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20240528-BJava
Commit 7bb05898 by Patryk Czarnik
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Gotowe przykłady RestKlient - jeszcze bez modelu

parent 09a2a7a9
Showing with 261 additions and 0 deletions
PC28-RestKlient/src/main/java/rest_klient/Klient01_URL.java 0 → 100644
package rest_klient;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
public class Klient01_URL {
public static void main(String[] args) {
// Najprostszy sposób w Javie, aby pobrać dane z adresu URL, to użyć klasy URL.
try {
URL url = new URL("http://localhost:8080/PC35-RestSerwer/products.json");
System.out.println("Odczytuję dane...");
try (InputStream input = url.openStream()) {
// teraz z inputa możemy czytać ciąg bajtów
// ja przerzucę bajty czytane z sieci bezpośrednio do System.out
// (w przypadku obcego serwisu może być to niebezpieczne)
input.transferTo(System.out);
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
PC28-RestKlient/src/main/java/rest_klient/Klient02_URL_JSON.java 0 → 100644
package rest_klient;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import jakarta.json.Json;
import jakarta.json.JsonArray;
import jakarta.json.JsonReader;
import jakarta.json.JsonValue;
public class Klient02_URL_JSON {
public static void main(String[] args) {
try {
URL url = new URL(Ustawienia.ADRES_USLUGI + "/products.json");
try(InputStream inputStream = url.openStream();
JsonReader reader = Json.createReader(inputStream)) {
JsonArray array = reader.readArray();
// System.out.println(array);
for(JsonValue jsonValue : array) {
//System.out.println(jsonValue);
System.out.println(jsonValue.asJsonObject().getString("productName"));
System.out.println(" opis: " + jsonValue.asJsonObject().getString("description", ""));
System.out.println(" cena: " + jsonValue.asJsonObject().getJsonNumber("price").bigDecimalValue());
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
PC28-RestKlient/src/main/java/rest_klient/Klient03_HttpClient.java 0 → 100644
package rest_klient;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.http.HttpResponse.BodyHandlers;
import java.nio.file.Path;
import java.nio.file.Paths;
public class Klient03_HttpClient {
/* W Java 11 pojawiło się rozwiązanie "HttpClient", które umożliwia komunikację HTTP z dużą kontrolą nad szczegółami.
* Wysyłając zapytanie, od razu trzeba podać odpowiedni "BodyHandler",
* który pozwoli nam odczytać treść odpowiedzi we właściwy dla nas sposób.
*
* W tej wersji wynik jest zapisywany do pliku.
*/
public static void main(String[] args) {
HttpClient httpClient = HttpClient.newHttpClient();
try {
URI uri = new URI(Ustawienia.ADRES_USLUGI + "/products.json");
HttpRequest request = HttpRequest.newBuilder(uri).build();
HttpResponse<Path> response = httpClient.send(request, BodyHandlers.ofFile(Paths.get("wynik03.json")));
System.out.println("response " + response);
System.out.println("status: " + response.statusCode());
System.out.println("Content-Type: " + response.headers().firstValue("Content-Type").orElse("BRAK"));
System.out.println("OK, zapisany plik: " + response.body());
} catch (URISyntaxException | IOException | InterruptedException e) {
e.printStackTrace();
}
}
}
PC28-RestKlient/src/main/java/rest_klient/Klient04_HttpClient_String.java 0 → 100644
package rest_klient;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.http.HttpResponse.BodyHandlers;
public class Klient04_HttpClient_String {
public static void main(String[] args) {
HttpClient httpClient = HttpClient.newHttpClient();
try {
URI uri = new URI(Ustawienia.ADRES_USLUGI + "/products.json");
HttpRequest request = HttpRequest.newBuilder(uri).build();
// Body z odpowiedzi pobierzemy jako obiekt String z całą treścią
HttpResponse<String> response = httpClient.send(request, BodyHandlers.ofString());
System.out.println("response " + response);
System.out.println("status: " + response.statusCode());
System.out.println("Content-Type: " + response.headers().firstValue("Content-Type").orElse("BRAK"));
System.out.println("Treść odpowiedzi:\n" + response.body()); // tutaj
} catch (URISyntaxException | IOException | InterruptedException e) {
e.printStackTrace();
}
}
}
PC28-RestKlient/src/main/java/rest_klient/Klient05_HttpClient_Accept.java 0 → 100644
package rest_klient;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.http.HttpResponse.BodyHandlers;
public class Klient05_HttpClient_Accept {
public static void main(String[] args) {
HttpClient httpClient = HttpClient.newHttpClient();
try {
URI uri = new URI(Ustawienia.ADRES_USLUGI + "/products");
// W tej wersji do zapytania dodajemy nagłówek Accept
HttpRequest request = HttpRequest.newBuilder(uri)
.header("Accept", "text/plain")
.build();
HttpResponse<String> response = httpClient.send(request, BodyHandlers.ofString());
System.out.println("response " + response);
System.out.println("status: " + response.statusCode());
System.out.println("Content-Type: " + response.headers().firstValue("Content-Type").orElse("BRAK"));
System.out.println("Treść odpowiedzi:\n" + response.body());
} catch (URISyntaxException | IOException | InterruptedException e) {
e.printStackTrace();
}
}
}
PC28-RestKlient/src/main/java/rest_klient/Klient06_HttpClient_JSON.java 0 → 100644
package rest_klient;
import java.io.IOException;
import java.io.InputStream;
import java.math.BigDecimal;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.http.HttpResponse.BodyHandlers;
import jakarta.json.Json;
import jakarta.json.JsonObject;
import jakarta.json.JsonReader;
public class Klient06_HttpClient_JSON {
/* W tej wersji używamy technologii Jakarta JSON P.
