Hessian is a lightweight RPC (Remote procedure call) framework based on Java. It uses binary to serialize and deserialize, providing a simple and efficient way to transmit Java objects across the network. The main features of the Hessian framework include: 1. Easy to use: The Hessian framework only requires one line of code to achieve service publishing and invocation. 2. Cross platform: Hessian supports interoperability between different programming languages and can communicate between Java and other languages that support the Hessian protocol. 3. Efficient performance: Hessian uses binary for serialization and deserialization, which can reduce network transmission and storage costs and improve system performance. The following is an introduction to commonly used methods in the Hessian framework and Java sample code: 1. Service release: Hessian provides a HessianServlet class for publishing Hessian services. It is necessary to inherit the HessianServlet and implement the corresponding business interface. ```java public class MyHessianServlet extends HessianServlet { public MyHessianServlet() { super(); } //Methods for implementing service interfaces public String sayHello(String name) { return "Hello, " + name; } } ``` 2. Service consumption: Hessian provides the HessianProxyFactory class for creating Hessian proxy objects and obtaining the results of the service through remote calls. ```java public class MyHessianClient { public static void main(String[] args) throws MalformedURLException { String URL=“ http://localhost:8080/hessian The URL address of the Hessian service HessianProxyFactory factory = new HessianProxyFactory(); MyService service=(MyService) factory. create (MyService. class, URL)// Create a Hessian proxy object String result=service. sayHello ("Alice")// Calling service methods System.out.println(result); } } ``` 3. Dependency Configuration: To use Hessian in the Maven project, it is necessary to add the corresponding dependency configuration in the pom.xml file: ```xml <dependencies> <dependency> <groupId>com.caucho</groupId> <artifactId>hessian</artifactId> <version>4.0.63</version> </dependency> </dependencies> ``` The above is a brief introduction to the Hessian framework and Java sample code for commonly used methods. To use Hessian for serialization and deserialization, you first need to publish Hessian services, and then make remote calls through Hessian proxy objects to obtain the results of the services. Please configure and code according to actual requirements and project structure.

Jackson is a fast JSON processing library for Java that can handle the conversion between JSON data and Java objects. It provides flexible ways to serialize and deserialize objects, supports multiple data binding methods (such as POJO, Map, List, etc.), and supports customization of serialization and deserialization details through annotations. Jackson mainly includes the following key classes and methods: 1. Object Mapper: The Object Mapper class is Jackson's core class used to serialize and deserialize objects. It provides a series of methods to handle the conversion between Java objects and JSON. 2. readValue(): The readValue() method is used to deserialize JSON data into Java objects. Can accept input from different data sources, such as strings, byte arrays, files, etc. 3. writeValue(): The writeValue() method is used to serialize Java objects into JSON data. It can be output to different targets, such as strings, byte arrays, files, etc. 4. Object Mapper Configuration: Using Object Mapper, multiple serialization and deserialization options can be configured, such as setting date format and whether to indent output. The following is a Java example code for serialization and deserialization using Jackson: ```java //Import Jackson's dependency package (requires adding a dependency on Jackson databind) //Maven Dependency: // <dependency> // <groupId>com.fasterxml.jackson.core</groupId> // <artifactId>jackson-databind</artifactId> // <version>2.12.4</version> // </dependency> import com.fasterxml.jackson.databind.ObjectMapper; public class JacksonExample { public static void main(String[] args) throws Exception { //Create an Object Mapper object ObjectMapper objectMapper = new ObjectMapper(); //Convert Java objects to JSON strings (serialization) Person person = new Person("John", 30); String json = objectMapper.writeValueAsString(person); System.out.println("Serialized JSON: " + json); //Convert JSON strings to Java objects (deserialize) Person deserializedPerson = objectMapper.readValue(json, Person.class); System.out.println("Deserialized Person: " + deserializedPerson); } //Define a POJO class static class Person { private String name; private int age; public Person(String name, int age) { this.name = name; this.age = age; } //Must have an parameterless construction method for creating objects during deserialization public Person() { } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } @Override public String toString() { return "Person{" + "name='" + name + '\'' + ", age=" + age + '}'; } } } ``` The above code demonstrates Jackson's serialization and deserialization functions in the most basic way. Convert the Java object 'Person' to a JSON string, and then convert the JSON string to a Java object. In this example, we used the 'writeValueAsString()' method of 'Object Mapper' for serialization and the 'readValue()' method for deserialization. In actual development, more complex operations such as Type conversion, custom serialization and deserialization may be required, which can be realized by using the annotation and configuration methods provided by Jackson.

