javaclient

❶ 用java 写出一个Server 和Client 能实现Client发送的消息显示在服务端上，Server发送的信息显示在客户端上

你好！
我写的很简单，你可以在此基础上完善，好了，废话不多说，直入正题。
首先，建立一个项目名为TestChat，然后建两个包，分别为server和client。
server包下建立一个类为Server，一个类为ServerListen。
client包建立一个类Client，一个类为ClentListen。
由于我时间仓促，你自行参考哈。

***********************************************************************

/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/

/*
* Server.java
*
* Created on 2011-5-8, 16:37:13
*/

package server;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
*
* @author Study
*/
public class Server extends javax.swing.JFrame {

/** Creates new form Server */
public Server() {
initComponents();
try {
ss = new ServerSocket(8888);
s = ss.accept();
in = new ObjectInputStream(getS().getInputStream());
out = new ObjectOutputStream(getS().getOutputStream());
this.startListen();
} catch (IOException ex) {
Logger.getLogger(Server.class.getName()).log(Level.SEVERE, null, ex);
}
}

/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {

jScrollPane1 = new javax.swing.JScrollPane();
messageShow = new javax.swing.JTextArea();
messageInput = new javax.swing.JTextField();
sendBtn = new javax.swing.JButton();

setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("服务器");

messageShow.setColumns(20);
messageShow.setEditable(false);
messageShow.setRows(5);
jScrollPane1.setViewportView(messageShow);

sendBtn.setText("发送");
sendBtn.addMouseListener(new java.awt.event.MouseAdapter() {
public void mousePressed(java.awt.event.MouseEvent evt) {
sendBtnMousePressed(evt);
}
});

javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 400, Short.MAX_VALUE)
.addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 400, Short.MAX_VALUE)
.addComponent(messageInput, javax.swing.GroupLayout.DEFAULT_SIZE, 400, Short.MAX_VALUE)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap(333, Short.MAX_VALUE)
.addComponent(sendBtn)
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 300, Short.MAX_VALUE)
.addGroup(layout.createSequentialGroup()
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 201, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(messageInput, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(sendBtn)
.addContainerGap(19, Short.MAX_VALUE))
);

pack();
}// </editor-fold>

private void sendBtnMousePressed(java.awt.event.MouseEvent evt) {
this.sendMessage();
this.messageInput.setText("");
}

/**
* @param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Server().setVisible(true);
}
});
}

// Variables declaration - do not modify
protected javax.swing.JScrollPane jScrollPane1;
protected javax.swing.JTextField messageInput;
protected javax.swing.JTextArea messageShow;
protected javax.swing.JButton sendBtn;
// End of variables declaration

private ServerSocket ss;
private Socket s;
private ObjectOutputStream out;
private ObjectInputStream in;

private void startListen() {
ServerListen listen = new ServerListen(this);
Thread t = new Thread(listen);
t.start();
}

/**
* @return the s
*/
public Socket getS() {
return s;
}

/**
* @return the out
*/
public ObjectOutputStream getOut() {
return out;
}

/**
* @return the in
*/
public ObjectInputStream getIn() {
return in;
}

/**
* @return the messageShow
*/
public javax.swing.JTextArea getMessageShow() {
return messageShow;
}

private void sendMessage() {
try {
out.writeObject("服务器说");
out.flush();
out.writeObject(this.messageInput.getText().trim());
out.flush();
} catch (IOException ex) {
Logger.getLogger(Server.class.getName()).log(Level.SEVERE, null, ex);
}
}

}

❷ java怎么创建hivemetastoreclient

下面就来解释下系统是如何生成meta client的！

先来看几段代码！

publicvoidcreateDatabase(Databasedb,booleanifNotExist)throwsAlreadyExistsException,HiveException{

try{

getMSC().createDatabase(db);

}catch(AlreadyExistsExceptione){

if(!ifNotExist){

throwe;

}

}catch(Exceptione){

thrownewHiveException(e);

}

}

=========

privateIMetaStoreClientgetMSC()throwsMetaException{

if(metaStoreClient==null){

metaStoreClient=createMetaStoreClient();

}

returnmetaStoreClient;

}

=========

()throwsMetaException{

HiveMetaHookLoaderhookLoader=newHiveMetaHookLoader(){

publicHiveMetaHookgetHook(org.apache.hadoop.hive.metastore.api.Tabletbl)throwsMetaException{

try{

if(tbl==null){

returnnull;

}

=HiveUtils.getStorageHandler(conf,

tbl.getParameters().get(META_TABLE_STORAGE));

if(storageHandler==null){

returnnull;

}

returnstorageHandler.getMetaHook();

