BAEL-4840: Read Flux<DataBuffer> into a single InputStream (#12500)
Co-authored-by: Tapan Avasthi <tavasthi@Tapans-MacBook-Air.local>
This commit is contained in:
Tapan Avasthi
GitHub
parent
343a79e402
commit
ba18865ff3
|
|
@ -0,0 +1,94 @@
|
|||
package com.baeldung.databuffer;
|
||||
|
||||
import org.slf4j.Logger;
|
||||
import org.slf4j.LoggerFactory;
|
||||
import org.springframework.core.io.buffer.DataBuffer;
|
||||
import org.springframework.core.io.buffer.DataBufferUtils;
|
||||
import org.springframework.web.reactive.function.BodyExtractors;
|
||||
import org.springframework.web.reactive.function.client.WebClient;
|
||||
|
||||
import reactor.core.publisher.Flux;
|
||||
|
||||
import java.io.IOException;
|
||||
import java.io.InputStream;
|
||||
import java.io.PipedInputStream;
|
||||
import java.io.PipedOutputStream;
|
||||
|
||||
public class DataBufferToInputStream {
|
||||
private static final Logger logger = LoggerFactory.getLogger(DataBufferToInputStream.class);
|
||||
private static final String REQUEST_ENDPOINT = "https://gorest.co.in/public/v2/users";
|
||||
|
||||
private static WebClient getWebClient() {
|
||||
WebClient.Builder webClientBuilder = WebClient.builder();
|
||||
return webClientBuilder.build();
|
||||
}
|
||||
|
||||
public static InputStream getResponseAsInputStream(WebClient client, String url) throws IOException, InterruptedException {
|
||||
|
||||
PipedOutputStream pipedOutputStream = new PipedOutputStream();
|
||||
PipedInputStream pipedInputStream = new PipedInputStream(1024 * 10);
|
||||
pipedInputStream.connect(pipedOutputStream);
|
||||
|
||||
Flux<DataBuffer> body = client.get()
|
||||
.uri(url)
|
||||
.exchangeToFlux(clientResponse -> {
|
||||
return clientResponse.body(BodyExtractors.toDataBuffers());
|
||||
})
|
||||
.doOnError(error -> {
|
||||
logger.error("error occurred while reading body", error);
|
||||
})
|
||||
.doFinally(s -> {
|
||||
try {
|
||||
pipedOutputStream.close();
|
||||
} catch (IOException e) {
|
||||
throw new RuntimeException(e);
|
||||
}
|
||||
})
|
||||
.doOnCancel(() -> {
|
||||
logger.error("Get request is cancelled");
|
||||
});
|
||||
|
||||
DataBufferUtils.write(body, pipedOutputStream)
|
||||
.log("Writing to output buffer")
|
||||
.subscribe();
|
||||
return pipedInputStream;
|
||||
}
|
||||
|
||||
private static String readContentFromPipedInputStream(PipedInputStream stream) throws IOException {
|
||||
StringBuffer contentStringBuffer = new StringBuffer();
|
||||
try {
|
||||
Thread pipeReader = new Thread(() -> {
|
||||
try {
|
||||
contentStringBuffer.append(readContent(stream));
|
||||
} catch (IOException e) {
|
||||
throw new RuntimeException(e);
|
||||
}
|
||||
});
|
||||
pipeReader.start();
|
||||
pipeReader.join();
|
||||
} catch (InterruptedException e) {
|
||||
throw new RuntimeException(e);
|
||||
} finally {
|
||||
stream.close();
|
||||
}
|
||||
|
||||
return String.valueOf(contentStringBuffer);
|
||||
}
|
||||
|
||||
private static String readContent(InputStream stream) throws IOException {
|
||||
StringBuffer contentStringBuffer = new StringBuffer();
|
||||
byte[] tmp = new byte[stream.available()];
|
||||
int byteCount = stream.read(tmp, 0, tmp.length);
|
||||
logger.info(String.format("read %d bytes from the stream\n", byteCount));
|
||||
contentStringBuffer.append(new String(tmp));
|
||||
return String.valueOf(contentStringBuffer);
|
||||
}
|
||||
|
||||
public static void main(String[] args) throws IOException, InterruptedException {
|
||||
WebClient webClient = getWebClient();
|
||||
InputStream inputStream = getResponseAsInputStream(webClient, REQUEST_ENDPOINT);
|
||||
Thread.sleep(3000);
|
||||
String content = readContentFromPipedInputStream((PipedInputStream) inputStream);
|
||||
logger.info("response content: \n{}", content.replace("}", "}\n"));
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,77 @@
|
|||
package databuffer;
|
||||
|
||||
import com.baeldung.databuffer.DataBufferToInputStream;
|
||||
|
||||
import io.restassured.internal.util.IOUtils;
|
||||
|
||||
import org.junit.jupiter.api.Test;
|
||||
import org.mockito.Mockito;
|
||||
import org.springframework.http.HttpStatus;
|
||||
import org.springframework.web.reactive.function.client.ClientResponse;
|
||||
import org.springframework.web.reactive.function.client.ExchangeFunction;
|
||||
