我有这个关于我正在处理的服务器客户端 NTP 项目的代码......当我运行它时我得到一个“java.lang.NullPointerException”......
-NullPointerException 已修复...我初始化了套接字，但我得到 java.net.SocketException: Socket is not connected 这个错误。有什么线索吗？
谁能帮帮我吗？
package ntp;
import java.io.*;
import java.net.*;
import java.text.SimpleDateFormat;
import java.util.*;
/**
* @author Anastasis Chirstodoulakis
*/
public class Server extends Thread {
private int totalTime=0;
private int x=0; //counter
private int moTime=0; //average time
private int PORT;
private Socket sock = new Socket();
public Server(int PORT) {
this.PORT=PORT;
}
private Server(Socket sock) {
this.sock = sock;
}
@Override
public void run(){
try {
//open socket
ServerSocket server = new ServerSocket(PORT);
InputStream in = sock.getInputStream();
OutputStream out = sock.getOutputStream();
PrintWriter w = new PrintWriter(out); //buffer
Scanner s = new Scanner(in);
SimpleDateFormat time = new SimpleDateFormat("HH.mm.ss.");
while(true){
sock = server.accept();
new Thread(new Server(sock)).start();
String msg=s.nextLine();
System.out.println(msg);
//get time and set format
Date date=new Date(); //get current time
SimpleDateFormat sd=new SimpleDateFormat("yyyy.MM.dd.HH:mm:ss");
String sdf=sd.format(date);
//convert time into seconds
String arr[]=msg.split(" ");
String st=arr[3];
String arr1[]=st.split("\\.");
int hh=Integer.parseInt(arr1[0]);
int mm=Integer.parseInt(arr1[1]);
int ss=Integer.parseInt(arr1[2]);
int secTime=(3600*hh)+(60*mm)+ss;
totalTime += secTime;
x++;
if(x==10){
moTime=totalTime/10; //to get average time
String moHour= secToTime(moTime);
w.println("Server time is:"+ moHour);
w.flush(); //to empty the buffer
}
in.close();
out.close();
sock.close();
}
}
catch (IOException ex) {
System.out.println(ex);
}
catch (NullPointerException ex){
System.out.println(ex);
}
}
public String secToTime(int totalSec){
//seconds to HH,mm,ss
int hour=totalSec/3600;
int remain=totalSec%3600;
int min=remain/60;
int sec=remain%60;
String hours = (hour < 10 ? "0" : "") + hour,
mins = (min < 10 ? "0" : "") + min,
secs = (sec < 10 ? "0" : "") + sec;
String send = hours + "." + mins + "." + secs + ".";
return send;
}
}
这是客户端代码，但我认为没关系...
package ntp;
import java.io.*;
import java.net.*;
import java.text.SimpleDateFormat;
import java.util.*;
/**
* @author Anastasis Christodoulakis
*/
public class Client extends Thread{
private Random r;
private int PORT;
public Client(int PORT) {
this.PORT=PORT;
r = new Random();
}
public String secToTime(int totalSec){
//seconds to HH,mm,ss
int hour=totalSec/3600;
int remain=totalSec%3600;
int min=remain/60;
int sec=remain%60;
String hours = (hour < 10 ? "0" : "") + hour,
mins = (min < 10 ? "0" : "") + min,
secs = (sec < 10 ? "0" : "") + sec;
String send = hours + "." + mins + "." + secs + ".";
return send;
}
@Override
public void run(){
try {
//open socket
Socket sock=new Socket("localhost",PORT);
InputStream in=sock.getInputStream();
OutputStream out=sock.getOutputStream();
Scanner s=new Scanner(in);
PrintWriter w=new PrintWriter(out); //buffer
for(int i=0;i<10;i++){
Date today=new Date(); //get current time
SimpleDateFormat sd=new SimpleDateFormat("yyy.MM.dd.HH.mm.ss"); //change time form
String sdf=sd.format(today); //time to String
//convert time into seconds
String ms[]=sdf.split("\\.");
int hh=Integer.parseInt(ms[3]);
int mm=Integer.parseInt(ms[4]);
int ss=Integer.parseInt(ms[5]);
int secTime=(3600*hh)+(60*mm)+ss;
//Random Delay (-0.5/0.5)
float lag=r.nextFloat()*(0.5f-0.5f)+0.5f;
secTime= (secTime - (int) (2 - lag));
w.println("Client time is: " + secToTime(secTime));
w.flush();
}
while(s.hasNextLine()){
String input=s.nextLine();
System.out.println(input);
}
in.close();
out.close();
sock.close();
} catch (IOException ex) {
System.out.println(ex);
}
}
}
和主要...
package ntp;
public class NTP {
public static void main(String[] args) {
Server server = new Server(2000); //set port
Client client = new Client(2000);
server.start();
client.start();
}
}
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感谢您的时间。