}catch(HiveExceptionex){

LOG.error(StringUtils.stringifyException(ex));

thrownewMetaException("Failedtoloadstoragehandler:"+ex.getMessage());

}

}

};

returnnewHiveMetaStoreClient(conf,hookLoader);

}

=========

publicHiveMetaStoreClient(HiveConfconf,HiveMetaHookLoaderhookLoader)

throwsMetaException{

this.hookLoader=hookLoader;

if(conf==null){

conf=newHiveConf(HiveMetaStoreClient.class);

}

this.conf=conf;

localMetaStore=conf.getBoolVar(ConfVars.METASTORE_MODE);

if(localMetaStore){

//

//throughthenetwork

client=newHiveMetaStore.HMSHandler("hiveclient",conf);

isConnected=true;

return;

}

//getthenumberretries

retries=HiveConf.getIntVar(conf,HiveConf.ConfVars.METASTORETHRIFTRETRIES);

retryDelaySeconds=conf.getIntVar(ConfVars.METASTORE_CLIENT_CONNECT_RETRY_DELAY);

//

if(conf.getVar(HiveConf.ConfVars.METASTOREURIS)!=null){

StringmetastoreUrisString[]=conf.getVar(

HiveConf.ConfVars.METASTOREURIS).split(",");

metastoreUris=newURI[metastoreUrisString.length];

try{

inti=0;

for(Strings:metastoreUrisString){

URItmpUri=newURI(s);

if(tmpUri.getScheme()==null){

("URI:"+s

+"doesnothaveascheme");

}

metastoreUris[i++]=tmpUri;

}

}catch(IllegalArgumentExceptione){

throw(e);

}catch(Exceptione){

MetaStoreUtils.logAndThrowMetaException(e);

}

}elseif(conf.getVar(HiveConf.ConfVars.METASTOREDIRECTORY)!=null){

metastoreUris=newURI[1];

try{

metastoreUris[0]=newURI(conf

.getVar(HiveConf.ConfVars.METASTOREDIRECTORY));

}catch(URISyntaxExceptione){

MetaStoreUtils.logAndThrowMetaException(e);

}

}else{

LOG.error("NOTgettingurisfromconf");

thrownewMetaException("");

}

//finallyopenthestore

open();

}

下面要认真分析下上面的这段代码，因为关联到一些参数的配置，对于理解生产环境的部署参数有帮助！先看下面这段代码

localMetaStore=conf.getBoolVar(ConfVars.METASTORE_MODE);

if(localMetaStore){

//

//connecting

//throughthenetwork

client=newHiveMetaStore.HMSHandler("hiveclient",conf);

isConnected=true;

return;

}

PS:ConfVars.METASTORE_MODE---METASTORE_MODE("hive.metastore.local",true),

❸ 有关java client——server 间传送文件的问题，本想通过server把client1 发来的信息传送给client2

client必须保持长连接，
简单说，你的client和server之间的连接是不能断开的，你每次启动client都是内直接尝试读取然后断掉链接容的话，
c1在传输文件的时候，c2的连接已经断掉了，server还如何和c2之间通讯呢？

❹ 求问 java中 client 和 implementer分别是什么 区别是什么谢谢

client? 这不是客户端吗？

在java中基于b/s架构的 client是浏览器
而基于 c/s 和三层 c/s 的 client是由程序员自己专门开发的一个软件，用于支持业务的显示(给用户用的界面，他可以用别的语言来编写 如 java ， c,c++等)

implementer?没见过
implement 接口
接口就是定义了一系列的方法，接口不能直接实例化，只能被实现
接口我举个例子，就像电脑 有 usb接口 你可以插 USB键盘，然后通过键盘来控制电脑

如:

public interface EmployeeDAO

{//这个是接口的定义，你懂的
public List<Employee> findAll() throws Exception;
public void delete(int id) throws Exception ;
public void save(Employee e) throws Exception ;
public Employee findById(int id) throws Exception;
public void modify(Employee e) throws Exception;
}

public class EmployeeJDBCImpl implements EmployeeDAO

{//这是实现接口，里面要不接口中定义的方法全都写出来，这里我就写一个啊throws 这是抛出异常，你可以不写的，前提是定义接口时的方法别写throws Exception
public List<Employee> findAll() throws Exception
{
return null;

}

public class ActionServlet extends HttpServlet {
public void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException

{
// EmployeeDAO = (EmployeeDAO) Factor.getInstance("EmployeeDAO"); 这个不用管
EmployeeDAO = (EmployeeDAO) new EmployeeJDBCImpl();//这个你懂的
List<Employee> employees = .findAll();
}//这个方法可以不写的，我这是把我自己的工程拷贝过来的

}