import org.springframework.web.reactive.function.client.WebClient;
|
||||
|
||||
import reactor.core.publisher.Mono;
|
||||
|
||||
import java.io.BufferedReader;
|
||||
import java.io.IOException;
|
||||
import java.io.InputStream;
|
||||
import java.io.InputStreamReader;
|
||||
import java.util.stream.Collectors;
|
||||
|
||||
import static org.junit.jupiter.api.Assertions.assertArrayEquals;
|
||||
|
||||
class DataBufferToInputStreamUnitTest {
|
||||
private String getResponseStub() throws IOException {
|
||||
InputStream inputStream = null;
|
||||
BufferedReader reader = null;
|
||||
String content = null;
|
||||
try {
|
||||
inputStream = this.getClass()
|
||||
.getClassLoader()
|
||||
.getResourceAsStream("user-response.json");
|
||||
if (inputStream != null) {
|
||||
reader = new BufferedReader(new InputStreamReader(inputStream));
|
||||
content = reader.lines()
|
||||
.collect(Collectors.joining(System.lineSeparator()));
|
||||
}
|
||||
} catch (Exception ex) {
|
||||
throw new RuntimeException("exception caught while getting response stub");
|
||||
} finally {
|
||||
reader.close();
|
||||
inputStream.close();
|
||||
}
|
||||
return content;
|
||||
}
|
||||
|
||||
private InputStream getResponseStubAsInputStream() {
|
||||
return this.getClass()
|
||||
.getClassLoader()
|
||||
.getResourceAsStream("user-response.json");
|
||||
}
|
||||
|
||||
private WebClient getMockWebClient() throws IOException {
|
||||
String content = getResponseStub();
|
||||
ClientResponse clientResponse = ClientResponse.create(HttpStatus.OK)
|
||||
.header("Content-Type", "application/json")
|
||||
.body(content)
|
||||
.build();
|
||||
|
||||
ExchangeFunction exchangeFunction = clientRequest -> Mono.just(clientResponse);
|
||||
|
||||
WebClient.Builder webClientBuilder = WebClient.builder()
|
||||
.exchangeFunction(exchangeFunction);
|
||||
WebClient webClient = webClientBuilder.build();
|
||||
return webClient;
|
||||
}
|
||||
|
||||
@Test
|
||||
public void testResponseAsInputStream() throws IOException, InterruptedException {
|
||||
String mockUrl = Mockito.anyString();
|
||||
WebClient mockWebClient = getMockWebClient();
|
||||
InputStream inputStream = DataBufferToInputStream.getResponseAsInputStream(mockWebClient, mockUrl);
|
||||
byte[] expectedBytes = IOUtils.toByteArray(getResponseStubAsInputStream());
|
||||
byte[] actualBytes = IOUtils.toByteArray(inputStream);
|
||||
assertArrayEquals(expectedBytes, actualBytes);
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,72 @@
|
|||
[
|
||||
{
|
||||
"id": 2683,
|
||||
"name": "Maheswar Kocchar",
|
||||
"email": "maheswar_kocchar@kihn.info",
|
||||
"gender": "male",
|
||||
"status": "active"
|
||||
},
|
||||
{
|
||||
"id": 2680,
|
||||
"name": "Lakshminath Khan",
|
||||
"email": "lakshminath_khan@barrows-cormier.biz",
|
||||
"gender": "female",
|
||||
"status": "inactive"
|
||||
},
|
||||
{
|
||||
"id": 2679,
|
||||
"name": "Tarun Arora",
|
||||
"email": "tarun_arora@rolfson.net",
|
||||
"gender": "female",
|
||||
"status": "inactive"
|
||||
},
|
||||
{
|
||||
"id": 2678,
|
||||
"name": "Agnivesh Dubashi",
|
||||
"email": "dubashi_agnivesh@senger.name",
|
||||
"gender": "male",
|
||||
"status": "inactive"
|
||||
},
|
||||
{
|
||||
"id": 2677,
|
||||
"name": "Dhanu Gowda",
|
||||
"email": "gowda_dhanu@hayes.org",
|
||||
"gender": "male",
|
||||
"status": "active"
|
||||
},
|
||||
{
|
||||
"id": 2675,
|
||||
"name": "Harinakshi Pilla Jr.",
|
||||
"email": "pilla_jr_harinakshi@rutherford-monahan.com",
|
||||
"gender": "female",
|
||||
"status": "inactive"
|
||||
},
|
||||
{
|
||||
"id": 2673,
|
||||
"name": "Kalpana Prajapat",
|
||||
"email": "prajapat_kalpana@wilkinson-schaefer.net",
|
||||
"gender": "female",
|
||||
"status": "active"
|
||||
},
|
||||
{
|
||||
"id": 2672,
|
||||
"name": "Chakradhar Jha",
|
||||
"email": "jha_chakradhar@baumbach.info",
|
||||
"gender": "male",
|
||||
"status": "active"
|
||||
},
|
||||
{
|
||||
"id": 2670,
|
||||
"name": "Divaakar Deshpande Jr.",
|
||||
"email": "deshpande_jr_divaakar@mertz.info",
|
||||
"gender": "female",
|
||||
"status": "inactive"
|
||||
},
|
||||
{
|
||||
"id": 2669,
|
||||
"name": "Prasanna Mehra",
|
||||
"email": "prasanna_mehra@ruecker-larkin.name",
|
||||
"gender": "female",
|
||||
"status": "active"
|
||||
}
|
||||
]
|
||||
Loading…
Reference in New Issue