ch06.htm

corba比较入门级的介绍详细间接了corba访问发布各种细节。

<TT>20:     SavingsAccountImpl(const char* accountNumber, const char*</TT>
<TT>21:             creationDate, CORBA::Float initialBalance, Customer_ptr</TT>
<TT>22:             customer, CORBA::Float interestRate);</TT>
<TT>23: </TT>
<TT>24:     // Destructor.</TT>
<TT>25:     ~SavingsAccountImpl();</TT>
<TT>26: </TT>
<TT>27:     // These methods are described in Account.idl.</TT>
<TT>28:     virtual char* accountNumber();</TT>
<TT>29:     virtual char* creationDate();</TT>
<TT>30:     virtual CORBA::Float balance();</TT>
<TT>31:     virtual CustomerList* getCustomers();</TT>
<TT>32:     virtual CORBA::Float withdraw(CORBA::Float amount);</TT>
<TT>33:     virtual CORBA::Float deposit(CORBA::Float amount);</TT>
<TT>34: </TT>
<TT>35:     // These methods are described in SavingsAccount.idl.</TT>
<TT>36:     virtual CORBA::Float interestRate();</TT>
<TT>37:     virtual CORBA::Float setInterestRate(CORBA::Float rate);</TT>
<TT>38: </TT>
<TT>39: private:</TT>
<TT>40: </TT>
<TT>41:     // Default constructor.</TT>
<TT>42:     SavingsAccountImpl();</TT>
<TT>43: </TT>
<TT>44:     // This Account's interest rate.</TT>
<TT>45:     CORBA::Float myInterestRate;</TT>
<TT>46: </TT>
<TT>47:     // My associated AccountImpl object.</TT>
<TT>48:     AccountImpl myAccount;</TT>
<TT>49: };</TT>
<TT>50: 
51: #endif</TT></FONT></PRE>
<H4><FONT COLOR="#000077">Listing 6.17. SavingsAccountImpl.cpp.</FONT></H4>
<PRE><FONT COLOR="#0066FF"><TT> 1: // SavingsAccountImpl.cpp</TT>
<TT> 2: </TT>
<TT> 3: #include &quot;SavingsAccountImpl.h&quot;</TT>
<TT> 4: </TT>
<TT> 5: // Constructor.</TT>
<TT> 6: //</TT>
<TT> 7: // accountNumber - Account number.</TT>
<TT> 8: // creationDate - Account creation date.</TT>
<TT> 9: // initialBalance - Initial Account balance.</TT>
<TT>10: // customer - Initial Account owner.</TT>
<TT>11: // interestRate - Initial Account interest rate.</TT>
<TT>12: SavingsAccountImpl::SavingsAccountImpl(const char* accountNumber,</TT>
<TT>13:         const char* creationDate, CORBA::Float initialBalance,</TT>
<TT>14:         Customer_ptr customer, CORBA::Float interestRate) :</TT>
<TT>15:         myAccount(accountNumber, creationDate, initialBalance,</TT>
<TT>16:         customer), myInterestRate(interestRate) {</TT>
<TT>17: </TT>
<TT>18: }</TT>
<TT>19: </TT>
<TT>20: // Default constructor.</TT>
<TT>21: SavingsAccountImpl::SavingsAccountImpl() : myAccount(NULL, NULL,</TT>
<TT>22:         0.0, Customer::_nil()), myInterestRate(0.0) {</TT>
<TT>23: </TT>
<TT>24: }</TT>
<TT>25: </TT>
<TT>26: // Destructor.</TT>
<TT>27: SavingsAccountImpl::~SavingsAccountImpl() {</TT>
<TT>28: </TT>
<TT>29: }</TT>
<TT>30: </TT>
<TT>31: char* SavingsAccountImpl::accountNumber() {</TT>
<TT>32: </TT>
<TT>33:     return myAccount.accountNumber();</TT>
<TT>34: }</TT>
<TT>35: </TT>
<TT>36: char* SavingsAccountImpl::creationDate() {</TT>
<TT>37: </TT>
<TT>38:     return myAccount.creationDate();</TT>
<TT>39: }</TT>
<TT>40: </TT>
<TT>41: CORBA::Float SavingsAccountImpl::balance() {</TT>
<TT>42: </TT>
<TT>43:     return myAccount.balance();</TT>
<TT>44: }</TT>
<TT>45: </TT>
<TT>46: CustomerList* SavingsAccountImpl::getCustomers() {</TT>
<TT>47: </TT>
<TT>48:     return myAccount.getCustomers();</TT>
<TT>49: }</TT>
<TT>50: </TT>
