Java 使用 HttpClient 调用 Banking Circle Connect M2M API 创建用户

以下是一个简单的 Java 示例，使用 Apache HttpClient 调用 Banking Circle Connect 的 M2M API 创建用户：

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.security.KeyManagementException;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.CertificateException;
import java.util.Base64;

import javax.net.ssl.SSLContext;

import org.apache.http.HttpEntity;
import org.apache.http.HttpHeaders;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.conn.ssl.NoopHostnameVerifier;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.conn.ssl.TrustAllStrategy;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.ssl.SSLContextBuilder;
import org.apache.http.util.EntityUtils;

public class M2MExample {
    
    private static final String BASE_URL = "https://api.bankingcircle.com/v1/";
    private static final String CLIENT_ID = "your_client_id";
    private static final String CLIENT_SECRET = "your_client_secret";
    private static final String USERNAME = "your_username";
    private static final String PASSWORD = "your_password";
    
    public static void main(String[] args) throws Exception {
        HttpClient httpClient = createHttpClient();
        HttpPost httpPost = new HttpPost(BASE_URL + "oauth2/token");
        httpPost.setHeader(HttpHeaders.CONTENT_TYPE, ContentType.APPLICATION_FORM_URLENCODED.getMimeType());
        String authHeader = "Basic " + Base64.getEncoder().encodeToString((CLIENT_ID + ":" + CLIENT_SECRET).getBytes(StandardCharsets.UTF_8));
        httpPost.setHeader(HttpHeaders.AUTHORIZATION, authHeader);
        StringEntity requestBody = new StringEntity("grant_type=password&username=" + USERNAME + "&password=" + PASSWORD,
                ContentType.APPLICATION_FORM_URLENCODED);
        httpPost.setEntity(requestBody);
        HttpResponse response = httpClient.execute(httpPost);
        HttpEntity responseEntity = response.getEntity();
        String responseBody = EntityUtils.toString(responseEntity);
        System.out.println(responseBody);
        String accessToken = extractAccessToken(responseBody);
        httpPost = new HttpPost(BASE_URL + "m2m/v1/users");
        httpPost.setHeader(HttpHeaders.AUTHORIZATION, "Bearer " + accessToken);
        httpPost.setHeader(HttpHeaders.CONTENT_TYPE, ContentType.APPLICATION_JSON.getMimeType());
        String userRequestBody = "{"firstName":"John","lastName":"Doe","email":"john.doe@example.com"}";
        StringEntity userRequestEntity = new StringEntity(userRequestBody, ContentType.APPLICATION_JSON);
        httpPost.setEntity(userRequestEntity);
        response = httpClient.execute(httpPost);
        responseEntity = response.getEntity();
        responseBody = EntityUtils.toString(responseEntity);
        System.out.println(responseBody);
    }
    
    private static HttpClient createHttpClient() throws NoSuchAlgorithmException, KeyStoreException,
            KeyManagementException, CertificateException {
        SSLContext sslContext = SSLContextBuilder.create()
                .loadTrustMaterial(new TrustAllStrategy())
                .build();
        SSLConnectionSocketFactory sslSocketFactory = new SSLConnectionSocketFactory(sslContext,
                NoopHostnameVerifier.INSTANCE);
        return HttpClients.custom()
                .setSSLSocketFactory(sslSocketFactory)
                .build();
    }
    
    private static String extractAccessToken(String responseBody) {
        String[] parts = responseBody.split("&");
        for (String part : parts) {
            String[] keyValue = part.split("=");
            if (keyValue.length == 2 && "access_token".equals(keyValue[0])) {
                return keyValue[1];
            }
        }
        return null;
    }
}

在这个示例中，我们首先使用 OAuth2 密码授权流程获取访问令牌。然后，我们使用访问令牌调用 M2M API 创建一个新用户。请注意，我们使用了一个自定义的 HttpClient，该客户端允许不验证 SSL 证书，这是为了方便演示目的。在实际应用中，您应该使用适当的证书验证来确保安全性。