我正在编写一个 Java 客户端/服务器应用程序，它将在每个程序之间来回通信 2 个映射。客户端填充初始映射并将其发送到服务器。服务器按预期接收地图并显示数据。然后，服务器构建一个响应映射，并将其返回给客户端。客户端按预期接收地图并显示数据。一切似乎都很好。现在客户端清除并使用更多数据重新填充地图并将地图发送到服务器。服务器按预期接收它，构建并发送响应映射。客户端读取地图的“objectinputstream”，但地图现在为空。客户端清除并使用更多数据重新填充地图，然后再次将地图发送到服务器。服务器似乎收到了地图，但是显示的数据是第二次成功传输时收到的数据，而不是当前数据。谁能阐明这里发生了什么？非常感谢所有帮助！
这是服务器的日志：
- awaiting connection - about to readobject - read this>I-InkjetBadLabel = `Send` - read this>I-LogoPakBadLabel = `Send` - read this>I-InkjetBadLabelAck = `Response` - read this>I-LogoPakBadLabelAck = `Response` - writing this>I-InkjetBadLabel = `Send` - writing this>I-LogoPakBadLabel = `Send` - writing this>I-InkjetBadLabelAck = `Response` - writing this>I-LogoPakBadLabelAck = `Response` - wrote socket - about to readobject - read this>InkjetBadLabel = `False0` - read this>LogoPakBadLabel = `False0` - writing this>InkjetBadLabel = `False0` - writing this>LogoPakBadLabel = `False0` - wrote socket - about to readobject - read this>InkjetBadLabel = `False0` - read this>LogoPakBadLabel = `False0` - writing this>InkjetBadLabel = `False0` - writing this>LogoPakBadLabel = `False0` - wrote socket - about to readobject - read this>InkjetBadLabel = `False0` - read this>LogoPakBadLabel = `False0` - writing this>InkjetBadLabel = `False0` - writing this>LogoPakBadLabel = `False0` - wrote socket - about to readobject - read this>InkjetBadLabel = `False0` - read this>LogoPakBadLabel = `False0` - writing this>InkjetBadLabel = `False0` - writing this>LogoPakBadLabel = `False0` - wrote socket
这是客户的日志：
- PLC_socket. open!! - istream = new ObjectInputStream - ostream = new ObjectOutputStream - sending externalProgramCommInitializeMap - externalProgramCommInitializeMap =>I-InkjetBadLabel = `Send` - externalProgramCommInitializeMap =>I-LogoPakBadLabel = `Send` - externalProgramCommInitializeMap =>I-InkjetBadLabelAck = `Response` - externalProgramCommInitializeMap =>I-LogoPakBadLabelAck = `Response` - ostream.writeObject - istream.readObject() 1 - initialize received externalProgramCommBitMapOutOfPFC response - - externalProgramCommBitMap =>I-InkjetBadLabel = `Send` - externalProgramCommBitMap =>I-LogoPakBadLabel = `Send` - externalProgramCommBitMap =>I-InkjetBadLabelAck = `Response` - externalProgramCommBitMap =>I-LogoPakBadLabelAck = `Response` - xx=0 - externalProgramCommBitMapIntoPFC.clear - externalProgramCommBitMapIntoPFC =>InkjetBadLabel = `False0` - externalProgramCommBitMapIntoPFC =>LogoPakBadLabel = `False0` - writing map! - ostream.flush - done writing - data - istream.readObject() - data - received externalProgramCommBitMapOutOfPFC response - !!!!!! RESPONSE MAP IS EMPTY !!!!!! - xx=1 - externalProgramCommBitMapIntoPFC.clear - externalProgramCommBitMapIntoPFC =>InkjetBadLabel = `False1` - externalProgramCommBitMapIntoPFC =>LogoPakBadLabel = `False1` - writing map! - ostream.flush - done writing - data - istream.readObject() - data - received externalProgramCommBitMapOutOfPFC response - !!!!!! RESPONSE MAP IS EMPTY !!!!!! - xx=2 - externalProgramCommBitMapIntoPFC.clear - externalProgramCommBitMapIntoPFC =>InkjetBadLabel = `False2` - externalProgramCommBitMapIntoPFC =>LogoPakBadLabel = `False2` - writing map! - ostream.flush - done writing - data - istream.readObject() - data - received externalProgramCommBitMapOutOfPFC response - !!!!!! RESPONSE MAP IS EMPTY !!!!!! - xx=3 - externalProgramCommBitMapIntoPFC.clear - externalProgramCommBitMapIntoPFC =>InkjetBadLabel = `False3` - externalProgramCommBitMapIntoPFC =>LogoPakBadLabel = `False3` - writing map! - ostream.flush - done writing - data - istream.readObject() - data - received externalProgramCommBitMapOutOfPFC response - !!!!!! RESPONSE MAP IS EMPTY !!!!!!
这是我的客户程序：
package com.agfa.Verify;
import java.io.*;
import java.net.*;
import java.net.UnknownHostException;
import java.util.*;
import org.apache.log4j.Logger;
public class testVerifyScannedLabels implements Serializable {
private static final long serialVersionUID = 1L;
private final Logger log = Logger.getLogger(testVerifyScannedLabels.class.getSimpleName());
private boolean debugEnabled = false;
private Map<String, String> externalProgramCommBitMapIntoPFC = new LinkedHashMap<String, String>();
private Map<String, String> externalProgramCommBitMapOutOfPFC = new LinkedHashMap<String, String>();
private Socket PLC_socket = null;
private Map<String, String> externalProgramCommInitializeMap = new LinkedHashMap<String, String>();
private ObjectOutputStream ostream = null;
private ObjectInputStream istream = null;
private List<String> errorMessages = new ArrayList<String>();
private void initialize() {
externalProgramCommInitializeMap.put("I-InkjetBadLabel", "Send");
externalProgramCommInitializeMap.put("I-LogoPakBadLabel", "Send");
externalProgramCommInitializeMap.put("I-InkjetBadLabelAck", "Response");
externalProgramCommInitializeMap.put("I-LogoPakBadLabelAck", "Response");
}
public testVerifyScannedLabels() {
initialize();
/***********************************************************************
* sockets client for PLC Communicator
**********************************************************************/
if (PLC_socket == null) {
log.debug("PLC_socket == null");
try {
istream = null;
ostream = null;
PLC_socket = new Socket(InetAddress.getLocalHost(), 60103);
PLC_socket.setKeepAlive(true);
log.debug("PLC_socket opened on port 60103");
} catch (NumberFormatException x) {
log.warn("PLC_CommMapPort-NumberFormatException Exception! " + x.getMessage());
} catch (ConnectException x) {
log.warn("PLC_CommMapPort-Connection Exception! " + x.getMessage());
} catch (UnknownHostException x) {
log.warn("PLC_CommMapPort-UnknownHostException Exception! " + x.getMessage());
} catch (IOException x) {
log.warn("PLC_CommMapPort-IOException Exception! " + x.getMessage());
}
}
if (PLC_socket == null) {
log.error("PLC_socket was not established!");
istream = null;
ostream = null;
} else {
log.debug("PLC_socket not null!!!");
try { // Socket client..
if (PLC_socket.isConnected() && !PLC_socket.isClosed()) {
log.info("PLC_socket. open!!");
if (istream == null) {
log.debug("istream = new ObjectInputStream");
istream = new ObjectInputStream(PLC_socket.getInputStream());
}
if (ostream == null) {
log.debug("ostream = new ObjectOutputStream");
ostream = new ObjectOutputStream(PLC_socket.getOutputStream());
log.debug("sending externalProgramCommInitializeMap");
final Iterator<Map.Entry<String, String>> it = externalProgramCommInitializeMap
.entrySet().iterator();
while (it.hasNext()) {
final Map.Entry<String, String> pairs = it.next();
log.debug("externalProgramCommInitializeMap =>" + pairs.getKey()
+ " = `" + pairs.getValue() + "`");
}
log.debug("ostream.writeObject");
ostream.writeObject(externalProgramCommInitializeMap);
log.debug("istream.readObject() 1 ");
externalProgramCommBitMapOutOfPFC = (Map<String, String>) istream
.readObject();
log.debug(" initialize received externalProgramCommBitMapOutOfPFC response -");
final Iterator<Map.Entry<String, String>> rit = externalProgramCommBitMapOutOfPFC
.entrySet().iterator();
while (rit.hasNext()) {
final Map.Entry<String, String> pairs = rit.next();
log.debug("externalProgramCommBitMap =>" + pairs.getKey() + " = `"
+ pairs.getValue() + "`");
}
}
for (int xx = 0; xx < 100; xx++) { // for testing only
log.debug("xx=" + xx);
log.debug("externalProgramCommBitMapIntoPFC.clear ");
externalProgramCommBitMapIntoPFC.clear();
externalProgramCommBitMapIntoPFC.put("InkjetBadLabel", "False" + xx);
externalProgramCommBitMapIntoPFC.put("LogoPakBadLabel", "False" + xx);
externalProgramCommBitMapOutOfPFC.clear();
for (String line : errorMessages) {
log.info("build externalProgramCommBitMapIntoPFC " + line.toUpperCase());
if (line.toUpperCase().contains("INKJET")) {
log.debug("in ink");
externalProgramCommBitMapIntoPFC.put("InkjetBadLabel", "True" + xx);
}
if (line.toUpperCase().contains("LOGOPAK")) {
log.debug("in logo");
externalProgramCommBitMapIntoPFC
.put("LogoPakBadLabel", "True" + xx);
}
}
final Iterator<Map.Entry<String, String>> wit = externalProgramCommBitMapIntoPFC
.entrySet().iterator();
while (wit.hasNext()) {
final Map.Entry<String, String> pairs = wit.next();
log.debug("externalProgramCommBitMapIntoPFC =>" + pairs.getKey()
+ " = `" + pairs.getValue() + "`");
}
log.debug("writing map!");
ostream.writeObject(externalProgramCommBitMapIntoPFC);
log.debug("ostream.flush");
ostream.flush();
log.debug("done writing");
log.debug("data - istream.readObject() ");
externalProgramCommBitMapOutOfPFC = (Map<String, String>) istream
.readObject();
log.debug("data - received externalProgramCommBitMapOutOfPFC response");
final Iterator<Map.Entry<String, String>> rit = externalProgramCommBitMapOutOfPFC
.entrySet().iterator();
if (rit.hasNext()) {
while (rit.hasNext()) {
final Map.Entry<String, String> pairs = rit.next();
log.debug("externalProgramCommBitMap =>" + pairs.getKey() + " = `"
+ pairs.getValue() + "`");
}
} else
log.debug(" !!!!!! RESPONSE MAP IS EMPTY !!!!!!");
Thread.sleep(4000L);
/**/} // end for testing ..
