文件＆＃34; /Users/username/Documents/workspace/LifeExp/bin/data/LifeExpectancyWorldBank.csv"缺失或无法访问

Question

我正在研究加州大学圣地亚哥分校的OOP课程。我必须获取一个CVS文件，然后处理它并将日期解析为他们给出的第二个赋值的哈希映射。但是当我尝试加载CSV文件时，似乎Java无法访问它。

package app;


import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import de.fhpotsdam.unfolding.UnfoldingMap;
import de.fhpotsdam.unfolding.providers.Google.GoogleMapProvider;
import de.fhpotsdam.unfolding.utils.MapUtils;

import processing.core.PApplet;

public class LifeExpectancy extends PApplet {

    //properties
    UnfoldingMap map;
    GoogleMapProvider provider; 
    File csvFile;

    //setup method
    //it only runs once, so write your code accordingly
    public void setup() {
        csvFile = new File("/data/LifeExpectancyWorldBank.csv");
        try {
            loadLifeExpectancyfromCSV(csvFile.getCanonicalPath());
        } catch (IOException e) {
            e.printStackTrace();
        }

        size(800, 600, OPENGL);
        provider = new GoogleMapProvider();
        map = new UnfoldingMap(this, 50, 50, 700, 500, provider);
        MapUtils.createDefaultEventDispatcher(this, map);


        }

    //draw method
    //it is dynamic, that means it runs through the program's runtime
    //so write your code accordingly
    public void draw() {
        map.draw();
    }

    //methods

    /**
     * Loads a CSV file, parses it and returns the parsed data accordingly
     * @param fileName name of the file that will be loaded
     * @return parsed data that comes from the file
     */
    private Map<String, Float> loadLifeExpectancyfromCSV(String fileName) {
        Map<String, Float> lifeExpMap = new HashMap<String, Float>();

        String[] rows = loadStrings(fileName);

        for (String row : rows) {
            String[] columns = row.split(",");
            float value = Float.parseFloat(columns[5]);
            lifeExpMap.put(columns[4], value);
        }

        return lifeExpMap;
    }
}

当我运行此代码时，会发生这种情况：

The file "/data/LifeExpectancyWorldBank.csv" is missing or inaccessible, make sure the URL is valid or that the file has been added to your sketch and is readable.
Exception in thread "Animation Thread" java.lang.NullPointerException
    at app.LifeExpectancy.loadLifeExpectancyfromCSV(LifeExpectancy.java:59)
    at app.LifeExpectancy.setup(LifeExpectancy.java:27)
    at processing.core.PApplet.handleDraw(PApplet.java:2361)
    at processing.core.PGraphicsJava2D.requestDraw(PGraphicsJava2D.java:240)
    at processing.core.PApplet.run(PApplet.java:2256)
    at java.lang.Thread.run(Thread.java:745

我错过了什么？