Gson is a framework for serialization and deserialization between Java objects and JSON strings. It can convert Java objects into JSON strings and convert JSON strings into Java objects. Gson provides a simple and easy-to-use API that can handle complex object relationships and supports custom serialization and deserialization rules. The common methods and example codes for Gson are as follows: 1. Create Gson object: ```java Gson gson = new Gson(); ``` 2. Convert the object to a JSON string (serialization): ```java MyObject obj = new MyObject(); String json = gson.toJson(obj); ``` Among them, 'MyObject' is the Java object that needs to be serialized. 3. Convert JSON strings to objects (deserialize): ```java String json = "{\"name\":\"John\",\"age\":30}"; MyObject obj = gson.fromJson(json, MyObject.class); ``` Among them, 'MyObject. class' is the class of the target object. 4. Custom serialization rules: If you need to customize the serialization and deserialization rules for objects, you can implement the 'JsonSerializer' and 'JsonDeserializer' interfaces and register them in the Gson object. ```java class MyObjectSerializer implements JsonSerializer<MyObject> { public JsonElement serialize(MyObject obj, Type typeOfSrc, JsonSerializationContext context) { JsonObject json = new JsonObject(); json.addProperty("name", obj.getName()); json.addProperty("age", obj.getAge()); return json; } } class MyObjectDeserializer implements JsonDeserializer<MyObject> { public MyObject deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException { JsonObject jsonObject = json.getAsJsonObject(); String name = jsonObject.get("name").getAsString(); int age = jsonObject.get("age").getAsInt(); return new MyObject(name, age); } } Gson gson = new GsonBuilder() .registerTypeAdapter(MyObject.class, new MyObjectSerializer()) .registerTypeAdapter(MyObject.class, new MyObjectDeserializer()) .create(); ``` The above is the basic usage and example code for serialization and deserialization using Gson. If you need to use Gson, you need to add the following Maven dependencies to the pom.xml file of the project: ```xml <dependency> <groupId>com.google.code.gson</groupId> <artifactId>gson</artifactId> <version>2.8.7</version> </dependency> ``` This will introduce the latest version of the Gson library.

Apache Avro is a data serialization system that provides a language independent and platform independent data serialization format. Its design goal is to provide efficient data compression and fast serialization/deserialization processes. Avro uses a compact binary format for serialization and supports dynamic typing. The key concepts of Avro include Schema and codec. Schema defines the structure of data, which can be written in JSON format. Each data item has an associated Schema. Schemes can be nested and referenced from other schemas. The definition of Schema plays an important role in data serialization and deserialization. The codec is responsible for converting data from object representations in memory to Avro binary format and restoring it to objects when needed. Avro provides a variety of codecs, including binary encoders, JSON encoders, and language specific encoders. The following are common methods for serialization and deserialization using Apache Avro: 1. Define Schema: First, you need to define the schema of the data. Schema can be written using Avro's Schema definition language or directly in JSON format. 2. Create data objects through a schema: Use a defined schema to create data objects. 3. Serialization: Encode data objects into Avro binary format. 4. Deserialization: Decode Avro binary format into a data object. The following is a simple example of using Apache Avro: 1. Define Schema: ```java String schemaStr = "{\"type\":\"record\",\"name\":\"Person\",\"fields\":[{\"name\":\"name\",\"type\":\"string\"},{\"name\":\"age\",\"type\":\"int\"}]}"; Schema schema = new Schema.Parser().parse(schemaStr); ``` 2. Create data objects through Schema: ```java GenericRecord person = new GenericData.Record(schema); person.put("name", "Alice"); person.put("age", 25); ``` 3. Serialization: ```java ByteArrayOutputStream out = new ByteArrayOutputStream(); DatumWriter<GenericRecord> writer = new GenericDatumWriter<>(schema); BinaryEncoder encoder = EncoderFactory.get().binaryEncoder(out, null); writer.write(person, encoder); encoder.flush(); out.close(); byte[] serializedBytes = out.toByteArray(); ``` 4. Deserialization: ```java ByteArrayInputStream in = new ByteArrayInputStream(serializedBytes); DatumReader<GenericRecord> reader = new GenericDatumReader<>(schema); BinaryDecoder decoder = DecoderFactory.get().binaryDecoder(in, null); GenericRecord deserializedPerson = reader.read(null, decoder); in.close(); ``` The above code uses Avro's Java API for serialization and deserialization operations. Regarding dependencies, Avro's core library and related codecs need to be used. The following Maven dependencies can be added to the pom.xml file of the project: ```xml <dependency> <groupId>org.apache.avro</groupId> <artifactId>avro</artifactId> <version>1.10.2</version> </dependency> <dependency> <groupId>org.apache.avro</groupId> <artifactId>avro-tools</artifactId> <version>1.10.2</version> </dependency> ``` This enables the use of Apache Avro for data serialization and deserialization operations in Java projects.