} else {
log.error("VerifyScannedLabels unable to connect to PLC_Datacomm via Sockets");
}
// end of Socket client
} catch (UnknownHostException e) {
log.error("VerifyScannedLabels unable to connect to PLC_Datacomm via Sockets "
+ e.getMessage());
PLC_socket = null;
} catch (IOException e) {
log.error("VerifyScannedLabels unable to connect to PLC_Datacomm via Sockets "
+ e.getMessage());
PLC_socket = null;
} catch (ClassNotFoundException e) {
log.error("VerifyScannedLabels unable to connect to PLC_Datacomm via Sockets "
+ e.getMessage());
PLC_socket = null;
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if (debugEnabled) {
log.debug("VerifyScannedLabels processing Ends.");
}
try {
Thread.sleep(1000L);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public static void main(String[] args) {
testVerifyScannedLabels vsl = new testVerifyScannedLabels();
}
}
这是我的服务器程序：
package com.agfa.sockets;
import java.net.*;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.io.*;
import org.apache.log4j.Logger;
public class testSocketThreadSendReceiveMap {
private Logger log = Logger.getLogger(testSocketThreadSendReceiveMap.class.getSimpleName());
private ServerSocket ssock = null;
private Socket socket = null;
private ObjectOutputStream ostream = null;
private ObjectInputStream istream = null;
private Map<String, String> dataMapIntoRemote = new LinkedHashMap<String, String>();
private Map<String, String> dataMapFromRemote = new LinkedHashMap<String, String>();
public static void main(String[] args) {
testSocketThreadSendReceiveMap tSTSRM = new testSocketThreadSendReceiveMap();
}
@SuppressWarnings("unchecked")
public testSocketThreadSendReceiveMap() {
try {
log.info("awaiting connection");
ssock = new ServerSocket(60103);
socket = ssock.accept();
ostream = new ObjectOutputStream(socket.getOutputStream());
istream = new ObjectInputStream(socket.getInputStream());
while (true) {
//log.debug("following is for testing - remove from production");
/*
* in real life dataMapIntoRemote will be provided by parent
* Thread
*/
dataMapIntoRemote.clear();
/****** remove above *****/
dataMapFromRemote.clear();
log.debug("about to readobject");
dataMapFromRemote.putAll((Map<String, String>) istream.readObject());
final Iterator<Map.Entry<String, String>> it = dataMapFromRemote.entrySet()
.iterator();
while (it.hasNext()) {
final Map.Entry<String, String> pairs = it.next();
log.debug("read this>" + pairs.getKey() + " = `" + pairs.getValue() + "`");
//log.debug("following is for testing - remove from production");
/*
* in real life dataMapIntoRemote will be provided by
* parent Thread
*/
dataMapIntoRemote.put(pairs.getKey(), pairs.getValue());
/****** remove above *****/
}
final Iterator<Map.Entry<String, String>> wit = dataMapIntoRemote.entrySet()
.iterator();
while (wit.hasNext()) {
final Map.Entry<String, String> pairs = wit.next();
log.debug("writing this>" + pairs.getKey() + " = `" + pairs.getValue() + "`");
}
ostream.writeObject(dataMapIntoRemote);
ostream.flush();
log.debug("wrote socket");
}
} catch (IOException e) {
log.error("SocketThreadSendReceiveMap-While(True).IOException! " + e.getMessage());
} catch (Exception e) {
log.error("SocketThreadSendReceiveMap-While(True).Exception! " + e.getMessage());
}
try {
log.warn("SocketThreadSendReceiveMap.class socket.close");
socket.close();
} catch (IOException e) {
log.error("SocketThreadSendReceiveMap-socket.close().IOException! " + e.getMessage());
}
}
}