上一篇文章中，介绍了netty实现UDP服务器的栗子。

本文将会对UDP服务器与spring boot整合起来，并使用RedisTemplate的操作类访问Redis和使用Spring DATA JPA链接MySQL数据库，其中会使用多线程、异步等知识。

只公布了一个框架，需要的同学可以根据此来进行扩展，增加自己需要的功能模块。如Controller部分。

本人使用的编辑器是IntelliJ IDEA 2017.1.exe版本(链接：http://pan.baidu.com/s/1pLODHm7 密码：dlx7)；建议使用STS或者是idea编辑器来进行spring的学习。

1)项目目录结构

整个项目的目录结构如下：

2)jar包

其中pom.xml文件的内容如下：

只有netty-all和commons-lang3是手动加入的jar包，其余的都是创建spring boot项目时候选择组件后自动导入的。

1 <?xml version="1.0" encoding="UTF-8"?>

2

3 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

4 4.0.0

5

6 com.example

7 udplearning

8 0.0.1-SNAPSHOT

9 jar

10

11 udplearning

12 Demo project for Spring Boot

13

14

15 org.springframework.boot

16 spring-boot-starter-parent

17 1.5.6.RELEASE

18

19

20

21

22 UTF-8

23 UTF-8

24 3.4

25 1.8

26

27

28

29

30

31

32

33 io.netty

34 netty-all

35 4.0.49.Final

36

37

38

39

40 org.apache.commons

41 commons-lang3

42 ${commons-lang3.version}

43

44

45

46

47

48 org.springframework.boot

49 spring-boot-starter-data-jpa

50

51

52 org.springframework.boot

53 spring-boot-starter-data-redis

54

55

56 org.springframework.boot

57 spring-boot-starter-jdbc

58

59

60 org.springframework.boot

61 spring-boot-starter-web

62

63

64 org.springframework.boot

65 spring-boot-starter-web-services

66

67

68

69 mysql

70 mysql-connector-java

71 runtime

72

73

74 org.springframework.boot

75 spring-boot-starter-test

76 test

77

78

79

80

81

82

83 org.springframework.boot

84 spring-boot-maven-plugin

85

86

87

88

89

90

3)配置文件application.properties

application.properties的内容：

1 spring.profiles.active=test2

3 spring.messages.encoding=utf-8

4

5 logging.config=classpath:logback.xml

“spring.profiles.active” 针对多种启动环境的spring boot配置方法，此时启动的是test运行环境，即默认是启动application-test.properties里面的配置信息；

“spring.messages.encoding=utf-8”是指编码方式utf-8；

“logging.config=classpath:logback.xml”是指日志文件位置。

application-test.properties的内容如下：

1 context.listener.classes=com.example.demo.init.StartupEvent2

3 #mysql4 spring.jpa.show-sql=true

5 spring.jpa.database=mysql6 #spring.jpa.hibernate.ddl-auto=update7 spring.datasource.url=jdbc:mysql://127.0.0.1/test

8 spring.datasource.username=root9 spring.datasource.password=123456

10 spring.datasource.driver-class-name=com.mysql.jdbc.Driver11 spring.datasource.jdbc-interceptors=ConnectionState;SlowQueryReport(threshold=0)12

13 spring.session.store-type=none14

15 # (RedisProperties)16 spring.redis.database=3

17 spring.redis.host=127.0.0.1

18 spring.redis.port=6379

19 spring.redis.password=123456

20 spring.redis.pool.max-active=8

21 spring.redis.pool.max-wait=-1

22 spring.redis.pool.max-idle=8

23 spring.redis.pool.min-idle=0

24 spring.redis.timeout=0

25

26

27 #UDP消息接收打端口28 sysfig.udpReceivePort = 7686

29

30 #线程池31 spring.task.pool.corePoolSize = 5

32 spring.task.pool.maxPoolSize = 100

33 spring.task.pool.keepAliveSeconds = 100

34 spring.task.pool.queueCapacity = 100

其中配置了context.listener.classes=com.example.demo.init.StartupEvent，将StartupEvent类作为Spring boot启动后执行文件。

其中还配置了一些mysql、redis和自定义的属性。可根据项目的实际情况修改。

4)日志文件logback.xml

logback.xml的内容如下：

1 <?xml version="1.0" encoding="UTF-8"?>

2

3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

4 xsi:schemaLocation="http://ch.qos.logback/xml/ns/logback

5 http://ch.qos.logback/xml/ns/logback/logback.xsd

6 http://ch.qos.logback/xml/ns/logback ">

7

8

9 ${APP_Name}

10

11

12

13 %d{yyyyMMddHHmmss}|%-5level| %logger{0}.%M | %msg | %thread %n

14

15

16

17

18

19 ${catalina.home}/logs/app.%d{yyyyMMdd}.log

20 30

21

22

23 %d{yyMMddHHmmss.SSS}|%-5level| %msg%n

24

25

26

27

28

29 ${catalina.home}/logs/run.%d{yyyyMMdd}.log

30 7

31

32

33 %d{yyMMddHHmmss.SSS}|%-5level| %msg%n

34

35

36

37

38

39

40

41

42

43

44

45

日志的级别是info级别  可以根据自己项目的实际情况进行设置。

5)StartupEvent.java

1 packagecom.example.demo.init;2

3 importorg.slf4j.Logger;4 importorg.slf4j.LoggerFactory;5 importorg.springframework.context.ApplicationContext;6 importorg.springframework.context.ApplicationListener;7 importorg.springframework.context.event.ContextRefreshedEvent;8

9 /**

10 *11 * Created by wj on 2017/8/28.12 */

13

14 public class StartupEvent implements ApplicationListener{15 private static final Logger log = LoggerFactory.getLogger(StartupEvent.class);16

17 private staticApplicationContext context;18

19 @Override20 public voidonApplicationEvent(ContextRefreshedEvent contextRefreshedEvent) {21

22 try{23

24 context =contextRefreshedEvent.getApplicationContext();25

26 SysConfig sysConfig = (SysConfig) context.getBean(SysConfig.class);27

28 //接收UDP消息并保存至redis中

29 UdpServer udpServer = (UdpServer)StartupEvent.getBean(UdpServer.class);30 udpServer.run(sysConfig.getUdpReceivePort());31

32

33 //这里可以开启多个线程去执行不同的任务34 //此处为工作的内容，不便公开！

35

36

37 } catch(Exception e) {38 log.error("Exception", e);39 }40 }41

42 public staticObject getBean(Class beanName) {43 return context != null ? context.getBean(beanName) : null;44 }45 }

6)UdpServer.java

1 packagecom.example.demo.init;2

3 importcom.example.demo.handle.UdpServerHandler;4 importio.netty.bootstrap.Bootstrap;5 importio.netty.channel.ChannelOption;6 importio.netty.channel.EventLoopGroup;7 importio.netty.channel.nio.NioEventLoopGroup;8 importio.netty.channel.socket.nio.NioDatagramChannel;9 importorg.slf4j.Logger;10 importorg.slf4j.LoggerFactory;11 importorg.springframework.scheduling.annotation.Async;12 importorg.springframework.stereotype.Component;13

14 /**

15 * server服务器16 * Created by wj on 2017/8/30.17 */

18 @Component19 public classUdpServer {20

21 private static final Logger log= LoggerFactory.getLogger(UdpServer.class);22

23 //private static final int PORT = Integer.parseInt(System.getProperty("port", "7686"));

24

25 @Async("myTaskAsyncPool")26 public void run(intudpReceivePort) {27

28 EventLoopGroup group = newNioEventLoopGroup();29 log.info("Server start! Udp Receive msg Port:" +udpReceivePort );30

31 try{32 Bootstrap b = newBootstrap();33 b.group(group)34 .channel(NioDatagramChannel.class)35 .option(ChannelOption.SO_BROADCAST, true)36 .handler(newUdpServerHandler());37

38 b.bind(udpReceivePort).sync().channel().closeFuture().await();39 } catch(InterruptedException e) {40 e.printStackTrace();41 } finally{42 group.shutdownGracefully();43 }44 }45

46 }

此处NioDatagramChannel.class采用的是非阻塞的模式接受UDP消息，若是接受的UDP消息少，可以采用阻塞式的方式接受UDP消息。

UdpServer.run()方法使用@Async将该方法定义成异步的，myTaskAsyncPool是自定义的线程池。

7)UdpServerHandler.java

1 packagecom.example.demo.handle;2

3 importcom.example.demo.init.StartupEvent;4 importcom.example.demo.mod.UdpRecord;5 importcom.example.demo.repository.mysql.UdpRepository;6 importcom.example.demo.repository.redis.RedisRepository;7 importio.netty.buffer.Unpooled;8 importio.netty.channel.ChannelHandlerContext;9 importio.netty.channel.SimpleChannelInboundHandler;10 importio.netty.channel.socket.DatagramPacket;11 importio.netty.util.CharsetUtil;12 importorg.apache.commons.lang3.StringUtils;13 importorg.slf4j.Logger;14 importorg.slf4j.LoggerFactory;15

16 importjava.sql.Timestamp;17 importjava.util.Date;18

19 /**

20 * 接受UDP消息，并保存至redis的list链表中21 * Created by wj on 2017/8/30.22 *23 */

24

25 public class UdpServerHandler extends SimpleChannelInboundHandler{26

27 private static final Logger log= LoggerFactory.getLogger(UdpServerHandler.class);28

