org.springframework.cloud.stream.schema.client.ConfluentSchemaRegistryClient.java Source code

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Here is the source code for org.springframework.cloud.stream.schema.client.ConfluentSchemaRegistryClient.java

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/*
 * Copyright 2016-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.cloud.stream.schema.client;

import java.util.Arrays;
import java.util.Collections;
import java.util.Map;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;

import org.springframework.cloud.stream.schema.SchemaNotFoundException;
import org.springframework.cloud.stream.schema.SchemaReference;
import org.springframework.cloud.stream.schema.SchemaRegistrationResponse;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.util.Assert;
import org.springframework.web.client.HttpClientErrorException;
import org.springframework.web.client.RestTemplate;

/**
 * @author Vinicius Carvalho
 * @author Marius Bogoevici
 * @author Jon Archer
 */
public class ConfluentSchemaRegistryClient implements SchemaRegistryClient {

    private RestTemplate template;

    private String endpoint = "http://localhost:8081";

    private ObjectMapper mapper;

    public ConfluentSchemaRegistryClient() {
        this.template = new RestTemplate();
        this.mapper = new ObjectMapper();
    }

    public void setEndpoint(String endpoint) {
        this.endpoint = endpoint;
    }

    @Override
    public SchemaRegistrationResponse register(String subject, String format, String schema) {
        Assert.isTrue("avro".equals(format), "Only Avro is supported");
        String path = String.format("/subjects/%s", subject);
        HttpHeaders headers = new HttpHeaders();
        headers.put("Accept", Arrays.asList("application/vnd.schemaregistry.v1+json",
                "application/vnd.schemaregistry+json", "application/json"));
        headers.add("Content-Type", "application/json");
        Integer version = null;
        try {
            String payload = this.mapper.writeValueAsString(Collections.singletonMap("schema", schema));
            HttpEntity<String> request = new HttpEntity<>(payload, headers);
            ResponseEntity<Map> response = this.template.exchange(this.endpoint + path, HttpMethod.POST, request,
                    Map.class);
            version = (Integer) response.getBody().get("version");
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }
        SchemaRegistrationResponse schemaRegistrationResponse = new SchemaRegistrationResponse();
        schemaRegistrationResponse.setId(version);
        schemaRegistrationResponse.setSchemaReference(new SchemaReference(subject, version, "avro"));
        return schemaRegistrationResponse;
    }

    @Override
    public String fetch(SchemaReference schemaReference) {
        String path = String.format("/subjects/%s/versions/%d", schemaReference.getSubject(),
                schemaReference.getVersion());
        HttpHeaders headers = new HttpHeaders();
        headers.put("Accept", Arrays.asList("application/vnd.schemaregistry.v1+json",
                "application/vnd.schemaregistry+json", "application/json"));
        headers.add("Content-Type", "application/vnd.schemaregistry.v1+json");
        HttpEntity<String> request = new HttpEntity<>("", headers);
        try {
            ResponseEntity<Map> response = this.template.exchange(this.endpoint + path, HttpMethod.GET, request,
                    Map.class);
            return (String) response.getBody().get("schema");
        } catch (HttpClientErrorException e) {
            if (e.getStatusCode() == HttpStatus.NOT_FOUND) {
                throw new SchemaNotFoundException(
                        String.format("Could not find schema for reference: %s", schemaReference));
            } else {
                throw e;
            }
        }
    }

    @Override
    public String fetch(int id) {
        String path = String.format("/schemas/ids/%d", id);
        HttpHeaders headers = new HttpHeaders();
        headers.put("Accept", Arrays.asList("application/vnd.schemaregistry.v1+json",
                "application/vnd.schemaregistry+json", "application/json"));
        headers.add("Content-Type", "application/vnd.schemaregistry.v1+json");
        HttpEntity<String> request = new HttpEntity<>("", headers);
        try {
            ResponseEntity<Map> response = this.template.exchange(this.endpoint + path, HttpMethod.GET, request,
                    Map.class);
            return (String) response.getBody().get("schema");
        } catch (HttpClientErrorException e) {
            if (e.getStatusCode() == HttpStatus.NOT_FOUND) {
                throw new SchemaNotFoundException(String.format("Could not find schema with id: %s", id));
            } else {
                throw e;
            }
        }
    }
}