java以太坊客户端配置

⑴ java写的客户端怎么和服务器端通信

写个简单点的服务器跟客服端就行了我写了个很简单的，只能在一个客户端跟一个服务器通信，在控制台输入下面这个是服务器import java.io.*;
import java.net.*;
import java.util.Scanner;public class Server
{
public static void main(String[] args)
{
try {
ServerSocket server=new ServerSocket(8888);//定义客户端的端口号
Socket client=server.accept();//定义一个Socket对象

InputStream is=client.getInputStream();//服务器接受信息输入流，也就是接受从服务器段发送过来的消息
BufferedReader br=new BufferedReader(new InputStreamReader(is));//用bufferedreader包装下输入流

OutputStream os=client.getOutputStream();//这是用来给服务器发送消息的输出流
PrintStream ps=new PrintStream(os);
Scanner scanner=new Scanner(System.in);//从键盘输入字符串

boolean flag=true;//定义一个死循环，让服务器不停的接受从客户端发送来的字符串
while(flag)
{
String s=br.readLine();//s是从客户端接受到得字符串
System.out.println(s);

String s2=scanner.nextLine();//s2是写给客户端的字符串
ps.println(s2); //给客户端发送你写的东西
}
client.close();
} catch (IOException e) {//try 跟catch你不用管，这是用来处理异常的，就是固定格式

e.printStackTrace();
}
}
} 下面是客户端import java.io.*;
import java.net.*;
import java.util.Scanner;public class Client
{ public static void main(String[] args)
{
try
{
Socket client=new Socket("192.168.--.--",8888);//IP地址是个字符串，端口号是个整数，这个端口号要跟前面你写的那个一样，还有IP地址，写你的机器的IP地址

InputStream is=client.getInputStream();//这边的两个流跟上面服务器的差不多的作用
BufferedReader bf=new BufferedReader(new InputStreamReader(is));

OutputStream os=client.getOutputStream();
PrintStream ps=new PrintStream(os);
Scanner scanner=new Scanner(System.in);
boolean flag=true;
while(flag)//这句话可以让客户端不停的说话

⑵ 用java代码实现客户端与服务端建立连接

套接字 Socket

import java.net.*;

Server:
ServerSocket server=new ServerSocket(port);//port是端口
Socket socket=server.accept();
//等待客户机的连接请求，若连接，则创建一套接字，并将返回。

Client:
Socket socket=new Socket("host",port);//host主机名（本机：127.0.0.1）

⑶ 我用Java代码编写的一个客户端界面Client.java，我在编写个登录界面Login.java后，

mport java.awt.HeadlessException;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import javax.swing.ImageIcon;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JOptionPane;import javax.swing.JPanel;import javax.swing.JPasswordField;import javax.swing.JTextField;@SuppressWarnings("serial")public class MainFrame extends JFrame {JLabel lbl1 = new JLabel("用户名:");JLabel lbl2 = new JLabel("密 码:");JTextField txt = new JTextField("admin",20);JPasswordField pwd = new JPasswordField(20);JButton btn = new JButton("登录");JPanel pnl = new JPanel();private int error = 0;public MainFrame(String title) throws HeadlessException {super(title);init();}private void init() {this.setResizable(false);pwd.setEchoChar('*');pnl.add(lbl1);pnl.add(txt);pnl.add(lbl2);pnl.add(pwd);pnl.add(btn);this.getContentPane().add(pnl);btn.addActionListener(new ActionListener() {@Overridepublic void actionPerformed(ActionEvent e) {if ("admin".equals(new String(pwd.getPassword()))){pnl.removeAll();JLabel lbl3 = new JLabel();ImageIcon icon = new ImageIcon(this.getClass().getResource("pic.jpg"));lbl3.setIcon(icon);pnl.add(lbl3);}else{if(error < 3){JOptionPane.showMessageDialog(null,"密码输入错误，请再试一次");error++;}else{JOptionPane.showMessageDialog(null,"对不起，您不是合法用户");txt.setEnabled(false);pwd.setEnabled(false);btn.setEnabled(false);}}}});}public static void main(String[] args) {MainFrame frm = new MainFrame("测试");frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);frm.setBounds(100, 100, 300, 120);frm.setVisible(true);}}

