java 中使用代理服务器的问题求教

rickxbx

需要从内网访问一个外网的网站,所以需要代理
如下访问,但是该怎么填写帐号和密码呢?(代理服务器需要帐号密码)

URL NetGet=new URL(Url);
Proxy proxy = new Proxy(Proxy.Type.HTTP,new InetSocketAddress("proxy_host",proxy_port));
URLConnection connection = NetGet.openConnection(proxy);
BufferedReader GetHtml=new BufferedReader(new InputStreamReader(connection.getInputStream()));

eTony

proxy_host:      user: pass@proxy_host

rickxbx

Post by eTony
proxy_host:      user: pass@proxy_host

i thoght it would be
but failed

rickxbx

UnknowHostException

eTony

sorry, 我也是想当然的,

没有做测试

eTony

看下这个, 对你应该有用:

http://resolute.ucsd.edu/diwaker/articles/java-proxy.html

rickxbx

Post by eTony
看下这个, 对你应该有用:

http://resolute.ucsd.edu/diwaker/articles/java-proxy.html

不好意思,我上不了国外网.能否把内容帖过来?多谢多谢
或者发到我的邮箱亦可:xu_baoxi@yahoo.com.cn

eTony

How to make your Java applications work across proxies and firewalls?

Introduction

Java provides a rich API for networking and I/O. The initial releases of the JDK did not contain native support for proxies and firewall authentications -- however, as of J2SDK1.4, Java also provides native support for proxies and authentication. In this article, I will cover three mechanisms for making your Java applications proxy-aware -- the first two are high-level, but slightly less powerful methods, and the last one is a slighly lower-level but more powerful method.
Configuring your Java Runtime Environment to use proxies

Irrespective of which method you choose to use, you will have to configure the JRE to use proxies. This is done by setting the following System properties:

                // This is for HTTP Proxies
                System.getProperties().put("proxySet", "true");
                System.getProperties().put("proxyHost", "proxy.somedomain.org");
                System.getProperties().put("proxyPort", "3128");

                // This is for FTP Proxies
                defaultProperties.put( "ftpProxySet", "true" );
                defaultProperties.put( "ftpProxyHost", "proxy-host-name" );
                defaultProperties.put( "ftpProxyPort", "85" );

                // This is for SOCKS Proxies
                System.getProperties().setProperty("socksProxySet", "true");
                System.getProperties().setProperty("socksProxyHost", proxyServerName);
                System.getProperties().setProperty("socksProxyPort", proxyServerPort);
            

Java 2 Native Support

Java 2 has a native authentication framework which can be used to provide authentication for a wide range of services in a platform and protocol independent mechanism. This is done by providing Authenticator objects.

                import java.net.*;
                import java.io.*;

                public class TestProxy{
                public static final String CRLF = "\r\n";

                public TestProxy(){
                try{
                System.getProperties().put("proxySet", "true");
                System.getProperties().put("proxyHost", "proxy.domain.com");
                System.getProperties().put("proxyPort", "3128");

                Authenticator.setDefault(new MyAuthenticator());

                URL url = new URL("http://www.google.com");
                URLConnection conn = url.openConnection();
                }catch(Exception e){
                e.printStackTrace();
                }
                }

                public static void main(String args[]){
                TestProxy tp = new TestProxy();
                }
                }

                class MyAuthenticator extends Authenticator{
                protected PasswordAuthentication getPasswordAuthentication(){
                return new PasswordAuthentication("username", "password".toCharArray());
                }
                }
            

Using URLConnection API

Prior to Java 2, the SDK did not have native support for proxies. So, how does you go about making your old Java code proxy aware? Well, actually its not all that difficult. Basically, you have to play aorund with the HTTP headers yourself.

For an HTTP proxy, all HTTP requests should contain a Proxy-Authorization header ([??]) which stores the user name and password in a Base-64 encoding. You can use any base-64 encoder (and there are many available) -- for this example, I have used the encoder provided by Sun itself. However, it is not part of the standard JDK, so this code is not guaranteed to work. A simple implementation of a Base-64 encoder can be found here [??]

Having encoded the user name and password, you simply need to open a URLConnection, and set the request propert as shown below. Thats it, you're done!

                String authString = "username" + ":" + "password";
                String auth = "Basic " + new sun.misc.BASE64Encoder().encode(authString.getBytes());

                URL url = new URL("http://www.google.com");
                URLConnection conn = url.openConnection();
                conn.setRequestProperty("roxy-Authorization", auth);
            

Using raw Socket Headers

The above two methods are nice and convinient, however, they are quite restrictive. For instance, consider the case of HTTP proxies. Both the methods discussed above will work only with the HTTP GET/PUT/POST methods. These work for most conventional web applications. But now suppose that you want to write a Jabber client which works behind firewalls. To do that, you will need a socket object which would work accross the proxy -- because you would like to do arbitrary read/writes to the server.