<TT>51: CORBA::Float SavingsAccountImpl::withdraw(CORBA::Float amount) {</TT>
<TT>52: </TT>
<TT>53:     return myAccount.withdraw(amount);</TT>
<TT>54: }</TT>
<TT>55: </TT>
<TT>56: CORBA::Float SavingsAccountImpl::deposit(CORBA::Float amount) {</TT>
<TT>57: </TT>
<TT>58:     return myAccount.deposit(amount);</TT>
<TT>59: }</TT>
<TT>60: </TT>
<TT>61: CORBA::Float SavingsAccountImpl::interestRate() {</TT>
<TT>62: </TT>
<TT>63:     return myInterestRate;</TT>
<TT>64: }</TT>
<TT>65: </TT>
<TT>66: CORBA::Float SavingsAccountImpl::setInterestRate(CORBA::Float rate) {</TT>
<TT>67: </TT>
<TT>68:     CORBA::Float oldInterestRate = myInterestRate;</TT>
<TT>69: </TT>
<TT>70:     myInterestRate = rate;</TT>
<TT>71: </TT>
<TT>72:     return oldInterestRate;
73: }</TT></FONT></PRE>
<H2><A NAME="Heading7"></A><FONT COLOR="#000077">Implementing Basic Client Capabilities</FONT></H2>
<P>Now that you have implemented the basic capabilities of the CORBA server for the
<TT>Bank</TT> application, you're ready to begin working on the basic client capabilities.
Since most of the work is done by the server in this application, you'll find the
client to be fairly simple by comparison.
<H3><A NAME="Heading8"></A><FONT COLOR="#000077">Implementing the Customer Interface</FONT></H3>
<P>The <TT>Customer</TT> interface encapsulates the attributes and behaviors of a
<TT>Customer</TT> of a <TT>Bank</TT>. For the most part, this interface serves as
a container for <TT>Account</TT> objects. The IDL definition for the <TT>Customer</TT>
interface is shown in Listing 6.18.
<H4><FONT COLOR="#000077">Listing 6.18. Customer.idl.</FONT></H4>
<PRE><FONT COLOR="#0066FF"><TT> 1: // Customer.idl</TT>
<TT> 2: </TT>
<TT> 3: // Forward declaration of Customer interface.</TT>
<TT> 4: interface Customer;</TT>
<TT> 5: </TT>
<TT> 6: #ifndef Customer_idl</TT>
<TT> 7: #define Customer_idl</TT>
<TT> 8: </TT>
<TT> 9: // sequence of Customers</TT>
<TT>10: typedef sequence&lt;Customer&gt; CustomerList;</TT>
<TT>11: </TT>
<TT>12: #include &quot;Account.idl&quot;</TT>
<TT>13: </TT>
<TT>14: // A Customer can hold one or more Accounts. Presumably, the</TT>
<TT>15: // Customer is what drives the rest of this application.</TT>
<TT>16: interface Customer {</TT>
<TT>17: </TT>
<TT>18:     // This Customer's name.</TT>
<TT>19:     attribute string name;</TT>
<TT>20: </TT>
<TT>21:     // This Customer's Social Security number.</TT>
<TT>22:     readonly attribute string socialSecurityNumber;</TT>
<TT>23: </TT>
<TT>24:     // This Customer's address.</TT>
<TT>25:     attribute string address;</TT>
<TT>26: </TT>
<TT>27:     // This Customer's mother's maiden name.</TT>
<TT>28:     readonly attribute string mothersMaidenName;</TT>
<TT>29: </TT>
<TT>30:     // Return a list of Accounts held (or co-held) by this</TT>
<TT>31:     // Customer.</TT>
<TT>32:     AccountList getAccounts();</TT>
<TT>33: };</TT>
<TT>34: 
35: #endif</TT> </FONT></PRE>
<P>You need to implement <TT>getname()</TT>, <TT>setname()</TT>, <TT>getsocialSecurityNumber()</TT>,
<TT>getaddress()</TT>, <TT>setAddress()</TT>, and <TT>getmothersMaidenName()</TT>,
which are the accessors and mutators for various attributes of <TT>Account</TT>,
along with <TT>getAccounts()</TT> and the class constructor (or constructors) and
destructor. The implementation for <TT>CustomerImpl</TT> appears in Listings 6.19
and 6.20.
