ch07.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>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>
<B><TT>52:</TT></B><TT>         <B>throw (InvalidAmountException, InsufficientFundsException)</B></TT>
<TT>53:         {</TT>
<TT>54: </TT>
<TT>55:     return myAccount.withdraw(amount);</TT>
<TT>56: }</TT>
<TT>57: </TT>
<B><TT>58:</TT></B><TT> CORBA::Float SavingsAccountImpl::deposit(CORBA::Float amount) <B>throw</B></TT>
<B><TT>59:</TT></B><TT>         <B>(InvalidAmountException) </B>{</TT>
<TT>60: </TT>
<TT>61:     return myAccount.deposit(amount);</TT>
<TT>62: }</TT>
<TT>63: </TT>
<TT>64: CORBA::Float SavingsAccountImpl::interestRate() {</TT>
<TT>65: </TT>
<TT>66:     return myInterestRate;</TT>
<TT>67: }</TT>
<TT>68: </TT>
<B><TT>69:</TT></B><TT> CORBA::Float SavingsAccountImpl::setInterestRate(CORBA::Float rate) <B>throw</B></TT>
<B><TT>70:</TT></B><TT>         <B>(InvalidAmountException)</B> {</TT>
<B><TT>71:</TT></B><TT> </TT>
<B><TT>72:</TT></B><TT>     <B>// Disallow negative interest rates and throw an exception if this is</B></TT>
<B><TT>73:</TT></B><TT>     <B>// attempted.</B></TT>
<B><TT>74:</TT></B><TT>     <B>if (rate &lt; 0.0) {</B></TT>
<B><TT>75:</TT></B><TT> </TT>
<B><TT>76:</TT></B><TT>         <B>throw InvalidAmountException();</B></TT>
<B><TT>77:</TT></B><TT>     <B>}</B></TT>
<TT>78: </TT>
<TT>79:     CORBA::Float oldInterestRate = myInterestRate;</TT>
<TT>80: </TT>
<TT>81:     myInterestRate = rate;</TT>
<TT>82: </TT>
<TT>83:     return oldInterestRate;
84: }</TT> </FONT></PRE>
<P>The changes in the <TT>withdraw()</TT> and <TT>deposit()</TT> methods in <TT>SavingsAccountImpl</TT>
copy their counterparts in <TT>CheckingAccountImpl</TT> exactly. In addition, the
<TT>setInterestRate()</TT> method is modified to disallow negative interest rates
(which would correspond to a savings account that loses money over time). If a client
attempts to set a negative interest rate for the <TT>SavingsAccount</TT>, an <TT>InvalidAmountException</TT>
is thrown.
<H3><A NAME="Heading14"></A><FONT COLOR="#000077">BankImpl</FONT></H3>
<P>The final server component to modify is the <TT>BankImpl</TT> itself. Only a single
method, <TT>deleteAccount()</TT>, is modified to throw an exception. The modified
<TT>BankImpl.h</TT> and <TT>BankImpl.cpp</TT> appear in Listings 7.22 and 7.23.
