黑马程序员技术交流社区
标题:
线程间关闭流
[打印本页]
作者:
张森
时间:
2013-1-3 04:22
标题:
线程间关闭流
我写了个TCP的服务端和客户端 我用的是BufferedWriter缓冲流 他们在传输的时候必须要执行bw.newLine()和bw.flush();这个我能理解。
问题：
1、但为什么 bw.write("")和bw.newLine()和bw.flush()必须紧挨着写 哪怕我在中间随便打印一个System.out.println("")，那么都会导致缓冲区的根本就没有flush呢？
2、请大家看看下面的程序 我在服务器端和客户端都判断了"quit"，其实这个只在客户端执行了，我的问题是 ，当我客户端判断从控制台输入的是quit的时候，我在客户端关闭了相应的流和socket。那么我在服务器端对应的流和socket他们也关闭了吗。 请大家最好用代码来说明这个问题。
<blockquote><div class="blockcode"><div class="blockcode">package cn.itcast;</div><div class="blockcode">
</div><div class="blockcode">import java.io.BufferedReader;</div><div class="blockcode">import java.io.BufferedWriter;</div><div class="blockcode">import java.io.IOException;</div><div class="blockcode">import java.io.InputStream;</div><div class="blockcode">import java.io.InputStreamReader;</div><div class="blockcode">import java.io.OutputStream;</div><div class="blockcode">import java.io.OutputStreamWriter;</div><div class="blockcode">import java.io.PrintWriter;</div><div class="blockcode">import java.io.StringWriter;</div><div class="blockcode">import java.net.ServerSocket;</div><div class="blockcode">import java.net.Socket;</div><div class="blockcode">import java.nio.charset.Charset;</div><div class="blockcode">import java.util.Scanner;</div><div class="blockcode">
</div><div class="blockcode">public class ServerTest {</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>public static void main(String[] agrs) {</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>ServerSocket ss = null;</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>try {</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>ss = new ServerSocket(8000);</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>} catch (IOException e) {</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>e.printStackTrace();</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>}</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>while (true) {</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>Socket s = null;</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>try {</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>s = ss.accept();</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>System.out.println(s.getInetAddress()+"我链接上来了");</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>} catch (IOException e) {</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>e.printStackTrace();</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>}</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>new Thread(new ServiceTotal(s)).start();</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>}</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>}</div><div class="blockcode">}</div><div class="blockcode">
</div><div class="blockcode">class ServiceTotal implements Runnable {</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>private Socket s;</div><div class="blockcode">
</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>public ServiceTotal() {</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>}</div><div class="blockcode">
</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>public ServiceTotal(Socket s) {</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>this.s = s;</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>}</div><div class="blockcode">
</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>public void run() {</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>try {</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>InputStream in = s.getInputStream();</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>OutputStream out = s.getOutputStream();</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>BufferedReader bf = new BufferedReader(new InputStreamReader(in));</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(out));</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>String str = null;</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>while((str = bf.readLine())!=null){</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>if(bf.equals("quit")){</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>destroy(s, bf, bw);</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>break;</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>}</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>System.out.println("来自"+s.getInetAddress()+"客户端的信息-----"+ str);</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>bw.write(new StringBuffer(str).reverse().toString());</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>bw.newLine();</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>bw.flush();</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>}</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>} catch (IOException e) {</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>e.printStackTrace();</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>}</div><div class="blockcode">
</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>}</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>public static void destroy(Socket s,BufferedReader br,BufferedWriter bw){</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>try {</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>br.close();</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>bw.close();</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>s.close();</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>} catch (IOException e) {</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>e.printStackTrace();</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>}</div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span></div><div class="blockcode"><span class="Apple-tab-span" style="white-space:pre"> </span>}</div><div class="blockcode">}</div></div><div>
</div>
复制代码
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Scanner;
public class Client {
public static void main(String[] args) {
Socket s = null;
InputStream in = null;
OutputStream out = null;
BufferedReader br = null;
BufferedWriter bw = null;
try {
s = new Socket("127.0.0.1", 8000);
String str = null;
Scanner scanner = new Scanner(System.in);
while ((str = scanner.nextLine())!=null) {
if(str.equals("quit")){
destroy(s,br,bw,scanner);
break;
}
in = s.getInputStream();
out = s.getOutputStream();
br = new BufferedReader(new InputStreamReader(in));
bw = new BufferedWriter(new OutputStreamWriter(out));
bw.write(str);
bw.newLine();
bw.flush();
System.out.println("来自服务器"+s.getInetAddress()+"的消息"+br.readLine());
}
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public static void destroy(Socket s,BufferedReader br,BufferedWriter bw,Scanner scanner){
try {
br.close();
bw.close();
s.close();
scanner.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
作者:
张森
时间:
2013-1-3 04:24
我晕死 不好意思刚刚出问题了 重发服务器端的代码
package cn.itcast;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.nio.charset.Charset;
import java.util.Scanner;
public class ServerTest {
public static void main(String[] agrs) {
ServerSocket ss = null;
try {
ss = new ServerSocket(8000);
} catch (IOException e) {
e.printStackTrace();
}
while (true) {
Socket s = null;
try {
s = ss.accept();
System.out.println(s.getInetAddress()+"我链接上来了");
} catch (IOException e) {
e.printStackTrace();
}
new Thread(new ServiceTotal(s)).start();
}
}
}
class ServiceTotal implements Runnable {
private Socket s;
public ServiceTotal() {
}
public ServiceTotal(Socket s) {
this.s = s;
}
public void run() {
try {
InputStream in = s.getInputStream();
OutputStream out = s.getOutputStream();
BufferedReader bf = new BufferedReader(new InputStreamReader(in));
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(out));
String str = null;
while((str = bf.readLine())!=null){
if(bf.equals("quit")){
destroy(s, bf, bw);
break;
}
System.out.println("来自"+s.getInetAddress()+"客户端的信息-----"+ str);
bw.write(new StringBuffer(str).reverse().toString());
bw.newLine();
bw.flush();
}
} catch (IOException e) {
e.printStackTrace();
}
}
public static void destroy(Socket s,BufferedReader br,BufferedWriter bw){
try {
br.close();
bw.close();
s.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
作者:
张森
时间:
2013-1-3 04:41
OK自己搞定 上面的程序写得不够健壮
当客户端突然断电没告诉服务器关闭的时候 服务器端是不会关闭socket和流的
但我们要在服务器端捕捉异常 当捕捉到异常的时候 然后再把服务器端的socket和流关闭
欢迎光临 黑马程序员技术交流社区 (http://bbs.itheima.com/)
黑马程序员IT技术论坛 X3.2