如何在java中实现TCP连接池？ [英] How to implement TCP connection pooling in java?
本文介绍了如何在java中实现TCP连接池？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
在这里，我设法在单个服务器和单个客户端之间建立连接，但现在我的新障碍是如何实现 TCP 在客户端在JAVA中的连接。我经历了许多网站，但最终没有找到有效的解决方案。这里是我用来获取连接到服务器的 类
public class TCPIPCommunicator {
private final String MODULE =TCPIPCommunicator：;
//私有DeviceEntity deviceEntity;
private static InetAddress inetServer = null;
private static int devicePort = -1;
private Socket clientSocket;
private BufferedOutputStream outputStream;
private BufferedInputStream inputStream;
private static boolean isLinkActive = false;
private String IP =;
public TCPIPCommunicator（String IP，int devicePort）{
this.IP = IP;
this.devicePort = devicePort;
initialize（）;
}
public static boolean isLinkActive（）{
return isLinkActive;
}
public static void setLinkStatus（boolean status）{
isLinkActive = status;
}
private void initialize（）{
System.out.println（MODULE +Inside initialize（））;
setLinkStatus（false）;
try {
inetServer = InetAddress.getByName（IP）;
} catch（UnknownHostException uhe）{
System.out.println（MODULE +创建inetaddress时出错，原因：+ uhe.getMessage（））;
}
System.out.println（MODULE +Connecting to - + inetServer.getHostAddress（）+：+ devicePort）;
establishConnection（）;
if（！isLinkActive（））{
//sendNotification(TCPIPConstants.LINK_DOWN）;
releaseResources（）;
// resumeLinkSanityHelper（）;
}
System.out.println（MODULE +out of initialize（），isLinkActive：+ isLinkActive（））;
}
public boolean establishConnection（）{
boolean isConnected = false;
//获取到PMS服务器的连接。
if（inetServer！= null&& devicePort> 0）{
try {
clientSocket = new Socket（inetServer，devicePort）;
clientSocket.setKeepAlive（true）;
} catch（ConnectException ce）{
ce.printStackTrace（）;
setLinkStatus（false）;
System.out.println（MODULE +Exception in initialize（）+Couldnot Connect Server。原因：+ ce.getMessage（））;
} catch（异常e）{
e.printStackTrace（）;
setLinkStatus（false）;
System.out.println（MODULE +Exception in initialize（）+while creating socket，Reason：+ e.getMessage（））;
}
//如果有连接，获取流。
if（clientSocket！= null&&！clientSocket.isClosed（））{
System.out.println（MODULE +in initialize（），Got Socket Connection。
try {
outputStream = new BufferedOutputStream（clientSocket.getOutputStream（））;
} catch（Exception e）{
e.printStackTrace（）;
outputStream = null;
setLinkStatus（false）;
System.out.println（MODULE +Exception in initialize（）while getting socket outputStream：+ e.getMessage（））;
}
if（outputStream！= null）{
try {
inputStream = new BufferedInputStream（clientSocket.getInputStream（））;
} catch（Exception e）{
setLinkStatus（false）;
System.out.println（MODULE +Exception in initialize（）+while get socket inputStream：+ e.getMessage（））;
}
setLinkStatus（true）;
}
if（outputStream！= null&& inputStream！= null）{
isConnected = true;
}
} else {
System.out.println（MODULE +in initialize（），Connection is closed or null。
setLinkStatus（false）;
}
}
return isConnected;
}
public int writeData（byte [] msg）{
int retValue = -1;
try {
if（isLinkActive（）&&（outputStream！= null））{
System.out.println（MODULE +Writting data :::+ new String msg）+::::）;
outputStream.write（msg）; // ed
outputStream.flush（）;
retValue = 1;
} else {
System.out.println（MODULE +in writeData（）link is down so status：+ retValue）;
}
} catch（异常e）{
e.printStackTrace（）;
retValue = -1;
System.out.println（MODULE +write（）中的异常要发送的消息为+ new String（msg）+>+ e.getMessage（））;
}
if（retValue == -1& isActive（））{
setLinkStatus（false）;
//sendNotification(TCPIPConstants.LINK_DOWN）;
// releaseResources（）;
// resumeLinkSanityHelper（）;
}
System.out.println（MODULE +in writeData（）Write state for+ new String（msg）+:: - >+ retValue）;
return retValue;
}
public String readData（）{
System.out.println（MODULE +\tInside readDAta）;
String response = null;
int bytesReceived = -1;
byte [] readBuffer = new byte [1024];
try {
long timetoread = System.currentTimeMillis（）;
if（inputStream == null ||！（isLinkActive（）））{
System.out.println（MODULE +Inputstream is null or link is down，returned null）;
return null;
}
try {
System.out.println（Waiting to read data）;
bytesReceived = inputStream.read（readBuffer）;
System.out.println（MODULE +＃Byte Received＃+ bytesReceived）;
} catch（Exception e）{
e.printStackTrace（）;
