Java tutorial
/* * Copyright 2005-2015 WSO2, Inc. (http://wso2.com) * * 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. */ package org.wso2.carbon.bpmn.extensions.rest; import java.nio.charset.Charset; import org.apache.axiom.om.OMElement; import org.apache.axiom.om.util.AXIOMUtil; import org.apache.commons.codec.binary.Base64; import org.apache.commons.io.FileUtils; import org.apache.commons.io.IOUtils; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.http.Header; import org.apache.http.client.config.RequestConfig; import org.apache.http.client.methods.CloseableHttpResponse; import org.apache.http.client.methods.HttpDelete; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.client.methods.HttpPut; import org.apache.http.client.methods.HttpRequestBase; import org.apache.http.entity.StringEntity; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.HttpClients; import org.apache.http.impl.conn.PoolingHttpClientConnectionManager; import org.apache.http.util.EntityUtils; import org.wso2.carbon.bpmn.core.BPMNConstants; import org.wso2.carbon.bpmn.core.types.datatypes.json.api.JsonNodeObject; import org.wso2.carbon.utils.CarbonUtils; import javax.xml.namespace.QName; import javax.xml.stream.XMLStreamException; import java.io.File; import java.io.IOException; import java.net.URI; import java.nio.charset.StandardCharsets; import java.util.Iterator; /** * Utility class for invoking HTTP endpoints. */ public class RESTInvoker { private static final Log log = LogFactory.getLog(RESTInvoker.class); private int maxTotalConnections; private int maxTotalConnectionsPerRoute; private int connectionTimeout; private int socketTimeout; private CloseableHttpClient client = null; private PoolingHttpClientConnectionManager connectionManager = null; { maxTotalConnectionsPerRoute = RESTConstants.MAX_TOTAL_CONNECTIONS_PER_ROUTE; maxTotalConnections = RESTConstants.MAX_TOTAL_CONNECTIONS; connectionTimeout = RESTConstants.CONNECTION_TIMEOUT; socketTimeout = RESTConstants.SOCKET_TIMEOUT; } public RESTInvoker() { configureHttpClient(); } /** * This method parse the following configuration in the activiti.xml * <bean id="restClientConfiguration"> * <property name="maxTotalConnections" value="200"/> * <property name="maxConnectionsPerRoute" value="200"/> * </bean> */ private void parseConfiguration() { String carbonConfigDirPath = CarbonUtils.getCarbonConfigDirPath(); String activitiConfigPath = carbonConfigDirPath + File.separator + BPMNConstants.ACTIVITI_CONFIGURATION_FILE_NAME; File configFile = new File(activitiConfigPath); try { String configContent = FileUtils.readFileToString(configFile); OMElement configElement = AXIOMUtil.stringToOM(configContent); Iterator beans = configElement .getChildrenWithName(new QName("http://www.springframework.org/schema/beans", "bean")); while (beans.hasNext()) { OMElement bean = (OMElement) beans.next(); String beanId = bean.getAttributeValue(new QName(null, "id")); if (beanId.equals(RESTConstants.REST_CLIENT_CONFIG_ELEMENT)) { Iterator beanProps = bean.getChildrenWithName( new QName("http://www.springframework.org/schema/beans", "property")); while (beanProps.hasNext()) { OMElement beanProp = (OMElement) beanProps.next(); String beanName = beanProp.getAttributeValue(new QName(null, "name")); if (RESTConstants.REST_CLIENT_MAX_TOTAL_CONNECTIONS.equals(beanName)) { String value = beanProp.getAttributeValue(new QName(null, "value")); if (value != null && !value.trim().equals("")) { maxTotalConnections = Integer.parseInt(value); } if (log.isDebugEnabled()) { log.debug("Max total http connections " + maxTotalConnections); } } else if (RESTConstants.REST_CLIENT_MAX_CONNECTIONS_PER_ROUTE.equals(beanName)) { String value = beanProp.getAttributeValue(new QName(null, "value")); if (value != null && !value.trim().equals("")) { maxTotalConnectionsPerRoute = Integer.parseInt(value); } if (log.isDebugEnabled()) { log.debug("Max total client connections per route " + maxTotalConnectionsPerRoute); } } else if (RESTConstants.REST_CLEINT_CONNECTION_TIMEOUT.equals(beanName)) { String value = beanProp.getAttributeValue(new