      * @exception  PortUnreachableException may be thrown if the socket is connected
     
106.      *       to a currently unreachable destination. Note, there is no guarantee that the
     
107.      *       exception will be thrown.
     
108.      * @since 1.4
     
109.      */
     
110.     protected abstract int peekData(DatagramPacket p) throws IOException;
     
111.     /***
     
112.      * Receive the datagram packet.
     
113.      * @param p the Packet Received.
     
114.      * @exception IOException if an I/O exception occurs
     
115.      * while receiving the datagram packet.
     
116.      * @exception  PortUnreachableException may be thrown if the socket is connected
     
117.      *       to a currently unreachable destination. Note, there is no guarantee that the
     
118.      *       exception will be thrown.
     
119.      */
     
120.     protected abstract void receive(DatagramPacket p) throws IOException;
     
121. 
     
122.     /***
     
123.      * Set the TTL (time-to-live) option.
     
124.      * @param ttl a byte specifying the TTL value
     
125.      *
     
126.      * @deprecated use setTimeToLive instead.
     
127.      * @exception IOException if an I/O exception occurs while setting
     
128.      * the time-to-live option.
     
129.      * @see #getTTL()
     
130.      */
     
131.     @Deprecated
     
132.     protected abstract void setTTL(byte ttl) throws IOException;
     
133. 
     
134.     /***
     
135.      * Retrieve the TTL (time-to-live) option.
     
136.      *
     
137.      * @exception IOException if an I/O exception occurs
     
138.      * while retrieving the time-to-live option
     
139.      * @deprecated use getTimeToLive instead.
     
140.      * @return a byte representing the TTL value
     
141.      * @see #setTTL(byte)
     
142.      */
     
143.     @Deprecated
     
144.     protected abstract byte getTTL() throws IOException;
     
145. 
     
146.     /***
     
147.      * Set the TTL (time-to-live) option.
     
148.      * @param ttl an <tt>int</tt> specifying the time-to-live value
     
149.      * @exception IOException if an I/O exception occurs
     
150.      * while setting the time-to-live option.
     
151.      * @see #getTimeToLive()
     
152.      */
     
153.     protected abstract void setTimeToLive(int ttl) throws IOException;
     
154. 
     
155.     /***
     
156.      * Retrieve the TTL (time-to-live) option.
     
157.      * @exception IOException if an I/O exception occurs
     
158.      * while retrieving the time-to-live option
     
159.      * @return an <tt>int</tt> representing the time-to-live value
     
160.      * @see #setTimeToLive(int)
     
161.      */
     
162.     protected abstract int getTimeToLive() throws IOException;
     
163. 
     
164.     /***
     
165.      * Join the multicast group.
     
166.      * @param inetaddr multicast address to join.
     
167.      * @exception IOException if an I/O exception occurs
     
168.      * while joining the multicast group.
     
169.      */
     
170.     protected abstract void join(InetAddress inetaddr) throws IOException;
     
171. 
     
172.     /***
     
173.      * Leave the multicast group.
     
174.      * @param inetaddr multicast address to leave.
     
175.      * @exception IOException if an I/O exception occurs
     
176.      * while leaving the multicast group.
     
177.      */
     
178.     protected abstract void leave(InetAddress inetaddr) throws IOException;
     
179. 
     
180.     /***
     
181.      * Join the multicast group.
     
182.      * @param mcastaddr address to join.
     
183.      * @param netIf specifies the local interface to receive multicast
     
184.      *        datagram packets
     
185.      * @throws IOException if an I/O exception occurs while joining
     
186.      * the multicast group
     
187.      * @since 1.4
     
188.      */
     
189.     protected abstract void joinGroup(SocketAddress mcastaddr,
     
190.                                       NetworkInterface netIf)
     
191.         throws IOException;
     
192. 
     
193.     /***
     
194.      * Leave the multicast group.
     
195.      * @param mcastaddr address to leave.
     
196.      * @param netIf specified the local interface to leave the group at
     
197.      * @throws IOException if an I/O exception occurs while leaving
     
198.      * the multicast group
     
199.      * @since 1.4
     
200.      */
     
201.     protected abstract void leaveGroup(SocketAddress mcastaddr,
     
202.                                        NetworkInterface netIf)
     
203.         throws IOException;
     
204. 
     
205.     /***
     
206.      * Close the socket.
     
207.      */
     
208.     protected abstract void close();
     
209. 
     
210.     /***
     
211.      * Gets the local port.
     
212.      * @return an <tt>int</tt> representing the local port value
     
213.      */
     
214.     protected int getLocalPort() {
     
215.         return localPort;
     
216.     }
     
217. 
     