<H4><FONT COLOR="#000077">Listing 6.19. CustomerImpl.h.</FONT></H4>
<PRE><FONT COLOR="#0066FF"><TT> 1: // CustomerImpl.h</TT>
<TT> 2: </TT>
<TT> 3: #ifndef CustomerImpl_h</TT>
<TT> 4: #define CustomerImpl_h</TT>
<TT> 5: </TT>
<TT> 6: #include &quot;../Customer_s.h&quot;</TT>
<TT> 7: </TT>
<TT> 8: class CustomerImpl : public _sk_Customer {</TT>
<TT> 9: </TT>
<TT>10: public:</TT>
<TT>11: </TT>
<TT>12:     // Constructor.</TT>
<TT>13:     //</TT>
<TT>14:     // name - Customer's name.</TT>
<TT>15:     // socialSecurityNumber - Customer's Social Security number.</TT>
<TT>16:     // address - Customer's address.</TT>
<TT>17:     // mothersMaidenName - Customer's mother's maiden name.</TT>
<TT>18:     CustomerImpl(const char* name, const char* socialSecurityNumber,</TT>
<TT>19:             const char* address, const char* mothersMaidenName);</TT>
<TT>20: </TT>
<TT>21:     // Destructor.</TT>
<TT>22:     ~CustomerImpl();</TT>
<TT>23: </TT>
<TT>24:     // These methods are described in Customer.idl.</TT>
<TT>25:     virtual char* name();</TT>
<TT>26:     virtual void name(const char* val);</TT>
<TT>27:     virtual char* socialSecurityNumber();</TT>
<TT>28:     virtual char* address();</TT>
<TT>29:     virtual void address(const char* val);</TT>
<TT>30:     virtual char* mothersMaidenName();</TT>
<TT>31:     virtual AccountList* getAccounts();</TT>
<TT>32: </TT>
<TT>33: private:</TT>
<TT>34: </TT>
<TT>35:     // Default constructor.</TT>
<TT>36:     CustomerImpl();</TT>
<TT>37: </TT>
<TT>38:     // This Customer's name.</TT>
<TT>39:     char* myName;</TT>
<TT>40: </TT>
<TT>41:     // This Customer's Social Security number.</TT>
<TT>42:     char* mySocialSecurityNumber;</TT>
<TT>43: </TT>
<TT>44:     // This Customer's address.</TT>
<TT>45:     char* myAddress;</TT>
<TT>46: </TT>
<TT>47:     // This Customer's mother's maiden name.</TT>
<TT>48:     char* myMothersMaidenName;</TT>
<TT>49: </TT>
<TT>50:     // This Customer's Accounts.</TT>
<TT>51:     AccountList myAccounts;</TT>
<TT>52: };</TT>
<TT>53: 
54: #endif</TT></FONT></PRE>
<H4><FONT COLOR="#000077">Listing 6.20. CustomerImpl.cpp.</FONT></H4>
<PRE><FONT COLOR="#0066FF"><TT> 1: // CustomerImpl.cpp</TT>
<TT> 2: </TT>
<TT> 3: #include &quot;CustomerImpl.h&quot;</TT>
<TT> 4: </TT>
<TT> 5: #include &lt;string.h&gt;</TT>
<TT> 6: </TT>
<TT> 7: // Constructor.</TT>
<TT> 8: //</TT>
<TT> 9: // name - Customer's name.</TT>
<TT>10: // socialSecurityNumber - Customer's Social Security number.</TT>
<TT>11: // address - Customer's address.</TT>
<TT>12: // mothersMaidenName - Customer's mother's maiden name.</TT>
