Java tutorial
/* * Copyright (c) 2010-2014 Jakub Biaek * * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated * documentation files (the "Software"), to deal in the Software without restriction, including without limitation the * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ package com.google.code.ssm.transcoders; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import lombok.EqualsAndHashCode; import lombok.Getter; import lombok.ToString; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.util.Assert; import com.fasterxml.jackson.databind.ObjectMapper; import com.google.code.ssm.json.Holder; import com.google.code.ssm.providers.CacheTranscoder; import com.google.code.ssm.providers.CachedObject; import com.google.code.ssm.providers.CachedObjectImpl; /** * * Transcoder responsible to decode and encode objects from/to JSON format. * * @author Jakub Biaek * @since 2.0.0 * */ @ToString @EqualsAndHashCode public class JsonTranscoder implements CacheTranscoder { // NO_UCD private static final Logger LOGGER = LoggerFactory.getLogger(JsonTranscoder.class); private static final int JSON_SERIALIZED = 8; // json format @Getter private final ObjectMapper mapper; public JsonTranscoder(final ObjectMapper mapper) { Assert.notNull(mapper, "'mapper' is required and cannot be null"); this.mapper = mapper; } public boolean asyncDecode(final CachedObject data) { return false; } @Override public Object decode(final CachedObject data) { if ((data.getFlags() & JSON_SERIALIZED) == 0) { LOGGER.warn("Cannot decode cached data {} using json transcoder", data); throw new RuntimeException("Cannot decode cached data using json transcoder"); } ByteArrayInputStream bais = new ByteArrayInputStream(data.getData()); try { return mapper.readValue(bais, Holder.class).getValue(); } catch (IOException e) { LOGGER.warn(String.format("Error deserializing cached data %s", data.toString()), e); throw new RuntimeException(e); } finally { try { bais.close(); } catch (IOException e) { LOGGER.warn("Error while closing stream", e); } } } @Override public CachedObject encode(final Object o) { ByteArrayOutputStream baos = new ByteArrayOutputStream(); try { mapper.writeValue(baos, new Holder(o)); return new CachedObjectImpl(JSON_SERIALIZED, baos.toByteArray()); } catch (IOException e) { LOGGER.warn(String.format("Error serializing object %s", o), e); throw new RuntimeException(e); } finally { try { baos.close(); } catch (IOException e) { LOGGER.warn("Error while closing stream", e); } } } public int getMaxSize() { return CachedObject.MAX_SIZE; } }