*
* Widzimy drzewo danych jsonowych i jego elementytakie jak JsonObject, JsonArray, ...
* Mamy dostęp do poszczególnych pól.
*/
public static void main(String[] args) {
HttpClient httpClient = HttpClient.newHttpClient();
try {
URI uri = new URI(Ustawienia.ADRES_USLUGI + "/products/1");
HttpRequest request = HttpRequest.newBuilder(uri)
.header("Accept", "application/json")
.build();
HttpResponse<InputStream> response = httpClient.send(request, BodyHandlers.ofInputStream());
System.out.println("response " + response);
System.out.println("status: " + response.statusCode());
System.out.println("Content-Type: " + response.headers().firstValue("Content-Type").orElse("BRAK"));
JsonReader reader = Json.createReader(response.body());
JsonObject product = reader.readObject();
System.out.println("Pobrany obiekt jsonowy: " + product);
String nazwa = product.getString("productName");
String opis = product.getString("description", "BRAK OPISU");
BigDecimal cena = product.getJsonNumber("price").bigDecimalValue();
System.out.println(nazwa + " za cenę " + cena + " , opis: " + opis);
reader.close();
} catch (URISyntaxException | IOException | InterruptedException e) {
e.printStackTrace();
}
}
}
PC28-RestKlient/src/main/java/rest_klient/Klient07_HttpClient_JSON_Lista.java 0 → 100644
package rest_klient;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.http.HttpResponse.BodyHandlers;
import jakarta.json.Json;
import jakarta.json.JsonArray;
import jakarta.json.JsonObject;
import jakarta.json.JsonReader;
import jakarta.json.JsonValue;
public class Klient07_HttpClient_JSON_Lista {
public static void main(String[] args) {
try {
JsonArray array = pobierzJsona(Ustawienia.ADRES_USLUGI + "/products.json");
for(JsonValue jsonValue : array) {
JsonObject jsonObject = jsonValue.asJsonObject();
System.out.println(jsonObject.getString("productName"));
if(jsonObject.containsKey("description")) {
System.out.println(" opis: " + jsonObject.getString("description", ""));
}
System.out.println(" cena: " + jsonObject.getJsonNumber("price").bigDecimalValue());
}
} catch (IOException | InterruptedException | URISyntaxException e) {
e.printStackTrace();
}
}
private static JsonArray pobierzJsona(String adres) throws IOException, InterruptedException, URISyntaxException {
HttpClient httpClient = HttpClient.newHttpClient();
URI uri = new URI(adres);
HttpRequest request = HttpRequest.newBuilder(uri).build();
HttpResponse<InputStream> response = httpClient.send(request, BodyHandlers.ofInputStream());
System.out.println("response " + response);
System.out.println("status: " + response.statusCode());
System.out.println("Content-Type: " + response.headers().firstValue("Content-Type").orElse("BRAK"));
return wczytajJsona(response.body());
}
private static JsonArray wczytajJsona(InputStream input) {
try(JsonReader reader = Json.createReader(input)) {
return reader.readArray();
}
}
}
PC28-RestKlient/src/main/java/rest_klient/Ustawienia.java 0 → 100644
package rest_klient;
public class Ustawienia {
public static final String ADRES_USLUGI = "http://localhost:8080/PC27-RestSerwer";
}
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