devicetcpservice.java~63~

用java写编写的一个GPS源代码请大家多多指教

package com.gps.center.dataservice;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import org.w3c.dom.Document;
import java.io.File;
import org.w3c.dom.NodeList;
import java.net.InetAddress;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.channels.SelectionKey;
import java.util.Set;
import java.util.Iterator;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.nio.CharBuffer;
import java.nio.charset.CharsetDecoder;
import com.gps.center.baseclass.MsgObj;
import java.nio.channels.ClosedChannelException;
import com.gps.center.baseclass.ParseData;

public class DeviceTcpService extends ParseData implements Runnable {
    private Selector sel = null;
    private ServerSocketChannel TerminalTcpServer = null;
    private SocketChannel socket = null;
    private int centerPort;
    private int MaxConnection;
    private String centerIP = new String("localhost");
    private String CodeType = "GB18030";
    public static int sessions = 0;
    public DeviceTcpService() {
        readxml();
    }

    public synchronized void incsessions() {
        sessions++;
    }

    public synchronized void reducesessions() {
        sessions--;
    }

    public void run() {
        initializeOperations();
        //System.out.println("Abt to block on select()");
        SelectionKey acceptKey = null; //选择方法每次创造选择器的注册表
        try {
            acceptKey = TerminalTcpServer.register(sel, SelectionKey.OP_ACCEPT); //记录渠道给选择器返回选择
        } catch (ClosedChannelException ex) {
            ex.printStackTrace();
        }
        try {
            while (acceptKey.selector().select() > 0) { //返回一组钥匙给相应的I/O操作通道
                Set readyKeys = sel.selectedKeys(); //返回这个选择器的设置
                Iterator it = readyKeys.iterator(); //列表存储

                while (it.hasNext()) {
                    SelectionKey key = (SelectionKey) it.next();
                    it.remove();

                    if (key.isAcceptable()) { //如果key's channel允许新的socket连接
                        //System.out.println("Key is Acceptable");
                        ServerSocketChannel ssc = (ServerSocketChannel) key.
                                                  channel(); //Returns the channel for which this key was created.
                        socket = (SocketChannel) ssc.accept(); //Accepts a connection made to this channel's socket.

                        incsessions();
                        if (sessions > MaxConnection) {
                            break;
                        }
                        socket.configureBlocking(false); //调整this channel's 模块化形式
                        SelectionKey another = socket.register(sel,
                                SelectionKey.OP_READ | SelectionKey.OP_WRITE); //记录 this channel with the given 选择器,
                    }
                    if (key.isReadable()) { //如果this channel's 准备好读取信息
                        //System.out.println("key.isReadable");
                        String ret = readMessage(key);
                        if (ret != null) {
                            if (ret.length() > 1) {
                                //System.out.println(ret.length());
                                MsgObj msg = new MsgObj();
                                msg.cMsgType = TCPMSG;
                                msg.cMsg = ret;
                                System.out.println("TCP接收到的消息:"+msg.cMsg);
                                msg.cSelectionKey = key;
                                super.addRecieveMsg(msg);
                            }
                        }
                    }
                }
            }
        } catch (Exception ex1) {
            System.out.println("Inside initialization");
        }
    }

    public void initializeOperations() { //初始化操作台
        System.out.println("Inside initialization");
        try {
            sel = Selector.open();
            TerminalTcpServer = TerminalTcpServer.open();
            TerminalTcpServer.configureBlocking(false); //调整channel's设计模块
            InetAddress ia = InetAddress.getLocalHost(); //获得主机IP
            //System.out.println(ia);
            InetSocketAddress isa = new InetSocketAddress(ia, centerPort); //创建SOCKET地址
            TerminalTcpServer.socket().bind(isa); //重新获得并且封装SOCKET通过信道
            //System.out.println("TCP use InetAddress" + ia.toString());
        } catch (IOException ex) {
            System.out.println(ex.getMessage());
            ex.printStackTrace();
        }
    }

    private String readMessage(SelectionKey key) throws IOException {
        int nBytes = 0;
        String result = null;
        socket = (SocketChannel) key.channel();
        ByteBuffer buf = ByteBuffer.allocate(512);
        try {
            nBytes = socket.read(buf);
            if (nBytes == -1) {
                socket.close();
                key.cancel();
                reducesessions();
                System.out.println("close socket");
            }
            buf.flip();
            //Charset charset = Charset.forName("GB18030");
            Charset charset = Charset.forName(CodeType);
            CharsetDecoder decoder = charset.newDecoder();
            CharBuffer charBuffer = decoder.decode(buf);
            result = new String(charBuffer.toString().trim());
            //System.out.println(result+"接收的信息");
            //System.out.println(buf.toString() + "12345");
        } catch (IOException e) {
            socket.close();
            key.cancel();
            reducesessions();
        }
        return result;
    }

    private void readxml() {
        String strport, strmax;
        try {
            File f = new File("CenterInfo.xml");
            if (f.exists()) {
                //创建工厂
                DocumentBuilderFactory factory = DocumentBuilderFactory.
                                                 newInstance();
                //创建解析器
                DocumentBuilder builder = factory.newDocumentBuilder();
                //解析文件创建Document对象
                Document doc = builder.parse(f);
                NodeList nl = doc.getElementsByTagName("Center");
                for (int i = 0; i < nl.getLength(); i++) {
                    /* centerIP = (doc.getElementsByTagName("CenterIP").item(i).
                                 getFirstChild().getNodeValue()).trim();*/
                    strport = (doc.getElementsByTagName("CenterPort").item(i).
                               getFirstChild().getNodeValue()).trim();
                    strmax = (doc.getElementsByTagName("MaxConnection").item(i).
                              getFirstChild().getNodeValue()).trim();
                    /* CodeType = (doc.getElementsByTagName("CodeType").item(i).
                                 getFirstChild().getNodeValue()).trim();*/
                    super.centerPort = strport;
                    super.centerIp = centerIP;
                    try {
                        if (strport.length() > 0) {
                            centerPort = Integer.parseInt(strport);
                            System.out.println("centerPort:" + centerPort);
                        } else {
                            System.out.println("terminalport err");
                            System.exit( -1);
                        }
                        if (strmax.length() > 0) {
                            MaxConnection = Integer.parseInt(strmax);
                        } else {
                            System.out.println("MaxConnection err");
                            System.exit( -1);
                        }
                    } catch (Exception e) {
                        System.out.println("centerPort and MaxConnection err");
                    }
                }
            } else {
                System.out.println("no find file: centerInfo.xml");
                System.exit( -1);
            }
        } catch (Exception e) {
            e.printStackTrace();
            System.exit( -1);
        }
    }
}