com.gooddata.sdk.service.AbstractService Maven / Gradle / Ivy
/*
* Copyright (C) 2004-2019, GoodData(R) Corporation. All rights reserved.
* This source code is licensed under the BSD-style license found in the
* LICENSE.txt file in the root directory of this source tree.
*/
package com.gooddata.sdk.service;
import static com.gooddata.sdk.common.util.Validate.notNull;
import static java.lang.String.format;
import static org.springframework.http.HttpMethod.GET;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.gooddata.sdk.common.GoodDataException;
import com.gooddata.sdk.common.GoodDataRestException;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.util.FileCopyUtils;
import org.springframework.util.StreamUtils;
import org.springframework.web.client.HttpMessageConverterExtractor;
import org.springframework.web.client.ResponseExtractor;
import org.springframework.web.client.RestTemplate;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.concurrent.TimeUnit;
/**
* Parent for GoodData services providing helpers for REST API calls and polling.
*/
public abstract class AbstractService {
protected final RestTemplate restTemplate;
private final GoodDataSettings settings;
protected final ObjectMapper mapper = new ObjectMapper();
private final ResponseExtractor reusableResponseExtractor = ReusableClientHttpResponse::new;
/**
* Sets RESTful HTTP Spring template. Should be called from constructor of concrete service extending
* this abstract one.
*
* @param restTemplate RESTful HTTP Spring template
* @param settings settings
*/
public AbstractService(final RestTemplate restTemplate, final GoodDataSettings settings) {
this.restTemplate = notNull(restTemplate, "restTemplate");
this.settings = notNull(settings, "settings");
}
final R poll(final PollHandler handler, long timeout, final TimeUnit unit) {
notNull(handler, "handler");
final long start = System.currentTimeMillis();
while (true) {
if (pollOnce(handler)) {
return handler.getResult();
}
if (unit != null && start + unit.toMillis(timeout) < System.currentTimeMillis()) {
throw new GoodDataException("timeout");
}
try {
Thread.sleep(settings.getPollSleep());
} catch (InterruptedException e) {
throw new GoodDataException("interrupted");
}
}
}
final boolean pollOnce(final PollHandler handler) {
notNull(handler, "handler");
final ClientHttpResponse response;
try {
response = restTemplate.execute(handler.getPolling(), GET, null, reusableResponseExtractor);
} catch (GoodDataRestException e) {
handler.handlePollException(e);
throw new GoodDataException("Handler " + handler.getClass().getName() + " didn't handle exception", e);
}
try {
if (handler.isFinished(response)) {
final P data = extractData(response, handler.getPollClass());
handler.handlePollResult(data);
} else if (HttpStatus.Series.CLIENT_ERROR.equals(response.getStatusCode().series())) {
throw new GoodDataException(
format("Polling returned client error HTTP status %s", response.getStatusCode().value())
);
}
} catch (IOException e) {
throw new GoodDataException("I/O error occurred during HTTP response extraction", e);
}
return handler.isDone();
}
protected final T extractData(ClientHttpResponse response, Class cls) throws IOException {
notNull(response, "response");
notNull(cls, "cls");
if (Void.class.isAssignableFrom(cls)) {
return null;
}
return new HttpMessageConverterExtractor<>(cls, restTemplate.getMessageConverters()).extractData(response);
}
private static class ReusableClientHttpResponse implements ClientHttpResponse {
private byte[] body;
private final HttpStatus statusCode;
private final int rawStatusCode;
private final String statusText;
private final HttpHeaders headers;
public ReusableClientHttpResponse(ClientHttpResponse response) {
try {
final InputStream bodyStream = response.getBody();
if (bodyStream != null) {
body = FileCopyUtils.copyToByteArray(bodyStream);
}
statusCode = response.getStatusCode();
rawStatusCode = response.getRawStatusCode();
statusText = response.getStatusText();
headers = response.getHeaders();
} catch (IOException e) {
throw new RuntimeException("Unable to read from HTTP response", e);
} finally {
if (response != null) {
response.close();
}
}
}
@Override
public HttpStatus getStatusCode() {
return statusCode;
}
@Override
public int getRawStatusCode() {
return rawStatusCode;
}
@Override
public String getStatusText() {
return statusText;
}
@Override
public HttpHeaders getHeaders() {
return headers;
}
@Override
public InputStream getBody() {
return body != null ? new ByteArrayInputStream(body) : StreamUtils.emptyInput();
}
@Override
public void close() {
//already closed
}
}
protected static class OutputStreamResponseExtractor implements ResponseExtractor {
private final OutputStream output;
public OutputStreamResponseExtractor(OutputStream output) {
this.output = output;
}
@Override
public Integer extractData(ClientHttpResponse response) throws IOException {
return FileCopyUtils.copy(response.getBody(), output);
}
}
}