src/main/java/org/apache/pulsar/manager/controller/exception/ErrorResourceSerializer.java

/**
 * 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.apache.pulsar.manager.controller.exception;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class ErrorResourceSerializer extends JsonSerializer<ErrorResource> {
    @Override
    public void serialize(ErrorResource value, JsonGenerator gen, SerializerProvider serializers) throws IOException, JsonProcessingException {
        Map<String, List<String>> json = new HashMap<>();
        gen.writeStartObject();
        gen.writeObjectFieldStart("errors");
        for (FieldErrorResource fieldErrorResource : value.getFieldErrors()) {
            if (!json.containsKey(fieldErrorResource.getField())) {
                json.put(fieldErrorResource.getField(), new ArrayList<String>());
            }
            json.get(fieldErrorResource.getField()).add(fieldErrorResource.getMessage());
        }
        for (Map.Entry<String, List<String>> pair : json.entrySet()) {
            gen.writeArrayFieldStart(pair.getKey());
            pair.getValue().forEach(content -> {
                try {
                    gen.writeString(content);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            });
            gen.writeEndArray();
        }
        gen.writeEndObject();
        gen.writeEndObject();
    }
}