Design And Implementation Of Earthquake Message Express Exchange System Based On ActiveMQ

Many earthquakes occurred in China.The timeliness of earthquake message express was emphasized.With the development of science and technology in seismic network,the exchange of earthquake message express has been changed from manual to automatic.At present,EQIM system is deployed for earthquake message express exchange and has played an important role in many earthquake event in recent years.But some problems is found in EQIM.For example,EQIM will lose data when the network is interrupted suddenly.The EQIM system for automatic earthquake message express and for manual earthquake message express are independent.The Earthquake Administration of Hebei Province decide to develop a new earthquake message express system.The new system is expected to solve the above problems,and meet the following conditions:(1)High speed: During procedure of exchange,system should minimize the delay.(2)High availability: The system should run continuously and reliably.(3)High security: The system should have a security mechanism.The message will not be destroyed during the exchange.(4)Scalability: The message exchange platform can be extended to national,provincial and municipal.(5)Standards and Openness: The underlying transport protocol between systems and between the server and the client should be a standard protocol.The system supports open interface,multi-language development and multiple operating systems.ActiveMQ is an open source messaging middleware software.It is highly available,high-performance,scalable,secure and reliable in enterprise messaging.The Earthquake Administration of Hebei Province developed an earthquake message express exchange system based on Active MQ.Earthquake message express is exchanged in the Nation-Province-City.The main work of this article includes the following aspects:(1)Design of the format of earthquake message.It is determined by the type of business and the type of data.The earthquake message express exchange format is XML.(2)Implementation of program for message exchange.Based on the message exchange mechanism and node expansion mechanism of ActiveMQ,we design and develop earthquakemessage express sending program and receiving program.Different destination types have different transmission modes.When the message is transmitted in the network,it is serialized by the OpenWire protocol.The receiving program using the asynchronous monitoring mechanism to obtain the earthquake message express in real time.(3)Message persistence and high availability.Persistence solves the problem of offline message loss in topic mode.In order to avoid data loss caused by system failure,the system uses hot standby for high availability.It enhances the stability of the system.(4)The database structure.The database tables and fields are determined by the characteristics of earthquake message express structural.DAO is used to separate the business logic and data access to implement earthquake message express backup.This improves system reusability and flexibility.(5)Publishing of the earthquake message.System read the earthquake message express from database record by JAVA request response mechanism.System calls Baidu map SDK and microblogging publishing SDK to achieve the message printing,epicenter mapping,microblogging publishing and other operations.It served the rescue of earthquake event,distribution of messages.