Proxy сервер для java

Как создать и использовать прокси-сервер на Java

Узнайте, как создать и использовать прокси-сервер на Java для обеспечения безопасности и управления доступом в нашей пошаговой статье!

Прокси-сервер — это сервер, который служит посредником между клиентом и другим сервером. Он может быть использован для различных целей, таких как обеспечение безопасности, управление доступом и кеширование данных. В этой статье мы рассмотрим, как создать и использовать прокси-сервер на Java.

Шаг 1: Создание прокси-сервера

Для создания прокси-сервера на Java, воспользуйтесь следующими шагами:

1. Создайте новый Java-проект и добавьте в него класс MyProxyServer .
2. В этом классе создайте два объекта Socket : один для соединения с клиентом, другой для соединения с целевым сервером.

Socket clientSocket = null; Socket targetServerSocket = null;

1. Создайте конструктор для класса MyProxyServer , который будет принимать порт прокси-сервера и адрес целевого сервера.

public MyProxyServer(int proxyPort, String targetServerAddress)

ServerSocket serverSocket = new ServerSocket(proxyPort);

1. В бесконечном цикле принимайте соединения от клиентов и создавайте потоки для обработки их запросов.

Шаг 2: Обработка запросов клиентов

1. Создайте класс ClientRequestHandler , который будет обрабатывать запросы клиентов.
2. В этом классе создайте конструктор, который будет принимать Socket клиента и адрес целевого сервера.

public ClientRequestHandler(Socket clientSocket, String targetServerAddress)

1. В методе run() класса ClientRequestHandler считывайте запрос клиента, обрабатывайте его и отправляйте на целевой сервер. Затем получите ответ от целевого сервера и перенаправьте его обратно клиенту.

InputStream clientInputStream = clientSocket.getInputStream(); OutputStream clientOutputStream = clientSocket.getOutputStream(); // Чтение запроса клиента и обработка данных // . // Отправка запроса на целевой сервер // . // Получение ответа от целевого сервера и отправка его клиенту // .

clientSocket.close(); targetServerSocket.close();

Шаг 3: Запуск прокси-сервера

Чтобы запустить ваш прокси-сервер, просто создайте и запустите объект MyProxyServer с необходимыми параметрами.

public static void main(String[] args)

Теперь ваш прокси-сервер готов к использованию! 😃

Заключение

В этой статье мы рассмотрели, как создать и использовать прокси-сервер на Java. Это может быть полезно для обеспечения безопасности, управления доступом или кеширования данных. Учтите, что приведенный код является базовым примером и может быть дополнен и оптимизирован в соответствии с вашими требованиями.

Не забудьте изучить дополнительные материалы и практиковаться для улучшения своих навыков в Java-разработке. Удачи вам в изучении Java! 🚀

Источник

Saved searches

Use saved searches to filter your results more quickly

You signed in with another tab or window. Reload to refresh your session. You signed out in another tab or window. Reload to refresh your session. You switched accounts on another tab or window. Reload to refresh your session.

This is a simple HTTP/HTTPS proxy server written in Java

stefano-lupo/Java-Proxy-Server

This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.

Name already in use

A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?

Sign In Required

Please sign in to use Codespaces.

Launching GitHub Desktop

If nothing happens, download GitHub Desktop and try again.

Launching GitHub Desktop

If nothing happens, download GitHub Desktop and try again.

Launching Xcode

If nothing happens, download Xcode and try again.

Launching Visual Studio Code

Your codespace will open once ready.

There was a problem preparing your codespace, please try again.

Latest commit

Git stats

Files

Failed to load latest commit information.