218.     /***
     
219.      * Gets the datagram socket file descriptor.
     
220.      * @return a <tt>FileDescriptor</tt> object representing the datagram socket
     
221.      * file descriptor
     
222.      */
     
223.     protected FileDescriptor getFileDescriptor() {
     
224.         return fd;
     
225.     }
     
226. }

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1. package java.net;
   
2. 
   
3. import java.io.FileDescriptor;
   
4. import java.io.IOException;
   
5. import java.io.InterruptedIOException;
   
6. 
   
7. /***
   
8. * Abstract datagram and multicast socket implementation base class.
   
9. * @author Pavani Diwanji
   
10. * @since  JDK1.1
    
11. */
    
12. 
    
13. public abstract class DatagramSocketImpl implements SocketOptions {
    
14. 
    
15.     /***
    
16.      * The local port number.
    
17.      */  
    
18.     protected int localPort;
    
19. 
    
20.     /***
    
21.      * The file descriptor object.
    
22.      */
    
23.     protected FileDescriptor fd;
    
24. 
    
25.     /***
    
26.      * Creates a datagram socket.
    
27.      * @exception SocketException if there is an error in the
    
28.      * underlying protocol, such as a TCP error.
    
29.      */
    
30.     protected abstract void create() throws SocketException;
    
31. 
    
32.     /***
    
33.      * Binds a datagram socket to a local port and address.
    
34.      * @param lport the local port
    
35.      * @param laddr the local address
    
36.      * @exception SocketException if there is an error in the
    
37.      * underlying protocol, such as a TCP error.
    
38.      */
    
39.     protected abstract void bind(int lport, InetAddress laddr) throws SocketException;
    
40. 
    
41.     /***
    
42.      * Sends a datagram packet. The packet contains the data and the
    
43.      * destination address to send the packet to.
    
44.      * @param p the packet to be sent.
    
45.      * @exception IOException if an I/O exception occurs while sending the
    
46.      * datagram packet.
    
47.      * @exception  PortUnreachableException may be thrown if the socket is connected
    
48.      * to a currently unreachable destination. Note, there is no guarantee that
    
49.      * the exception will be thrown.
    
50.      */
    
51.     protected abstract void send(DatagramPacket p) throws IOException;
    
52. 
    
53.     /***
    
54.      * Connects a datagram socket to a remote destination. This associates the remote
    
55.      * address with the local socket so that datagrams may only be sent to this destination
    
56.      * and received from this destination. This may be overridden to call a native
    
57.      * system connect.
    
58.      *
    
59.      * <p>If the remote destination to which the socket is connected does not
    
60.      * exist, or is otherwise unreachable, and if an ICMP destination unreachable
    
61.      * packet has been received for that address, then a subsequent call to
    
62.      * send or receive may throw a PortUnreachableException.
    
63.      * Note, there is no guarantee that the exception will be thrown.
    
64.      * @param address the remote InetAddress to connect to
    
65.      * @param port the remote port number
    
66.      * @exception   SocketException may be thrown if the socket cannot be
    
67.      * connected to the remote destination
    
68.      * @since 1.4
    
69.      */
    
70.     protected void connect(InetAddress address, int port) throws SocketException {}
    
71. 
    
72.     /***
    
73.      * Disconnects a datagram socket from its remote destination.
    
74.      * @since 1.4
    
75.      */
    
76. 
    
77. 
    
78.     /***
    
79.      * Peek at the packet to see who it is from. Updates the specified <code>InetAddress</code>
    
80.      * to the address which the packet came from.
    
81.      * @param i an InetAddress object
    
82.      * @return the port number which the packet came from.
    
83.      * @exception IOException if an I/O exception occurs
    
84.      * @exception  PortUnreachableException may be thrown if the socket is connected
    
85.      *       to a currently unreachable destination. Note, there is no guarantee that the
    
86.      *       exception will be thrown.
    
87. 
    
88.      */
    
89.     protected abstract int peek(InetAddress i) throws IOException;
    
90. 
    
91.     /***
    
92.      * Peek at the packet to see who it is from. The data is copied into the specified
    
93.      * <code>DatagramPacket</code>. The data is returned,
    
94.      * but not consumed, so that a subsequent peekData/receive operation
    
95.      * @param p the Packet Received.
    
96.      * @exception IOException if an I/O exception occurs
    
97.      * @exception  PortUnreachableException may be thrown if the socket is connected
    
98.      *       to a currently unreachable destination. Note, there is no guarantee that the
    
99.      *       exception will be thrown.
    