⑷ 用Java 的socket实现客户端的功能

//服务端程序：
importjava.io.*;
importjava.net.*;

publicclassTCPServer{
publicstaticvoidmain(String[]args)throwsIOException{
newTCPServer().init();
}
@SuppressWarnings("static-access")
privatevoidinit()throwsIOException{
@SuppressWarnings("resource")
ServerSocketserver=newServerSocket(1000);
Socketclient=null;
while(true){
try{
client=server.accept();
BufferedInputStreambis=newBufferedInputStream(client.getInputStream());
byte[]b=newbyte[1024];
intlen=0;
Stringmessage="";
while((len=bis.read(b))!=-1){
message=newString(b,0,len);
System.out.print("客户端："+client.getInetAddress().getLocalHost().getHostAddress()+"发来消息："+message);
if("byte".equals(message.trim()))
client.close();
PrintWriterpw=newPrintWriter(client.getOutputStream(),true);
pw.println(message);
}
}catch(Exceptione){
System.err.println("客户端："+client.getInetAddress().getLocalHost().getHostAddress()+"已断开连接！");
}
}
}
}

//客户端程序：
importjava.io.*;
importjava.net.Socket;

{
publicstaticvoidmain(String[]args)throwsIOException{
newTCPClient().init();
}
privatevoidinit()throwsIOException{
@SuppressWarnings("resource")
finalSocketclient=newSocket("127.0.0.1",1000);
BufferedReaderin=newBufferedReader(newInputStreamReader(System.in));
Stringsend="";
while(true){
send=in.readLine();
PrintWriterout=newPrintWriter(client.getOutputStream(),true);
if(!"byte".equals(send.trim()))
out.println(send);
else{
out.println(send);
System.exit(0);
}
newThread(newTCPClient(){
@SuppressWarnings("static-access")
publicvoidrun(){
try{
BufferedInputStreambis=newBufferedInputStream(client.getInputStream());
byte[]b=newbyte[1024];
intlen=0;
while((len=bis.read(b))!=-1){
System.out.println("服务器："+client.getInetAddress().getLocalHost().getHostAddress()+"发来消息："+newString(b,0,len).trim());
}
}catch(IOExceptione){
System.err.println("连接服务器失败!");
}
}
}).start();
}
}
publicvoidrun(){}
}

//服务器测试结果：

客户端：192.168.0.200发来消息：001 byte

客户端：192.168.0.200发来消息：byte

客户端：192.168.0.200 已断开连接！

客户端：192.168.0.200发来消息：adasd

客户端：192.168.0.200 已断开连接！

//客户端测试结果：

---001号客户端--

001byte

服务器：192.168.0.200发来消息：001byte

byte //001礼貌说跟服务器说byte

---002号客户端--

adasd //002客户端直接关闭程序

服务器：192.168.0.200发来消息：adasd

⑸ 用Java编写创建一对客户端/服务器程序,利用数据报将一个文件从一台主机传送到另一

下面是我自己写的一个读取并显示txt文件的demo，希望对您有帮助。
publicclassClient{
	publicstaticvoidmain(String[]args){
		ClientFramef=newClientFrame();
	}
}

importjava.awt.BorderLayout;
importjava.awt.Container;
importjava.awt.Dimension;
importjava.awt.GridLayout;
importjava.awt.Toolkit;
importjava.awt.event.ActionEvent;
importjava.awt.event.ActionListener;
importjava.io.DataInputStream;
importjava.io.DataOutputStream;
importjava.io.IOException;
importjava.net.Socket;
importjava.net.UnknownHostException;
importjava.util.Vector;

importjavax.swing.BorderFactory;
importjavax.swing.JButton;
importjavax.swing.JFrame;
importjavax.swing.JList;
importjavax.swing.JScrollPane;
importjavax.swing.JTextArea;
importjavax.swing.event.ListSelectionEvent;
importjavax.swing.event.ListSelectionListener;

,ListSelectionListener{
	privateJListlist=null;
	privateJButtonsbtn=null;
	privateJButtoncbtn=null;
	privateVectorv=null;
	privateJTextAreatxt=null;
	privateContainercontrol=null;
	privateContainerbtn=null;
	privateSocketclient=null;
	privateDataInputStreamreader=null;
	privateDataOutputStreamwriter=null;
	
	publicClientFrame(){
		this.list=newJList();
		this.list.setBorder(BorderFactory.createTitledBorder("文件列表"));
		this.list.addListSelectionListener(this);
		
		this.sbtn=newJButton("显示");
		this.sbtn.addActionListener(this);
		this.cbtn=newJButton("清除");
		this.cbtn.addActionListener(this);
		
