Java tutorial
// // Licensed to the Apache Software Foundation (ASF) under one // or more contributor license agreements. See the NOTICE file // distributed with this work for additional information // regarding copyright ownership. The ASF licenses this file // to you 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 com.cloud.network.nicira; import java.io.IOException; import java.util.HashMap; import java.util.Map; import org.apache.http.HttpEntity; import org.apache.http.StatusLine; import org.apache.http.client.methods.CloseableHttpResponse; import org.apache.http.client.methods.HttpUriRequest; import org.apache.http.client.protocol.HttpClientContext; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.util.EntityUtils; import org.apache.log4j.Logger; import com.cloud.utils.rest.BasicRestClient; import com.cloud.utils.rest.CloudstackRESTException; import com.cloud.utils.rest.HttpConstants; import com.cloud.utils.rest.HttpMethods; import com.cloud.utils.rest.HttpStatusCodeHelper; import com.cloud.utils.rest.HttpUriRequestBuilder; public class NiciraRestClient extends BasicRestClient { private static final Logger s_logger = Logger.getLogger(NiciraRestClient.class); private static final String CONTENT_TYPE = HttpConstants.CONTENT_TYPE; private static final String TEXT_HTML_CONTENT_TYPE = HttpConstants.TEXT_HTML_CONTENT_TYPE; private static final int DEFAULT_BODY_RESP_MAX_LEN = 1024; private static final int DEFAULT_EXECUTION_LIMIT = 5; private final ExecutionCounter counter; private final int maxResponseErrorMesageLength; private final int executionLimit; private final String username; private final String password; private final String loginUrl; private NiciraRestClient(final Builder builder) { super(builder.client, builder.clientContext, builder.hostname); executionLimit = builder.executionLimit; counter = new ExecutionCounter(executionLimit); maxResponseErrorMesageLength = builder.maxResponseErrorMesageLength; username = builder.username; password = builder.password; loginUrl = builder.loginUrl; } public static Builder create() { return new Builder(); } @Override public CloseableHttpResponse execute(final HttpUriRequest request) throws CloudstackRESTException { return execute(request, 0); } private CloseableHttpResponse execute(final HttpUriRequest request, final int previousStatusCode) throws CloudstackRESTException { if (counter.hasReachedExecutionLimit()) { throw new CloudstackRESTException("Reached max executions limit of " + executionLimit); } counter.incrementExecutionCounter(); s_logger.debug( "Executing " + request.getMethod() + " request [execution count = " + counter.getValue() + "]"); final CloseableHttpResponse response = super.execute(request); final StatusLine statusLine = response.getStatusLine(); final int statusCode = statusLine.getStatusCode(); s_logger.debug("Status of last request: " + statusLine.toString()); if (HttpStatusCodeHelper.isUnauthorized(statusCode)) { return handleUnauthorizedResponse(request, previousStatusCode, response, statusCode); } else if (HttpStatusCodeHelper.isSuccess(statusCode)) { return handleSuccessResponse(request, response); } else if (HttpStatusCodeHelper.isConflict(statusCode)) { throw new CloudstackRESTException("Conflict: " + statusLine.getReasonPhrase(), statusCode); } else { throw new CloudstackRESTException("Unexpected status code: " + statusCode, statusCode); } } private CloseableHttpResponse handleUnauthorizedResponse(final HttpUriRequest request, final int previousStatusCode, final CloseableHttpResponse response, final int statusCode) throws CloudstackRESTException { super.closeResponse(response); if (HttpStatusCodeHelper.isUnauthorized(previousStatusCode)) { s_logger.error(responseToErrorMessage(response)); throw new CloudstackRESTException( "Two consecutive failed attempts to authenticate against REST server"); } final HttpUriRequest authenticateRequest = createAuthenticationRequest(); final CloseableHttpResponse loginResponse = execute(authenticateRequest, statusCode); final int loginStatusCode = loginResponse.getStatusLine().getStatusCode(); super.closeResponse(loginResponse); return execute(request, loginStatusCode); } private CloseableHttpResponse handleSuccessResponse(final HttpUriRequest request, final CloseableHttpResponse response) { if (!request.getURI().getPath().contains(loginUrl)) { counter.resetExecutionCounter(); } return response; } private HttpUriRequest createAuthenticationRequest() { final Map<String, String> parameters = new HashMap<>(); parameters.put("username", username); parameters.put("password", password); return HttpUriRequestBuilder.create().method(HttpMethods.POST).methodParameters(parameters).path(loginUrl) .build(); } private String responseToErrorMessage(final CloseableHttpResponse response) { String errorMessage = response.getStatusLine().toString(); if (response.containsHeader(CONTENT_TYPE) && TEXT_HTML_CONTENT_TYPE.equals(response.getFirstHeader(CONTENT_TYPE).getValue())) { try { final HttpEntity entity = response.getEntity(); final String respobnseBody = EntityUtils.toString(entity); errorMessage = respobnseBody.subSequence(0, maxResponseErrorMesageLength).toString(); } catch (final IOException e) { s_logger.debug("Could not read repsonse body. Response: " + response, e); } } return errorMessage; } protected static class Builder extends BasicRestClient.Builder<Builder> { private CloseableHttpClient client; private HttpClientContext clientContext; private String hostname; private String username; private String password; private String loginUrl; private int executionLimit = DEFAULT_EXECUTION_LIMIT; private int maxResponseErrorMesageLength = DEFAULT_BODY_RESP_MAX_LEN; public Builder hostname(final String hostname) { this.hostname = hostname; return this; } public Builder username(final String username) { this.username = username; return this; } public Builder password(final String password) { this.password = password; return this; } public Builder loginUrl(final String loginUrl) { this.loginUrl = loginUrl; return this; } @Override public Builder client(final CloseableHttpClient client) { this.client = client; return this; } @Override public Builder clientContext(final HttpClientContext clientContext) { this.clientContext = clientContext; return this; } public Builder executionLimit(final int executionLimit) { this.executionLimit = executionLimit; return this; } public Builder maxResponseErrorMesageLength(final int maxResponseErrorMesageLength) { this.maxResponseErrorMesageLength = maxResponseErrorMesageLength; return this; } @Override public NiciraRestClient build() { return new NiciraRestClient(this); } } }