Protobuf is a data serialization framework developed by Google, also known as Protocol Buffers. It can serialize structured data into binary format and restore binary data to structured data through deserialization. Due to its efficient serialization and deserialization performance, as well as its compact data storage format, Protobuf is widely used in distributed systems. To use Protobuf in Java, the following steps need to be followed: 1. Define message structure: Use Protobuf language to define the structure of a message, which is similar to a data model used to describe the fields and types of data. 2. Compile. proto files: Use the Protobuf compiler to compile. proto files into Java classes, thereby using these classes in Java code. 3. Use the Protobuf API: Serialize and deserialize messages using compiled Java classes. Here are some commonly used Protobuf methods and corresponding Java code examples: 1. Encoder method ```java //Create a Protobuf encoder com.google.protobuf.CodedOutputStream output = CodedOutputStream.newInstance(outputStream); //Serializing a message message.writeTo(output); //Turn off encoder output.flush(); output.close(); ``` 2. Decoder method ```java //Create a Protobuf decoder com.google.protobuf.CodedInputStream input = CodedInputStream.newInstance(inputStream); //Read a message from the input stream MyMessage message = MyMessage.parseFrom(input); //Turn off decoder input.checkLastTagWas(0); ``` 3. Serialization and Deserialization Methods ```java //Serializing messages as byte arrays byte[] data = message.toByteArray(); //Deserialize byte arrays into messages MyMessage message = MyMessage.parseFrom(data); ``` 4. Maven Dependency In order to use Protobuf in Java projects, corresponding Maven dependencies need to be added: ```xml <dependency> <groupId>com.google.protobuf</groupId> <artifactId>protobuf-java</artifactId> <version>3.10.0</version> </dependency> ``` The above is the basic method and sample code for serialization and deserialization using Protobuf. By defining message structures, compiling. proto files, and using the Protobuf API, it is easy to serialize and deserialize data. Also, remember to add Protobuf's Maven dependency to the Java project's dependencies.

Apache Thrift is an extensible, cross language communication framework for efficient network communication and data transmission. It allows developers to use a simple definition file to define data types and services, and automatically generate code for different programming languages. Thrift supports multiple programming languages, including Java, C++, Python, and provides high-performance serialization and deserialization capabilities. During the process of Thrift serialization and deserialization, objects are converted into byte streams for transmission, enabling data exchange between different programming languages. Thrift defines a binary protocol called TBinaryProtocol as the default serialization protocol, which transfers data in the form of byte streams. To use Thrift for serialization and deserialization in Java, it is necessary to first define the data type and service, and use the Thrift compiler to generate Java code. Then, the generated Java code can be used for serialization and deserialization operations. The following are common methods and Java example code for serialization and deserialization using Thrift: 1. Define the Thrift data type: The Thrift data type definition file usually uses the Thrift file suffix name, as shown in the following example: ```thrift namespace java com.example.thrift struct Person { 1: required string name, 2: optional i32 age, } ``` 2. Use the Thrift compiler to generate Java code: You can use the Thrift compiler to compile defined data types into Java code. Use the following command on the command line: ``` thrift --gen java example.thrift ``` The generated Java code will be placed in the specified package path. 3. Serialization and Deserialization: Use the generated Java code for serialization and deserialization operations. The example code is as follows: ```java import com.example.thrift.Person; import org.apache.thrift.protocol.TBinaryProtocol; import org.apache.thrift.transport.TIOStreamTransport; import org.apache.thrift.transport.TMemoryBuffer; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; public class ThriftSerializationExample { public static void main(String[] args) throws Exception { // Create a Thrift object Person person = new Person(); person.setName("Alice"); person.setAge(25); // Serialize the Thrift object TMemoryBuffer buffer = new TMemoryBuffer(1024); TBinaryProtocol protocol = new TBinaryProtocol.Factory().getProtocol(buffer); person.write(protocol); byte[] serializedData = buffer.toByteArray(); System.out.println("Serialized data: " + new String(serializedData)); // Deserialize the Thrift object ByteArrayInputStream inputStream = new ByteArrayInputStream(serializedData); TIOStreamTransport transport = new TIOStreamTransport(inputStream); TBinaryProtocol deserializer = new TBinaryProtocol.Factory().getProtocol(transport); Person deserializedPerson = new Person(); deserializedPerson.read(deserializer); System.out.println("Deserialized person: " + deserializedPerson.getName() + ", " + deserializedPerson.getAge()); } } ``` In the above example, we created a Thrift object named Person and set the name and age attributes. Then, we serialize using TMemoryBuffer and write the Thrift object to the buffer. Next, we obtain the serialized byte array and print it out. Then, we use ByteArrayInputStream to take the byte array as the input stream and create a TIOStreamTransport for data transfer. Next, we use TBinaryProtocol for deserialization to read the Thrift object data from the input stream. Finally, we can obtain the data before serialization by accessing the properties of the deserialized Thrift object. If you need to use Thrift's Java library, you can add the following Maven dependencies to the pom.xml file of the project: ```xml <dependencies> <dependency> <groupId>org.apache.thrift</groupId> <artifactId>libthrift</artifactId> <version>0.14.1</version> </dependency> </dependencies> ``` The above is a brief introduction and sample code for serialization and deserialization using Thrift. The specific usage can be adjusted and expanded according to the actual situation.

