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Android example source code file (LocalSocket.java)

This example Android source code file (LocalSocket.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" TM.

Java - Android tags/keywords

credentials, filedescriptor, inputstream, integer, io, ioexception, localsocketaddress, localsocketimpl, net, network, outputstream, override, string, unsupportedoperationexception

The LocalSocket.java Android example source code

/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * 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 android.net;

import java.io.FileDescriptor;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.SocketOptions;

/**
 * Creates a (non-server) socket in the UNIX-domain namespace. The interface
 * here is not entirely unlike that of java.net.Socket
 */
public class LocalSocket {

    private LocalSocketImpl impl;
    private volatile boolean implCreated;
    private LocalSocketAddress localAddress;
    private boolean isBound;
    private boolean isConnected;

    /**
     * Creates a AF_LOCAL/UNIX domain stream socket.
     */
    public LocalSocket() {
        this(new LocalSocketImpl());
        isBound = false;
        isConnected = false;
    }

    /**
     * for use with AndroidServerSocket
     * @param impl a SocketImpl
     */
    /*package*/ LocalSocket(LocalSocketImpl impl) {
        this.impl = impl;
        this.isConnected = false;
        this.isBound = false;
    }

    /** {@inheritDoc} */
    @Override
    public String toString() {
        return super.toString() + " impl:" + impl;
    }

    /**
     * It's difficult to discern from the spec when impl.create() should be
     * called, but it seems like a reasonable rule is "as soon as possible,
     * but not in a context where IOException cannot be thrown"
     *
     * @throws IOException from SocketImpl.create()
     */
    private void implCreateIfNeeded() throws IOException {
        if (!implCreated) {
            synchronized (this) {
                if (!implCreated) {
                    implCreated = true;
                    impl.create(true);
                }
            }
        }
    }

    /**
     * Connects this socket to an endpoint. May only be called on an instance
     * that has not yet been connected.
     *
     * @param endpoint endpoint address
     * @throws IOException if socket is in invalid state or the address does
     * not exist.
     */
    public void connect(LocalSocketAddress endpoint) throws IOException {
        synchronized (this) {
            if (isConnected) {
                throw new IOException("already connected");
            }

            implCreateIfNeeded();
            impl.connect(endpoint, 0);
            isConnected = true;
            isBound = true;
        }
    }

    /**
     * Binds this socket to an endpoint name. May only be called on an instance
     * that has not yet been bound.
     *
     * @param bindpoint endpoint address
     * @throws IOException
     */
    public void bind(LocalSocketAddress bindpoint) throws IOException {
        implCreateIfNeeded();

        synchronized (this) {
            if (isBound) {
                throw new IOException("already bound");
            }

            localAddress = bindpoint;
            impl.bind(localAddress);
            isBound = true;
        }
    }

    /**
     * Retrieves the name that this socket is bound to, if any.
     *
     * @return Local address or null if anonymous
     */
    public LocalSocketAddress getLocalSocketAddress() {
        return localAddress;
    }

    /**
     * Retrieves the input stream for this instance.
     *
     * @return input stream
     * @throws IOException if socket has been closed or cannot be created.
     */
    public InputStream getInputStream() throws IOException {
        implCreateIfNeeded();
        return impl.getInputStream();
    }

    /**
     * Retrieves the output stream for this instance.
     *
     * @return output stream
     * @throws IOException if socket has been closed or cannot be created.
     */
    public OutputStream getOutputStream() throws IOException {
        implCreateIfNeeded();
        return impl.getOutputStream();
    }

    /**
     * Closes the socket.
     *
     * @throws IOException
     */
    public void close() throws IOException {
        implCreateIfNeeded();
        impl.close();
    }

    /**
     * Shuts down the input side of the socket.
     *
     * @throws IOException
     */
    public void shutdownInput() throws IOException {
        implCreateIfNeeded();
        impl.shutdownInput();
    }

    /**
     * Shuts down the output side of the socket.
     *
     * @throws IOException
     */
    public void shutdownOutput() throws IOException {
        implCreateIfNeeded();
        impl.shutdownOutput();
    }
    
    public void setReceiveBufferSize(int size) throws IOException {
        impl.setOption(SocketOptions.SO_RCVBUF, Integer.valueOf(size));
    }
    
    public int getReceiveBufferSize() throws IOException {
        return ((Integer) impl.getOption(SocketOptions.SO_RCVBUF)).intValue();
    }

    public void setSoTimeout(int n) throws IOException {
        impl.setOption(SocketOptions.SO_TIMEOUT, Integer.valueOf(n));
    }
    
    public int getSoTimeout() throws IOException {
        return ((Integer) impl.getOption(SocketOptions.SO_TIMEOUT)).intValue();
    }

    public void setSendBufferSize(int n) throws IOException {
        impl.setOption(SocketOptions.SO_SNDBUF, Integer.valueOf(n));
    }
    
    public int getSendBufferSize() throws IOException {
        return ((Integer) impl.getOption(SocketOptions.SO_SNDBUF)).intValue();
    }

    //???SEC
    public LocalSocketAddress getRemoteSocketAddress() {
        throw new UnsupportedOperationException();
    }

    //???SEC
    public synchronized boolean isConnected() {
        return isConnected;
    }

    //???SEC
    public boolean isClosed() {
        throw new UnsupportedOperationException();
    }

    //???SEC
    public synchronized boolean isBound() {
        return isBound;
    }

    //???SEC
    public boolean isOutputShutdown() {
        throw new UnsupportedOperationException();
    }

    //???SEC
    public boolean isInputShutdown() {
        throw new UnsupportedOperationException();
    }

    //???SEC
    public void connect(LocalSocketAddress endpoint, int timeout)
            throws IOException {
        throw new UnsupportedOperationException();
    }

    /**
     * Enqueues a set of file descriptors to send to the peer. The queue
     * is one deep. The file descriptors will be sent with the next write
     * of normal data, and will be delivered in a single ancillary message.
     * See "man 7 unix" SCM_RIGHTS on a desktop Linux machine.
     *
     * @param fds non-null; file descriptors to send.
     */
    public void setFileDescriptorsForSend(FileDescriptor[] fds) {
        impl.setFileDescriptorsForSend(fds);
    }

    /**
     * Retrieves a set of file descriptors that a peer has sent through
     * an ancillary message. This method retrieves the most recent set sent,
     * and then returns null until a new set arrives.
     * File descriptors may only be passed along with regular data, so this
     * method can only return a non-null after a read operation.
     *
     * @return null or file descriptor array
     * @throws IOException
     */
    public FileDescriptor[] getAncillaryFileDescriptors() throws IOException {
        return impl.getAncillaryFileDescriptors();
    }

    /**
     * Retrieves the credentials of this socket's peer. Only valid on
     * connected sockets.
     *
     * @return non-null; peer credentials
     * @throws IOException
     */
    public Credentials getPeerCredentials() throws IOException {
        return impl.getPeerCredentials();
    }

    /**
     * Returns file descriptor or null if not yet open/already closed
     *
     * @return fd or null
     */
    public FileDescriptor getFileDescriptor() {
        return impl.getFileDescriptor();
    }    
}

Other Android examples (source code examples)

Here is a short list of links related to this Android LocalSocket.java source code file:

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