Java中的数据传输对象设计模式（Data Transfer Object Design Pattern）

<b>public</b>  <b>class</b>  CustomerDto {
     <b>private</b>  <b>final</b>  String id;
    <b>private</b>  <b>final</b>  String firstName;
    <b>private</b>  <b>final</b>  String lastName;

    / **
      * @param id customer id 
     * @param firstName customer first name 
     * @param lastName customer name name 
/ / <b>public</b> CustomerDto（ String id， String firstName， String lastName）{
         <b>this</b> 。id = id;
        这个。firstName = firstName;
        这个。lastName = lastName;     
        
    }

    <b>public</b>  String  getId（）{
         <b>return</b> id;
    }

    <b>public</b>  String  getFirstName（）{
         <b>return</b> firstName;
    }

    <b>public</b>  String  getLastName（）{
         <b>return</b> lastName;
    }
}

<b>public</b> <b>class</b> CustomerResource {
    <b>private</b> List < CustomerDto > customers;

    <font><i>/**
     * @param customers initialize resource with existing customers. Act as database.
     */</i></font><font>
    <b>public</b> CustomerResource(List < CustomerDto > customers) {
        <b>this</b>.customers = customers;
    }

    </font><font><i>/**
     * @return : all customers in list.
     */</i></font><font>
    <b>public</b> List < CustomerDto > getAllCustomers() {
        <b>return</b> customers;
    }

    </font><font><i>/**
     * @param customer save new customer to list.
     */</i></font><font>
    <b>public</b> <b>void</b> save(CustomerDto customer) {
        customers.add(customer);
    }

    </font><font><i>/**
     * @param customerId delete customer with id {@code customerId}
     */</i></font><font>
    <b>public</b> <b>void</b> delete(String customerId) {
        customers.removeIf(customer - > customer.getId().equals(customerId));
    }
}
</font>

<b>public</b> <b>class</b> CustomerClientApp {

    <b>private</b> <b>static</b> <b>final</b> Logger LOGGER = LoggerFactory.getLogger(CustomerClientApp.<b>class</b>);

    <font><i>/**
     * Method as act client and request to server for details.
     *
     * @param args program argument.
     */</i></font><font>
    <b>public</b> <b>static</b> <b>void</b> main(String[] args) {
        List < CustomerDto > customers = <b>new</b> ArrayList < > ();
        CustomerDto customerOne = <b>new</b> CustomerDto(</font><font>"1"</font><font>, </font><font>"Kelly"</font><font>, </font><font>"Brown"</font><font>);
        CustomerDto customerTwo = <b>new</b> CustomerDto(</font><font>"2"</font><font>, </font><font>"Alfonso"</font><font>, </font><font>"Bass"</font><font>);
        customers.add(customerOne);
        customers.add(customerTwo);

        CustomerResource customerResource = <b>new</b> CustomerResource(customers);

        LOGGER.info(</font><font>"All customers:-"</font><font>);
        List < CustomerDto > allCustomers = customerResource.getAllCustomers();
        printCustomerDetails(allCustomers);

        LOGGER.info(</font><font>"----------------------------------------------------------"</font><font>);

        LOGGER.info(</font><font>"Deleting customer with id {1}"</font><font>);
        customerResource.delete(customerOne.getId());
        allCustomers = customerResource.getAllCustomers();
        printCustomerDetails(allCustomers);

        LOGGER.info(</font><font>"----------------------------------------------------------"</font><font>);

        LOGGER.info(</font><font>"Adding customer three}"</font><font>);
        CustomerDto customerThree = <b>new</b> CustomerDto(</font><font>"3"</font><font>, </font><font>"Lynda"</font><font>, </font><font>"Blair"</font><font>);
        customerResource.save(customerThree);
        allCustomers = customerResource.getAllCustomers();
        printCustomerDetails(allCustomers);
    }

    <b>private</b> <b>static</b> <b>void</b> printCustomerDetails(List < CustomerDto > allCustomers) {
        allCustomers.forEach(customer - > LOGGER.info(customer.getFirstName()));
    }
}
</font>