应用程序

Socket客户端套接字.连接方法()

demo

java net包-socket

1.SocketImpl1

class SocksSocketImpl extends PlainSocketImpl implements SocksConsts { 复制代码

2.SocketImpl2

/* * This class PlainSocketImpl simply delegates to the appropriate real * SocketImpl. We do this because PlainSocketImpl is already extended * by SocksSocketImpl. * 
 * There are two possibilities for the real SocketImpl, * TwoStacksPlainSocketImpl or DualStackPlainSocketImpl. We use * DualStackPlainSocketImpl on systems that have a dual stack * TCP implementation. Otherwise we create an instance of * TwoStacksPlainSocketImpl and delegate to it. * * @author Chris Hegarty */class PlainSocketImpl extends AbstractPlainSocketImpl{ /**     * Constructs an empty instance.     */    PlainSocketImpl() {        if (useDualStackImpl) {            impl = new DualStackPlainSocketImpl(exclusiveBind);        } else {            impl = new TwoStacksPlainSocketImpl(exclusiveBind);        }    }复制代码

//https://github.com/frohoff/jdk8u-dev-jdk/blob/master/src/windows/classes/java/net/DualStackPlainSocketImpl.java

void socketConnect(InetAddress address, int port, int timeout)        throws IOException {        int nativefd = checkAndReturnNativeFD();        if (address == null)            throw new NullPointerException("inet address argument is null.");        int connectResult;        if (timeout <= 0) {            connectResult = connect0(nativefd, address, port);        } else {            configureBlocking(nativefd, false);            try {                connectResult = connect0(nativefd, address, port);                if (connectResult == WOULDBLOCK) {                    waitForConnect(nativefd, timeout);                }            } finally {                configureBlocking(nativefd, true);            }        }        /*         * We need to set the local port field. If bind was called         * previous to the connect (by the client) then localport field         * will already be set.         */        if (localport == 0)            localport = localPort0(nativefd);    }复制代码

static native int connect0(int fd, InetAddress remote, int remotePort)throws IOException; //最终的话 都是调用 操作系统的套接字连接，具体流程是：jdk socket——》jvm native——》操作系统复制代码

总结

1.关于包

nio类都在jdk nio包。

2.流程