Kryo 是一个快速高效的 Java 对象图形序列化框架，主要特点是性能、高效和易用。该项目用来序列化对象到文件、数据库或者网络。

代码地址：https://github.com/EsotericSoftware/kryo

样例代码地址：https://github.com/nettm/public

Kryo的序列化及反序列速度很快，据说很多大公司都在用。我在把对象序列化都转换成了字符串形式，是为了把对象存储到缓存中。我们日常项目中使用的数据形式包括对象、List、Set和Map，因此主要把这几种类型的数据进行了序列化及反序列化，支持对象中包含List、Set和Map。

首先在项目的pom文件中引入：

<dependency> <groupId>com.esotericsoftware</groupId> <artifactId>kryo-shaded</artifactId> <version>3.0.3</version></dependency>

代码KryoTest：

package com.nettm.serializable;import java.io.ByteArrayInputStream;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.io.Serializable;import java.util.ArrayList;import java.util.HashMap;import java.util.HashSet;import java.util.List;import java.util.Map;import java.util.Set;import org.apache.commons.codec.binary.Base64;import org.testng.Assert;import org.testng.annotations.AfterTest;import org.testng.annotations.BeforeTest;import org.testng.annotations.Test;import com.esotericsoftware.kryo.Kryo;import com.esotericsoftware.kryo.io.Input;import com.esotericsoftware.kryo.io.Output;import com.esotericsoftware.kryo.serializers.CollectionSerializer;import com.esotericsoftware.kryo.serializers.JavaSerializer;import com.esotericsoftware.kryo.serializers.MapSerializer;public class KryoTest { private long time; @BeforeTest public void beforeTest() { time = System.currentTimeMillis(); } @AfterTest public void afterTest() { System.out.println(System.currentTimeMillis() - time); } @Test(invocationCount = 1, threadPoolSize = 1) public void testObject() { CustomItemDto val = new CustomItemDto(); val.setId(Long.parseLong(String.valueOf(1))); val.setItemCode(""); val.setItemDespositPrice(32.45); val.setItemMemo(null); val.setItemName("张金"); val.setItemPrice(89.02); val.setSort(10); String a = serializationObject(val); CustomItemDto newValue = deserializationObject(a, CustomItemDto.class); Assert.assertEquals(val.getId(), newValue.getId()); } @Test(invocationCount = 1, threadPoolSize = 1) public void testList() { List<CustomItemDto> lst = new ArrayList<CustomItemDto>(); for (int i = 0; i < 10; i++) { CustomItemDto val = new CustomItemDto(); val.setId(Long.parseLong(String.valueOf(i))); val.setItemCode(""); val.setItemDespositPrice(32.45); val.setItemMemo(null); val.setItemName("张金"); val.setItemPrice(89.02); val.setSort(10); lst.add(val); } String a = serializationList(lst, CustomItemDto.class); List<CustomItemDto> newValue = deserializationList(a, CustomItemDto.class); Assert.assertEquals(lst.size(), newValue.size()); } @Test(invocationCount = 1, threadPoolSize = 1) public void testBean() { List<CustomCategoryDto> lst = new ArrayList<CustomCategoryDto>(); for (int j = 0; j < 10; j++) { CustomCategoryDto dto = new CustomCategoryDto(); dto.setCategoryCode("ABCD_001"); dto.setCategoryName("呼吸系统"); for (int i = 0; i < 10; i++) { CustomItemDto val = new CustomItemDto(); val.setId(Long.parseLong(String.valueOf(i))); val.setItemCode(""); val.setItemDespositPrice(32.45); val.setItemMemo(null); val.setItemName("张金"); val.setItemPrice(89.02); val.setSort(10); dto.getCustomItemList().add(val); } for (int i = 0; i < 10; i++) { CustomItemDto val = new CustomItemDto(); val.setId(Long.parseLong(String.valueOf(i))); val.setItemCode(""); val.setItemDespositPrice(32.45); val.setItemMemo(null); val.setItemName("张金"); val.setItemPrice(89.02); val.setSort(10); dto.getCustomItemSet().add(val); } for (int i = 0; i < 10; i++) { CustomItemDto val = new