<H4><FONT COLOR="#000077">Listing 7.22. Modified BankImpl.h.</FONT></H4>
<PRE><FONT COLOR="#0066FF"><TT> 1: // BankImpl.h</TT>
<TT> 2: </TT>
<TT> 3: #ifndef BankImpl_h</TT>
<TT> 4: #define BankImpl_h</TT>
<TT> 5: </TT>
<TT> 6: #include &lt;vector&gt;</TT>
<TT> 7: </TT>
<TT> 8: #include &quot;../Bank_s.h&quot;</TT>
<TT> 9: </TT>
<TT>10: class BankImpl : public _sk_Bank {</TT>
<TT>11: </TT>
<TT>12: public:</TT>
<TT>13: </TT>
<TT>14:     // Constructor.</TT>
<TT>15:     //</TT>
<TT>16:     // name - This Bank's name.</TT>
<TT>17:     BankImpl(const char* name);</TT>
<TT>18: </TT>
<TT>19:     // Destructor.</TT>
<TT>20:     ~BankImpl();</TT>
<TT>21: </TT>
<TT>22:     // These methods are described in Bank.idl.</TT>
<TT>23:     virtual char* name();</TT>
<TT>24:     virtual void name(const char* val);</TT>
<TT>25:     virtual char* address();</TT>
<TT>26:     virtual void address(const char* val);</TT>
<TT>27:     virtual Account_ptr createAccount(Customer_ptr customer,</TT>
<TT>28:             const char* accountType, CORBA::Float openingBalance);</TT>
<B><TT>29:</TT></B><TT>     virtual void deleteAccount(Account_ptr account) <B>throw</B></TT>
<B><TT>30:</TT></B><TT>             <B>(InvalidAccountException);</B></TT>
<TT>31:     virtual AccountList* getAccounts();</TT>
<TT>32: </TT>
<TT>33: protected:</TT>
<TT>34: </TT>
<TT>35:     // Return the next available account number. The result is</TT>
<TT>36:     // returned in a static buffer.</TT>
<TT>37:     char* getNextAccountNumber();</TT>
<TT>38: </TT>
<TT>39:     // Return the current date in the form &quot;Mmm DD YYYY&quot;. The result</TT>
<TT>40:     // is returned in a static buffer.</TT>
<TT>41:     char* getCurrentDate();</TT>
<TT>42: </TT>
<TT>43: private:</TT>
<TT>44: </TT>
<TT>45:     // Default constructor.</TT>
<TT>46:     BankImpl();</TT>
<TT>47: </TT>
<TT>48:     // This Bank's name.</TT>
<TT>49:     char* myName;</TT>
<TT>50: </TT>
<TT>51:     // This Bank's address.</TT>
<TT>52:     char* myAddress;</TT>
<TT>53: </TT>
<TT>54:     // This Bank's Accounts.</TT>
<TT>55:     std::vector&lt;Account_ptr&gt; myAccounts;</TT>
<TT>56: </TT>
<TT>57:     // The next available account number.</TT>
<TT>58:     unsigned int myNextAccountNumber;</TT>
<TT>59: };
60: 
61: #endif</TT></FONT></PRE>
<H4><FONT COLOR="#000077">Listing 7.23. Modified BankImpl.cpp.</FONT></H4>
<PRE><FONT COLOR="#0066FF"><TT>  1: // BankImpl.cpp</TT>
<TT>  2: </TT>
<TT>  3: #include &quot;BankImpl.h&quot;</TT>
<TT>  4: </TT>
<TT>  5: #include &lt;time.h&gt;</TT>
<TT>  6: #include &lt;string.h&gt;</TT>
<TT>  7: #include &lt;iostream.h&gt;</TT>
<TT>  8: #include &lt;algorithm&gt;</TT>
<TT>  9: #include &lt;functional&gt;</TT>
<TT> 10: </TT>
<TT> 11: #include &quot;SavingsAccountImpl.h&quot;</TT>
<TT> 12: #include &quot;CheckingAccountImpl.h&quot;</TT>
<TT> 13: </TT>
<TT> 14: extern CORBA::BOA_var boa;</TT>
<TT> 15: </TT>
<TT> 16: // STL-derived unary function which returns TRUE if Accounts are</TT>
<TT> 17: // equal.</TT>
<TT> 18: class IsAccountEqual : public std::unary_function&lt;Account_ptr,</TT>
<TT> 19:         bool&gt; {</TT>
<TT> 20: public:</TT>
<TT> 21:     IsAccountEqual(argument_type account) { myAccount = account; }</TT>
<TT> 22:     result_type operator()(argument_type account) { return account-&gt;</TT>
<TT> 23:             _is_equivalent(myAccount) != 0; }</TT>
<TT> 24: private:</TT>
<TT> 25:     argument_type myAccount;</TT>
<TT> 26: };</TT>
<TT> 27: </TT>
<TT> 28: // Constructor.</TT>
<TT> 29: //</TT>
<TT> 30: // name - This Bank's name.</TT>
<TT> 31: BankImpl::BankImpl(const char* name) : _sk_Bank(name), myAccounts(),</TT>
<TT> 32:         myName(strdup(name)), myAddress(strdup(&quot;123 Elm Street, &quot;</TT>
<TT> 33:         &quot;Anywhere USA 12345&quot;)), myNextAccountNumber(0) {</TT>
<TT> 34: </TT>
<TT> 35: }</TT>
<TT> 36: </TT>
<TT> 37: // Default constructor.</TT>
<TT> 38: BankImpl::BankImpl() : myAccounts(), myName(NULL), myAddress(NULL),</TT>
<TT> 39:         myNextAccountNumber(0) {</TT>
<TT> 40: </TT>
<TT> 41: }</TT>
<TT> 42: </TT>
<TT> 43: // Destructor.</TT>
<TT> 44: BankImpl::~BankImpl() {</TT>
<TT> 45: </TT>
<TT> 46:     cout &lt;&lt; &quot;Bank \&quot;&quot; &lt;&lt; name() &lt;&lt; &quot;\&quot; being destroyed.&quot; &lt;&lt; endl;</TT>
<TT> 47:     free(myName);</TT>
<TT> 48:     free(myAddress);</TT>
<TT> 49: }</TT>
<TT> 50: </TT>
<TT> 51: char* BankImpl::name() {</TT>
<TT> 52: </TT>
<TT> 53:     return CORBA::strdup(myName);</TT>
<TT> 54: }</TT>
<TT> 55: </TT>
<TT> 56: void BankImpl::name(const char* val) {</TT>
<TT> 57: </TT>
<TT> 58:     free(myName);</TT>
<TT> 59:     myName = strdup(val);</TT>
<TT> 60: }</TT>
<TT> 61: </TT>
<TT> 62: char* BankImpl::address() {</TT>
<TT> 63: </TT>
<TT> 64:     return CORBA::strdup(myAddress);</TT>
<TT> 65: }</TT>
<TT> 66: </TT>
<TT> 67: void BankImpl::address(const char* val) {</TT>
<TT> 68: </TT>
<TT> 69:     free(myAddress);</TT>
<TT> 70:     myAddress = strdup(val);</TT>
<TT> 71: }</TT>
<TT> 72: </TT>
<TT> 73: Account_ptr BankImpl::createAccount(Customer_ptr customer,</TT>
<TT> 74:         const char* accountType, CORBA::Float openingBalance) {</TT>
<TT> 75: </TT>
<TT> 76:     Account_ptr newAccount;</TT>
<TT> 77: </TT>
<TT> 78:     if (strcmp(accountType, &quot;savings&quot;) == 0) {</TT>
<TT> 79: </TT>
<TT> 80:         // Create a new SavingsAccountImpl object for the Account.</TT>
<TT> 81:         cout &lt;&lt; &quot;BankImpl: Creating new SavingsAccount for &quot;</TT>
<TT> 82:                 &quot;Customer &quot; &lt;&lt; customer-&gt;name() &lt;&lt; &quot;.&quot; &lt;&lt; endl;</TT>
<TT> 83:         newAccount = new SavingsAccountImpl(getNextAccountNumber(),</TT>
<TT> 84:                 getCurrentDate(), openingBalance, customer, 10.0);</TT>
<TT> 85:     } else if (strcmp(accountType, &quot;checking&quot;) == 0) {</TT>
<TT> 86: </TT>
<TT> 87:         // Create a new CheckingAccountImpl object for the Account.</TT>
<TT> 88:         cout &lt;&lt; &quot;BankImpl: Creating new CheckingAccount for &quot;</TT>
<TT> 89:                 &quot;Customer &quot; &lt;&lt; customer-&gt;name() &lt;&lt; &quot;.&quot; &lt;&lt; endl;</TT>
<TT> 90:         newAccount = new CheckingAccountImpl(getNextAccountNumber(),</TT>
<TT> 91:                 getCurrentDate(), openingBalance, customer);</TT>
<TT> 92:     } else {</TT>
<TT> 93: </TT>
<TT> 94:         // Invalid Account type; do nothing.</TT>
<TT> 95:         cout &lt;&lt; &quot;BankImpl: Customer &quot; &lt;&lt; customer-&gt;name() &lt;&lt;</TT>
<TT> 96:                 &quot; requested invalid Account type \&quot;&quot; &lt;&lt; accountType</TT>
<TT> 97:                 &lt;&lt; &quot;\&quot;.&quot; &lt;&lt; endl;</TT>
