Proxy Plugins¶

The proxy converter and its derived converters support proxy plugins that have the following features.

Conversion for the particular Java types can be easily turned on or off by the plugins.
The plugins can extend the capabilities of the particular Java types to simulate the native JS types.
The public Java fields and methods are available as well.

Built-in Proxy Plugins¶

The built-in proxy plugins provide the basic support. They are turned off by default in the JavetProxyConverter, and turned on by default in the JavetBridgeConverter. They can be easily turned on or off once the converter is created to allow fine-grained control over the conversion.

Plugin	Types
JavetProxyPluginDefault	`BigInteger`, `Boolean`, `Byte`, `Character`, `Double`, `Float`, `Integer`, `Long`, `Short`, `String`, `ZonedDateTime`.
JavetProxyPluginArray	`boolean[]`, `byte[]`, `char[]`, `double[]`, `float[]`, `int[]`, `long[]`, `short[]`, `Object[]`.
JavetProxyPluginList	`List<?>`
JavetProxyPluginMap	`Map<?, ?>`
JavetProxyPluginSet	`Set<?>`

JavetProxyPluginDefault¶

The default plugin maps all primitive types, BigInteger, String and ZonedDateTime to their corresponding JS types.

Java Type	JS Type
`BigInteger`	`bigint`
`Boolean`	`boolean`
`Byte`	`number`
`Character`	`string`
`Double`	`number`
`Float`	`number`
`Integer`	`number`
`Long`	`bigint`
`Short`	`number`
`String`	`string`
`ZonedDateTime`	`Date`

// 2n**65n
BigInteger bigInteger = new BigInteger("36893488147419103232");
v8Runtime.getGlobalObject().set("l", bigInteger);
assertEquals(
    bigInteger.add(new BigInteger("1")),
    v8Runtime.getExecutor("1n + l").executeBigInteger());
v8Runtime.getGlobalObject().delete("l");

JavetProxyPluginArray¶

The array plugin maps all primitive arrays and object arrays to the JS array.

int[] intArray = new int[]{1, 2};
v8Runtime.getGlobalObject().set("intArray", intArray);
assertSame(intArray, v8Runtime.getGlobalObject().getObject("intArray"));
assertTrue(v8Runtime.getExecutor("Array.isArray(intArray)").executeBoolean());
assertTrue(v8Runtime.getExecutor("0 in intArray").executeBoolean());
assertFalse(v8Runtime.getExecutor("2 in intArray").executeBoolean());
assertEquals("Array", v8Runtime.getExecutor("intArray.constructor.name").executeString());
assertEquals(
        "[1,2]",
        v8Runtime.getExecutor("JSON.stringify(intArray)").executeString());
assertEquals(
        "[[0,1],[1,2]]",
        v8Runtime.getExecutor("JSON.stringify([...intArray.entries()])").executeString());
assertEquals(3, v8Runtime.getExecutor("intArray[0] = 3; intArray[0]").executeInteger());
assertEquals(1, v8Runtime.getExecutor("intArray[0] = 1; intArray[0]").executeInteger());
assertEquals(2, v8Runtime.getExecutor("intArray.length").executeInteger());
v8Runtime.getGlobalObject().delete("intArray");

JavetProxyPluginList¶

The list plugin maps List<?> to the JS array.

List<Object> list = SimpleList.of("x", "y");
v8Runtime.getGlobalObject().set("list", list);
assertTrue(v8Runtime.getExecutor("Array.isArray(list)").executeBoolean());
assertEquals("Array", v8Runtime.getExecutor("list.constructor.name").executeString());
assertTrue(v8Runtime.getExecutor("0 in list").executeBoolean());
assertFalse(v8Runtime.getExecutor("2 in list").executeBoolean());
assertTrue(v8Runtime.getExecutor("list.contains('x')").executeBoolean());
assertTrue(v8Runtime.getExecutor("list.contains('y')").executeBoolean());
assertFalse(v8Runtime.getExecutor("list.contains('z')").executeBoolean());
assertEquals(4, v8Runtime.getExecutor("list.push('z', '1')").executeInteger());
assertEquals("1", v8Runtime.getExecutor("list.pop()").executeString());
assertEquals(
        "[\"x\",\"y\",\"z\"]",
        v8Runtime.getExecutor("JSON.stringify(list)").executeString());
v8Runtime.getGlobalObject().delete("list");

JavetProxyPluginMap¶

The map plugin maps Map<?, ?> to the JS object.

Map<String, Object> map = SimpleMap.of("x", 1, "y", "2");
v8Runtime.getGlobalObject().set("map", map);
assertTrue(v8Runtime.getExecutor("map.containsKey('x')").executeBoolean());
assertEquals("Object", v8Runtime.getExecutor("map.constructor.name").executeString());
assertTrue(v8Runtime.getExecutor("'x' in map").executeBoolean());
assertFalse(v8Runtime.getExecutor("1 in map").executeBoolean());
assertEquals(1, v8Runtime.getExecutor("map['x']").executeInteger());
assertEquals("2", v8Runtime.getExecutor("map['y']").executeString());
assertEquals(1, v8Runtime.getExecutor("map.x").executeInteger());
assertEquals("2", v8Runtime.getExecutor("map.y").executeString());
assertEquals(
        "[\"x\",\"y\",\"z\"]",
        v8Runtime.getExecutor("JSON.stringify(Object.getOwnPropertyNames(map).sort());").executeString());
assertEquals(
        "[[\"x\",1],[\"y\",\"2\"],[\"z\",\"4\"]]",
        v8Runtime.getExecutor("JSON.stringify([...map.entries()].sort((a,b)=>a[0]-b[0]));").executeString());
v8Runtime.getGlobalObject().delete("map");

JavetProxyPluginSet¶

The set plugin maps Set<?> to the JS Set.

Set<String> set = SimpleSet.of("x", "y");
v8Runtime.getGlobalObject().set("set", set);
assertEquals("Set", v8Runtime.getExecutor("set.constructor.name").executeString());
assertTrue(v8Runtime.getExecutor("'x' in set").executeBoolean());
assertFalse(v8Runtime.getExecutor("1 in set").executeBoolean());
assertTrue(v8Runtime.getExecutor("set.contains('x')").executeBoolean());
assertTrue(v8Runtime.getExecutor("set.contains('y')").executeBoolean());
assertFalse(v8Runtime.getExecutor("set.contains('z')").executeBoolean());
assertEquals(2, v8Runtime.getExecutor("set.size").executeInteger());
assertEquals(
        "[\"x\",\"y\",\"z\"]",
        v8Runtime.getExecutor("JSON.stringify(Object.getOwnPropertyNames(set).sort());").executeString());
v8Runtime.getGlobalObject().delete("set");

Add or Remove Proxy Plugins¶

The proxy plugins are stored in the JavetConverterConfig.

// Add a proxy plugin
converter.getConfig().getProxyPlugins().add(0, JavetProxyPluginList.getInstance());
// Remove a proxy plugin
converter.getConfig().getProxyPlugins().removeIf(p -> p instanceof JavetProxyPluginList);

Create a New Proxy Plugin¶

There are typically two ways to create a new proxy plugin.

Implement IClassProxyPlugin from scratch.
Subclass an existing proxy plugin.

It's recommended to review the source code of the built-in proxy plugins to learn how to create your own proxy plugin.