在javax.script API中重定向KotlinScriptEngine的标准输出

Question

我正在使用javax.script API执行kotlin脚本。我想捕获输出并稍后打印日志。

我可以在nashorn脚本引擎上做到这一点，但在KotlinScriptEngine上不能这样做。

    public void testExampleNashorn() throws ScriptException {
        ScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn");
        ScriptContext context = engine.getContext();
        StringWriter writer = new StringWriter();
        context.setWriter(writer);

        engine.eval("print(\"Welocme to java worldddd\")");

        String output = writer.toString();

        System.out.println("Script output: " + output);
    }

Nashorn的输出

Script output: Welocme to java worldddd

为kotlin调整时的相同代码片段，如下所示

    public void testExampleKotlin() throws ScriptException {
        ScriptEngine engine = new ScriptEngineManager().getEngineByName("kotlin");
        ScriptContext context = engine.getContext();
        StringWriter writer = new StringWriter();
        context.setWriter(writer);

        engine.eval("println(\"Welocme to java worldddd\")");

        String output = writer.toString();

        System.out.println("Script output: " + output);
    }

kotlin的输出

Welocme to java worldddd
Script output: 
null

我正在使用kotlin版本1.3.72，任何帮助都是非常感谢的。谢谢。

Answer 1

这就是我如何设法捕获KotlinScriptEngine执行日志的方法。

public Object captureOut(String script,Bindings bindings)  {
        Object result=null;
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        PrintStream ps = new PrintStream(os);
        PrintStream console = System.out;
        System.setOut(ps);

        try {
            result = kotlinScriptingEngine.eval(script,bindings);
        } catch (ScriptException scriptException) {
            scriptException.printStackTrace(ps);
        }  finally {
            System.out.flush();
            System.setOut(console);
        }
        System.out.println("Kotlin Script Output: " + os.toString());
        return result;
}