Question

我正在尝试从R调用一些Java代码，我已经编译了Java类，并且可以手动执行代码-很好！

但是，当从R调用相同的代码位时，会引发此错误： 4. stop(structure(list(message = "java.lang.ArrayIndexOutOfBoundsException", call = .jcall(obj, "[[Ljava/lang/String;", "findPattern", location), jobj = new("jobjRef", jobj = <pointer: 0x00000000195abf30>, jclass = "java/lang/ArrayIndexOutOfBoundsException")), class = c("ArrayIndexOutOfBoundsException", ... 3. .jcheck() 2. .jcall(obj, "[[Ljava/lang/String;", "findPattern", location) 1. findPattern()

由于手动运行Java可以正常运行，因此问题似乎出在我从r执行Java上。

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

class PatternFinder
{
    private static final Pattern pattern = Pattern.compile("([1-9])(4-5)([asuy])");

    public static void main(String[] args)
    {
        if (args.length == 1)
        {
            findPattern(args[0]);
        }
        else
        {
            System.err.println("No arguments specified");
            System.exit(1);
        }
    }

    public static String[][] findPattern(String filePath)
    {
        String[][] df = null;
        List<String> g1 = new ArrayList<>();
        List<String> g2 = new ArrayList<>();
        List<String> g3 = new ArrayList<>();
        try (BufferedReader br = new BufferedReader(new FileReader(filePath)))
        {
            String line;
            while ((line = br.readLine()) != null)
            {
                Matcher matcher = pattern.matcher(line);
                while (matcher.find())
                {
                    g1.add(matcher.group(1).trim());
                    g2.add(matcher.group(2).trim());
                    g3.add(matcher.group(3).trim());
                }

            }
            df = new String[g1.size()][3];
            for (int i = 0; i < g1.size(); i++)
            {
                df[i][0] = g1.get(i);
                df[i][1] = g2.get(i);
                df[i][2] = g3.get(i);
            }
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        return df;
    }
}

这是R代码：

library(rJava)
.jinit("C:\\Program Files\\Java\\jdk1.8.0_45", "C:\\PatternFinder")
obj=.jnew("PatternFinder")

patternFinder <-function(location = "C:\\largeFile.txt")
{
  result = .jcall(obj,"[[Ljava/lang/String;", "findPattern", location)
  df = sapply(result,.jevalArray)
  df
}

patternFinder()

尝试尝试.jcall时出现ArrayIndexOutOfBoundsException（对象，“ [[Ljava / lang / String;”，“ staticMethod”，methodParam）

0 个答案: