java netconf 代码

以下是一个简单的 Java Netconf 客户端代码示例：

import java.io.IOException;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.List;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.ByteToMessageDecoder;
import io.netty.handler.codec.MessageToByteEncoder;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.util.CharsetUtil;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

public class NetconfClient {
    private static final String NETCONF_HELLO = "<hello xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\"><capabilities><capability>urn:ietf:params:netconf:base:1.0</capability></capabilities></hello>";
    private static final String NETCONF_GET_TIME = "<rpc message-id=\"1\" xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\"><get><system-clock/></get></rpc>";
    private static final String NETCONF_CLOSE = "<rpc message-id=\"2\" xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\"><close-session/></rpc>";
    private static final String NETCONF_END_PATTERN = "]]>]]>";
    private static final int MAX_FRAME_LENGTH = 1024;
    private static final String NETCONF_SERVER_IP = "localhost";
    private static final int NETCONF_SERVER_PORT = 830;

    public static void main(String[] args) throws Exception {
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            Bootstrap b = new Bootstrap();
            b.group(workerGroup);
            b.channel(NioSocketChannel.class);
            b.option(ChannelOption.TCP_NODELAY, true);
            b.handler(new ChannelInitializer<SocketChannel>() {
                @Override
                public void initChannel(SocketChannel ch) throws Exception {
                    ChannelPipeline pipeline = ch.pipeline();
                    pipeline.addLast(new StringEncoder(CharsetUtil.UTF_8));
                    pipeline.addLast(new StringDecoder(CharsetUtil.UTF_8));
                    pipeline.addLast(new NetconfMessageDecoder());
                    pipeline.addLast(new NetconfMessageEncoder());
                    pipeline.addLast(new NetconfClientHandler());
                }
            });

            ChannelFuture f = b.connect(NETCONF_SERVER_IP, NETCONF_SERVER_PORT).sync();
            f.channel().closeFuture().sync();
        } finally {
            workerGroup.shutdownGracefully();
        }
    }

    private static class NetconfMessageDecoder extends ByteToMessageDecoder {
        @Override
        protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
            String message = in.toString(CharsetUtil.UTF_8);
            int end = message.indexOf(NETCONF_END_PATTERN);
            if (end != -1) {
                out.add(message.substring(0, end + NETCONF_END_PATTERN.length()));
            }
        }
    }

    private static class NetconfMessageEncoder extends MessageToByteEncoder<String> {
        @Override
        protected void encode(ChannelHandlerContext ctx, String msg, ByteBuf out) throws Exception {
            out.writeBytes(msg.getBytes());
            out.writeBytes(NETCONF_END_PATTERN.getBytes());
        }
    }

    private static class NetconfClientHandler extends ChannelInboundHandlerAdapter {
        @Override
        public void channelActive(ChannelHandlerContext ctx) {
            ctx.writeAndFlush(NETCONF_HELLO);
            ctx.writeAndFlush(NETCONF_GET_TIME);
        }

        @Override
        public void channelRead(ChannelHandlerContext ctx, Object msg) {
            String response = (String)msg;
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = factory.newDocumentBuilder();
            Document doc = builder.parse(new InputSource(new StringReader(response)));
            NodeList nodeList = doc.getElementsByTagName("system-clock");
            if (nodeList.getLength() > 0) {
                Element clockElement = (Element)nodeList.item(0);
                String dateTime = clockElement.getChildNodes().item(0).getNodeValue();
                System.out.println("System clock is: " + dateTime);
                ctx.writeAndFlush(NETCONF_CLOSE);
            }
        }

        @Override
        public void channelReadComplete(ChannelHandlerContext ctx) {
            ctx.close();
        }

        @Override
        public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
            cause.printStackTrace();
            ctx.close();
        }
    }
}

该代码使用 Netty 实现了一个简单的 Netconf 客户端，可以连接到 Netconf 服务器并执行一些基本操作，例如获取系统时间。