View Problem
Implement and use an Interface
Create a Serializable interface consisting of
* Accept a stream or handle or descriptor argument for the source or destination
* Save to destination or restore from source the properties or data members of the implementing class (restrict yourself to the primitive types
Next, create a Person class which has
perl 5
perl
java 1.3 and above
Submit a new solution for perl or java
There are 11 other solutions in additional languages (clojure, cpp, fantom, fsharp ...)
'save' and 'restore' methods, each of which:
* Accept a stream or handle or descriptor argument for the source or destination
* Save to destination or restore from source the properties or data members of the implementing class (restrict yourself to the primitive types
'int' and 'string')
Next, create a Person class which has
'name' and 'age' properties or data members and implements this interface. Instantiate a Person object, save it to a serial stream, and instantiate a new Person object by restoring it from the serial stream.
package Person;
use Moose;
use MooseX::Storage;
with Storage('format' => 'JSON', 'io' => 'File');
has 'name' => (is => 'rw', isa => 'Str');
has 'age' => (is => 'rw', isa => 'Int');
1;
Person->new( name => 'David B.', age => 28)->store('person.json');
my $p = Person->load('person.json');
use Moose;
use MooseX::Storage;
with Storage('format' => 'JSON', 'io' => 'File');
has 'name' => (is => 'rw', isa => 'Str');
has 'age' => (is => 'rw', isa => 'Int');
1;
Person->new( name => 'David B.', age => 28)->store('person.json');
my $p = Person->load('person.json');
{
package Serializable;
use Role::Basic;
use Storable qw'store_fd retrieve_fd';
use Scalar::Util 'blessed';
use IO::Handle;
use Carp;
sub save {
my $self = shift;
my $fd = shift or croak 'Needs target file handle';
$DB::single = (1);
store_fd($self, $fd);
}
sub restore {
my $class = shift;
my $fd = shift or croak 'Needs source file handle';
my $self = retrieve_fd( $fd );
bless $self, $class
}
}
{
package Person;
use Role::Basic 'with';
use Scalar::Util 'looks_like_number';
use Carp;
with 'Serializable';
sub new {
my $class = shift;
croak 'Invalid parameters' if (@_ % 2);
%parameters = @_;
do {
croak "Missing $_" unless defined $parameters{$_}
} for qw/name age/;
croak 'Invalid age' unless looks_like_number($parameters{age});
bless \%parameters, $class
}
sub name {
$self{name}
}
sub age {
$self{age}
}
}
use IO::Handle;
my $p1 = Person->new(age => 42, name => 'Milly Fogg');
open my $fh, '+>', 'person.store';
$p1->save( $fh );
seek $fh, 0, SEEK_SET;
my $p2 = Person->restore( $fh );
package Serializable;
use Role::Basic;
use Storable qw'store_fd retrieve_fd';
use Scalar::Util 'blessed';
use IO::Handle;
use Carp;
sub save {
my $self = shift;
my $fd = shift or croak 'Needs target file handle';
$DB::single = (1);
store_fd($self, $fd);
}
sub restore {
my $class = shift;
my $fd = shift or croak 'Needs source file handle';
my $self = retrieve_fd( $fd );
bless $self, $class
}
}
{
package Person;
use Role::Basic 'with';
use Scalar::Util 'looks_like_number';
use Carp;
with 'Serializable';
sub new {
my $class = shift;
croak 'Invalid parameters' if (@_ % 2);
%parameters = @_;
do {
croak "Missing $_" unless defined $parameters{$_}
} for qw/name age/;
croak 'Invalid age' unless looks_like_number($parameters{age});
bless \%parameters, $class
}
sub name {
$self{name}
}
sub age {
$self{age}
}
}
use IO::Handle;
my $p1 = Person->new(age => 42, name => 'Milly Fogg');
open my $fh, '+>', 'person.store';
$p1->save( $fh );
seek $fh, 0, SEEK_SET;
my $p2 = Person->restore( $fh );
// Serialization to a file
class Person implements Serializable {
private static final long serialVersionUID = 1L;
private String name;
private int age;
public void setAge(int age) {
this.age = age;
}
public int getAge() {
return age;
}
public void setName(String name) {
this.name = name;
}
public String getName() {
return name;
}
public boolean equals(Object obj) {
if(obj == this) return true;
if(obj instanceof Person) {
Person p = (Person) obj;
return (p.getName().equals(this.getName())
& p.getAge() == this.getAge());
}
return false;
}
public String toString() {
return "Name: " + name + ", age: " + age;
}
}
Person person = new Person();
person.setName("Gaylord Focker");
person.setAge(21);
try {
File file = new File("ser.obj");
FileOutputStream fos = new FileOutputStream(file);
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(person);
oos.close();
FileInputStream fis = new FileInputStream(file);
ObjectInputStream ois = new ObjectInputStream(fis);
Person deserializedPerson = (Person) ois.readObject();
ois.close();
System.out.println(deserializedPerson);
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
class Person implements Serializable {
private static final long serialVersionUID = 1L;
private String name;
private int age;
public void setAge(int age) {
this.age = age;
}
public int getAge() {
return age;
}
public void setName(String name) {
this.name = name;
}
public String getName() {
return name;
}
public boolean equals(Object obj) {
if(obj == this) return true;
if(obj instanceof Person) {
Person p = (Person) obj;
return (p.getName().equals(this.getName())
& p.getAge() == this.getAge());
}
return false;
}
public String toString() {
return "Name: " + name + ", age: " + age;
}
}
Person person = new Person();
person.setName("Gaylord Focker");
person.setAge(21);
try {
File file = new File("ser.obj");
FileOutputStream fos = new FileOutputStream(file);
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(person);
oos.close();
FileInputStream fis = new FileInputStream(file);
ObjectInputStream ois = new ObjectInputStream(fis);
Person deserializedPerson = (Person) ois.readObject();
ois.close();
System.out.println(deserializedPerson);
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
Submit a new solution for perl or java
There are 11 other solutions in additional languages (clojure, cpp, fantom, fsharp ...)
