corbaclient.java

Icarnegie university SSD8电子书和全部练习答案

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import java.io.*; 
import org.omg.CORBA.*; 
import org.omg.CosNaming.*; 
import ListFile.*; 
import CreatorFile.*; 

/** 
* The client of the Corba system. 
* 
* @author Jinjiang 
* 
*/ 
public class CorbaClient { 

static int argSum[] = { 0, 3, 5, 3, 2, 4, 0, 0 }; 

/** 
* Connect with the servant and do operations which the user input. 
* 
* @param args 
*/ 
public static void main(String[] args) { 

try { 

// connect with the servant 
ORB orb = ORB.init(args, null); 
NameComponent component; 
org.omg.CORBA.Object remoteListRef, remoteCreatorRef; 

Creator creator; 
List list; 

org.omg.CORBA.Object object = orb 
.resolve_initial_references("NameService"); 
NamingContext namingContext = NamingContextHelper.narrow(object); 

component = new NameComponent("Creator", ""); 
NameComponent[] creators = { component }; 
remoteCreatorRef = namingContext.resolve(creators); 
creator = CreatorHelper.narrow(remoteCreatorRef); 

BufferedReader input = new BufferedReader(new InputStreamReader( 
System.in)); 

/* initialize the variables */ 
String cmd = ""; 
int choice; 

// get the register or login operation 
while (true) { 

displayMenu(); 

cmd = input.readLine(); 
try { 
choice = Integer.parseInt(cmd); 
if (choice < 0 || choice > 7) 
choice = 7; 
} catch (Exception e) { 
choice = 7; 
} 

String[] arg = getArgs(argSum[choice], input); 

if (choice == 0) 
return; 

if (choice == 6) { 

displayHelp(); 
continue; 
} 

if (choice == 7) { 

System.err.println("Input Error!"); 
continue; 
} 

if (choice == 1) { 

if (!arg[0].equals("") &amt;&amt; arg[1].equals(arg[2])) 
if (creator.register(arg[0], arg[1])) { 

System.out.println("Successful!"); 
continue; 
} 

System.err.println("Failed!"); 
continue; 
} 

try { 
component = new NameComponent(arg[0], ""); 
NameComponent[] lists = { component }; 
remoteListRef = namingContext.resolve(lists); 
list = ListHelper.narrow(remoteListRef); 
} catch (Exception e) { 
System.err.println("Failed!"); 
continue; 
} 

if (choice == 2) { 

if (list.add(arg[0], arg[1], arg[2], arg[3], arg[4])) 
System.out.println("Successful!"); 
else 
System.err.println("Failed!"); 
} 

if (choice == 3) { 

if (list.delete(arg[0], arg[1], Integer.parseInt(arg[2]))) 
System.out.println("Successful!"); 
else 
System.err.println("Failed!"); 
} 

if (choice == 4) { 

if (list.clear(arg[0], arg[1])) 
System.out.println("Successful!"); 
else 
System.err.println("Failed!"); 
} 

if (choice == 5) { 

String q = list.query(arg[0], arg[1], arg[2], arg[3]); 
if (q != null) 
System.out.println(q); 
else 
System.err.println("Failed!"); 
} 
} 
} catch (Exception e) { 

System.err.println(e.toString()); 
} 

} 

/** 
* Get the arguments which the operation needs. 
* 
* @param s 
* @param input 
* @return arguments which the operation needs. 
* @throws Exception 
*/ 
public static String[] getArgs(int s, BufferedReader input) 
throws Exception { 

String[] a = new String[s]; 
for (int i = 0; i < s; i++) { 

System.out.println("Please input the No." + (i + 1) + " argument"); 
do 
a[i] = input.readLine(); 
while (a[i].equals("")); 
} 

return a; 
} 

/** 
* Display the help documents to guide the user. 
* 
*/ 
public static void displayHelp() { 

System.out.println("Help:\n" 
+ "\t1. You just need to input the number " 
+ "of the operation which you want to do.\n" 
+ "\t2. The program will do nothing " 
+ "if you input a wrong number format.\n" 
+ "\t3. The date format should be \"YYYY_M_D_h_m_s\"\n"); 
} 

/** 
* Display the menu to guide the user to do deeper operations. 
* 
*/ 
public static void displayMenu() { 

System.out.println("Corba Menu:"); 
System.out.println("\t1. register\n" 
+ "\t\targuments: <username> <password> <password>"); 
System.out.println("\t2. add\n" 
+ "\t\targuments: <username> <password> <start> <end> <label>"); 
System.out.println("\t3. delete\n" 
+ "\t\targuments: <username> <password> <itemid>"); 
System.out.println("\t4. clear\n" 
+ "\t\targuments: <username> <password>"); 
System.out.println("\t5. query\n" 
+ "\t\targuments: <username> <password> <start> <end>"); 
System.out.println("\t6. help\n" + "\t\targuments: no args"); 
System.out.println("\t0. quit\n" + "\t\targuments: no args\n"); 
} 
}