System.out.println（MODULE +readData（）中出错，原因：+ e.getMessage（））;
if（isLinkActive（））{
setLinkStatus（false）;
//sendNotification(TCPIPConstants.LINK_DOWN）;
releaseResources（）;
// resumeLinkSanityHelper（）;
}
}
if（bytesReceived> 0）{
response = new String（readBuffer，0，bytesReceived）; // ed
timetoread = System.currentTimeMillis（） - timetoread;
System.out.println（MODULE +Total Bytes Received：+ bytesReceived）;
System.out.println（MODULE +Total Time Taken：+ timetoread）;
System.out.println（MODULE +received data data：+ response.length（））;
System.out.println（MODULE +Data Received：####+ response +####）;
} else {
//////////这里意味着TCP连接状态将CLOSE_WAIT
//////////因此释放连接。
System.out.println（MODULE +Releasing Resource，bytesReceived is <= 0：Total Bytes Received：+ bytesReceived）;
if（isLinkActive（））{
setLinkStatus（false）;
//sendNotification(TCPIPConstants.LINK_DOWN）;
releaseResources（）;
// resumeLinkSanityHelper（）;
}
System.out.println（MODULE +Resource has been released。）;
}
} catch（Exception e）{
e.printStackTrace（）;
System.out.println（MODULE +In catch：Data Received：####+ response +####）;
System.out.println（MODULE +readdata（）：+ e）;
} finally {
readBuffer = null;
}
返回响应;
}
public void releaseResources（）{
System.out.println（MODULE +Releasing Resources ....）;
try {
if（clientSocket！= null）
clientSocket.close（）;
} catch（Exception e）{
System.out.println（MODULE +In releaseResources（）：Error closed socket。+ e.getMessage（））;
}
try {
if（inputStream！= null）
inputStream.close（）;
} catch（Exception e）{
System.out.println（MODULE +In releaseResources（）：Error close inputStream。+ e.getMessage（））;
}
try {
if（outputStream！= null）{
outputStream.close（）;
}
} catch（Exception e）{
System.out.println（MODULE +in releaseResources（）：Error close outputStream。
}
System.out.println（MODULE +Resources Relased ...）;
}
}
这里 establishConnection（）方法将建立连接到服务器。
ThreadPoolExecutor 但是因为要求是同步的，所以我放弃了使用它的想法。 解决方案
您可以创建一个变量 Set< Socket& sockets 来存储你创建的所有 clientSocket 。每次连接到服务器套接字时，都可以将客户端
套接字set。因此这个集合作为池。
Here, I managed to get a connection between a single server and single client but now my new hurdle is how to achieve a pool of TCP connections on client side in JAVA. I had gone through many sites but at the end no fruitful solution was found. Here the class which I had used for obtaining connection to a server
public class TCPIPCommunicator {
private final String MODULE="TCPIPCommunicator :";
//private DeviceEntity deviceEntity;
private static InetAddress inetServer = null;
private static int devicePort = -1;
private Socket clientSocket;
private BufferedOutputStream outputStream;
private BufferedInputStream inputStream;
private static boolean isLinkActive = false;
private String IP="";
public TCPIPCommunicator(String IP, int devicePort) {
this.IP=IP;
this.devicePort=devicePort;
initialize();
}
public static boolean isLinkActive(){
return isLinkActive;
}
public static void setLinkStatus(boolean status){
isLinkActive = status;
}
private void initialize() {
System.out.println(MODULE+ "Inside initialize()" );
setLinkStatus(false);
try{
inetServer = InetAddress.getByName(IP);
}catch (UnknownHostException uhe) {
System.out.println(MODULE+ "Error while creating inetaddress, Reason:"+uhe.getMessage());
}
System.out.println(MODULE+ "Connecting to - " +inetServer.getHostAddress() + ":" + devicePort);
establishConnection();
if(!isLinkActive()){
//sendNotification(TCPIPConstants.LINK_DOWN);
releaseResources();
//resumeLinkSanityHelper();
}
System.out.println(MODULE+ "out of initialize(), isLinkActive :" + isLinkActive() );
}
public boolean establishConnection(){
boolean isConnected = false;
//Get the Connection to PMS Server.
if(inetServer != null && devicePort > 0){
try{
clientSocket = new Socket(inetServer, devicePort);
clientSocket.setKeepAlive(true);
}catch(ConnectException ce){
ce.printStackTrace();
setLinkStatus(false);
System.out.println(MODULE+ "Exception in initialize() " + "Couldnot Connect Server. Reason:"+ce.getMessage());
}catch(Exception e){
e.printStackTrace();
setLinkStatus(false);
System.out.println(MODULE+ "Exception in initialize() " + "while creating socket ,Reason: " + e.getMessage());
}
//If got connection, Get the streams.
