[编织消息框架][传输协议]sctp简单开发

jdk1.7支持sctp协议，需要linux安装sctp支持库

测试代码

public class ServerSCTP {
    static int SERVER_PORT = 3456;
    static int US_STREAM = 0;
    static int FR_STREAM = 1;

    static SimpleDateFormat USformatter = new SimpleDateFormat("h:mm:ss a EEE d MMM yy, zzzz", Locale.US);
    static SimpleDateFormat FRformatter = new SimpleDateFormat("h:mm:ss a EEE d MMM yy, zzzz", Locale.FRENCH);

    @SuppressWarnings("restriction")
    public static void main(String[] args) throws IOException {
        com.sun.nio.sctp.SctpServerChannel ssc = com.sun.nio.sctp.SctpServerChannel.open();
        ssc.bind(new InetSocketAddress(SERVER_PORT));

        ByteBuffer buf = ByteBuffer.allocateDirect(60);
        CharBuffer cbuf = CharBuffer.allocate(60);
        CharsetEncoder encoder = Charset.forName("ISO-8859-1").newEncoder();

        while (true) {
            com.sun.nio.sctp.SctpChannel sc = ssc.accept();

            /* get the current date */
            Date today = new Date();
            cbuf.put(USformatter.format(today)).flip();
            encoder.encode(cbuf, buf, true);
            buf.flip();

            /* send the message on the US stream */
            com.sun.nio.sctp.MessageInfo messageInfo = com.sun.nio.sctp.MessageInfo.createOutgoing(null, US_STREAM);
            sc.send(buf, messageInfo);

            /* update the buffer with French format */
            cbuf.clear();
            cbuf.put(FRformatter.format(today)).flip();
            buf.clear();
            encoder.encode(cbuf, buf, true);
            buf.flip();

            /* send the message on the French stream */
            messageInfo.streamNumber(FR_STREAM);
            sc.send(buf, messageInfo);

            cbuf.clear();
            buf.clear();

            sc.close();
        }
    }
}

@SuppressWarnings("restriction")
public class ClientSCTP {
    static int SERVER_PORT = 3456;
    public void run() throws IOException {
        ByteBuffer buf = ByteBuffer.allocateDirect(60);
        Charset charset = Charset.forName("ISO-8859-1");
        CharsetDecoder decoder = charset.newDecoder();

        com.sun.nio.sctp.SctpChannel sc = com.sun.nio.sctp.SctpChannel.open(new InetSocketAddress("localhost", SERVER_PORT), 0, 0);

        /* handler to keep track of association setup and termination */
        AssociationHandler assocHandler = new AssociationHandler();
        /* expect two messages and two notifications */
        com.sun.nio.sctp.MessageInfo messageInfo = null;
        do {
            messageInfo = sc.receive(buf, System.out, assocHandler);
            buf.flip();

            if (buf.remaining() > 0 && messageInfo.streamNumber() == ServerSCTP.US_STREAM) {

            System.out.println("(US) " + decoder.decode(buf).toString());
            } else if (buf.remaining() > 0 && messageInfo.streamNumber() == ServerSCTP.FR_STREAM) {
            System.out.println("(FR) " + decoder.decode(buf).toString());
            }
            buf.clear();
        } while (messageInfo != null);

        sc.close();
    }

    public static void main(String[] args) throws IOException {
        new ClientSCTP().run();
    }

    static class AssociationHandler extends com.sun.nio.sctp.AbstractNotificationHandler<PrintStream> {
        public com.sun.nio.sctp.HandlerResult handleNotification(com.sun.nio.sctp.AssociationChangeNotification not, PrintStream stream) {
            if (not.event().equals(com.sun.nio.sctp.AssociationChangeNotification.AssocChangeEvent.COMM_UP)) {
                int outbound = not.association().maxOutboundStreams();
                int inbound = not.association().maxInboundStreams();
                stream.printf("New association setup with %d outbound streams" + ", and %d inbound streams.
", outbound, inbound);
            }

            return com.sun.nio.sctp.HandlerResult.CONTINUE;
        }

        public com.sun.nio.sctp.HandlerResult handleNotification(com.sun.nio.sctp.ShutdownNotification not, PrintStream stream) {
            stream.printf("The association has been shutdown.
");
            return com.sun.nio.sctp.HandlerResult.RETURN;
        }
    }
}

导出ClientSCTP.class,ServerSCTP.class

环境部署

1.linux检查是否支持sctp，官方提示必须内核2.6版本以上，有信息显示代表已安装

lsmod | grep sctp

1.1如果没有就下载

官方：http://lksctp.sourceforge.net/

github:https://github.com/sctp/lksctp-tools

tar -zxf lksctp-tools-1.0.17.tar.gz

cd lksctp-tools-1.0.17

./configure

make

make install

2.执行  ./java8.sh -jar testsctp.jar 抛异常 

java.lang.UnsupportedOperationException: libsctp.so.1: cannot open shared object file: No such file or directory

原因是没有配置 $LD_LIBRARY_PATH 环境变量

echo $LD_LIBRARY_PATH
export LD_LIBRARY_PATH=/usr/local/lib

继续执行 ./java8.sh -jar testsctp.jar 还是抛异常 

java.net.SocketException: Protocol not supported

原因是系统没有加载lksctp模块

modprobe sctp

lsmod |grep sctp

再执行出现连接异常 

java.net.SocketException: Permission denied

原因是linux selinux 安全限制，解决方式临时关闭

setenforce 0

永久关闭

ehco "SELINUX=disabled" >> /etc/selinux/config 

本人测试：连接60000client没aio快，原因是sctp建立链接要求四次握手