<TT>13: CustomerImpl::CustomerImpl(const char* name, const char*</TT>
<TT>14:         socialSecurityNumber, const char* address, const char*</TT>
<TT>15:         mothersMaidenName) : myName(strdup(name)),</TT>
<TT>16:         mySocialSecurityNumber(strdup(socialSecurityNumber)),</TT>
<TT>17:         myAddress(strdup(address)),</TT>
<TT>18:         myMothersMaidenName(strdup(mothersMaidenName)),</TT>
<TT>19:         myAccounts() {</TT>
<TT>20: </TT>
<TT>21: }</TT>
<TT>22: </TT>
<TT>23: // Default constructor.</TT>
<TT>24: CustomerImpl::CustomerImpl() : myName(NULL),</TT>
<TT>25:         mySocialSecurityNumber(NULL), myAddress(NULL),</TT>
<TT>26:         myMothersMaidenName(NULL), myAccounts() {</TT>
<TT>27: </TT>
<TT>28: }</TT>
<TT>29: </TT>
<TT>30: // Destructor.</TT>
<TT>31: CustomerImpl::~CustomerImpl() {</TT>
<TT>32: </TT>
<TT>33:     free(myName);</TT>
<TT>34:     free(mySocialSecurityNumber);</TT>
<TT>35:     free(myAddress);</TT>
<TT>36:     free(myMothersMaidenName);</TT>
<TT>37: }</TT>
<TT>38: </TT>
<TT>39: char* CustomerImpl::name() {</TT>
<TT>40: </TT>
<TT>41:     return CORBA::strdup(myName);</TT>
<TT>42: }</TT>
<TT>43: </TT>
<TT>44: void CustomerImpl::name(const char* val) {</TT>
<TT>45: </TT>
<TT>46:     free(myName);</TT>
<TT>47:     myName = strdup(val);</TT>
<TT>48: }</TT>
<TT>49: </TT>
<TT>50: char* CustomerImpl::socialSecurityNumber() {</TT>
<TT>51: </TT>
<TT>52:     return CORBA::strdup(mySocialSecurityNumber);</TT>
<TT>53: }</TT>
<TT>54: </TT>
<TT>55: char* CustomerImpl::address() {</TT>
<TT>56: </TT>
<TT>57:     return CORBA::strdup(myAddress);</TT>
<TT>58: }</TT>
<TT>59: </TT>
<TT>60: void CustomerImpl::address(const char* val) {</TT>
<TT>61: </TT>
<TT>62:     free(myAddress);</TT>
<TT>63:     myAddress = strdup(val);</TT>
<TT>64: }</TT>
<TT>65: </TT>
<TT>66: char* CustomerImpl::mothersMaidenName() {</TT>
<TT>67: </TT>
<TT>68:     return CORBA::strdup(myMothersMaidenName);</TT>
<TT>69: }</TT>
<TT>70: </TT>
<TT>71: AccountList* CustomerImpl::getAccounts() {</TT>
<TT>72: </TT>
<TT>73:     return &amp;myAccounts;
74: }</TT></FONT></PRE>
<H3><A NAME="Heading9"></A><FONT COLOR="#000077">Implementing Additional Client Functionality</FONT></H3>
<P>In addition to the <TT>Customer</TT> interface, any useful client needs to implement
additional functionality. An examination of the <TT>Customer</TT> implementation
will suggest to you why this is so: Although the implementation allows a <TT>Customer</TT>
to interact with various other components of the <TT>Bank</TT> application (su