rpc

网络编程

♀尐吖头ヾ 提交于 2019-12-20 04:01:57
概述 通过通信线路(有线或无线)可以把不同地理位置且相互独立的计算机连同其外部设备连接起来,组成计算机网络。在操作系统、网络管理软件及网络通信协议的管理和协调下,可以实现计算机之间的资源共享和信息的传递。 网络编程是指用来实现网络互联的不同计算机上运行的程序间可以进行数据交换。对我们来说即如何用编程语言 java 实现计算机网络中不同计算机之间的通信。 1.网络通信三要素 IP地址 网络中计算机的唯一标识; 32bit(4 字节),一般用“点分十进制”表示,如 192.168.1.158; IP 地址=网络地址+主机地址 可分类: A 类:第 1 个 8 位表示网络地址。剩下的 3 个 8 位表示主机地址 (主要留给ZF或者大型企业) B 类:前 2 个 8 位表示网络地址。剩下的 2 个 8 位表示主机地址 (主要分配给中等规模的公司) C 类:前 3 个 8 位表示网络地址。剩下的 1 个 8 位表示主机地址 (分配给小公司或者个人) D 类地址用于在 IP 网络中的组播 E 类地址保留作研究之用。 Java 编程中可使用 InetAddress 类来操纵 IP 地址 public static void main(String[] args) throws UnknownHostException { InetAddress localHost = InetAddress

Loadrunner如何监控Linux系统资源

时间秒杀一切 提交于 2019-12-19 19:17:38
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> Linux 查看连接数: netstat -tn | grep 126 | awk '/^tcp/{++state[$NF]} END {for(key in state) print key ,"t", state[key]}' 一 简述:LoadRunner监控Linux资源时弹出如下错误:   Monitor name :UNIX Resources. Cannot initialize the monitoring on 192.168.52.189. Error while creating the RPC client. Ensure that the machine can be connected and that it runs the rstat daemon (use rpcinfo utility for this verification). Detailed error: RPC: Failed to create RPC client. RPC-TCP: Failed to establish RPC server address.   上述问题的实质是Linux系统中未安装rpc.rstatd,服务未开启的原因造成。 首先查看rpc.rstatd是否安装 [root

dubbo和springcloud的区别

非 Y 不嫁゛ 提交于 2019-12-18 20:34:00
dubbo和springcloud的区别 1)springcloud 相对来说更加完善一点。因为都是已经集成的,但是也不代表dubbo就不完善,需要另外整合进来 2)springcloud相对来说不用引入那么多组件,大部分都是java开发的,直接运行即可。 3)从通信方面来说,采用的协议不同,dubbo采用的是RPC的方式,springcloud采用的基于http的REST方式。 dubbo采用的是 RMI 协议 springcloud 采用的是 http 协议 RPC(Remote Procedure Call)远程过程调用,是一种技术思想,客户端需要把方法的参数以二进制的方式传给远程的方法调用,远程的方法执行之后返回结果给客户端。 4)springcloud的发展更好,更有前景。毕竟是spring系列的。 5)定位不同 Dubbo的定位始终是一款RPC框架, Spring Cloud的目的是微服务架构下的一站式解决方案。 来源: CSDN 作者: 我是全村最靓的仔 链接: https://blog.csdn.net/xyb0926/article/details/103603725

WMI The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)

*爱你&永不变心* 提交于 2019-12-18 16:57:44
问题 My application requirement is like below. Application will run on domain admin system which will ping all machine under that domain, it will take disk drive, CPU and RAM details from all domain systems. Whenever I'm trying to ping machine I'm getting error that "The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)" Code I'm using to connect remote machine is ConnectionOptions options = new ConnectionOptions(); options.EnablePrivileges = true; options.Impersonation =

Log all network interactions of Java application

百般思念 提交于 2019-12-18 14:15:41
问题 I have a monstrous Java app (a client of little-known application server GNUEnterprise) and its source, which I can compile back after making some changes to it. The app uses network heavily and I need to monitor each request and response. I could use a sniffer like Wireshark, but the application works with its server over SSL, so not knowing SSL-certificate's private key any sniffed traffic is pretty useless. What can I do to make every request and response to be logged from the application

How many Datastore reads consume each Fetch, Count and Query operations?

我与影子孤独终老i 提交于 2019-12-18 11:08:27
问题 I'm reading on Google App Engine groups many users (Fig1, Fig2, Fig3) that can't figure out where the high number of Datastore reads in their billing reports come from. As you might know, Datastore reads are capped to 50K operations/day, above this budget you have to pay. 50K operations sounds like a lot of resources, but unluckily, it seems that each operation (Query, Entity fetch, Count..), hides several Datastore reads. Is it possible to know via API or some other approach, how many

How can I call a GWT RPC method on a server from a non GWT (but Java) gapplication?

一笑奈何 提交于 2019-12-18 10:45:08
问题 I have a regular Java application and want to access an GWT RPC endpoint. Any idea how to make this happen? My GWT application is on a GAE/J and I could use REST for example but I already have the GWT RPC endpoints and don't want to build another façade. Yes, I have seen Invoke a GWT RPC service from Java directly, but this discussion goes into a different direction. 回答1: GWT SyncProxy allows you to access GWT RPC services (e.g methods) from pure Java (not JSNI) code. See http://www.gdevelop

Google Web Toolkit (GWT) + Google App Engine (GAE) + Detached Data Persistence

五迷三道 提交于 2019-12-18 10:16:24
问题 I would like to develop a web-app requiring data persistence using GWT and GAE. As I understand it, my only (or at least by far the most convenient) option for data persistence is GAE's Datastore, using JDO or JPA annotated objects. I would also like to be able to send my objects back and forth client-server using GWT Remote Procedure Calls (RPC), therefore my objects must be able to "detach". However, GWT RPC serialization cannot handle detached JDO/JPA objects and it doesn't appear as

ClassFormatError: 56 while using hessian in j2me

浪尽此生 提交于 2019-12-18 09:07:14
问题 I am trying to use the hessian j2me implementation @ http://hessian.caucho.com/ using java me sdk 3.0. http://hessian.caucho.com/doc/hessian-overview.xtp#Hessian%20Client%20for%20a%20cell-phone mentions the usage for j2me. The application builds without any errors/warning. But, the moment the line where MicroHessianOutput is instantiated is hit, a ClassFormatError ( java.lang.Error: ClassFormatError: 56 ) is thrown. Heres the trace : TRACE: <at java.lang.Error: ClassFormatError: 56>, startApp

GWT Simple RPC use case problem : Code included

旧时模样 提交于 2019-12-18 04:54:30
问题 I am trying to work out how to send a domain object from the server-side to the client-side using GWT RPC. I've coded a really simple use case that represents the sort of thing I (and others?) need to be able to do but presently can't get to work. I have scoured the docs, tutorials and forums but they either show Strings being passed around or offer explanations that (when I apply them to this) still don't work. Hopefully someone can explain to me and others why this code doesn't work and how