Kryo is an efficient Java object serialization framework that can replace Java's native serialization methods. Compared to native serialization, Kryo has faster serialization speed, smaller serialized data volume, and supports more data types and custom data structures. Kryo provides the following commonly used methods: 1. Create Kryo objects: You can use the new keyword or use KryoFactory to create Kryo objects. ```java Kryo kryo = new Kryo(); ``` 2. Register the class to be serialized: Before serialization and deserialization, the class to be serialized needs to be registered first. ```java kryo.register(MyClass.class); ``` 3. Serialization method: Use an Output object to serialize Java objects into byte arrays. ```java Output output = new Output(new FileOutputStream("file.bin")); kryo.writeObject(output, object); output.close(); ``` 4. Deserialization method: Use an Input object to deserialize a byte array into a Java object. ```java Input input = new Input(new FileInputStream("file.bin")); MyClass object = kryo.readObject(input, MyClass.class); input.close(); ``` 5. Register custom serializers and deserializers: For certain special data types, Kryo may not be able to provide default serialization and deserialization support. In this case, you can register custom serializers and deserializers. ```java kryo.register(CustomSerializer.class, new CustomSerializer()); ``` When using Kryo, it is necessary to introduce Kryo's dependencies in the project. The following Maven dependencies can be used to introduce Kryo: ```xml <dependency> <groupId>com.esotericsoftware</groupId> <artifactId>kryo</artifactId> <version>5.0.0</version> </dependency> ``` The following is a complete example that demonstrates how to use Kryo for serialization and deserialization: ```java import com.esotericsoftware.kryo.Kryo; import com.esotericsoftware.kryo.io.Input; import com.esotericsoftware.kryo.io.Output; import java.io.*; public class KryoSerializationExample { public static void main(String[] args) throws IOException { Kryo kryo = new Kryo(); kryo.register(MyClass.class); //Serializing Objects MyClass object = new MyClass("Hello World!", 123); Output output = new Output(new FileOutputStream("file.bin")); kryo.writeObject(output, object); output.close(); //Deserialize objects Input input = new Input(new FileInputStream("file.bin")); MyClass deserializedObject = kryo.readObject(input, MyClass.class); input.close(); System.out.println(deserializedObject); } } class MyClass implements Serializable { private String message; private int value; public MyClass(String message, int value) { this.message = message; this.value = value; } @Override public String toString() { return "MyClass{" + "message='" + message + '\'' + ", value=" + value + '}'; } } ``` The above code first serializes the 'MyClass' object into a byte array through Kryo and stores it in the' file. bin 'file. Then read the byte array from the 'file. bin' file and deserialize it into a 'MyClass' object using Kryo. Finally, print the deserialized object content.

FST (Fast Serialization) is an efficient Java serialization/deserialization framework. Compared to Java's built-in Serializable interface and other serialization frameworks, FST has faster speed and smaller serialization volume. It uses displacement based algorithms to optimize serialization and deserialization operations, which can provide advantages in performance and resource utilization. Introduction to FST serialization and deserialization methods: 1. FSTConfiguration. createDefaultConfiguration (): Create an instance of FSTConfiguration. The FSTConfiguration class is the core class of the FST framework, which provides a way to configure FST behavior. Example code: ```java import org.nustaq.serialization.FSTConfiguration; FSTConfiguration conf = FSTConfiguration.createDefaultConfiguration(); ``` 2. conf. asByteArray (obj): Serializes the given object into a byte array. Example code: ```java byte[] serializedData = conf.asByteArray(obj); ``` 3. conf. asObject (serializedData): Deserializes a byte array into the original object. Example code: ```java Object obj = conf.asObject(serializedData); ``` For the Maven project, the following dependencies can be added to the pom.xml file: ```xml <dependency> <groupId>de.ruedigermoeller</groupId> <artifactId>fst</artifactId> <version>2.59</version> </dependency> ``` The version number in the above code may need to be changed according to the actual situation. Note: When using FST for serialization and deserialization, the serialized class needs to implement the Serializable interface and ensure that all its Member variable are also serializable.

XStream is a serialization and deserialization framework between Java objects and XML, which can convert Java objects into XML format and also convert XML formatted data back into Java objects. The design goal of XStream is to simplify the conversion between Java objects and XML data, providing a simple API interface that eliminates the need for developers to pay attention to the details of XML data structures. The following is an introduction to the key methods commonly used in XStream and sample code: 1. Initialize XStream object Firstly, we need to create an XStream object and perform some basic configuration. ```java XStream xstream = new XStream(); ``` 2. Serialize Java objects into XML The toXML () method can be used to convert Java objects into XML formatted strings. ```java Person person = new Person("John", 25); String xml = xstream.toXML(person); System.out.println(xml); ``` 3. Deserialize XML into Java objects The from XML () method can be used to convert XML formatted strings into Java objects. ```java String xml = "<person><name>John</name><age>25</age></person>"; Person person = (Person) xstream.fromXML(xml); System.out.println(person.getName()); System.out.println(person.getAge()); ``` 4. Custom XML tag name If you need to use a custom XML tag name, you can use the alias() method to map the Java class name to the XML tag name. ```java xstream.alias("person", Person.class); ``` 5. Ignore a field If you do not want to include a field in XML, you can use the omitField() method to ignore it. ```java xstream.omitField(Person.class, "age"); ``` 6. Add additional XML tags In addition to the fields of Java objects, we can also manually add some additional XML tags. ```java xstream.aliasField("full-name", Person.class, "name"); ``` Maven Dependency: ```xml <dependency> <groupId>com.thoughtworks.xstream</groupId> <artifactId>xstream</artifactId> <version>1.4.17</version> </dependency> ``` Through the above introduction, you can use the XStream framework for serialization and deserialization operations between Java objects and XML.

FastJSON is a high-performance JSON processing framework open-source by Alibaba, which can achieve mutual conversion between Java objects and JSON strings, and supports serialization and deserialization of complex object nesting and generics. Fastjson has the following characteristics: 1. Fast: FastJSON has a faster JSON encoding and decoding speed compared to other JSON processing frameworks. 2. Low memory consumption: Fastjson adopts a direct memory graph model to reduce string duplication. 3. Usability: Fastjson provides a simple and easy-to-use API that can be flexibly configured and used. 4. Compatibility: Fastjson supports automatic parsing of JavaBeans, arrays, Collections, strings, numbers, and other types. The commonly used methods of Fastjson include serialization and deserialization, and the following is sample code that introduces these methods: 1. JSON serialization example: ```java import com.alibaba.fastjson.JSON; public class Person { private String name; private int age; public Person(String name, int age) { this.name = name; this.age = age; } public String getName() { return name; } public int getAge() { return age; } public static void main(String[] args) { Person person = new Person("Alice", 20); //Serializing Java objects into JSON strings String jsonString = JSON.toJSONString(person); System.out.println(jsonString); } } ``` Output results: ``` {"age":20,"name":"Alice"} ``` 2. JSON deserialization example: ```java import com.alibaba.fastjson.JSON; public class Person { private String name; private int age; public Person() { } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public static void main(String[] args) { String jsonString = "{\"age\":20,\"name\":\"Alice\"}"; //Deserialize JSON strings into Java objects Person person = JSON.parseObject(jsonString, Person.class); System.out.println(person.getName()); System.out.println(person.getAge()); } } ``` Output results: ``` Alice 20 ``` If Maven is used to build a project, the following dependencies can be added to the pom.xml of the project: ```xml <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.78</version> </dependency> ```