29 //用来计算server接收到多少UDP消息

30 private static int count = 0;31

32 @Override33 public void channelRead0(ChannelHandlerContext ctx, DatagramPacket packet) throwsException {34

35 String receiveMsg =packet.content().toString(CharsetUtil.UTF_8);36

37 log.info("Received UDP Msg:" +receiveMsg);38

39 UdpRecord udpRecord = newUdpRecord();40

41 //判断接受到的UDP消息是否正确(未实现)

42 if(StringUtils.isNotEmpty(receiveMsg) ){43

44 //计算接收到的UDP消息的数量

45 count++;46

47 //获取UdpRepository对象，将接收UDP消息的日志保存至mysql中

48 udpRecord.setUdpMsg(receiveMsg);49 udpRecord.setTime(getTime());50 UdpRepository udpRepository = (UdpRepository) StartupEvent.getBean(UdpRepository.class);51 udpRepository.save(udpRecord);52

53 //获取RedirRepository对象

54 RedisRepository redisRepository = (RedisRepository) StartupEvent.getBean(RedisRepository.class);55 //将获取到的UDP消息保存至redis的list列表中

56 redisRepository.lpush("udp:msg", receiveMsg);57 redisRepository.setKey("UDPMsgNumber", String.valueOf(count));58

59

60 //在这里可以返回一个UDP消息给对方，告知已接收到UDP消息，但考虑到这是UDP消息，此处可以注释掉

61 ctx.write(newDatagramPacket(62 Unpooled.copiedBuffer("QOTM: " + "Got UDP Message!", CharsetUtil.UTF_8), packet.sender()));63

64 }else{65 log.error("Received Error UDP Messsage:" +receiveMsg);66 }67 }68

69 @Override70 public voidchannelReadComplete(ChannelHandlerContext ctx) {71 ctx.flush();72 }73

74 @Override75 public voidexceptionCaught(ChannelHandlerContext ctx, Throwable cause) {76 cause.printStackTrace();77 //We don't close the channel because we can keep serving requests.

78 }79

80 publicTimestamp getTime(){81 Date date = newDate();82 Timestamp time = newTimestamp(date.getTime());83 returntime;84 }85

86 }

此处若不借用ApplicationContext.getBean，是无法获取到RedisRepository对象的。

注：这里是无法使用注解@Autowired来获取到redisTemplate对象的。

8)repository

RedisRepository.java

1 packagecom.example.demo.repository.redis;2

3 importorg.slf4j.Logger;4 importorg.slf4j.LoggerFactory;5 importorg.springframework.beans.factory.annotation.Autowired;6 importorg.springframework.data.redis.core.RedisTemplate;7 importorg.springframework.stereotype.Service;8

9 /**

10 * 链接redis11 * 实现list lpush和rpop12 * Created by wj on 2017/8/30.13 */

14

15

16 @Service17 public classRedisRepository {18 private static final Logger log = LoggerFactory.getLogger(RedisRepository.class);19

20 @Autowired21 private RedisTemplateredisTemplate;22

23 //----------------String-----------------------

24 public voidsetKey(String key,String value){25 redisTemplate.opsForValue().set(key, value);26 }27

28

29 //----------------list----------------------

30 public Long lpush(String key, String val) throwsException{31 log.info("UDP Msg保存至redis中，key:" + key + ",val:" +val);32 returnredisTemplate.opsForList().leftPush(key, val);33 }34

35 public String rpop(String key) throwsException {36 returnredisTemplate.opsForList().rightPop(key);37 }38

39 }

使用springframework框架中的RedisTemplate类去链接redis，此处是将收到的UDP消息左保存(lpush)至list链表中,然后右边弹出(rpop)。

UdpRepository.java

1 packagecom.example.demo.repository.mysql;2

3 importcom.example.demo.mod.UdpRecord;4 importorg.springframework.data.jpa.repository.JpaRepository;5

6 /**

7 * Created by wj on 2017/8/31.8 */

9 public interface UdpRepository extends JpaRepository{10

11 }

定义Spring Data JPA接口，链接数据库。

其中

UdpRecord.java

1 packagecom.example.demo.mod;2

3 importjavax.persistence.Entity;4 importjavax.persistence.GeneratedValue;5 importjavax.persistence.Id;6 importjavax.persistence.Table;7 importjava.sql.Timestamp;8

