java servlet proxy

最新推荐文章于 2023-12-07 16:32:17 发布

翻译最新推荐文章于 2023-12-07 16:32:17 发布 · 768 阅读

文章标签：

#java #servlet #proxy

java 专栏收录该内容

59 篇文章

订阅专栏

本文介绍了一个简单的HTTP代理服务实现，该服务支持GET和POST请求，并能够转发到指定URL。通过使用Apache Commons HttpClient库来处理HTTP请求，实现了基本的代理功能。

import java.io.IOException; import java.io.OutputStreamWriter;
import java.net.URLDecoder; import java.util.Enumeration;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.httpclient.Header;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.HttpMethod;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.lang.NotImplementedException;



public class SimpleProxy {

    public final void proxyAjaxCall( String url,
                                     HttpServletRequest request,
                                     HttpServletResponse response) throws IOException {

        // URL needs to be url decoded

        url = URLDecoder.decode(url, "utf-8");
        OutputStreamWriter writer = new OutputStreamWriter(response.getOutputStream());
        HttpClient client = new HttpClient();
        try {

            HttpMethod method = null;

            // Split this according to the type of request
            if (request.getMethod().equals("GET")) {

                method = new GetMethod(url);

            } else if (request.getMethod().equals("POST")) {

                method = new PostMethod(url);

                // Set any eventual parameters that came with our original // request (POST params, for instance)
                Enumeration paramNames = request.getParameterNames();
                while (paramNames.hasMoreElements()) {
                    String paramName = paramNames.nextElement().toString();
                    ((PostMethod) method).setParameter(paramName, request.getParameter(paramName));
                }
            }else {

                throw new NotImplementedException( "This proxy only supports GET and POST methods.");
            }

            // Execute the method
            client.executeMethod(method);

            // Set the content type, as it comes from the server
            Header[] headers = method.getResponseHeaders();
            for (Header header : headers) {
                if ("Content-Type".equalsIgnoreCase(header.getName())) {
                    response.setContentType(header.getValue());
                }
            }
            // Write the body, flush and close
            writer.write(method.getResponseBodyAsString());
            writer.flush();
            writer.close();
        } catch (HttpException e) {
            //log.error("Oops, something went wrong in the HTTP proxy", null, e);
            writer.write(e.toString());
            throw e;

        } catch (IOException e) {

            e.printStackTrace(); writer.write(e.toString()); throw e;
        }
    }

}