QName(null, "value")); if (value != null && !value.trim().equals("")) { connectionTimeout = Integer.parseInt(value); } } else if (RESTConstants.REST_CLEINT_SOCKET_TIMEOUT.equals(beanName)) { String value = beanProp.getAttributeValue(new QName(null, "value")); if (value != null && !value.trim().equals("")) { socketTimeout = Integer.parseInt(value); } } } } } } catch (IOException | XMLStreamException e) { log.error("Error in processing http connection settings, using default settings", e); } } private void configureHttpClient() { parseConfiguration(); RequestConfig defaultRequestConfig = RequestConfig.custom().setExpectContinueEnabled(true) .setConnectTimeout(connectionTimeout).setSocketTimeout(socketTimeout).build(); connectionManager = new PoolingHttpClientConnectionManager(); connectionManager.setDefaultMaxPerRoute(maxTotalConnectionsPerRoute); connectionManager.setMaxTotal(maxTotalConnections); client = HttpClients.custom().setConnectionManager(connectionManager) .setDefaultRequestConfig(defaultRequestConfig).build(); if (log.isDebugEnabled()) { log.debug("BPMN REST client initialized with" + "maxTotalConnection = " + maxTotalConnections + "maxConnectionsPerRoute = " + maxTotalConnectionsPerRoute + "connectionTimeout = " + connectionTimeout); } } public void closeHttpClient() { IOUtils.closeQuietly(client); IOUtils.closeQuietly(connectionManager); } private CloseableHttpResponse sendReceiveRequest(HttpRequestBase requestBase, String username, String password) throws IOException { CloseableHttpResponse response; if (username != null && !username.equals("") && password != null) { String combinedCredentials = username + ":" + password; byte[] encodedCredentials = Base64.encodeBase64(combinedCredentials.getBytes(StandardCharsets.UTF_8)); requestBase.addHeader("Authorization", "Basic " + new String(encodedCredentials)); response = client.execute(requestBase); } else { response = client.execute(requestBase); } return response; } private void processHeaderList(HttpRequestBase request, JsonNodeObject jsonHeaders) { if (jsonHeaders != null) { Iterator<String> iterator = jsonHeaders.fieldNames(); while (iterator.hasNext()) { String key = iterator.next(); String value = jsonHeaders.findValue(key).textValue(); request.addHeader(key, value); } } } /** * Invokes the http GET method * * @param uri endpoint/service url * @param jsonHeaders header list * @param username username for authentication * @param password password for authentication * @return RESTResponse of the GET request (can be the response body or the response status code) * @throws Exception */ public RESTResponse invokeGET(URI uri, JsonNodeObject jsonHeaders, String username, String password) throws IOException { HttpGet httpGet = null; CloseableHttpResponse response = null; Header[] headers; int httpStatus; String contentType = null; String output = null; try { httpGet = new HttpGet(uri); processHeaderList(httpGet, jsonHeaders); response = sendReceiveRequest(httpGet, username, password); //response entity may be null (eg: 204 response) if (response.getEntity() != null) { output = IOUtils.toString(response.getEntity().getContent()); if (response.getEntity().getContentType() != null) { contentType = response.getEntity().getContentType().getValue(); } } headers = response.getAllHeaders(); httpStatus = response.getStatusLine().getStatusCode(); if (log.isTraceEnabled()) { log.trace("Invoked GET " + uri.toString() + " - Response message: " + output); } EntityUtils.consume(response.getEntity()); } finally { if (response != null) { IOUtils.closeQuietly(response); } if (httpGet != null) { httpGet.releaseConnection(); } } return new RESTResponse(contentType, output, headers, httpStatus); } /** * Invokes the http POST method * * @param uri endpoint/service url * @param jsonHeaders header list * @param username username for authentication * @param password password for authentication * @param payload payload body passed * @return RESTResponse of the POST request (can be the response body or the response status code) * @throws Exception */ public