我用 Java 编写 UDP 服务器和客户端,以将消息从客户端发送到服务器。就我而言,来自客户端的每条消息都将存储在数据库中。我尝试使用固定线程池制作多线程 UDP 服务器。但是现在我遇到了一个问题,我发现来自客户端的一条消息可以由多个线程处理。我的服务器看起来像这样:
DatagramSocket serverSocket = new DatagramSocket(9876);
Map<String, Integer> retryMap = new ConcurrentHashMap<>();
byte[] receiveData = new byte[1024];
ExecutorService executor = Executors.newFixedThreadPool(2);
while(true){
DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);
serverSocket.receive(receivePacket);
executor.execute(new ThreadServer(receivePacket, retryMap));
}
线程服务器类:
public void run(){
String temp = new String(packet.getData(), 0, packet.getLength());
long threadId = Thread.currentThread().getId();
System.out.println("Thread Id = "+threadId+" Message = "+temp);
// insert message to db
}
我的客户看起来像这样:
public class UDPClient1{
String message;
public UDPClient1(String message){
this.message = message;
try{
byte[] sendData;
DatagramSocket clientSocket = new DatagramSocket();
InetAddress IPAddress = InetAddress.getByName("localhost");
sendData = message.getBytes("UTF-8");
DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, IPAddress, 9876);
clientSocket.send(sendPacket);
clientSocket.close();
}catch(Exception e){
e.printStackTrace();
}
}
public static void main(String args[]) throws InterruptedException{
int i = 0;
while(i < 1000){
new UDPClient1("T000"+i+"_"+i);
System.out.println(i);
i++;
Thread.sleep(2);
}
}}
服务器的输出显示有时来自客户端的一条消息将由 2 个线程或更多线程处理。
Thread Id = 18 Routing Id = T000975 09:54:11,759 ERROR LogRoutingFileDaoImpl:59 - AMS - Error insert to database org.springframework.dao.DuplicateKeyException: PreparedStatementCallback; SQL [INSERT INTO LOG_ROUTING_FILE (ID_ROUTING_FILE, FILE_NM , PATH, TYPES, PROTOCOL, SOURCE_NM, TARGET_NM) VALUES (?,?,?,?,?,?,?)]; ERROR: duplicate key value violates unique constraint "log_routing_file_id_routing_file_key"; nested exception is org.postgresql.util.PSQLException: ERROR: duplicate key value violates unique constraint "log_routing_file_id_routing_file_key"
Thread Id = 9 Routing Id = T000975 09:54:11,759 ERROR LogRoutingFileDaoImpl:59 - AMS - Error insert to database org.springframework.dao.DuplicateKeyException: PreparedStatementCallback; SQL [INSERT INTO LOG_ROUTING_FILE (ID_ROUTING_FILE, FILE_NM , PATH, TYPES, PROTOCOL, SOURCE_NM, TARGET_NM) VALUES (?,?,?,?,?,?,?)]; ERROR: duplicate key value violates unique constraint "log_routing_file_id_routing_file_key"; nested exception is org.postgresql.util.PSQLException: ERROR: duplicate key value violates unique constraint "log_routing_file_id_routing_file_key"
消息 T000975 由线程 9 和 18 处理。谁能帮我解决这个问题?:)