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Kei Inoue edited this page Apr 19, 2019 · 8 revisions

PHPJava - JVM Emulator by PHP

contributions welcome Compatibility Build Status Total Downloads License: MIT

What is the PHPJava?

The PHPJava is an experimental library which emulates JVM (a.k.a. Java Virtual Machine) by PHP 🐘 The PHPJava reads binary from pre-compiled Java file(s) ☕ This project referred to Java Virtual Machine Specification documentation at the time we made it.

We are welcoming any contributions to this project 💪

Contribution guide is here:

Requirements

  • PHP >= 7.2
  • Composer
  • ext-zip

Quick start

    1. Install the PHPJava into your project:
$ composer require memory-agape/php-java
    1. Write Java:
class HelloWorld 
{
    public static void main(String[] args)
    {
        System.out.println(args[0]);
    }
}
    1. Compile Java:
$ javac -UTF8 /path/to/HelloWorld.java
    1. Call the main method as follows:
<?php
use PHPJava\Core\JavaClass;
use PHPJava\Core\Stream\Reader\FileReader;

(new JavaClass(new FileReader('/path/to/HelloWorld.class')))
    ->getInvoker()
    ->getStatic()
    ->getMethods()
    ->call(
        'main',
        ["Hello World!"]
    );
    1. Get the result
$ php /path/to/HelloWorld.php
Hello World!

Java Archive (Execute to *.jar file)

    1. Build your Java files to class. An example is shown below:
$ javac -encoding UTF8 -d build src/*
$ cd build && jar -cvfe ../Test.jar Test *
    1. Execute jar on PHPJava with either an enrtypoint or your targeted method.
<?php
use PHPJava\Core\JavaArchive;

// You must pass parameters to entrypoint within the `execute` method.
// The `execute` method haven't default parameters.
(new JavaArchive('Test.jar'))->execute([]);

// or
(new JavaArchive('Test.jar'))
    ->getClassByName('Test')
    ->getInvoker()
    ->getStatic()
    ->getMethods()
    ->call(
        'main',
        []
    );

Get/Set static fields

  • ex) Set or Get static fields as follows:
<?php
use PHPJava\Core\JavaClass;
use PHPJava\Core\Stream\Reader\FileReader;

$staticFieldAccessor = (new JavaClass(new FileReader('/path/to/HelloWorld.class')))
    ->getInvoker()
    ->getStatic()
    ->getFields();

// Set
$staticFieldAccessor->set('fieldName', 'value');

// Get
echo $staticFieldAccessor->get('fieldName');

Call a static method

  • ex) Call a static method as follows:
<?php
use PHPJava\Core\JavaClass;
use PHPJava\Core\Stream\Reader\FileReader;

(new JavaClass(new FileReader('/path/to/HelloWorld.class')))
    ->getInvoker()
    ->getStatic()
    ->getMethods()
    ->call(
        'methodName',
        $firstArgument,
        $secondArgument,
        $thirdArgument,
        ...
    );

// Or if called method have return value then you can store to variable.
$result = (new JavaClass(new FileReader('/path/to/HelloWorld.class')))
   ->getInvoker()
   ->getStatic()
   ->getMethods()
   ->call(
       'methodWithSomethingReturn',
       $firstArgument,
       $secondArgument,
       $thirdArgument,
       ...
   );

// The $result you want is output.
echo $result;

Get/Set dynamic fields

If you want to get/set dynamic fields, you need to call the construct method on Java by PHPJava.

  • ex) Call dynamic field as follows:
<?php
use PHPJava\Core\JavaClass;
use PHPJava\Core\Stream\Reader\FileReader;

$javaClass = new JavaClass(new FileReader('/path/to/HelloWorld.class'));

$javaClass->getInvoker()->construct();

$dynamicFieldAccessor = $javaClass
    ->getInvoker()
    ->getDynamic()
    ->getFields();

// Set
$dynamicFieldAccessor->set('fieldName', 'value');

// Get
echo $dynamicFieldAccessor->get('fieldName');

Call a dynamic method

If you want to get/set dynamic method (same as a field), you need to call the construct method on Java by PHPJava.