100.      * @since 1.4
     
101.      */
     
102.     protected abstract int peekData(DatagramPacket p) throws IOException;
     
103.     /***
     
104.      * Receive the datagram packet.
     
105.      * @param p the Packet Received.
     
106.      * @exception IOException if an I/O exception occurs
     
107.      * while receiving the datagram packet.
     
108.      *       to a currently unreachable destination. Note, there is no guarantee that the
     
109.      *       exception will be thrown.
     
110.      */
     
111.     protected abstract void receive(DatagramPacket p) throws IOException;
     
112.     /***
     
113.      * Set the TTL (time-to-live) option.
     
114.      * @param ttl a byte specifying the TTL value
     
115.      *
     
116.      * @deprecated use setTimeToLive instead.
     
117.      * @exception IOException if an I/O exception occurs while setting
     
118.      * the time-to-live option.
     
119.      * @see #getTTL()
     
120.      */
     
121.     @Deprecated
     
122.     protected abstract void setTTL(byte ttl) throws IOException;
     
123.     /***
     
124.      * Retrieve the TTL (time-to-live) option.
     
125.      *
     
126.      * @exception IOException if an I/O exception occurs
     
127.      * while retrieving the time-to-live option
     
128.      * @deprecated use getTimeToLive instead.
     
129.      * @return a byte representing the TTL value
     
130.      * @see #setTTL(byte)
     
131.      */
     
132.     @Deprecated
     
133.     protected abstract byte getTTL() throws IOException;
     
134.     /***
     
135.      * Set the TTL (time-to-live) option.
     
136.      * @param ttl an <tt>int</tt> specifying the time-to-live value
     
137.      * @exception IOException if an I/O exception occurs
     
138.      * while setting the time-to-live option.
     
139.      * @see #getTimeToLive()
     
140.      */
     
141.     protected abstract void setTimeToLive(int ttl) throws IOException;
     
142.     /***
     
143.      * Retrieve the TTL (time-to-live) option.
     
144.      * @exception IOException if an I/O exception occurs
     
145.      * while retrieving the time-to-live option
     
146.      * @return an <tt>int</tt> representing the time-to-live value
     
147.      */
     
148.     protected abstract int getTimeToLive() throws IOException;
     
149. 
     
150.     /***
     
151.      * Join the multicast group.
     
152.      * @param inetaddr multicast address to join.
     
153.      * @exception IOException if an I/O exception occurs
     
154.      */
     
155.     protected abstract void join(InetAddress inetaddr) throws IOException;
     
156.     /***
     
157.      * Leave the multicast group.
     
158.      * @exception IOException if an I/O exception occurs
     
159.      * while leaving the multicast group.
     
160.      */
     
161.     protected abstract void leave(InetAddress inetaddr) throws IOException;
     
162. 
     
163.     /***
     
164.      * Join the multicast group.
     
165.      * @param mcastaddr address to join.
     
166.      * @param netIf specifies the local interface to receive multicast
     
167.      *        datagram packets
     
168.      * @throws IOException if an I/O exception occurs while joining
     
169.      * @since 1.4
     
170.     protected abstract void joinGroup(SocketAddress mcastaddr,
     
171.                       NetworkInterface netIf)
     
172.     throws IOException;
     
173. 
     
174.     /***
     
175.      * Leave the multicast group.
     
176.      * @param mcastaddr address to leave.
     
177.      * @param netIf specified the local interface to leave the group at
     
178.      * @throws IOException if an I/O exception occurs while leaving
     
179.      * the multicast group
     
180.      * @since 1.4
     
181.      */
     
182.     protected abstract void leaveGroup(SocketAddress mcastaddr,
     
183.                        NetworkInterface netIf)
     
184.     throws IOException;
     
185.     /***
     
186.      * Close the socket.
     
187.      */
     
188.     protected abstract void close();
     
189.     /***
     
190.      * Gets the local port.
     
191.      */
     
192.     protected int getLocalPort() {
     
193.     return localPort;
     
194.     }
     
195. 
     
196.     /***
     
197.      * Gets the datagram socket file descriptor.
     
198.      * @return a <tt>FileDescriptor</tt> object representing the datagram socket
     
199.      * file descriptor
     
200.      */
     
201.     protected FileDescriptor getFileDescriptor() {
     
202.     return fd;
     
203.     }
     
204. }
     

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DatagramSocketImpl类和Iterator类使用一样的，都是内部类的父类，在内部类（或匿名内部类）中覆盖它的方法；所以看不到它的实现类；