在JavaScript中调用Java类和接口的方法

var ArrayList = Java.type("java.util.ArrayList");
var intType = Java.type("int");
var StringArrayType = Java.type("java.lang.String[]");
var int2DArrayType = Java.type("int[][]");

var anArrayList = new Java.type("java.util.ArrayList");

var ArrayList = Java.type("java.util.ArrayList");
var defaultSizeArrayList = new ArrayList;
var customSizeArrayList = new ArrayList(16);

var File = Java.type("java.io.File");
File.createTempFile("nashorn", ".tmp");

var Float = Java.type("java.awt.geom.Arc2D$Float");

var Arc2D = Java.type("java.awt.geom.Arc2D")
var Float = Arc2D.Float

var ArrayList = Java.type("java.util.ArrayList");
var a = new ArrayList;

// All of the following are true:
print("Type acts as target of instanceof: " + (a instanceof ArrayList));
print("Class doesn't act as target of instanceof: " + !(a instanceof a.getClass()));
print("Type is not the same as instance's getClass(): " + (a.getClass() !== ArrayList));
print("Type's `class` property is the same as instance's getClass(): " + (a.getClass() === ArrayList.class));
print("Type is the same as the `static` property of the instance's getClass(): " + (a.getClass().static === ArrayList));

// Load compatibility script
load("nashorn:mozilla_compat.js");
// Import the java.awt package
importPackage(java.awt);
// Import the java.awt.Frame class
importClass(java.awt.Frame);
// Create a new Frame object
var frame = new java.awt.Frame("hello");
// Call the setVisible() method
frame.setVisible(true);
// Access a JavaBean property
print(frame.title);

// Create a JavaImporter object with specified packages and classes to import
var Gui = new JavaImporter(java.awt, javax.swing);

// Pass the JavaImporter object to the "with" statement and access the classes
// from the imported packages by their simple names within the statement's body
with (Gui) {
 var awtframe = new Frame("AWT Frame");
 var jframe = new JFrame("Swing JFrame");
};

var StringArray = Java.type("java.lang.String[]");
var a = new StringArray(5);

// Set the value of the first element
a[0] = "Scripting is great!";
// Print the length of the array
print(a.length);
// Print the value of the first element
print(a[0]);

// 创建一个 JavaScript 数组
var anArray = [1, "13", false];

// 将数组转换成 java 的 int[] 数组
var javaIntArray = Java.to(anArray, "int[]");
print(javaIntArray[0]); // prints the number 1
print(javaIntArray[1]); // prints the number 13
print(javaIntArray[2]); // prints the number 0

// 将 JavaScript 数组转换成 Java 的 String[] 数组
var javaStringArray = Java.to(anArray, Java.type("java.lang.String[]"));
print(javaStringArray[0]); // prints the string "1"
print(javaStringArray[1]); // prints the string "13"
print(javaStringArray[2]); // prints the string "false"

// 将 JavaScript 数组转换成 Java 的 Object[] 数组
var javaObjectArray = Java.to(anArray);
print(javaObjectArray[0]); // prints the number 1
print(javaObjectArray[1]); // prints the string "13"
print(javaObjectArray[2]); // prints the boolean value "false"

// Get the Java File type object
var File = Java.type("java.io.File");
// Create a Java array of File objects
var listCurDir = new File(".").listFiles();
// Convert the Java array to a JavaScript array
var jsList = Java.from(listCurDir);
// Print the JavaScript array
print(jsList);

// Create an object that implements the Runnable interface by implementing
// the run() method as a JavaScript function
var r = new java.lang.Runnable() {
 run: function() {
  print("running...\n");
 }
};

// The r variable can be passed to Java methods that expect an object implementing
// the java.lang.Runnable interface
var th = new java.lang.Thread(r);
th.start();
th.join();

// Define a JavaScript function
function func() {
 print("I am func!");
};

// Pass the JavaScript function instead of an object that implements
// the java.lang.Runnable interface
var th = new java.lang.Thread(func);
th.start();
th.join();

var TimerTask = Java.type("java.util.TimerTask");
var task = new TimerTask({ run: function() { print("Hello World!") } });

var task = new TimerTask {
 run: function() {
  print("Hello World!")
 }
};

var task = new TimerTask(function() { print("Hello World!") });

var Timer = Java.type("java.util.Timer");
Timer.schedule(function() { print("Hello World!") });

var t = new java.lang.Thread({ run: function() { print("Thread running!") } });

var Thread = Java.type("java.lang.Thread");
var threadExtender = Java.extend(Thread);
var t = new threadExtender() {
 run: function() { print("Thread running!") }};

Example 3-1 访问父类的方法 (super.js)

var Exception = Java.type("java.lang.Exception");
var ExceptionAdapter = Java.extend(Exception);

var exception = new ExceptionAdapter("My Exception Message") {
 getMessage: function() {
  var _super_ = Java.super(exception);
  return _super_.getMessage().toUpperCase();
 }
}

try {
 throw exception;
} catch (ex) {
 print(exception);
}

jdk.nashorn.javaadapters.java.lang.Exception: MY EXCEPTION MESSAGE

var Runnable = java.lang.Runnable;
var r1 = new Runnable(function() { print("I'm runnable 1!") });
var r2 = new Runnable(function() { print("I'm runnable 2!") });
r1.run();
r2.run();
print("We share the same class: " + (r1.class === r2.class));

I'm runnable 1!
I'm runnable 2!
We share the same class: true

var RunnableImpl1 = Java.extend(java.lang.Runnable, function() { print("I'm runnable 1!") });
var RunnableImpl2 = Java.extend(java.lang.Runnable, function() { print("I'm runnable 2!") });
var r1 = new RunnableImpl1();var r2 = new RunnableImpl2();
r1.run();
r2.run();
print("We share the same class: " + (r1.class === r2.class));

I'm runnable 1!
I'm runnable 2!
We share the same class: false

var RunnableImpl = Java.extend(java.lang.Runnable, function() { print("I'm runnable 1!") });
var r1 = new RunnableImpl();
var r2 = new RunnableImpl(function() { print("I'm runnable 2!") });
r1.run();
r2.run();
print("We share the same class: " + (r1.class === r2.class));

I'm runnable 1!
I'm runnable 2!
We share the same class: true

var out = java.lang.System.out;
out["println(Object)"]("hello");