Java14 동기 HttpClient 예제 – 개요 및 간단한 자습서 – send()

게시 됨: 2020-09-06

개요 및 간단한 Java14 동기 HttpClient 클라이언트 자습서

Java는 최근 Java 14 JDK를 출시했습니다. 이 자습서에서는 개요 및 단순 Java 동기 HttpClient 클라이언트 자습서를 살펴보겠습니다.

아래 질문 중 하나가 있으면 올바른 위치에 있습니다.

  • JAVA에서 비동기 HTTP 요청을 생성하는 방법
  • 동기 연결에 HttpClient를 사용하는 이유
  • Java 11의 HttpClient에 대한 간단한 소개
  • 자바 11 HTTP/2 API 튜토리얼
  • 자바 HTTP 클라이언트 OpenJDK 소개
  • Java HTTP 클라이언트 – 예제 및 레시피

HttpClient 를 사용하여 요청을 보내고 응답을 검색할 수 있습니다. HttpClient는 빌더를 통해 생성됩니다.

시작하자:

파일 생성 CrunchifyJavaSynchronousHTTPClient.java

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package crunchify . com . tutorial ;
 
import java . io . IOException ;
import java . net . URI ;
import java . net . http . HttpClient ;
import java . net . http . HttpHeaders ;
import java . net . http . HttpRequest ;
import java . net . http . HttpResponse ;
import java . time . Duration ;
 
/**
* @author Crunchify.com
* Overview and Simple Java Synchronous HttpClient Client Tutorial
*/
 
public class CrunchifyJavaSynchronousHTTPClient {
 
     private static final HttpClient crunchifyHttpClient = HttpClient . newBuilder ( )
             . version ( HttpClient . Version . HTTP_1_1 )
             . connectTimeout ( Duration . ofSeconds ( 5 ) )
             . build ( ) ;
 
     // HttpClient: An HttpClient can be used to send requests and retrieve their responses. An HttpClient is created through a builder.
 
     // Duration: A time-based amount of time, such as '5 seconds'.
     // send() This class models a quantity or amount of time in terms of seconds and nanoseconds. It can be accessed using other duration-based units, such as minutes and hours.
     // In addition, the DAYS unit can be used and is treated as exactly equal to 24 hours, thus ignoring daylight savings effects. See Period for the date-based equivalent to this class.
     public static void main ( String [ ] args ) {
 
         HttpRequest crunchifyRequest = HttpRequest . newBuilder ( )
                 . GET ( )
                 . uri ( URI . create ( "https://crunchify.com/wp-content/java/crunchify-java-httpclient-tutorial.html" ) )
                 . setHeader ( "User-Agent" , "Crunchify Java Synchronous HTTPClient Example..." )
                 . build ( ) ;
 
         // HttpResponse: An HttpResponse is not created directly, but rather returned as a result of sending an HttpRequest.
         HttpResponse < String > crunchifyResponse = null ;
         try {
 
             // CompletableFuture: A Future that may be explicitly completed (setting its value and status), and may be used as a CompletionStage, supporting dependent functions and actions that trigger upon its completion.
             // send: Sends the given request using this client, blocking if necessary to get the response.
             // The returned HttpResponse<T> contains the response status, headers, and body ( as handled by given response body handler ).
             crunchifyResponse = crunchifyHttpClient . send ( crunchifyRequest , HttpResponse . BodyHandlers . ofString ( ) ) ;
 
             // print response headers
             HttpHeaders crunchifyHeaders = crunchifyResponse . headers ( ) ;
             crunchifyHeaders . map ( ) . forEach ( ( k , v ) - > System . out . println ( k + ":" + v ) ) ;
 
             // print status code
             crunnchifyPrint ( crunchifyResponse . statusCode ( ) ) ;
 
             // print response body
             crunnchifyPrint ( crunchifyResponse . body ( ) ) ;
 
         } catch ( IOException e ) {
             e . printStackTrace ( ) ;
 
         } catch ( InterruptedException e ) {
             e . printStackTrace ( ) ;
         }
     }
 
     private static void crunnchifyPrint ( Object data ) {
         System . out . println ( data ) ;
 
     }
 
}

crunchifyHttpClient.send() 자바 API는 이 클라이언트를 사용하여 주어진 요청을 보내고 응답을 받기 위해 필요한 경우 차단합니다.

반환된 HttpResponse<T> 에는 응답 상태, 헤더 및 본문(주어진 응답 본문 처리기에 의해 처리됨)이 포함됩니다.

crunchifyHttpClient.send() 자바 API

위의 코드를 Java 프로그램으로 실행하면 아래와 같은 응답을 볼 수 있습니다.

콘솔 결과:

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/ Library / Java / JavaVirtualMachines / jdk - 14.0.2.jdk / Contents / Home / bin / java - javaagent : / Applications / IntelliJ IDEA . app crunchify . com . tutorial . CrunchifyJavaSynchronousHTTPClient
accept - ranges : [ bytes ]
connection : [ keep - alive ]
content - length : [ 108 ]
content - type : [ text / html ; charset = UTF - 8 ]
date : [ Sun , 06 Sep 2020 02 : 02 : 58 GMT ]
etag : [ "5f5442af-6c" ]
last - modified : [ Sun , 06 Sep 2020 02 : 00 : 15 GMT ]
server : [ nginx ]
x - edge - location - klb : [ VhPBsSUriL2dZtW2Pu8FgAke45e082923ff37191eace6947ec35b35d ]
200
< ! DOCTYPE html >
< html >
< body >
 
< h1 > Hey . . This is Crunchify ' s Java HTTPClient Tutorial . < / h1 >
 
< / body >
< / html >
 
Process finished with exit code 0

Java 코드 위에서 실행되는 문제에 직면하면 알려주십시오.

무엇 향후 계획?

Java 비동기 HttpClient 개요 및 자습서 – sendAsync()