		this.control=newContainer();
		this.control.setPreferredSize(newDimension(150,400));
		this.control.setLayout(newBorderLayout());
		this.control.add(newJScrollPane(this.list),BorderLayout.CENTER);
		this.btn=newContainer();
		this.btn.setLayout(newGridLayout(1,2));
		btn.add(sbtn);
		btn.add(cbtn);
		this.control.add(this.btn,BorderLayout.SOUTH);	
		
		this.txt=newJTextArea();
		this.txt.setEditable(false);
		this.txt.setSize(350,400);

		this.setTitle("客户端");
		this.setSize(500,400);
		this.setVisible(true);
		DimensiondisplaySize=Toolkit.getDefaultToolkit().getScreenSize();
		this.setLocation((displaySize.width-this.getWidth())/2,(displaySize.height-this.getHeight())/2);
		this.setLayout(newBorderLayout());
		this.add(this.control,BorderLayout.WEST);
		this.add(newJScrollPane(this.txt),BorderLayout.CENTER);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		
		try{
			//this.client=newSocket("192.168.32.34",6666);
			this.client=newSocket("192.168.1.100",6666);
			this.reader=newDataInputStream(client.getInputStream());
			this.writer=newDataOutputStream(client.getOutputStream());
		}catch(UnknownHostExceptione){
			e.printStackTrace();
		}catch(IOExceptione){
			e.printStackTrace();
		}
	}

publicvoidactionPerformed(ActionEventevent){
		if(event.getSource()==sbtn){
			if(v==null){
				v=newVector();
			}
			else{
				v.clear();
			}
			
			try{				
				writer.writeUTF("getfilelist");
				writer.flush();
				Stringt=reader.readUTF();
				while(t!=null&&!t.equals("")){
					v.add(t);
					t=reader.readUTF();
				}
			}catch(UnknownHostExceptione){
				e.printStackTrace();
			}catch(IOExceptione){
				e.printStackTrace();
			}
			this.list.setListData(v);
		}
		
		if(event.getSource()==cbtn){
			this.txt.setText("");
		}
	}

publicvoidvalueChanged(ListSelectionEvente){
		inti=this.list.getSelectedIndex();
		if(!this.list.getValueIsAdjusting()&&i!=-1){
			try{
				writer.writeUTF("getfilecontent_"+i);
				writer.flush();
				Stringtmp=reader.readUTF();
				this.txt.setText(tmp);
			}catch(IOExceptione1){
				e1.printStackTrace();
			}
		}
	}

}

importjava.io.DataInputStream;
importjava.io.DataOutputStream;
importjava.io.File;
importjava.io.FileInputStream;
importjava.io.IOException;
importjava.io.InputStreamReader;
importjava.io.Reader;
importjava.net.ServerSocket;
importjava.net.Socket;
importjava.util.ArrayList;
importjava.util.Iterator;

publicclassServer{
	staticArrayList<File>fileArray=newArrayList<File>();
	publicstaticvoidmain(Stringargs[]){
		ServerSocketserver=null;
		Socketclient=null;
		Stringcmd="";
		try{
			server=newServerSocket(6666);
			client=server.accept();
			
			DataInputStreamreader=newDataInputStream(client.getInputStream());
			DataOutputStreamwriter=newDataOutputStream(client.getOutputStream());

			while(true){
				cmd=reader.readUTF();
				System.out.println(cmd);
				if(cmd.equals("getfilelist")){
					fileArray.clear();
					//fileArray=getFile(newFile("D:/tmp"));
					fileArray=getFile(newFile("D:/学习/教程/学习笔记"));				
					Stringfn="";
					for(intk=0;k<fileArray.size();k++){
						fn=fileArray.get(k).getName();
						writer.writeUTF(fn);
						writer.flush();
					}
					writer.writeUTF("");
				}
				if(cmd.startsWith("getfilecontent_")){
					inti=Integer.parseInt(cmd.split("_")[1]);
					Filef=fileArray.get(i);
					Readerin=newInputStreamReader(newFileInputStream(f));
					inttempbyte;
					Stringstr="";
		while((tempbyte=in.read())!=-1){
			str+=(char)tempbyte;
			//System.out.println(str);
		}
		in.close();
	writer.writeUTF(str);
				}
			}
			
		}catch(IOExceptione){
			e.printStackTrace();
		}
	}

privatestaticArrayList<File>getFile(Filef){
		File[]ff=f.listFiles();
		for(Filechild:ff){
			if(child.isDirectory()){
				getFile(child);
			}else{
				fileArray.add(child);
			}
		}
		returnfileArray;
	}
}

