Question

如何在Hazelcast中为ConcurrentHashMap应用DataSerializable？ public class User实现DataSerializable { public User（）{ } 私人约会日期; 私人长身份; @覆盖 public void writeData（ObjectDataOutput out）throws IOException { out.writeLong（this.date.getTime（））; out.writeLong（this.id）; } @覆盖 public void readData（ObjectDataInput in）throws IOException { this.date = new Date（in.readLong（））; this.id = in.readLong（）; } } ＆LT;赫兹：序列＆GT; ＆LT;赫兹：串行＆GT; ＆lt; hz：serializer type-class =＆＃34; java.util.concurrent.ConcurrentHashMap＆＃34;类名=＆＃34;的ConcurrentHashMap＆＃34;实施=＆＃34; HashMapStreamSerializer＆＃34; /＆GT; ＆LT; /赫兹：串行＆GT; ＆LT; /赫兹：序列＆GT; 用户user = new User（）; user.setId（1L）; 地图＆lt;长，用户＆gt; concurrentHashMap = new ConcurrentHashMap＆lt;＆gt;（）; concurrentHashMap.put（1L，user）; iMap.put（1L，concurrentHashMap）; // IMap是Hazelcast的分布式地图我想将concurrentHashMap放到已经实现了DataSerializable的分布式IMap和User类中。当我运行代码时，我得到了以下异常 com.hazelcast.nio.serialization.HazelcastSerializationException：无法序列化＆＃39; java.util.concurrent.ConcurrentHashMap＆＃39;。

Answer 1

您可以为未实现DataSerialisable的类实现Custom Serializer。

首先，让我们创建一个简单的对象。

public class Employee {
  private String surname;

  public Employee( String surname ) {
    this.surname = surname;
  }
}

现在，让我们为Employee类实现StreamSerializer。

public class EmployeeStreamSerializer
    implements StreamSerializer<Employee> {

  @Override
  public int getTypeId () {
    return 1; 
  }

  @Override
  public void write( ObjectDataOutput out, Employee employee )
      throws IOException { 
    out.writeUTF(employee.getSurname());
  }

  @Override
  public Employee read( ObjectDataInput in ) 
      throws IOException { 
    String surname = in.readUTF();
    return new Employee(surname);
  }

  @Override
  public void destroy () { 
  }
}

这里有完整的例子： http://docs.hazelcast.org/docs/3.7/manual/html-single/index.html#custom-serialization

如何在Hazelcast中为ConcurrentHashMap应用DataSerializable？

1 个答案: