我目前正在学习网络,并且需要一些帮助来找出通过UDP从Java程序向C ++程序发送字节数组的最简单方法。以前,我用Java创建了一个非常简单的客户端和服务器程序,并且能够使用Java类DatagramSocket和DatagramPacket在两个java客户端/服务器程序之间发送和接收数据包。
但是现在,我有一个网络模拟器,我需要通过C ++编写,所以我担心它不会识别DatagramSocket和DatagramPacket数据,因为它们是Java类。
如果我有用C ++编写的网络仿真器的主机名和监听UDP端口,我该如何用Java发送字节数组呢?
答案 0 :(得分:2)
您对Java类无法识别的担心是错误的,因为当您编写UDP数据包时,您说的是不同的API(UDP是network protocol)。您不是序列化 Java对象。
下面是一个工作示例,Java客户端将UDP数据包发送到PureData(即非Java)服务器(来自codesounding):
package codesounding;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
/*
Every instruction type triggers an UDP message, each on different ports:
Variable declaration: 7001
Start block ({): 7002
End block (}): 7003
break: 7004
continue: 7005
do: 7006
for: 7007
if: 7008
return: 7009
throw: 7010
while: 7011
*/
public class UDPProcessor extends SilentProcessor {
private static final String TARGET = "target"; //target host name
private final DatagramPacket packetVar;
private final DatagramPacket packetStart;
private final DatagramPacket packetEnd;
private final DatagramPacket packetBreak;
private final DatagramPacket packetContinue;
private final DatagramPacket packetDo;
private final DatagramPacket packetFor;
private final DatagramPacket packetIf;
private final DatagramPacket packetReturn;
private final DatagramPacket packetThrow;
private final DatagramPacket packetWhile;
final DatagramSocket socket;
final byte[] signal = "1;\n".getBytes(); //this message will trigger both PureData and MaxMSP UDP receivers; see the example patches
public UDPProcessor() {
try {
String target = "127.0.0.1";
if (System.getProperty(TARGET) != null && !System.getProperty(TARGET).equals("")) {
target = System.getProperty(TARGET);
}
System.out.println("Sending to "+target+"...");
socket = new DatagramSocket();
InetAddress address = InetAddress.getByName(target);
packetVar = new DatagramPacket(signal, signal.length, address, 7001);
packetStart = new DatagramPacket(signal, signal.length, address, 7002);
packetEnd = new DatagramPacket(signal, signal.length, address, 7003);
packetBreak = new DatagramPacket(signal, signal.length, address, 7004);
packetContinue = new DatagramPacket(signal, signal.length, address, 7005);
packetDo = new DatagramPacket(signal, signal.length, address, 7006);
packetFor = new DatagramPacket(signal, signal.length, address, 7007);
packetIf = new DatagramPacket(signal, signal.length, address, 7008);
packetReturn = new DatagramPacket(signal, signal.length, address, 7009);
packetThrow = new DatagramPacket(signal, signal.length, address, 7010);
packetWhile = new DatagramPacket(signal, signal.length, address, 7011);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
private synchronized void send(DatagramPacket packet) {
try {
socket.send(packet);
} catch (IOException e) {
e.printStackTrace();
//skipping
}
}
public void getVarDeclaration() {
send(packetVar);
}
public void getStartBlock() {
send(packetStart);
}
public void getEndBlock() {
send(packetEnd);
}
public void getIfStatement() {
send(packetIf);
}
public void getForStatement() {
send(packetFor);
}
public void getDoStatement() {
send(packetDo);
}
public void getWhileStatement() {
send(packetWhile);
}
public void getReturnStatement() {
send(packetReturn);
}
public void getBreakStatement() {
send(packetBreak);
}
public void getContinueStatement() {
send(packetContinue);
}
public void getThrowStatement() {
send(packetThrow);
}
}