<TT> 98:         return Account::_nil();</TT>
<TT> 99:     }</TT>
<TT>100: </TT>
<TT>101:     // Add the created Account at the end of the list and return it.</TT>
<TT>102:     ::boa-&gt;obj_is_ready(newAccount);</TT>
<TT>103:     myAccounts.push_back(Account::_duplicate(newAccount));</TT>
<TT>104:     return newAccount;</TT>
<TT>105: }</TT>
<TT>106: </TT>
<B><TT>107:</TT></B><TT> void BankImpl::deleteAccount(Account_ptr account) <B>throw</B></TT>
<B><TT>108:</TT></B><TT>         <B>(InvalidAccountException)</B> {</TT>
<TT>109: </TT>
<TT>110:     std::vector&lt;Account_ptr&gt;::iterator first = myAccounts.begin();</TT>
<TT>111:     std::vector&lt;Account_ptr&gt;::iterator last = myAccounts.end();</TT>
<TT>112:     IsAccountEqual predicate(account);</TT>
<TT>113: </TT>
<TT>114:     std::vector&lt;Account_ptr&gt;::iterator matchedAccount = std::</TT>
<TT>115:             find_if(first, last, predicate);</TT>
<TT>116:     if (matchedAccount == last) {</TT>
<TT>117: </TT>
<B><TT>118:</TT></B><TT>         <B>// Invalid Account; throw an exception.</B></TT>
<B><TT>119:</TT></B><TT>         <B>cout &lt;&lt; &quot;BankImpl: Attempted to delete invalid Account.&quot; &lt;&lt;</B></TT>
<B><TT>120:</TT></B><TT>                 <B>endl;</B></TT>
<B><TT>121:</TT></B><TT>         <B>throw InvalidAccountException();</B></TT>
<B><TT>122:</TT></B><TT>     <B>}</B></TT>
<TT>123:     cout &lt;&lt; &quot;BankImpl: Deleting Account \&quot;&quot; &lt;&lt; account-&gt;</TT>
<TT>124:             accountNumber() &lt;&lt; &quot;\&quot;.&quot; &lt;&lt; endl;</TT>
<TT>125: </TT>
<TT>126:     // Delete the given Account.</TT>
<TT>127:     myAccounts.erase(matchedAccount);</TT>
<TT>128:     account-&gt;_release();</TT>
<TT>129: }</TT>
<TT>130: </TT>
<TT>131: AccountList* BankImpl::getAccounts() {</TT>
<TT>132: </TT>
<TT>133:     AccountList* list = new AccountList(myAccounts.size());</TT>
<TT>134:     CORBA::Long i;</TT>
<TT>135: </TT>
<TT>136:     for (i = 0; i &lt; myAccounts.size(); i++) {</TT>
<TT>137:         (*list)[i] = Account::_duplicate(myAccounts[i]);</TT>
<TT>138:     }</TT>
<TT>139: </TT>
<TT>140:     return list;</TT>
<TT>141: }</TT>
<TT>142: </TT>
<TT>143: // Return the next available account number. The result is returned</TT>
<TT>144: // in a static buffer.</TT>
<TT>145: char* BankImpl::getNextAccountNumber() {</TT>
<TT>146: </TT>
<TT>147:     static char accountNumber[16] = &quot;Account        &quot;;</TT>
<TT>148: </TT>
<TT>149:     sprintf(accountNumber + 7, &quot;%08u&quot;, myNextAccountNumber++);</TT>
<TT>150: </TT>
<TT>151:     return accountNumber;</TT>
<TT>152: }</TT>
<TT>153: </TT>
<TT>154: // Return the current date in the form &quot;Mmm DD YYYY&quot;. The result is</TT>
<TT>155: // returned in a static buffer.</TT>
<TT>156: char* BankImpl::getCurrentDate() {</TT>
<TT>157: </TT>
<TT>158:     static char currentDate[12] = &quot;           &quot;;</TT>
<TT>159: </TT>
<TT>160:     time_t ltime;</TT>
<TT>161:     time(&amp;ltime);</TT>
<TT>162:     char* ctimeResult = ctime(&amp;ltime);</TT>
<TT>163: </TT>
<TT>164:     memcpy(currentDate, ctimeResult + 4, 3);</TT>
<TT>165:     memcpy(currentDate + 4, ctimeResult + 8, 2);</TT>
<TT>166:     memcpy(currentDate + 7, ctimeResult + 20, 4);</TT>
<TT>167: </TT>
<TT>168:     return currentDate;
169: }</TT> </FONT></PRE>
<P>The logic in <TT>deleteAccount()</TT> is identical to tha