序列化和反序列化-Avro

感受最快的序列化和反序列化工具：Avro
参考阅读：
http://tech.meituan.com/serialization_vs_deserialization.html
官网：
http://avro.apache.org/docs/current/gettingstartedjava.html#Creating+users
代码结构图：


pmo 引入：

<dependency>
		  <groupId>org.apache.avro</groupId>
		  <artifactId>avro</artifactId>
		  <version>1.7.7</version>
		</dependency>

<build>
   <plugins>
      <plugin>
  <groupId>org.apache.avro</groupId>
  <artifactId>avro-maven-plugin</artifactId>
  <version>1.7.7</version>
  <executions>
    <execution>
      <phase>generate-sources</phase>
      <goals>
        <goal>schema</goal>
      </goals>
      <configuration>
        <sourceDirectory>${project.basedir}/src/main/avro/</sourceDirectory>
        <outputDirectory>${project.basedir}/src/main/java/</outputDirectory>
      </configuration>
    </execution>
  </executions>
</plugin>
<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-compiler-plugin</artifactId>
  <configuration>
    <source>1.6</source>
    <target>1.6</target>
  </configuration>
</plugin>
   </plugins>
</build>

user.avsc

{"namespace": "com.gym.backadmin.controller",
 "type": "record",
 "name": "User",
 "fields": [
     {"name": "name", "type": "string"},
     {"name": "favorite_number",  "type": ["int", "null"]},
     {"name": "favorite_color", "type": ["string", "null"]}
 ]
}

特殊注意：通过以上avsc文件可以直接生成User类代码。

public class Deserializing {
	public static void main(String[] args) throws Exception {
		File file = new File("users.avro");
		DatumReader<User> userDatumReader = new SpecificDatumReader<User>(User.class);
		DataFileReader<User> dataFileReader = new DataFileReader<User>(file, userDatumReader);
		User user = null;
		while (dataFileReader.hasNext()) {
		// Reuse user object by passing it to next(). This saves us from
		// allocating and garbage collecting many objects for files with
		// many items.
		user = dataFileReader.next(user);
		System.out.println(user);
		}
	}
}

public class Serializing {
	public static void main(String[] args) throws IOException {
		User user1 = new User();
		user1.setName("Alyssa");
		user1.setFavoriteNumber(256);
		// Leave favorite color null

		// Alternate constructor
		User user2 = new User("Ben", 7, "red");

		// Construct via builder
		User user3 = User.newBuilder()
		             .setName("Charlie")
		             .setFavoriteColor("blue")
		             .setFavoriteNumber(null)
		             .build();
		DatumWriter<User> userDatumWriter = new SpecificDatumWriter<User>(User.class);
		DataFileWriter<User> dataFileWriter = new DataFileWriter<User>(userDatumWriter);
		dataFileWriter.create(user1.getSchema(), new File("users.avro"));
		dataFileWriter.append(user1);
		dataFileWriter.append(user2);
		dataFileWriter.append(user3);
		dataFileWriter.close();
	}
}