CustomItemDto(); val.setId(Long.parseLong(String.valueOf(i))); val.setItemCode(""); val.setItemDespositPrice(32.45); val.setItemMemo(null); val.setItemName("张金"); val.setItemPrice(89.02); val.setSort(10); dto.getCustomItemMap().put(String.valueOf(i), val); } lst.add(dto); } String a = serializationList(lst, CustomCategoryDto.class); List<CustomCategoryDto> newValue = deserializationList(a, CustomCategoryDto.class); Assert.assertEquals(lst.size(), newValue.size()); } @Test(invocationCount = 1, threadPoolSize = 1) public void testMap() { Map<String, CustomItemDto> map = new HashMap<String, CustomItemDto>(); for (int i = 0; i < 10; i++) { CustomItemDto val = new CustomItemDto(); val.setId(Long.parseLong(String.valueOf(i))); val.setItemCode(""); val.setItemDespositPrice(32.45); val.setItemMemo(null); val.setItemName("张金"); val.setItemPrice(89.02); val.setSort(10); map.put(new ObjectId().toString(), val); } String a = serializationMap(map, CustomItemDto.class); Map<String, CustomItemDto> newValue = deserializationMap(a, CustomItemDto.class); Assert.assertEquals(map.size(), newValue.size()); } @Test(invocationCount = 1, threadPoolSize = 1) public void testSet() { Set<CustomItemDto> set = new HashSet<CustomItemDto>(); for (int i = 0; i < 10; i++) { CustomItemDto val = new CustomItemDto(); val.setId(Long.parseLong(String.valueOf(i))); val.setItemCode(""); val.setItemDespositPrice(32.45); val.setItemMemo(null); val.setItemName("金星"); val.setItemPrice(89.02); val.setSort(10); set.add(val); } String a = serializationSet(set, CustomItemDto.class); Set<CustomItemDto> newValue = deserializationSet(a, CustomItemDto.class); Assert.assertEquals(set.size(), newValue.size()); } private <T extends Serializable> String serializationObject(T obj) { Kryo kryo = new Kryo(); kryo.setReferences(false); kryo.register(obj.getClass(), new JavaSerializer()); ByteArrayOutputStream baos = new ByteArrayOutputStream(); Output output = new Output(baos); kryo.writeClassAndObject(output, obj); output.flush(); output.close(); byte[] b = baos.toByteArray(); try { baos.flush(); baos.close(); } catch (IOException e) { e.printStackTrace(); } return new String(new Base64().encode(b)); } @SuppressWarnings("unchecked") private <T extends Serializable> T deserializationObject(String obj, Class<T> clazz) { Kryo kryo = new Kryo(); kryo.setReferences(false); kryo.register(clazz, new JavaSerializer()); ByteArrayInputStream bais = new ByteArrayInputStream( new Base64().decode(obj)); Input input = new Input(bais); return (T) kryo.readClassAndObject(input); } private <T extends Serializable> String serializationList(List<T> obj, Class<T> clazz) { Kryo kryo = new Kryo(); kryo.setReferences(false); kryo.setRegistrationRequired(true); CollectionSerializer serializer = new CollectionSerializer(); serializer.setElementClass(clazz, new JavaSerializer()); serializer.setElementsCanBeNull(false); kryo.register(clazz, new JavaSerializer()); kryo.register(ArrayList.class, serializer); ByteArrayOutputStream baos = new ByteArrayOutputStream(); Output output = new Output(baos); kryo.writeObject(output, obj); output.flush(); output.close(); byte[] b = baos.toByteArray(); try { baos.flush(); baos.close(); } catch (IOException e) { e.printStackTrace(); } return new String(new Base64().encode(b)); } @SuppressWarnings("unchecked") private <T extends Serializable> List<T> deserializationList(String obj, Class<T> clazz) { Kryo kryo = new