Java tutorial
package org.iipg.hurricane.jmx.client; /* * Copyright 2009-2013 Roland Huss * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.io.*; import java.net.URI; import java.net.URISyntaxException; import java.nio.charset.Charset; import java.util.List; import java.util.Map; import java.util.regex.Pattern; import org.apache.http.*; import org.apache.http.client.methods.*; import org.apache.http.entity.StringEntity; import org.json.simple.*; import org.json.simple.parser.JSONParser; import org.json.simple.parser.ParseException; /** * Class doing the hard work of conversion between HTTP request/responses and * J4p request/responses. * * @author roland * @since Apr 25, 2010 */ public abstract class JMXRequestHandler { // j4p agent URL for the agent server private URI serverUrl; // Optional default target configuration private JMXTargetConfig defaultTargetConfig; /** * Constructor * * @param pServerUrl URL to remote agent * @param pTargetConfig optional default target configuration for proxy requests */ public JMXRequestHandler(String pServerUrl, JMXTargetConfig pTargetConfig) { try { serverUrl = new URI(pServerUrl); defaultTargetConfig = pTargetConfig; } catch (URISyntaxException e) { throw new IllegalArgumentException("Invalid URL " + pServerUrl, e); } } /** * Get the HttpRequest for executing the given single request * * @param pRequest request to convert * @param pPreferredMethod HTTP method preferred * @param pProcessingOptions optional map of processiong options * @return the request used with HttpClient to obtain the result. */ public abstract HttpUriRequest getHttpRequest(JMXRequest pRequest, String pPreferredMethod, Map<JMXQueryParameter, String> pProcessingOptions) throws UnsupportedEncodingException, URISyntaxException; /* String method = pPreferredMethod; if (method == null) { method = pRequest.getPreferredHttpMethod(); } if (method == null) { method = doUseProxy(pRequest) ? HttpPost.METHOD_NAME : HttpGet.METHOD_NAME; } String queryParams = prepareQueryParameters(pProcessingOptions); // GET request if (method.equals(HttpGet.METHOD_NAME)) { if (doUseProxy(pRequest)) { throw new IllegalArgumentException("Proxy mode can only be used with POST requests"); } List<String> parts = pRequest.getRequestParts(); // If parts == null the request decides, that POST *must* be used if (parts != null) { String base = prepareBaseUrl(serverUrl); StringBuilder requestPath = new StringBuilder(base); for (String p : parts) { requestPath.append("/"); requestPath.append(escape(p)); } return new HttpGet(createRequestURI(requestPath.toString(),queryParams)); } } // We are using a post method as fallback JSONObject requestContent = getJsonRequestContent(pRequest); HttpPost postReq = new HttpPost(createRequestURI(serverUrl.getPath(),queryParams)); postReq.setEntity(new StringEntity(requestContent.toJSONString(),"utf-8")); return postReq; }*/ protected boolean doUseProxy(JMXRequest pRequest) { return defaultTargetConfig != null || pRequest.getTargetConfig() != null; } protected String prepareBaseUrl(URI pUri) { String base = pUri.getPath(); if (base == null) { return "/"; } else if (!base.endsWith("/")) { return base + "/"; } else { return base; } } /** * Get an HTTP Request for requesting multiples requests at once * * @param pRequests requests to put into a HTTP request * @return HTTP request to send to the server */ public <T extends JMXRequest> HttpUriRequest getHttpRequest(List<T> pRequests, Map<JMXQueryParameter, String> pProcessingOptions) throws UnsupportedEncodingException, URISyntaxException { JSONArray bulkRequest = new JSONArray(); String queryParams = prepareQueryParameters(pProcessingOptions); HttpPost postReq = new HttpPost(createRequestURI(serverUrl.getPath(), queryParams)); for (T request : pRequests) { JSONObject requestContent = getJsonRequestContent(request); bulkRequest.add(requestContent); } postReq.setEntity(new StringEntity(bulkRequest.toJSONString(), "utf-8")); return postReq; } /** * Extract the complete JSON response out of a HTTP response * * @param pHttpResponse the resulting http response * @return JSON content of the answer */ @SuppressWarnings("PMD.PreserveStackTrace") public JSONAware extractJsonResponse(HttpResponse pHttpResponse) throws IOException, ParseException { HttpEntity entity = pHttpResponse.getEntity(); try { JSONParser parser = new JSONParser(); Header contentEncoding = entity.getContentEncoding(); if (contentEncoding != null) { return (JSONAware) parser.parse( new InputStreamReader(entity.getContent(), Charset.forName(contentEncoding.getValue()))); } else { return (JSONAware) parser.parse(new InputStreamReader(entity.getContent())); } } finally { if (entity != null) { entity.consumeContent(); } } } /** * Get the J4p Server URL * @return the URL to the Jolokia agent on the server side */ public URI getServerUrl() { return serverUrl; } // ============================================================================================================= protected JSONObject getJsonRequestContent(JMXRequest pRequest) { JSONObject requestContent = pRequest.toJson(); if (defaultTargetConfig != null && pRequest.getTargetConfig() == null) { requestContent.put("target", defaultTargetConfig.toJson()); } return requestContent; } // Escape a part for usage as part of URI path: / -> \/, \ -> \\ private static final String ESCAPE = "!"; private static final Pattern ESCAPE_PATTERN = Pattern.compile(ESCAPE); private static final Pattern SLASH_PATTERN = Pattern.compile("/"); protected String escape(String pPart) { String ret = ESCAPE_PATTERN.matcher(pPart).replaceAll(ESCAPE + ESCAPE); return SLASH_PATTERN.matcher(ret).replaceAll(ESCAPE + "/"); } // Create the request URI to use protected URI createRequestURI(String path, String queryParams) throws URISyntaxException { return new URI(serverUrl.getScheme(), serverUrl.getUserInfo(), serverUrl.getHost(), serverUrl.getPort(), path, queryParams, null); } // prepare query parameters protected String prepareQueryParameters(Map<JMXQueryParameter, String> pProcessingOptions) { if (pProcessingOptions != null && pProcessingOptions.size() > 0) { StringBuilder queryParams = new StringBuilder(); for (Map.Entry<JMXQueryParameter, String> entry : pProcessingOptions.entrySet()) { queryParams.append(entry.getKey().getParam()).append("=").append(entry.getValue()).append("&"); } return queryParams.substring(0, queryParams.length() - 1); } else { return null; } } }