Question

你好，我想写一个java服务器端程序，当客户端给出一个请求，就会访问数据库中的内容，并且返回！

希望有个参考代码

Answer 1

public class ServerConnect {
private static final int BUF_SIZE = 1024;
private static final int PORT = 8080;
private static final int TIMEOUT = 3000;

public static void main(String[] args) {
selector();
}

public static void handleAccept(SelectionKey key) throws IOException {
ServerSocketChannel ssChannel = (ServerSocketChannel) key.channel();
SocketChannel sc = ssChannel.accept();
sc.configureBlocking(false);
sc.register(key.selector(), SelectionKey.OP_READ,
ByteBuffer.allocateDirect(BUF_SIZE));
}

public static void handleRead(SelectionKey key) throws IOException {
SocketChannel sc = (SocketChannel) key.channel();
ByteBuffer buf = (ByteBuffer) key.attachment();
long bytesRead = sc.read(buf);
while (bytesRead > 0) {
buf.flip();
while (buf.hasRemaining()) {
byte b= buf.get();
System.out.print((char) buf.get());
}
System.out.println();
buf.clear();
bytesRead = sc.read(buf);
}
if (bytesRead == -1) {
sc.close();
}
}

public static void handleWrite(SelectionKey key) throws IOException {
ByteBuffer buf = (ByteBuffer) key.attachment();
buf.flip();
SocketChannel sc = (SocketChannel) key.channel();
while (buf.hasRemaining()) {
sc.write(buf);
}
buf.compact();
}

public static void selector() {
Selector selector = null;
ServerSocketChannel ssc = null;
try {
selector = Selector.open();
ssc = ServerSocketChannel.open();
ssc.socket().bind(new InetSocketAddress(PORT));
ssc.configureBlocking(false);
ssc.register(selector, SelectionKey.OP_ACCEPT);

while (true) {
if (selector.select(TIMEOUT) == 0) {
System.out.println("==");
continue;
}
Iterator<SelectionKey> iter = selector.selectedKeys()
.iterator();
int count = 0;
while (iter.hasNext()) {
count++;
SelectionKey key = iter.next();
if (key.isAcceptable()) {
handleAccept(key);
}
if (key.isReadable()) {
handleRead(key);
}
if (key.isWritable() && key.isValid()) {
handleWrite(key);
}
if (key.isConnectable()) {
System.out.println("isConnectable = true");
}
iter.remove();
}
System.out.println(count);
}

} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (selector != null) {
selector.close();
}
if (ssc != null) {
ssc.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
不知道客户端的请求是什么形式的请求socket?webservice?http?
你这个这是用nio写的一个socket服务端程序，监听的是本地8080端口，在handleWrite方法体类处理jdbc获取数据放入ByteBuffer里就可以了，jdbc操作这里就不写了。

Answer 2

我可以给你写一个。
不忙的时候我看看。