Kryo(); kryo.setReferences(false); kryo.setRegistrationRequired(true); CollectionSerializer serializer = new CollectionSerializer(); serializer.setElementClass(clazz, new JavaSerializer()); serializer.setElementsCanBeNull(false); kryo.register(clazz, new JavaSerializer()); kryo.register(ArrayList.class, serializer); ByteArrayInputStream bais = new ByteArrayInputStream( new Base64().decode(obj)); Input input = new Input(bais); return (List<T>) kryo.readObject(input, ArrayList.class, serializer); } private <T extends Serializable> String serializationMap( Map<String, T> obj, Class<T> clazz) { Kryo kryo = new Kryo(); kryo.setReferences(false); kryo.setRegistrationRequired(true); MapSerializer serializer = new MapSerializer(); serializer.setKeyClass(String.class, new JavaSerializer()); serializer.setKeysCanBeNull(false); serializer.setValueClass(clazz, new JavaSerializer()); serializer.setValuesCanBeNull(true); kryo.register(clazz, new JavaSerializer()); kryo.register(HashMap.class, serializer); ByteArrayOutputStream baos = new ByteArrayOutputStream(); Output output = new Output(baos); kryo.writeObject(output, obj); output.flush(); output.close(); byte[] b = baos.toByteArray(); try { baos.flush(); baos.close(); } catch (IOException e) { e.printStackTrace(); } return new String(new Base64().encode(b)); } @SuppressWarnings("unchecked") private <T extends Serializable> Map<String, T> deserializationMap( String obj, Class<T> clazz) { Kryo kryo = new Kryo(); kryo.setReferences(false); kryo.setRegistrationRequired(true); MapSerializer serializer = new MapSerializer(); serializer.setKeyClass(String.class, new JavaSerializer()); serializer.setKeysCanBeNull(false); serializer.setValueClass(clazz, new JavaSerializer()); serializer.setValuesCanBeNull(true); kryo.register(clazz, new JavaSerializer()); kryo.register(HashMap.class, serializer); ByteArrayInputStream bais = new ByteArrayInputStream( new Base64().decode(obj)); Input input = new Input(bais); return (Map<String, T>) kryo.readObject(input, HashMap.class, serializer); } public static <T extends Serializable> String serializationSet(Set<T> obj, Class<T> clazz) { Kryo kryo = new Kryo(); kryo.setReferences(false); kryo.setRegistrationRequired(true); CollectionSerializer serializer = new CollectionSerializer(); serializer.setElementClass(clazz, new JavaSerializer()); serializer.setElementsCanBeNull(false); kryo.register(clazz, new JavaSerializer()); kryo.register(HashSet.class, serializer); ByteArrayOutputStream baos = new ByteArrayOutputStream(); Output output = new Output(baos); kryo.writeObject(output, obj); output.flush(); output.close(); byte[] b = baos.toByteArray(); try { baos.flush(); baos.close(); } catch (IOException e) { e.printStackTrace(); } return new String(new Base64().encode(b)); } @SuppressWarnings("unchecked") public static <T extends Serializable> Set<T> deserializationSet( String obj, Class<T> clazz) { Kryo kryo = new Kryo(); kryo.setReferences(false); kryo.setRegistrationRequired(true); CollectionSerializer serializer = new CollectionSerializer(); serializer.setElementClass(clazz, new JavaSerializer()); serializer.setElementsCanBeNull(false); kryo.register(clazz, new JavaSerializer()); kryo.register(HashSet.class, serializer); ByteArrayInputStream bais = new ByteArrayInputStream( new Base64().decode(obj)); Input input = new Input(bais); return (Set<T>) kryo.readObject(input, HashSet.class, serializer); }}

总结

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