RESTResponse invokePOST(URI uri, JsonNodeObject jsonHeaders, String username, String password, String payload) throws IOException { HttpPost httpPost = null; CloseableHttpResponse response = null; Header[] headers; int httpStatus; String contentType = null; String output = null; try { httpPost = new HttpPost(uri); httpPost.setEntity(new StringEntity(payload, Charset.defaultCharset())); processHeaderList(httpPost, jsonHeaders); response = sendReceiveRequest(httpPost, username, password); if (response.getEntity() != null) { output = IOUtils.toString(response.getEntity().getContent()); if (response.getEntity().getContentType() != null) { contentType = response.getEntity().getContentType().getValue(); } } headers = response.getAllHeaders(); httpStatus = response.getStatusLine().getStatusCode(); if (log.isTraceEnabled()) { log.trace("Invoked POST " + uri.toString() + " - Input payload: " + payload + " - Response message: " + output); } EntityUtils.consume(response.getEntity()); } finally { if (response != null) { IOUtils.closeQuietly(response); } if (httpPost != null) { httpPost.releaseConnection(); } } return new RESTResponse(contentType, output, headers, httpStatus); } /** * Invokes the http PUT method * * @param uri endpoint/service url * @param jsonHeaders header list * @param username username for authentication * @param password password for authentication * @param payload payload body passed * @return RESTResponse of the PUT request (can be the response body or the response status code) * @throws Exception */ public RESTResponse invokePUT(URI uri, JsonNodeObject jsonHeaders, String username, String password, String payload) throws IOException { HttpPut httpPut = null; CloseableHttpResponse response = null; Header[] headers; int httpStatus; String contentType = null; String output = null; try { httpPut = new HttpPut(uri); httpPut.setEntity(new StringEntity(payload, Charset.defaultCharset())); processHeaderList(httpPut, jsonHeaders); response = sendReceiveRequest(httpPut, username, password); if (response.getEntity() != null) { output = IOUtils.toString(response.getEntity().getContent()); if (response.getEntity().getContentType() != null) { contentType = response.getEntity().getContentType().getValue(); } } headers = response.getAllHeaders(); httpStatus = response.getStatusLine().getStatusCode(); if (log.isTraceEnabled()) { log.trace("Invoked PUT " + uri.toString() + " - Response message: " + output); } EntityUtils.consume(response.getEntity()); } finally { if (response != null) { IOUtils.closeQuietly(response); } if (httpPut != null) { httpPut.releaseConnection(); } } return new RESTResponse(contentType, output, headers, httpStatus); } /** * Invokes the http DELETE method * * @param uri endpoint/service url * @param jsonHeaders header list * @param username username for authentication * @param password password for authentication * @return RESTResponse of the DELETE (can be the response status code or the response body) * @throws Exception */ public RESTResponse invokeDELETE(URI uri, JsonNodeObject jsonHeaders, String username, String password) throws IOException { HttpDelete httpDelete = null; CloseableHttpResponse response = null; Header[] headers; int httpStatus; String contentType = null; String output = null; try { httpDelete = new HttpDelete(uri); processHeaderList(httpDelete, jsonHeaders); response = sendReceiveRequest(httpDelete, username, password); if (response.getEntity() != null) { output = IOUtils.toString(response.getEntity().getContent()); if (response.getEntity().getContentType() != null) { contentType = response.getEntity().getContentType().getValue(); } } headers = response.getAllHeaders(); httpStatus = response.getStatusLine().getStatusCode(); if (log.isTraceEnabled()) { log.trace("Invoked DELETE " + uri.toString() + " - Response message: " + output); } EntityUtils.consume(response.getEntity()); } finally { if (response != null) { IOUtils.closeQuietly(response); } if (httpDelete != null) { httpDelete.releaseConnection(); } } return new RESTResponse(contentType, output, headers, httpStatus); } }