商业源码 java ssm项目 如何在项目启动时 建立一个socket链接。并在项目中可以随时调用
你的问题的重点是项目启动时创建socket，只要socket创建成功就能通过tcp或udp协议进行访问了。如何项目启动时创建可以有2种方法：
创建一个继承了ServletContextListener接口的类，在contextInitialized方法里建立socket server端
新建一个Servlet，并设置<load-on-startup>0</load-on-startup>，在service方法里建立socket server端。
下面是一个简单的通讯实例，进行Server和Client之间的文件传输。。如果是简单的文本传输的话简化掉文本操作的内容即可。。
1服务器端
package sterning;
import javaioBufferedInputStream;
import javaioDataInputStream;
import javaioDataOutputStream;
import javaioFile;
import javaioFileInputStream;
import javanetServerSocket;
import javanetSocket;
public class ServerTest {
int port = 8821;
void start() {
Socket s = null;
try {
ServerSocket ss = new ServerSocket(port);
while (true) {
// 选择进行传输的文件
String filePath = "D:\\librar";
File fi = new File(filePath);
Systemoutprintln("文件长度:" + (int) filength());
// public Socket accept() throws
// IOException侦听并接受到此套接字的连接。此方法在进行连接之前一直阻塞。
s = ssaccept();
Systemoutprintln("建立socket链接");
DataInputStream dis = new DataInputStream(new BufferedInputStream(sgetInputStream()));
disreadByte();
DataInputStream fis = new DataInputStream(new BufferedInputStream(new FileInputStream(filePath)));
DataOutputStream ps = new DataOutputStream(sgetOutputStream());
//将文件名及长度传给客户端。这里要真正适用所有平台，例如中文名的处理，还需要加工，具体可以参见Think In Java 4th里有现成的代码。
pswriteUTF(figetName());
psflush();
pswriteLong((long) filength());
psflush();
int bufferSize = 8192;
byte[] buf = new byte[bufferSize];
while (true) {
int read = 0;
if (fis != null) {
read = fisread(buf);
}
if (read == -1) {
break;
}
pswrite(buf, 0, read);
}
psflush();
// 注意关闭socket链接哦，不然客户端会等待server的数据过来，
// 直到socket超时，导致数据不完整。
fisclose();
sclose();
Systemoutprintln("文件传输完成");
}
} catch (Exception e) {
eprintStackTrace();
}
}
public static void main(String arg[]) {
new ServerTest()start();
}
}
2socket的Util辅助类
package sterning;
import javanet;
import javaio;
public class ClientSocket {
private String ip;
private int port;
private Socket socket = null;
DataOutputStream out = null;
DataInputStream getMessageStream = null;
public ClientSocket(String ip, int port) {
thisip = ip;
thisport = port;
}
/ //
创建socket连接
@throws Exception
exception
/
public void CreateConnection() throws Exception {
try {
socket = new Socket(ip, port);
} catch (Exception e) {
eprintStackTrace();
if (socket != null)
socketclose();
throw e;
} finally {
}
}
public void sendMessage(String sendMessage) throws Exception {
try {
out = new DataOutputStream(socketgetOutputStream());
if (sendMessageequals("Windows")) {
outwriteByte(0x1);
outflush();
return;
}
if (sendMessageequals("Unix")) {
outwriteByte(0x2);
outflush();
return;
}
if (sendMessageequals("Linux")) {
outwriteByte(0x3);
outflush();
} else {
outwriteUTF(sendMessage);
outflush();
}
} catch (Exception e) {
eprintStackTrace();
if (out != null)
outclose();
throw e;
} finally {
}
}
public DataInputStream getMessageStream() throws Exception {
try {
getMessageStream = new DataInputStream(new BufferedInputStream(socketgetInputStream()));
return getMessageStream;
} catch (Exception e) {
eprintStackTrace();
if (getMessageStream != null)
getMessageStreamclose();
throw e;
} finally {
}
}
public void shutDownConnection() {
try {
if (out != null)
outclose();
if (getMessageStream != null)
getMessageStreamclose();
if (socket != null)
socketclose();
} catch (Exception e) {
}
}
}
3客户端
package sterning;
import javaioBufferedOutputStream;
import javaioDataInputStream;
import javaioDataOutputStream;
import javaioFileOutputStream;
public class ClientTest {
private ClientSocket cs = null;
private String ip = "localhost";// 设置成服务器IP
private int port = 8821;
private String sendMessage = "Windwos";
public ClientTest() {
try {
if (createConnection()) {
sendMessage();
getMessage();
}
} catch (Exception ex) {
exprintStackTrace();
}
}
private boolean createConnection() {
cs = new ClientSocket(ip, port);
try {
csCreateConnection();
Systemoutprint("连接服务器成功!" + "\n");
return true;
} catch (Exception e) {
Systemoutprint("连接服务器失败!" + "\n");
return false;
}
}
private void sendMessage() {
if (cs == null)
return;
try {
cssendMessage(sendMessage);
} catch (Exception e) {
Systemoutprint("发送消息失败!" + "\n");
}
}
private void getMessage() {
if (cs == null)
return;
DataInputStream inputStream = null;
try {
inputStream = csgetMessageStream();
} catch (Exception e) {
Systemoutprint("接收消息缓存错误\n");
return;
}
try {
//本地保存路径，文件名会自动从服务器端继承而来。
String savePath = "E:\\";
int bufferSize = 8192;
byte[] buf = new byte[bufferSize];
int passedlen = 0;
long len=0;
savePath += inputStreamreadUTF();
DataOutputStream fileOut = new DataOutputStream(new BufferedOutputStream(newBufferedOutputStream(new FileOutputStream(savePath))));
len = inputStreamreadLong();
Systemoutprintln("文件的长度为:" + len + "\n");
Systemoutprintln("开始接收文件!" + "\n");
while (true) {
int read = 0;
if (inputStream != null) {
read = inputStreamread(buf);
}
passedlen += read;
if (read == -1) {
break;
}
//下面进度条本为图形界面的prograssBar做的，这里如果是打文件，可能会重复打印出一些相同的百分比
Systemoutprintln("文件接收了" + (passedlen 100/ len) + "%\n");
fileOutwrite(buf, 0, read);
}
Systemoutprintln("接收完成，文件存为" + savePath + "\n");
fileOutclose();
} catch (Exception e) {
Systemoutprintln("接收消息错误" + "\n");
return;
}
}
public static void main(String arg[]) {
new ClientTest();
}
}
服务端监听：ServerSocket
server=new
ServerSocket(port);//port：绑定的端口号
Socket
client=serveraccept();//监听端口，一旦取得连接则获得客户端的socket连接对象client
客户端：
Socket
s=new
Socket(ip,port);//要连接的服务器的ip以及端口号
如果正常连接上之后，socket的对象可以获得InputStream和OutputStreame，然后就可以进行通信了
完成通信之后，执行socket对象的close（）方法关闭连接，完成一次完整的socket连接
0条评论