用于查找实际客户端IP地址的Java套接字

我正在尝试使用Java小程序获取真正的客户端IP地址。我希望最终在PHP脚本中使用它，以帮助实现安全性和身份验证。所有的PHP方法都无法工作，因为各种HTTP头都不可用，并且很容易被欺骗

因此，我采用了和中建议的方法

但是，我无法编译我的简单小程序。我是Java新手，所以有点困惑

代码是：

import java.net.*;
import java.io.*;

public class SimpleSocketClient
{
    public SimpleSocketClient()
    {
        try
        {
            Socket socket = new Socket("89.185.150.131", 80);
        }
        catch(Exception exc)
        {
            System.out.println("Error in initialising the network - " + exc.toString());
        }

        InetAddress addr = socket.getLocalAddress();
        String hostAddr = addr.getHostAddress();
        System.out.println("Addr: " + hostAddr);

    }

}

编译时，出现以下错误：

C:\mba>javac SimpleSocketClient.java
SimpleSocketClient.java:18: cannot find symbol
symbol  : variable socket
location: class SimpleSocketClient
        InetAddress addr = socket.getLocalAddress();
                           ^
1 error

C:\mba>

---

谢谢

您的

套接字

变量在

try

块内声明，因此在该块外无法访问。您可以通过将所有代码按入

try

来进行轻微更改：

public SimpleSocketClient()
{
    try
    {
        Socket socket = new Socket("89.185.150.131", 80);

        InetAddress addr = socket.getLocalAddress();
        String hostAddr = addr.getHostAddress();
        System.out.println("Addr: " + hostAddr);
    }
    catch(Exception exc)
    {
        System.out.println("Error in initialising the network - " + exc.toString());
    }
}

public SimpleSocketClient()
{
    Socket socket = null;
    try
    {
        socket = new Socket("89.185.150.131", 80);
    }
    catch(Exception exc)
    {
        System.out.println("Error in initialising the network - " + exc.toString());
    }
    if(socket != null) {
        InetAddress addr = socket.getLocalAddress();
        String hostAddr = addr.getHostAddress();
        System.out.println("Addr: " + hostAddr);
    }
}

或者通过在

try

之外声明

套接字

：

public SimpleSocketClient()
{
    try
    {
        Socket socket = new Socket("89.185.150.131", 80);

        InetAddress addr = socket.getLocalAddress();
        String hostAddr = addr.getHostAddress();
        System.out.println("Addr: " + hostAddr);
    }
    catch(Exception exc)
    {
        System.out.println("Error in initialising the network - " + exc.toString());
    }
}

public SimpleSocketClient()
{
    Socket socket = null;
    try
    {
        socket = new Socket("89.185.150.131", 80);
    }
    catch(Exception exc)
    {
        System.out.println("Error in initialising the network - " + exc.toString());
    }
    if(socket != null) {
        InetAddress addr = socket.getLocalAddress();
        String hostAddr = addr.getHostAddress();
        System.out.println("Addr: " + hostAddr);
    }
}

---

“我正在尝试使用Java小程序获取真正的客户端IP地址。”为什么？答案是正确的-我强烈建议您接受它。