⑹ Java用来编写客户端还是服务器端

两者都可以...不过java的垃圾回收机制因为是自动的所以执行客户端程序的时候效率特别慢...一般用于服务器端或WEB开发...学java的重点就是以j2ee技术为核心的。想写客户端之类的用C语言是最佳的..不过内存处理机制全部自己编写..难度不是一般的高。

⑺ 怎么用java编写简单客户端程序

我这里有一个例子希望能够帮助你

public class Client{
private Socket socket;
try{
Socket socket=new Socket ("localhoast',8088);
ip=InetAddress.getLocalHost();
String localip=ip.getHostAddress();
System.out.println(localip);
String name=ip.getHostName();
System.out.println(name);
}
catch(Exception e){

}
public void start(){
try{
Run r2=new Run();
Thread t1=new Thread(r2);
t1.setDaemon(true);
t1.start();

Scanner sc=new Scanner(System.in);
OutputStream os=socket.getOutputStream();
OutputStreamWriter osw=new OutputStreamWriter(os);
PrintWriter writer=new PrintWriter(osw,true);

while(true){
writer.println(sc.nextLine());
}
}catch(Exception e){

}

}
public static void main(String args[]){
Client client=new Client();
client.start();
}
class Run implements Runnable{
public void run() {
while(true){
try {
InputStream is=socket.getInputStream();
InputStreamReader isr=new InputStreamReader(is);
BufferedReader br=new BufferedReader(isr);
while(true){
String str=br.readLine();
System.out.println("服务器说:"+str);
if("bye".equals(str)){
System.out.println("再见客户端");
System.out.println("聊天结束");

}
}
} catch (IOException e) {
e.printStackTrace();
} finally{
try {
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}

}
}
}

⑻ Java中客户端与服务器之间怎样连接

public class SocketClient extends Thread {
private Socket socket;
private int port = 10020;
private String hostIp = "127.0.0.9";
public SocketClient(byte[] b){
try {
BufferedReader in = null;
PrintWriter out = null;

socket = new Socket(hostIp, port);
in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
out = new PrintWriter(socket.getOutputStream(), true);
System.out.println(Arrays.toString(b));
out.println(Arrays.toString(b)); //发送到服务端
System.out.println("Back回客户的数据 message from server:[" + in.readLine() + "]");
out.close();
in.close();
socket.close();
} catch (Exception e) {
e.printStackTrace();
}
} //这是客户连服务端，，
}

//这是服务端
public class SocketServer {
private ServerSocket serverSocket;
private Socket socket;
private int port = 10020;
private ExecutorService executeService = Executors.newFixedThreadPool(10); //线程池
public SocketServer(){
try {
serverSocket = new ServerSocket(port);
System.out.println("SocketServer have been started.[" + serverSocket + "]");
while(true){
socket = serverSocket.accept();

executeService.submit(new Runnable(){
public void run(){
try{
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
PrintWriter out = new PrintWriter(socket.getOutputStream(), true);

String s1 = in.readLine();
System.out.println("Server Received:[" + s1 + "]"); //输出
out.println("Server Received:[" + s1 + "]"); //放回到客户端的
out.close();
in.close();
}catch (Exception e) {
}finally{
try {
System.out.println("关闭连接");
socket.close();
} catch (IOException e) {
System.out.println("close socket error.");
e.printStackTrace();
}
}
}
});
}
} catch (Exception e) {
e.printStackTrace();
}finally{
try {
if(null != serverSocket){
serverSocket.close();
System.out.println("连接池关闭 ");
}
} catch (Exception e) {
e.printStackTrace();
}
}
}

}

⑼ 编写java程序实现客户端和服务端的通信

服务器端：
public class Server{
public static void main(String[] args){
ServerSocket ss = new ServerSocket(端口号);
Socket s = ss.accept();
BufferedReader br = new BufferedReader(new InputStreamReader(s.getInputStream()));
String str = br.readLine();
System.out.println(str);
br.close();
s.close();
ss.close();
}
}

客户端：
public class Client{
public static void main(String[] args){
Socket s = new Socket(ip,端口)
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
bw.write("hello");
bw.flush();
bw.close();
s.close();
}
}

先启动服务器端在启动客户端，两个端口要一致，如果是同一台电脑的ip可写为"127.0.0.1"