loansserver.java

服务/客户端 查询 非完全版本

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


public class LoansServer {
	ServerSocket socket = null;
	int port = 0;
	 	
	public LoansServer(int port)
	{
		this.port=port;
	}
	
	public void run(String path)
	{
		
			//Read Loans File into an array and printout
		    try {
		         FileReader input = new FileReader(path);					
		         int n=-1;
		         String[] StringArr = new String[5];
			     BufferedReader bufRead = new BufferedReader(input);
			     String line=""; 	// String that holds current file line
		         line = bufRead.readLine();
		         while (line != null){
		             	 n++;
		            	String lineNew = "";
		            	lineNew = line;
		                line = bufRead.readLine();
		                StringArr[n] = new String(lineNew);  
		              }
		           	 for(int   x=0;x<StringArr.length;x++){   
		               System.out.println(StringArr[x]);}
		         bufRead.close();
					
		        }catch (ArrayIndexOutOfBoundsException e){
		            /* If no file was passed on the command line, this exception is
					generated. */
					System.out.println("Usage: java ReadFile filename\n");			

				}catch (IOException e){
					// If another exception is generated, print a stack trace
		            e.printStackTrace();
		        }
		//Listen for incoming requests on given port 		
		try
			{ 
			socket = new ServerSocket(port);
			Socket clientSock = null;
			PrintWriter out = null;
			BufferedReader in = null;
			System.err.println("LoansServer waiting for incoming connections");
			while(true)
			{
				try{clientSock = socket.accept();
				/*System.out.println("LoansServer Connection accepted from " +
						clientSock.getInetAddress().getHostName() +
					    " port " + clientSock.getPort());*/}
				catch (SocketException e2){e2.printStackTrace();}

			    // Create a PrintWriter and BufferedReader for interaction with our stream
			   	out = new PrintWriter(clientSock.getOutputStream(), 
				    true);
			    in = new BufferedReader(
				    new InputStreamReader(clientSock.getInputStream()));

			  //Accepts Query Client request and response
			    String line1;
			  			    while ((line1=in.readLine()) != null) {
					String[] split = line1.split(" ");
					if(split[0].equals("L"))
					{
					   try {
							FileReader input = new FileReader("loans-file");					
				            int n=-1;
				            String[] StringArr = new String[5];
					      BufferedReader bufRead = new BufferedReader(input);
					        String line=""; 	
				            line = bufRead.readLine();
				            while (line != null){
				              	 n++;
				            	String lineNew = "";
				            	lineNew = line;
				                line = bufRead.readLine();
				                StringArr[n] = new String(lineNew);  
				              }
				          	bufRead.close();
				          	//Search Loans by user id
				            for   (int   i=0;i<StringArr.length;i++){   
				            	if(StringArr[i].substring(0, 6).equals(split[1])){
					   		    	//System.out.println("Loans record of user id "+split[1]+" is "+StringArr[i]);
					   		    	 out.println("Loans record of "+split[1]+": "+StringArr[i]);
				   		    	  }}
				           
				        }catch (ArrayIndexOutOfBoundsException e){
				            
							System.out.println("Usage: java ReadFile filename\n");			

						}catch (IOException e){
							
				            e.printStackTrace();
				        }
						
						//Acknowledge closure and print to stderr
						System.err.println("LoansServer Connection closed");
						System.err.println("LoansServer waiting for incoming connections");
						break;
					}
					else {if(split[0].equals("D")) 
					{
						try {
							
				        	FileReader input = new FileReader("loans-file");					
				            int n=-1;
				            String[] StringArr = new String[5];
					        BufferedReader bufRead = new BufferedReader(input);
					        String line=""; 	// String that holds current file line
				            line = bufRead.readLine();
				            while (line != null){
				                n++;
				            	String lineNew = "";
				            	lineNew = line;
				                line = bufRead.readLine();
				                StringArr[n] = new String(lineNew);  
				              }
				           
				            bufRead.close();
				          //Search due date by book id
				            for   (int   i=0;i<StringArr.length;i++){   
				            	if(StringArr[i].substring(7, 13).equals(split[1])){
					   		    	//System.out.println("This book's due date:"+StringArr[i].substring(14, 22));
					   		    	 out.println("The due date of book id "+split[1]+" is "+StringArr[i].substring(14, 22)); 
				   		    	  }}
				            
				             
				        }catch (ArrayIndexOutOfBoundsException e){
				            
							System.out.println("Usage: java ReadFile filename\n");			

						}catch (IOException e){
							
				            e.printStackTrace();
				        }
						
						//Acknowledge closure and print to stderr
						System.err.println("LoansServer Connection closed");
						System.err.println("LoansServer waiting for incoming connections");
						break;
					}
				}
					    out.close();
					    in.close();
					    clientSock.close();
			    }
					    	  
			}	
		    
		}
		
		catch (IOException e) {
			System.err.println("LoansServer unable to listen on given port");
			System.exit(0);
		}
		
	}
	


	public static void main(String[] args) throws IOException {
		
		try
		{
				
			(new LoansServer(Integer.parseInt(args[0]))).run("loans-file");
						
		} catch (NumberFormatException e)
		{
			System.err.println("Invalid command line arguments for LoansServer");
		}

}
}