使用ServerSocket
类的implAccept
方法可以使用accept
方法返回一个Socket
子类对象。但implAccept
是protected
方法，因此，必须在ServerSocket
类的子类中覆盖accept
方法，然后在accept
方法中使用implAccept
方法重新设置Socket
对象。implAccept
方法的定义如下：
protected
final
void
implAccept(Socket s)
throws
IOException
只要通过implAccept
方法设置一个未连接的Socket
子类对象，accept
方法就会返回一个已经连接的Socket
子类对象（accept
返回的是Socket
对象，要想得到Socket
子类对象，必须进行类型转换）。在大多数时候不需要改变accept
方法的行为，但有时需要一个有更多特性的Socket
类。通过implAccept
方法就可以达到这个目的。
下面的代码定义了一个从Socket
继承的HttpSocket
类，这个类除了具有Socket
类的一切特性外，还增加了一个方法getRequestHeaders
，用于返回HTTP
请求的头信息。
package
server;
import java.net. * ;
import java.io. * ;
class HttpSocket extends Socket
{
public String getRequestHeaders() throws Exception
{
InputStreamReader isr = new InputStreamReader(getInputStream());
BufferedReader br = new BufferedReader(isr);
String s = "" , result = "" ;
while ( ! (s = br.readLine()).equals( "" ))
result = result + s + " \r\n " ;
return result;
}
}
class HttpServerSocket extends ServerSocket
{
public HttpServerSocket( int port) throws IOException
{
super (port);
}
public Socket accept() throws IOException // 覆盖accept方法
{
Socket s = new HttpSocket();
implAccept(s); // 将accept方法返回的对象类型设为HttpSocket
return s;
}
}
public class CustomAccept
{
public static void main(String[] args) throws Exception
{
HttpServerSocket httpServerSocket = new HttpServerSocket( 1234 );
HttpSocket httpSocket = (HttpSocket) httpServerSocket.accept();
System.out.println(httpSocket.getRequestHeaders()); // 向控制台输出HTTP请求头
httpServerSocket.close();
}
}
import java.net. * ;
import java.io. * ;
class HttpSocket extends Socket
{
public String getRequestHeaders() throws Exception
{
InputStreamReader isr = new InputStreamReader(getInputStream());
BufferedReader br = new BufferedReader(isr);
String s = "" , result = "" ;
while ( ! (s = br.readLine()).equals( "" ))
result = result + s + " \r\n " ;
return result;
}
}
class HttpServerSocket extends ServerSocket
{
public HttpServerSocket( int port) throws IOException
{
super (port);
}
public Socket accept() throws IOException // 覆盖accept方法
{
Socket s = new HttpSocket();
implAccept(s); // 将accept方法返回的对象类型设为HttpSocket
return s;
}
}
public class CustomAccept
{
public static void main(String[] args) throws Exception
{
HttpServerSocket httpServerSocket = new HttpServerSocket( 1234 );
HttpSocket httpSocket = (HttpSocket) httpServerSocket.accept();
System.out.println(httpSocket.getRequestHeaders()); // 向控制台输出HTTP请求头
httpServerSocket.close();
}
}
测试
执行如下命令：
执行如下命令：
java server.CustomAccept
在IE的地址栏中输入如下Url：
http:
//
localhost:1234
CustomAccept在控制台中的运行结果：
GET / HTTP/
1.1
Accept: */*
Accept-Language: zh-cn
UA-CPU: x86
Accept-Encoding: gzip , deflate
User-Agent: Mozilla/ 4.0 (compatible ; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727; InfoPath.1; InfoPath.2)
Host: localhost: 1234
Connection: Keep-Alive
Accept: */*
Accept-Language: zh-cn
UA-CPU: x86
Accept-Encoding: gzip , deflate
User-Agent: Mozilla/ 4.0 (compatible ; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727; InfoPath.1; InfoPath.2)
Host: localhost: 1234
Connection: Keep-Alive
本文转自 androidguy 51CTO博客，原文链接：
http://blog.51cto.com/androidguy/214344
，如需转载请自行联系原作者