Many HTTP proxies allow this functionality via the HTTP CONNECT method. Basically, the proxy opens a socket to the server on your behalf and returns a handle of the socket to you. Any further traffic on that socket will be forward AS-IS without any inspection/modification by the proxy. For doing this in Java, you need to supply HTTP headers manually over a raw TCP socket. Here is how to do this:

                String authString = "username" + ":" + "password";
                String auth = "Basic " + new sun.misc.BASE64Encoder().encode(authString.getBytes());
                Socket socket = new Socket("vsnlproxy.iitk.ac.in", 3128);
                OutputStream out = socket.getOutputStream();

                out.write(("CONNECT toc.oscar.aol.com:9898 HTTP/1.1" + CRLF + "Host: toc.oscar.aol.com:9898" + CRLF).getBytes());
                out.write(("roxy-Authorization: " + auth + CRLF).getBytes());
                out.write(CRLF.getBytes());

rickxbx

Post by eTony
How to make your Java applications work across proxies and firewalls?

Introduction

Java provides a rich API for networking and I/O. The initial releases of the JDK did not contain native support for proxies and firewall authentications -- however, as of J2SDK1.4, Java also provides native support for proxies and authentication. In this article, I will cover three mechanisms for making your Java applications proxy-aware -- the first two are high-level, but slightly less powerful methods, and the last one is a slighly lower-level but more powerful method.
Configuring your Java Runtime Environment to use proxies

Irrespective of which method you choose to use, you will have to configure the JRE to use proxies. This is done by setting the following System properties:

                // This is for HTTP Proxies
                System.getProperties().put("proxySet", "true");
                System.getProperties().put("proxyHost", "proxy.somedomain.org");
                System.getProperties().put("proxyPort", "3128");

                // This is for FTP Proxies
                defaultProperties.put( "ftpProxySet", "true" );
                defaultProperties.put( "ftpProxyHost", "proxy-host-name" );
                defaultProperties.put( "ftpProxyPort", "85" );

                // This is for SOCKS Proxies
                System.getProperties().setProperty("socksProxySet", "true");
                System.getProperties().setProperty("socksProxyHost", proxyServerName);
                System.getProperties().setProperty("socksProxyPort", proxyServerPort);
            

Java 2 Native Support

Java 2 has a native authentication framework which can be used to provide authentication for a wide range of services in a platform and protocol independent mechanism. This is done by providing Authenticator objects.

                import java.net.*;
                import java.io.*;

                public class TestProxy{
                public static final String CRLF = "\r\n";

                public TestProxy(){
                try{
                System.getProperties().put("proxySet", "true");
                System.getProperties().put("proxyHost", "proxy.domain.com");
                System.getProperties().put("proxyPort", "3128");

                Authenticator.setDefault(new MyAuthenticator());

                URL url = new URL("http://www.google.com");
                URLConnection conn = url.openConnection();
                }catch(Exception e){
                e.printStackTrace();
                }
                }

                public static void main(String args[]){
                TestProxy tp = new TestProxy();
                }
                }

                class MyAuthenticator extends Authenticator{
                protected PasswordAuthentication getPasswordAuthentication(){
                return new PasswordAuthentication("username", "password".toCharArray());
                }
                }
            

Using URLConnection API

Prior to Java 2, the SDK did not have native support for proxies. So, how does you go about making your old Java code proxy aware? Well, actually its not all that difficult. Basically, you have to play aorund with the HTTP headers yourself.

For an HTTP proxy, all HTTP requests should contain a Proxy-Authorization header ([??]) which stores the user name and password in a Base-64 encoding. You can use any base-64 encoder (and there are many available) -- for this example, I have used the encoder provided by Sun itself. However, it is not part of the standard JDK, so this code is not guaranteed to work. A simple implementation of a Base-64 encoder can be found here [??]

Having encoded the user name and password, you simply need to open a URLConnection, and set the request propert as shown below. Thats it, you're done!

                String authString = "username" + ":" + "password";
                String auth = "Basic " + new sun.misc.BASE64Encoder().encode(authString.getBytes());

                URL url = new URL("http://www.google.com");
                URLConnection conn = url.openConnection();
                conn.setRequestProperty("roxy-Authorization", auth);
            

Using raw Socket Headers

The above two methods are nice and convinient, however, they are quite restrictive. For instance, consider the case of HTTP proxies. Both the methods discussed above will work only with the HTTP GET/PUT/POST methods. These work for most conventional web applications. But now suppose that you want to write a Jabber client which works behind firewalls. To do that, you will need a socket object which would work accross the proxy -- because you would like to do arbitrary read/writes to the server.

Many HTTP proxies allow this functionality via the HTTP CONNECT method. Basically, the proxy opens a socket to the server on your behalf and returns a handle of the socket to you. Any further traffic on that socket will be forward AS-IS without any inspection/modification by the proxy. For doing this in Java, you need to supply HTTP headers manually over a raw TCP socket. Here is how to do this:

                String authString = "username" + ":" + "password";
                String auth = "Basic " + new sun.misc.BASE64Encoder().encode(authString.getBytes());
                Socket socket = new Socket("vsnlproxy.iitk.ac.in", 3128);
                OutputStream out = socket.getOutputStream();

                out.write(("CONNECT toc.oscar.aol.com:9898 HTTP/1.1" + CRLF + "Host: toc.oscar.aol.com:9898" + CRLF).getBytes());
                out.write(("roxy-Authorization: " + auth + CRLF).getBytes());
                out.write(CRLF.getBytes());

多谢多谢