README.md

Java HTTP/HTTPS Proxy Server

A proxy server is a server that sits between the client and the remote server in which the client wishes to retrieve files from. All traffic that originates from the client, is sent to the proxy server and the proxy server makes requests to the remote server on the client’s behalf. Once the proxy server receives the required files, it then forwards them on to the client. This can be beneficial as it allows the proxy server administrator some control over what the machines on its network can do. For example, certain websites may be blocked by the proxy server, meaning clients will not be able to access them. It is also beneficial as frequently visited pages can be cached by the proxy server. This means that when the client (or other clients) make subsequent requests for any files that have been cached, the proxy can issue them the files straight away, without having to request them from the remote server which can be much quicker if both the proxy and the clients are on the same network. Although these files are known to be contained in the proxy’s cache, it is worth noting that the clients have no knowledge of this and may be maintaining their own local caches. The benefit of the proxy cache is when multiple clients are using the proxy and thus pages cached due to one client can be accessed by another client.

The proxy was implemented using Java and made extensive use of TCP sockets. Firefox was set up to issue all of its traffic to the specified port and ip address which were then used in the proxy configuration. There are two main components to the implementation — the Proxy class and the RequestHandler class. The Proxy Class The Proxy class is responsible for creating a ServerSocket which can accept incoming socket connections from the client. However it is vital that the implementation be multithreaded as the server must be able to serve multiple clients simultaneously. Thus once a socket connection arrives, it is accepted and the Proxy creates a new thread which services the request (see the RequestHandler class). As the server does not need to wait for the request to be fully serviced before accepting a new socket connection, multiple clients may have their requests serviced asynchronously.

The Proxy class is also responsible for implementing caching and blocking functionality. That is, the proxy is able to cache sites that are requested by clients and dynamically block clients from visiting certain websites. As speed is of utmost importance for the proxy server, it is desirable to store references to currently blocked sites and sites that are contained in the cache in a data structure with an expected constant order lookup time. For this reason a HashMap was chosen. This results in extremely fast cache and blocked site lookup times. This results in only a small overhead if the file is not contained in the cache, and an increase in performance if the file was contained in the cache. Finally the proxy class is also responsible for the providing a dynamic console management system. This allows an administrator to add/remove files to and from the cache and websites to and from the blacklist, in real time.

The RequestHandler class is responsible for servicing the requests that come through to the proxy. The RequestHandler examines the request received and services the request appropriately. The requests can be subdivided into three main categories — HTTP GET requests, HTTP GET requests for file contained in the cache and HTTPS CONNECT requests.

These are the standard requests made when a client attempts to load a webpage. Servicing these requests is a simple task: -Parse out the URL associated with the request. -Create a HTTP connection to this URL. -Echo the client’s GET request to the remote servr. -Echo the server’s response back to the cliet. -Save a local copy of the file into the proxy’s cache.

HTTP GET for File in Cache

As before, these are the typical requests made by clients, only in this case, the file is contained in the proxy’s cache. -Parse out the URL associated with the request -Hash the URL and use this as the key for the HashMap data structure. -Open the resulting file for reading. -Echo the contents of the file back to the client. -Close the file.

HTTPS connections make use of secure sockets (SSL). Data transferred between the client and the server is encrypted. This is widely used in the financial sector in order to ensure secure transactions, but is becoming increasingly more widespread on the internet. However at first glance it poses a problem for proxy servers: How is the proxy to know what to do with this encrypted data coming from the client? In order to overcome this problem, initially, another type of HTTP request is made by the client, a CONNECT request. This request is standard HTTP and thus is unencrypted and contains the address of who the client wants to create a HTTPS connection with and this can be extracted by the proxy. This is a process known as HTTP Connect Tunneling and works as follows: -Client issues a CONNECT Request -Proxy extracts the destination URL. -Proxy creates a standard socket connection to the remote server specified by the URL. -If successful, the proxy sends a ‘200 Connection Established ‘ response to the client, indicating that the client can now begin to transmit the encrypted data to the proxy. -The proxy then simultaneously forwards any data sent to it from the client to the remote server, and any data received from the remote server back to the client.

All of this data will be encrypted and thus the proxy cannot cache or even interpret the data.

About

This is a simple HTTP/HTTPS proxy server written in Java

Источник