JRI：如何在 Java 字符串中获取控制台输出

Question

我在我的 Java 程序中声明 JRI 引擎如下：

REngine eng = REngine.engineForClass("org.rosuda.REngine.JRI.JRIEngine", 
    args, new REngineStdOutput(), false);

这工作正常，但我想在 Java 字符串而不是 Java 控制台中获取控制台输出。

我研究了 REngineStdOutput 但找不到太多。有任何想法吗？

Answer 1

您必须实现 org.rosuda.JRI.RMainLoopCallbacks 接口 - 特别是 rWriteConsole() 将与每个输出字符串一起调用。

Answer 2

Bellow 是如何将 R 输出显示为 Java 的示例。您基本上必须实施 RMainLoopCallbacks.

import org.rosuda.JRI.RMainLoopCallbacks;
import org.rosuda.JRI.Rengine;
import java.util.logging.Logger;

public class Runner {

    private static Logger log = Logger.getLogger("Runner");

    static class LoggingConsole implements RMainLoopCallbacks {
        private Logger log;

        LoggingConsole(Logger log) {
            this.log = log;
        }

        public void rWriteConsole(Rengine re, String text, int oType) {
            log.info(String.format("rWriteConsole: %s", text));
        }

        public void rBusy(Rengine re, int which) {
            log.info(String.format("rBusy: %s", which));
        }

        public void rShowMessage(Rengine re, String message) {
            log.info(String.format("rShowMessage: %s",  message));
        }

        public String rReadConsole(Rengine re, String prompt, int addToHistory) {
            return null;
        }

        public String rChooseFile(Rengine re, int newFile) {
            return null;
        }

        public void rFlushConsole(Rengine re) {
        }

        public void rLoadHistory(Rengine re, String filename) {
        }

        public void rSaveHistory(Rengine re, String filename) {
        }
    }

    Rengine engine = new Rengine(new String[] {"--no-save"}, false, new LoggingConsole(log));
    ...
    // Use the engine somewhere to evaluate a R method and see the output
    engine.eval("library(caret)");
}

JRI：如何在 Java 字符串中获取控制台输出

JRI: how to get the console output in a Java String

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