我希望获得端口中正在使用的服务名称。但是，我无法。我要做的是检查是否使用了端口。如果使用它，那么我想获取该端口上的服务详细信息。我怎样才能做到这一点以及我做错了什么？
public int checkPort(int port){
try {
InetAddress inetAddress = InetAddress.getLocalHost();
ss = new Socket(inetAddress.getHostAddress(), port);
if(ss.isBound()) {
System.out.println("Port " + port + " is being used by ");
Process p1 = Runtime.getRuntime().exec("grep -w " + port + " /etc/services");
p1.waitFor();
BufferedReader reader = new BufferedReader(new InputStreamReader(p1.getInputStream()));
String line = reader.readLine();
while(line != null) {
System.out.println(line);
line = reader.readLine();
}
}
ss.close();
} catch (Exception e) {
System.out.println("Port " +port+ " is not being used");
}
return 0;
}
结果
端口139被
使用未使用端口139
答案 0 :(得分：0)
好吧，假设您使用的是Windows（在其他操作系统上可能有所不同），则可能会遇到此异常。
无法运行程序“ grep”：CreateProcess error = 2，系统找不到指定的文件
至少，这就是我得到的。您可能会得到一个完全不同的错误。这里的主要问题是，有一个大的try catch块没有e.printStackTrace()，它捕获了每个异常。这意味着当出现错误时，无法知道原因。
希望这对您有用。具有讽刺意味的是，您不需要套接字即可测试端口上的服务，因此它可能是XY problem。
我在端口上查找服务的解决方案如下。
SocketTester.java
package socket;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.TreeSet;
/**
* An answer for <a href="https://stackoverflow.com/questions/51123167/unable-to-get-service-details-on-port">Unable to get service details on port?</a>
*
* @see <a href="https://stackoverflow.com/questions/51123167/unable-to-get-service-details-on-port">Unable to get service details on port?</a>
* @version 1.0
* @author Dan
*/
public class SocketTester {
/**
* This method checks whether a port is being used by any services.
* It will output any information to the system console.
*
* @param port The port to be checked for any services
*/
public static void checkPort(int port) {
TreeSet<String> pids = null;
List<Service> services = null;
pids = getPIDs(port);
if(pids != null) {
services = getServices(port, pids);
}
listInformation(port, services);
}
/**
* This method checks whether there are any PIDs on the specified port.
* If there are these are then returned.
*
* @param port The port to check for PIDs
* @return It returns a TreeSet containing any found PIDs on the specified port
*/
private static TreeSet<String> getPIDs(int port) {
TreeSet<String> returnVal = new TreeSet<String>();
ProcessBuilder pidProcessBuilder = new ProcessBuilder("cmd.exe", "/C", "netstat -ano | find \"" + port + "\"");
pidProcessBuilder.redirectErrorStream(true);
Process pidProcess = null;
try {
pidProcess = pidProcessBuilder.start();
} catch (IOException e) {
return null;
}
BufferedReader pidProcessOutputReader = new BufferedReader(new InputStreamReader(pidProcess.getInputStream()));
String outputLine = null;
try {
outputLine = pidProcessOutputReader.readLine();
} catch (IOException e) {
return null;
}
while (outputLine != null) {
List<String> outputLineParts = new ArrayList<String>(Arrays.asList(outputLine.split(" ")));
outputLineParts.removeAll(Arrays.asList(""));
//outputLineParts.get(1) is the local address. We don't want a foreign address to accidently be found
//outputLineParts.size() - 1 is the PID
if(outputLineParts.get(1).contains(":" + port) && !returnVal.contains(outputLineParts.get(outputLineParts.size() - 1))) {
returnVal.add(outputLineParts.get(outputLineParts.size() - 1));
}
try {
outputLine = pidProcessOutputReader.readLine();
} catch (IOException e) {
return null;
}
}
try {
pidProcess.waitFor();
} catch (InterruptedException e) {
return null;
}
return returnVal;
}
/**
* This method checks whether there are any services related to the PID.
* If there are these are then returned.
*
* @param port A reference to the PIDs port
* @param pids A list of PIDs found by getPIDs
* @return It returns a List containing any found services on the specified PIDs
*/
private static List<Service> getServices(int port, TreeSet<String> pids) {
List<Service> returnVal = new ArrayList<Service>();
for(String pid : pids) {
ProcessBuilder serviceProcessBuilder = new ProcessBuilder("cmd.exe", "/C", "tasklist /svc /FI \"PID eq " + pid + "\" | find \"" + pid + "\"");
serviceProcessBuilder.redirectErrorStream(true);
Process serviceProcess = null;
try {
serviceProcess = serviceProcessBuilder.start();
} catch (IOException e) {
return null;
}
BufferedReader serviceProcessOutputReader = new BufferedReader(new InputStreamReader(serviceProcess.getInputStream()));
String outputLine = null;
try {
outputLine = serviceProcessOutputReader.readLine();
} catch (IOException e) {
return null;
}
while(outputLine != null) {
List<String> outputLineParts = new ArrayList<String>(Arrays.asList(outputLine.split(" ")));
outputLineParts.removeAll(Arrays.asList(""));
//outputLineParts.get(0) is the service
returnVal.add(new Service(port, pid, outputLineParts.get(0)));
try {
outputLine = serviceProcessOutputReader.readLine();
} catch (IOException e) {
return null;
}
}
try {
serviceProcess.waitFor();
} catch (InterruptedException e) {
return null;
}
}
return returnVal;
}
/**
* This method lists the information found by checkPort
*
* @param port The port that has been checked for services
* @param servicesRunning The services found on the port
*/
private static void listInformation(int port, List<Service> servicesRunning) {
if(servicesRunning != null && servicesRunning.size() != 0) {
System.out.println("The following services are being run on port " + port);
for(Service service : servicesRunning) {
System.out.println("\t" + service.getService());
}
} else {
System.out.println("There are no services being run on port " + port);
}
}
public static void main(String[] args) {
final int portToCheck = 135;
checkPort(portToCheck);
}
}
Sevice.java
package socket;
/**
* An supplementary class to support SocketTester
*
* @see <a href="https://stackoverflow.com/questions/51123167/unable-to-get-service-details-on-port">Unable to get service details on port?</a>
* @version 1.0
* @author Dan
*/
public class Service {
private int port;
private String pid;
private String service;
public Service(int port, String pid, String service) {
this.port = port;
this.pid = pid;
this.service = service;
}
public int getPort() {
return port;
}
public String getPID() {
return pid;
}
public String getService() {
return service;
}
@Override
public String toString() {
return "Service \"" + "\" is being run on port " + port + " and has the PID " + pid;
}
}