Java tutorial
/* * Copyright 2014-2015 CyberVision, Inc. * * 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.kaaproject.avro.ui.sandbox.services; import java.io.ByteArrayOutputStream; import java.nio.charset.Charset; import org.apache.avro.Schema; import org.apache.avro.generic.GenericDatumReader; import org.apache.avro.generic.GenericDatumWriter; import org.apache.avro.generic.GenericRecord; import org.apache.avro.io.DatumReader; import org.apache.avro.io.DatumWriter; import org.apache.avro.io.DecoderFactory; import org.apache.avro.io.EncoderFactory; import org.apache.avro.io.JsonDecoder; import org.apache.avro.io.JsonEncoder; import org.codehaus.jackson.JsonEncoding; import org.codehaus.jackson.JsonFactory; import org.codehaus.jackson.JsonGenerator; import org.kaaproject.avro.ui.converter.FormAvroConverter; import org.kaaproject.avro.ui.converter.SchemaFormAvroConverter; import org.kaaproject.avro.ui.sandbox.services.util.Utils; import org.kaaproject.avro.ui.sandbox.shared.services.AvroUiSandboxService; import org.kaaproject.avro.ui.sandbox.shared.services.AvroUiSandboxServiceException; import org.kaaproject.avro.ui.shared.RecordField; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.InitializingBean; import org.springframework.stereotype.Service; @Service("avroUiSandboxService") public class AvroUiSandboxServiceImpl implements AvroUiSandboxService, InitializingBean { /** The Constant LOG. */ private static final Logger LOG = LoggerFactory.getLogger(AvroUiSandboxServiceImpl.class); private static final Charset UTF8 = Charset.forName("UTF-8"); private SchemaFormAvroConverter schemaFormConverter; @Override public void afterPropertiesSet() throws Exception { schemaFormConverter = new SchemaFormAvroConverter(); } @Override public RecordField generateFormFromSchema(String avroSchema) throws AvroUiSandboxServiceException { try { Schema schema = new Schema.Parser().parse(avroSchema); RecordField generatedForm = FormAvroConverter.createRecordFieldFromSchema(schema); return generatedForm; } catch (Exception e) { throw Utils.handleException(e); } } @Override public String getJsonStringFromRecord(RecordField field) throws AvroUiSandboxServiceException { try { GenericRecord record = FormAvroConverter.createGenericRecordFromRecordField(field); ByteArrayOutputStream baos = new ByteArrayOutputStream(); JsonGenerator jsonGenerator = new JsonFactory().createJsonGenerator(baos, JsonEncoding.UTF8); jsonGenerator.useDefaultPrettyPrinter(); JsonEncoder jsonEncoder = EncoderFactory.get().jsonEncoder(record.getSchema(), jsonGenerator); DatumWriter<GenericRecord> datumWriter = new GenericDatumWriter<GenericRecord>(record.getSchema()); datumWriter.write(record, jsonEncoder); jsonEncoder.flush(); baos.flush(); return new String(baos.toByteArray(), UTF8); } catch (Exception e) { throw Utils.handleException(e); } } @Override public RecordField generateFormDataFromJson(String avroSchema, String json) throws AvroUiSandboxServiceException { try { Schema schema = new Schema.Parser().parse(avroSchema); JsonDecoder jsonDecoder = DecoderFactory.get().jsonDecoder(schema, json); DatumReader<GenericRecord> datumReader = new GenericDatumReader<GenericRecord>(schema); GenericRecord genericRecord = datumReader.read(null, jsonDecoder); return FormAvroConverter.createRecordFieldFromGenericRecord(genericRecord); } catch (Exception e) { throw Utils.handleException(e); } } @Override public RecordField getEmptySchemaForm() throws AvroUiSandboxServiceException { try { return schemaFormConverter.getEmptySchemaFormInstance(); } catch (Exception e) { throw Utils.handleException(e); } } @Override public RecordField generateSchemaFormFromSchema(String avroSchema) throws AvroUiSandboxServiceException { try { Schema schema = new Schema.Parser().parse(avroSchema); RecordField generatedForm = schemaFormConverter.createSchemaFormFromSchema(schema); return generatedForm; } catch (Exception e) { throw Utils.handleException(e); } } @Override public String getJsonStringFromSchemaForm(RecordField field) throws AvroUiSandboxServiceException { try { Schema schema = schemaFormConverter.createSchemaFromSchemaForm(field); return SchemaFormAvroConverter.createSchemaString(schema, true); } catch (Exception e) { throw Utils.handleException(e); } } }