  • ex) Call dynamic method as follows:
<?php
use PHPJava\Core\JavaClass;
use PHPJava\Core\Stream\Reader\FileReader;

$dynamicMethodAccessor = (new JavaClass(new FileReader('/path/to/HelloWorld.class')))
     ->getInvoker()
     ->construct()
     ->getDynamic()
     ->getMethods(); 

$dynamicMethodAccessor
    ->call(
        'methodName',
        $firstArgument,
        $secondArgument,
        $thirdArgument,
        ...
    );

// Or if called method have return value then you can store to variable.
$dynamicMethodAccessor
   ->call(
       'methodWithSomethingReturn',
       $firstArgument,
       $secondArgument,
       $thirdArgument,
       ...
   );

// The $result you want is output.
echo $result;

Call ambiguous method into Java from PHP

  • PHP types are ambiguous than Java.
  • You may want to call a methods in PHP that contain long type in Java. In its case, you can call a method as follows:

ex. ) [Recommended] Wrap with \PHPJava\Kernel\Types\\_Long.

In Java
class Test
{
    public static void includingLongTypeParameter(long n)
    {
        System.out.println(n);
    }

}
In PHP
<?php
$javaClass->getInvoker()->getStatic()->getMethods()->call(
    'includingLongTypeParameter',
    new \PHPJava\Kernel\Types\\_Long(1234)
);

The example will return 1234.

ex. ) Set false to strict mode within options.

In PHP
<?php
use PHPJava\Core\JavaClass;
use PHPJava\Core\Stream\Reader\FileReader;

$javaClass = new JavaClass(
    new Stream\Reader\FileReader('Test'),
    [
        'strict' => false,
    ]
);

Runtime options

  • Available options on JavaClass or JavaArchive is below:
Options Value Default Description Targeted
entrypoint string or null null Specify to run entrypoint in JAR. JavaArchive
max_stack_exceeded integer 9999 Execute more than the specified number of times be stopped the operation. JavaClass
max_execution_time integer 30 This option control max execution times. JavaClass
strict boolean true If strict mode is true then execute method, variables and so on with strict. But if strict mode is false then execute ambiguously method, variable and etc in PHPJava. Both
preload boolean false preload is pre-read JavaClass in emulating JAR. This may be a lot of consuming memories by large JAR file. but JavaArchive use defer loading if this option is false. JavaArchive
validation.method.arguments_count_only boolean false If this mode true then ClassResolver validate arguments size only. JavaClass
operations.enable_trace boolean true Store operations history into memory if this is enabled. JavaClass
operations.temporary_code_stream string php://memory Operation code will be outputted to temporary stream. Change temporary stream if your code is heavy. You'll get happy. JavaClass
operations.injector.before callable null Inject an executor before from executing an operation. JavaClass
operations.injector.after callable null Inject an executor after to executing an operation. JavaClass
log.level int Logger::EMERGENCY This option set Monolog output level. Both
log.path string or resource php://stdout This option set Monolog output destination. Both
dry_run (Not Implemented) boolean false Dry-run denotes to check JavaClass/JavaArchive structures only. If this options is true then to run dry-run mode. Both
env (Not Implemented) enum Environment::EXPERIMENTAL Set your environment. Both
  • For example in JavaClass:
<?php
use PHPJava\Core\JavaClass;
use PHPJava\Core\Stream\Reader\FileReader;

$javaClass = new JavaClass(
    new FileReader('Test'),
    [
        'max_stack_exceeded' => 12345,
        'validation' => [
            'method' => [
                'arguments_count_only' => true,
            ],
        ],
    ]
);
  • For example in GlobalOptions
<?php
use PHPJava\Core\JVM\Parameters\GlobalOptions;
use Monolog\Logger;

GlobalOptions::set([
    'log' => [
        'level' => Logger::DEBUG,
    ],
    'validation' => [
        'method' => [
            'arguments_count_only' => true,
        ],
    ],
]);

Output PHPJava operations

  • Output debug trace as follows if you want to show operation log:
<?php
use PHPJava\Core\JavaClass;
use PHPJava\Core\Stream\Reader\FileReader;

$javaClass = new JavaClass(new FileReader('/path/to/HelloWorld.class'));