if(clientSocket != null && !clientSocket.isClosed()){
System.out.println(MODULE+ "in initialize(), Got Socket Connection." );
try{
outputStream = new BufferedOutputStream(clientSocket.getOutputStream());
}catch(Exception e){
e.printStackTrace();
outputStream=null;
setLinkStatus(false);
System.out.println(MODULE+ "Exception in initialize() while getting socket outputStream : " + e.getMessage());
}
if(outputStream != null){
try{
inputStream = new BufferedInputStream(clientSocket.getInputStream());
}catch(Exception e){
setLinkStatus(false);
System.out.println(MODULE+ "Exception in initialize() " + "while getting socket inputStream : " + e.getMessage());
}
setLinkStatus(true);
}
if(outputStream != null && inputStream != null){
isConnected = true;
}
}else{
System.out.println(MODULE+ "in initialize(), Connection is closed or null." );
setLinkStatus(false);
}
}
return isConnected;
}
public int writeData(byte[] msg){
int retValue = -1;
try{
if(isLinkActive() && (outputStream !=null)){
System.out.println(MODULE+ "Writting data ::::" + new String(msg)+ "::::");
outputStream.write(msg);// ed
outputStream.flush();
retValue = 1;
}else{
System.out.println(MODULE+ " in writeData() link is down so status:" + retValue );
}
}catch(Exception e){
e.printStackTrace();
retValue = -1;
System.out.println(MODULE+ "Exception in write() < message to be sent was = " + new String(msg) + " > : " + e.getMessage());
}
if(retValue == -1 && isLinkActive()){
setLinkStatus(false);
//sendNotification(TCPIPConstants.LINK_DOWN);
//releaseResources();
//resumeLinkSanityHelper();
}
System.out.println(MODULE+ " in writeData() Write status for ::"+ new String(msg) + ":: -->" +retValue);
return retValue;
}
public String readData() {
System.out.println(MODULE+"\tInside readDAta");
String response = null;
int bytesReceived=-1;
byte[] readBuffer = new byte[1024];
try{
long timetoread = System.currentTimeMillis();
if(inputStream == null || !(isLinkActive())){
System.out.println(MODULE+"Inputstream is null or link is down, returning null");
return null;
}
try{
System.out.println("Waiting to read data");
bytesReceived = inputStream.read(readBuffer);
System.out.println(MODULE+"# Byte Receieved #" + bytesReceived);
}catch(Exception e){
e.printStackTrace();
System.out.println(MODULE+"Error in readData() , Reason:"+e.getMessage());
if(isLinkActive()){
setLinkStatus(false);
//sendNotification(TCPIPConstants.LINK_DOWN);
releaseResources();
//resumeLinkSanityHelper();
}
}
if(bytesReceived > 0){
response = new String(readBuffer,0,bytesReceived); // ed
timetoread = System.currentTimeMillis() - timetoread;
System.out.println(MODULE + "Total Bytes Received: " + bytesReceived);
System.out.println(MODULE+ "Total Time Taken : " + timetoread);
System.out.println(MODULE+ "Length of data received : " + response.length());
System.out.println(MODULE+ "Data Received : ####" + response + "####");
}else{
////////// HERE MEANS TCP CONNECTION STATUS WILL CLOSE_WAIT
////////// SO RELEASING CONNECTION.
System.out.println(MODULE+ " Releasing Resource. bytesReceived is <= 0 : Total Bytes Received :"+ bytesReceived );
if(isLinkActive()){
setLinkStatus(false);
//sendNotification(TCPIPConstants.LINK_DOWN);
releaseResources();
//resumeLinkSanityHelper();
}
System.out.println(MODULE+ " Resource has been released.");
}
}catch(Exception e){
e.printStackTrace();
System.out.println(MODULE+ "In catch : Data Received : ####" + response + "####");
System.out.println(MODULE+ "Exception in readdata() : " + e);
}finally{
readBuffer=null;
}
return response;
}
public void releaseResources(){
System.out.println(MODULE+ "Releasing Resources....");
try{
if(clientSocket !=null)
clientSocket.close();
}catch(Exception e){
System.out.println(MODULE+ "In releaseResources() :Error closing socket."+e.getMessage());
}
try{
if(inputStream !=null )
inputStream.close();
}catch(Exception e){
System.out.println(MODULE+ "In releaseResources() :Error closing inputStream."+e.getMessage());
}
try{
if(outputStream != null){
outputStream.close();
}
}catch(Exception e){
System.out.println(MODULE+ "in releaseResources() :Error closing outputStream.");
}
System.out.println(MODULE + "Resources Relased...");
}
}
Here establishConnection() method will be establish the connection to the server. Any help would be a tons of help.
Note: I was thinking on using ThreadPoolExecutor but as the requirement is for synchronous so I dropped this idea of using it.
解决方案
You can create a variable Set<Socket> sockets to store all the clientSocket you created.Every time you connect to the server socket, you can put the client
socket into this set.So this set works as the pool.
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