node-jvm —— 纯node.js 的 JVM 实现

node-jvm，使用纯node.js实现了JVM，太酷了！

例如，下面是一段生成斐波纳契数列并计算生成时间的Java代码：

public class Main {
    public static long fib(int n) {
        if (n <= 1) return n;
        return fib(n-1) + fib(n-2);
    }

    public static void main(String[] args) {
        if (args.length == 0) {
                System.out.print("help: java Main.class {Number}");
                return;
        }

        int N = Integer.parseInt(args[0]);
        long start = System.currentTimeMillis();            
        System.out.format("Fibonacci from 1 to %s:\n", N);
        for (int i = 1; i <= N; i++) {
            System.out.println(i + ": " + fib(i));
        }
        long stop = System.currentTimeMillis();
        System.out.println("time: " + (stop - start) + "ms");

        System.out.println("done.");
    }
}

将它保存为Main.jar，然后加载到node-jvm中：

var JVM = require("node-jvm");
var jvm = new JVM();
jvm.setLogLevel(7);
var entryPointClassName = jvm.loadJarFile("./Main.jar");
jvm.setEntryPointClassName(entryPointClassName);
jvm.on("exit", function(code) {
    process.exit(code);
});
jvm.run([15]);

构建：

cd examples/fibonacci
make

运行：

./fibonacci.js

输出：

Fibonacci from 1 to 15:
1: 1
2: 1
3: 2
4: 3
5: 5
6: 8
7: 13
8: 21
9: 34
10: 55
11: 89
12: 144
13: 233
14: 377
15: 610
time: 106ms
done.

node-jvm在MIT许可下发布，项目主页在此。

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编撰 SegmentFault