$javaClass
    ->getInvoker()
    ->getStatic()
    ->getMethods()
    ->call(
        'main',
        ["Hello", 'World']
    );

// Show debug traces.
$javaClass->debug();
  • Output debug trace is shown below:
[method]
public static void main(java.lang.String[])

[code]
<0xb2> <0x00> <0x02> <0x2a> <0x03> <0x32> <0xb6> <0x00> <0x03> <0xb2> <0x00> <0x02> <0x2a> <0x04> <0x32> <0xb6> <0x00> <0x03> <0xb2> <0x00>
<0x02> <0x2a> <0x05> <0x32> <0xb6> <0x00> <0x03> <0xb1>

[executed]
      PC | OPCODE | MNEMONIC             | OPERANDS   | LOCAL STORAGE  
---------+--------+----------------------+------------+-----------------
       0 | 0xB2   | getstatic            | 0          | 1              
       3 | 0x2A   | aload_0              | 1          | 1              
       4 | 0x03   | iconst_0             | 2          | 1              
       5 | 0x32   | aaload               | 3          | 1              
       6 | 0xB6   | invokevirtual        | 2          | 1              
       9 | 0xB2   | getstatic            | 0          | 1              
      12 | 0x2A   | aload_0              | 1          | 1              
      13 | 0x04   | iconst_1             | 2          | 1              
      14 | 0x32   | aaload               | 3          | 1              
      15 | 0xB6   | invokevirtual        | 2          | 1              
      18 | 0xB2   | getstatic            | 0          | 1              
      21 | 0x2A   | aload_0              | 1          | 1              
      22 | 0x05   | iconst_2             | 2          | 1              
      23 | 0x32   | aaload               | 3          | 1              
      24 | 0xB6   | invokevirtual        | 2          | 1              
      27 | 0xB1   | return               | 0          | 1              
---------+--------+----------------------+------------+-----------------
  • [method] shows the called method.
  • [code] shows the JVM's real programs.
  • [executed] shows the executed programs.
    • PC shows the Program Counter.
    • OPCODE shows the Operation Codes.
    • MNEMONIC shows the names of the Operation Codes.
    • OPERANDS shows the stacked items on memory.
    • LOCAL STORAGE shows the stacked items on a method.

PHP problems

  • Problem 1: PHP cannot calculate big numbers because PHP is different from Java. But PHPJava uses bcmath functions and gmp functions to a certain extent to cover such calculations. Therefore, PHPJava returns a mixed value and we recommend to cast them to string on PHPJava.

  • Problem 2: PHPJava cannot completely cover Java types because PHP is different from Java. The comparison table of Java and PHPJava is shown below:

Java PHPJava
null null
boolean \PHPJava\Kernel\Types\_Boolean (including __toString)
char \PHPJava\Kernel\Types\_Char (including __toString)
byte \PHPJava\Kernel\Types\_Byte (including __toString)
short \PHPJava\Kernel\Types\_Short (including __toString)
int \PHPJava\Kernel\Types\_Int (including __toString)
long \PHPJava\Kernel\Types\_Long (including __toString)
float \PHPJava\Kernel\Types\_Float (including __toString)
double \PHPJava\Kernel\Types\_Double (including __toString)
  • Problem 3: PHPJava cannot calculate big number of double and float because gmp_pow cannot calculate negative exponents. So, PHPJavas use built-in function pow.

Run Kotlin on the PHPJava

Are you wanna run Kotlin on the PHPJava? Are you a serious? Haha, yes you can. But this feature is experimental currently.

Quick Start

    1. Write Kotlin:
fun main(args: Array<String>) {
    println("Hello World!")
}
    1. Compile Kotlin:
$ kotlinc HelloWorld.kt -include-runtime -d HelloWorld.jar
    1. Execute JAR as follows:
<?php
use PHPJava\Core\JavaArchive;

$jar = new JavaArchive(__DIR__ . '/HelloWorld.jar');
$jar->execute([]);

You'll get a result Hello World!.

Run unit tests

  • To run a PHPUnit test:
$ ./vendor/bin/phpunit tests
  • To run PHP Coding standards test:
$ ./vendor/bin/phpcs --standard=phpcs.xml src
  • To run all tests:
$ composer run tests

Reference

License

MIT

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