9 /**

10 * Created by wj on 2017/8/31.11 *12 * 用来记录接收的UDP消息的日志13 */

14 @Entity15 @Table16 public classUdpRecord {17

18 private longid;19 privateString udpMsg;20 privateTimestamp time;21

22 @Id23 @GeneratedValue24 public longgetId() {25 returnid;26 }27

28 public void setId(longid) {29 this.id =id;30 }31

32 publicString getUdpMsg() {33 returnudpMsg;34 }35

36 public voidsetUdpMsg(String udpMsg) {37 this.udpMsg =udpMsg;38 }39

40 publicTimestamp getTime() {41 returntime;42 }43

44 public voidsetTime(Timestamp time) {45 this.time =time;46 }47 }

注解@Entity和@Table辨明这是一个实体类表格 ，其中的@Id和@GeneratedValue表明id是key值并且是自动递增的。

9)线程池的相关信息

TaskExecutePool.java

1 packagecom.example.demo.thread;2

3 importcom.example.demo.init.SysConfig;4 importorg.springframework.beans.factory.annotation.Autowired;5 importorg.springframework.context.annotation.Bean;6 importorg.springframework.context.annotation.Configuration;7 importorg.springframework.scheduling.annotation.EnableAsync;8 importorg.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;9

10 importjava.util.concurrent.Executor;11 importjava.util.concurrent.ThreadPoolExecutor;12

13 /**

14 * Created by wangjian on 2017/8/29.15 */

16 @Configuration17 @EnableAsync18 public classTaskExecutePool {19

20 @Autowired21 privateSysConfig config;22

23 @Bean24 publicExecutor myTaskAsyncPool() {25 ThreadPoolTaskExecutor executor = newThreadPoolTaskExecutor();26 executor.setCorePoolSize(config.getCorePoolSize());27 executor.setMaxPoolSize(config.getMaxPoolSize());28 executor.setQueueCapacity(config.getQueueCapacity());29 executor.setKeepAliveSeconds(config.getKeepAliveSeconds());30 executor.setThreadNamePrefix("MyExecutor-");31

32 //rejection-policy：当pool已经达到max size的时候，如何处理新任务33 //CALLER_RUNS：不在新线程中执行任务，而是由调用者所在的线程来执行

34 executor.setRejectedExecutionHandler(newThreadPoolExecutor.CallerRunsPolicy());35 executor.initialize();36 returnexecutor;37 }38 }

10)配置文件SysConfig.java

1 packagecom.example.demo.init;2

3 importorg.springframework.boot.context.properties.ConfigurationProperties;4 importorg.springframework.stereotype.Component;5

6 /**

7 * Created by wj on 2017/8/30.8 */

9 @Component10 @ConfigurationProperties(prefix="sysfig")11 public classSysConfig {12 private int UdpReceivePort;//UDP消息接收端口13

14 //线程池信息

15 private intCorePoolSize;16

17 private intMaxPoolSize;18

19 private intKeepAliveSeconds;20

21 private intQueueCapacity;22

23 public intgetCorePoolSize() {24 returnCorePoolSize;25 }26

27 public void setCorePoolSize(intcorePoolSize) {28 CorePoolSize =corePoolSize;29 }30

31 public intgetMaxPoolSize() {32 returnMaxPoolSize;33 }34

35 public void setMaxPoolSize(intmaxPoolSize) {36 MaxPoolSize =maxPoolSize;37 }38

39 public intgetKeepAliveSeconds() {40 returnKeepAliveSeconds;41 }42

43 public void setKeepAliveSeconds(intkeepAliveSeconds) {44 KeepAliveSeconds =keepAliveSeconds;45 }46

47 public intgetQueueCapacity() {48 returnQueueCapacity;49 }50

51 public void setQueueCapacity(intqueueCapacity) {52 QueueCapacity =queueCapacity;53 }54

55 public intgetUdpReceivePort() {56 returnUdpReceivePort;57 }58

59 public void setUdpReceivePort(intudpReceivePort) {60 UdpReceivePort =udpReceivePort;61 }62 }

11)小结

其实发送UDP和接收UDP消息的核心代码很简单，只是netty框架将其包装了。

UDP发送消息是

1 byte[] buffer =...2 InetAddress address = InetAddress.getByName("localhost");3

4 DatagramPacket packet = newDatagramPacket(5 buffer, buffer.length, address, 9999);6 DatagramSocket datagramSocket = newDatagramSocket();7 datagramSocket.send(packet);

udp接收消息是

1 DatagramSocket datagramSocket = new DatagramSocket(9999);2

3 byte[] buffer =....4 DatagramPacket packet = newDatagramPacket(buffer, buffer.length);5

6 datagramSocket.receive(packet);

看起来是不是很简单？？？

12)源代码下载地址

这里只公布了一个框架，其他很多部分由于涉及到了工作内容不便公布。

有需要的同学可以自行下载对其代码进行更改。