WebSocket 获取客户端的IP

今天用到websocket,希望服务器端在连接建立时获取到客户端的IP,看了源码没有找到提供的api,后来一顿百度,在stackoverflow 找到了解决方案,经过测试可以使用,总结了一下, 下边是代码:

import java.lang.reflect.Field;
import java.net.InetSocketAddress;
import javax.websocket.RemoteEndpoint.Async;
import javax.websocket.Session;
public class WebsocketUtil {
	public static InetSocketAddress getRemoteAddress(Session session) {
		if (session == null) {
			return null;
		}
		Async async = session.getAsyncRemote();
		//在Tomcat 8.0.x版本有效
//		InetSocketAddress addr = (InetSocketAddress) getFieldInstance(async,"base#sos#socketWrapper#socket#sc#remoteAddress");
		//在Tomcat 8.5以上版本有效
		InetSocketAddress addr = (InetSocketAddress) getFieldInstance(async,"base#socketWrapper#socket#sc#remoteAddress");
		return addr;
	}
	private static Object getFieldInstance(Object obj, String fieldPath) {
		String fields[] = fieldPath.split("#");
		for (String field : fields) {
			obj = getField(obj, obj.getClass(), field);
			if (obj == null) {
				return null;
			}
		}
		return obj;
	}
	private static Object getField(Object obj, Class<?> clazz, String fieldName) {
		for (; clazz != Object.class; clazz = clazz.getSuperclass()) {
			try {
				Field field;
				field = clazz.getDeclaredField(fieldName);
				field.setAccessible(true);
				return field.get(obj);
			} catch (Exception e) {
			}
		}
		return null;
	}
}

调用测试:

    /**
     * 连接建立成功调用的方法*/
    @OnOpen
    public void onOpen(Session session) {
    	InetSocketAddress remoteAddress = WebsocketUtil.getRemoteAddress(session);
        System.out.println("有新连接加入！" + remoteAddress);    	
    }

输出结果: