这个参数用于什么？

Question

主类：

import java.util.ArrayList;

public class readingfiles {
public static void main (String args[])
{
        ArrayList<Double> result2 = lol2016.ReadNumberFile("lel");  
        System.out.println("Result 2: " + result2);
}
}

无论我在参数中输入什么，都没有变化？

  

ArrayList result2 = lol2016.ReadNumberFile（“lel”）;

import java.util.*;
import java.io.*;
public class lol2016 
{
static public ArrayList<Double> ReadNumberFile(String filename)
{
    ArrayList<Double> res = new ArrayList<Double>();
    Reader r;
    try
    {
        r = new BufferedReader(new FileReader("C:\\Users\\Documents\\Primes.txt"));
        StreamTokenizer stok = new StreamTokenizer(r);
        stok.parseNumbers();
        stok.nextToken();
        while (stok.ttype != StreamTokenizer.TT_EOF) 
        {
            if (stok.ttype == StreamTokenizer.TT_NUMBER)
            {
                res.add(stok.nval);
            }
            stok.nextToken();
        }
    }
    catch(Exception E)
    {
        System.out.println("+++ReadFile: "+E.getMessage());
    }
    return(res);
}
}

无论我在这些参数之间放置什么，输出都保持不变，我的问题是应该去哪里？顺便说一下，这是一个更大的项目的一部分，但我相信这是足够的代码，以帮助我理解我可以放在那些会影响我的输出的参数。

输出：

Result 2: [2.0, 3.0, 5.0, 7.0, 11.0, 13.0, 17.0, 19.0, 23.0, 29.0, 31.0, 37.0, 41.0, 43.0, 47.0, 53.0, 59.0, 61.0, 67.0, 71.0, 73.0, 79.0, 83.0, 89.0, 97.0, 101.0, 103.0, 107.0, 109.0, 113.0, 127.0, 131.0, 137.0, 139.0, 149.0, 151.0, 157.0, 163.0, 167.0, 173.0, 179.0, 181.0, 191.0, 193.0, 197.0, 199.0, 211.0, 223.0, 227.0, 229.0, 233.0, 239.0, 241.0, 251.0, 257.0, 263.0, 269.0, 271.0, 277.0, 281.0, 283.0, 293.0, 307.0, 311.0, 313.0, 317.0, 331.0, 337.0, 347.0, 349.0, 353.0, 359.0, 367.0, 373.0, 379.0, 383.0, 389.0, 397.0, 401.0, 409.0, 419.0, 421.0, 431.0, 433.0, 439.0, 443.0, 449.0, 457.0, 461.0, 463.0, 467.0, 479.0, 487.0, 491.0, 499.0, 503.0, 509.0, 521.0, 523.0, 541.0, 547.0, 557.0, 563.0, 569.0, 571.0, 577.0, 587.0, 593.0, 599.0, 601.0, 607.0, 613.0, 617.0, 619.0, 631.0, 641.0, 643.0, 647.0, 653.0, 659.0, 661.0, 673.0, 677.0, 683.0, 691.0, 701.0, 709.0, 719.0, 727.0, 733.0, 739.0, 743.0, 751.0, 757.0, 761.0, 769.0, 773.0, 787.0, 797.0, 809.0, 811.0, 821.0, 823.0, 827.0, 829.0, 839.0, 853.0, 857.0, 859.0, 863.0, 877.0, 881.0, 883.0, 887.0, 907.0, 911.0, 919.0, 929.0, 937.0, 941.0, 947.0, 953.0, 967.0, 971.0, 977.0, 983.0, 991.0, 997.0, 1009.0, 1013.0, 1019.0, 1021.0, 1031.0, 1033.0, 1039.0, 1049.0, 1051.0, 1061.0, 1063.0, 1069.0, 1087.0, 1091.0, 1093.0, 1097.0, 1103.0, 1109.0, 1117.0, 1123.0, 1129.0, 1151.0, 1153.0, 1163.0, 1171.0, 1181.0, 1187.0, 1193.0, 1201.0, 1213.0, 1217.0, 1223.0, 1229.0, 1231.0, 1237.0, 1249.0, 1259.0, 1277.0, 1279.0, 1283.0, 1289.0, 1291.0, 1297.0, 1301.0, 1303.0, 1307.0, 1319.0, 1321.0, 1327.0, 1361.0, 1367.0, 1373.0, 1381.0, 1399.0, 1409.0, 1423.0, 1427.0, 1429.0, 1433.0, 1439.0, 1447.0, 1451.0, 1453.0, 1459.0, 1471.0, 1481.0, 1483.0, 1487.0, 1489.0, 1493.0, 1499.0, 1511.0, 1523.0, 1531.0, 1543.0, 1549.0, 1553.0, 1559.0, 1567.0, 1571.0, 1579.0, 1583.0, 1597.0, 1601.0, 1607.0, 1609.0, 1613.0, 1619.0, 1621.0, 1627.0, 1637.0, 1657.0, 1663.0, 1667.0, 1669.0, 1693.0, 1697.0, 1699.0, 1709.0, 1721.0, 1723.0, 1733.0, 1741.0, 1747.0, 1753.0, 1759.0, 1777.0, 1783.0, 1787.0, 1789.0, 1801.0, 1811.0, 1823.0, 1831.0, 1847.0, 1861.0, 1867.0, 1871.0, 1873.0, 1877.0, 1879.0, 1889.0, 1901.0, 1907.0, 1913.0, 1931.0, 1933.0, 1949.0, 1951.0, 1973.0, 1979.0, 1987.0, 1993.0, 1997.0, 1999.0, 2003.0, 2011.0, 2017.0, 2027.0, 2029.0, 2039.0, 2053.0, 2063.0, 2069.0, 2081.0, 2083.0, 2087.0, 2089.0, 2099.0, 2111.0, 2113.0, 2129.0, 2131.0, 2137.0, 2141.0, 2143.0, 2153.0, 2161.0, 2179.0, 2203.0, 2207.0, 2213.0, 2221.0, 2237.0, 2239.0, 2243.0, 2251.0, 2267.0, 2269.0, 2273.0, 2281.0, 2287.0, 2293.0, 2297.0, 2309.0, 2311.0, 2333.0, 2339.0, 2341.0, 2347.0, 2351.0, 2357.0, 2371.0, 2377.0, 2381.0, 2383.0, 2389.0, 2393.0, 2399.0, 2411.0, 2417.0, 2423.0, 2437.0, 2441.0, 2447.0, 2459.0, 2467.0, 2473.0, 2477.0, 2503.0, 2521.0, 2531.0, 2539.0, 2543.0, 2549.0, 2551.0, 2557.0, 2579.0, 2591.0, 2593.0, 2609.0, 2617.0, 2621.0, 2633.0, 2647.0, 2657.0, 2659.0, 2663.0, 2671.0, 2677.0, 2683.0, 2687.0, 2689.0, 2693.0, 2699.0, 2707.0, 2711.0, 2713.0, 2719.0, 2729.0, 2731.0, 2741.0, 2749.0, 2753.0, 2767.0, 2777.0, 2789.0, 2791.0, 2797.0, 2801.0, 2803.0, 2819.0, 2833.0, 2837.0, 2843.0, 2851.0, 2857.0, 2861.0, 2879.0, 2887.0, 2897.0, 2903.0, 2909.0, 2917.0, 2927.0, 2939.0, 2953.0, 2957.0, 2963.0, 2969.0, 2971.0, 2999.0, 3001.0, 3011.0, 3019.0, 3023.0, 3037.0, 3041.0, 3049.0, 3061.0, 3067.0, 3079.0, 3083.0, 3089.0, 3109.0, 3119.0, 3121.0, 3137.0, 3163.0, 3167.0, 3169.0, 3181.0, 3187.0, 3191.0, 3203.0, 3209.0, 3217.0, 3221.0, 3229.0, 3251.0, 3253.0, 3257.0, 3259.0, 3271.0, 3299.0, 3301.0, 3307.0, 3313.0, 3319.0, 3323.0, 3329.0, 3331.0, 3343.0, 3347.0, 3359.0, 3361.0, 3371.0, 3373.0, 3389.0, 3391.0, 3407.0, 3413.0, 3433.0, 3449.0, 3457.0, 3461.0, 3463.0, 3467.0, 3469.0, 3491.0, 3499.0, 3511.0, 3517.0, 3527.0, 3529.0, 3533.0, 3539.0, 3541.0, 3547.0, 3557.0, 3559.0, 3571.0, 3581.0, 3583.0, 3593.0, 3607.0, 3613.0, 3617.0, 3623.0, 3631.0, 3637.0, 3643.0, 3659.0, 3671.0, 3673.0, 3677.0, 3691.0, 3697.0, 3701.0, 3709.0, 3719.0, 3727.0, 3733.0, 3739.0, 3761.0, 3767.0, 3769.0, 3779.0, 3793.0, 3797.0, 3803.0, 3821.0, 3823.0, 3833.0, 3847.0, 3851.0, 3853.0, 3863.0, 3877.0, 3881.0, 3889.0, 3907.0, 3911.0, 3917.0, 3919.0, 3923.0, 3929.0, 3931.0, 3943.0, 3947.0, 3967.0, 3989.0, 4001.0, 4003.0, 4007.0, 4013.0, 4019.0, 4021.0, 4027.0, 4049.0, 4051.0, 4057.0, 4073.0, 4079.0, 4091.0, 4093.0, 4099.0, 4111.0, 4127.0, 4129.0, 4133.0, 4139.0, 4153.0, 4157.0, 4159.0, 4177.0, 4201.0, 4211.0, 4217.0, 4219.0, 4229.0, 4231.0, 4241.0, 4243.0, 4253.0, 4259.0, 4261.0, 4271.0, 4273.0, 4283.0, 4289.0, 4297.0, 4327.0, 4337.0, 4339.0, 4349.0, 4357.0, 4363.0, 4373.0, 4391.0, 4397.0, 4409.0, 4421.0, 4423.0, 4441.0, 4447.0, 4451.0, 4457.0, 4463.0, 4481.0, 4483.0, 4493.0, 4507.0, 4513.0, 4517.0, 4519.0, 4523.0, 4547.0, 4549.0, 4561.0, 4567.0, 4583.0, 4591.0, 4597.0, 4603.0, 4621.0, 4637.0, 4639.0, 4643.0, 4649.0, 4651.0, 4657.0, 4663.0, 4673.0, 4679.0, 4691.0, 4703.0, 4721.0, 4723.0, 4729.0, 4733.0, 4751.0, 4759.0, 4783.0, 4787.0, 4789.0, 4793.0, 4799.0, 4801.0, 4813.0, 4817.0, 4831.0, 4861.0, 4871.0, 4877.0, 4889.0, 4903.0, 4909.0, 4919.0, 4931.0, 4933.0, 4937.0, 4943.0, 4951.0, 4957.0, 4967.0, 4969.0, 4973.0, 4987.0, 4993.0, 4999.0, 5003.0, 5009.0, 5011.0, 5021.0, 5023.0, 5039.0, 5051.0, 5059.0, 5077.0, 5081.0, 5087.0, 5099.0, 5101.0, 5107.0, 5113.0, 5119.0, 5147.0, 5153.0, 5167.0, 5171.0, 5179.0, 5189.0, 5197.0, 5209.0, 5227.0, 5231.0, 5233.0, 5237.0, 5261.0, 5273.0, 5279.0, 5281.0, 5297.0, 5303.0, 5309.0, 5323.0, 5333.0, 5347.0, 5351.0, 5381.0, 5387.0, 5393.0, 5399.0, 5407.0, 5413.0, 5417.0, 5419.0, 5431.0, 5437.0, 5441.0, 5443.0, 5449.0, 5471.0, 5477.0, 5479.0, 5483.0, 5501.0, 5503.0, 5507.0, 5519.0, 5521.0, 5527.0, 5531.0, 5557.0, 5563.0, 5569.0, 5573.0, 5581.0, 5591.0, 5623.0, 5639.0, 5641.0, 5647.0, 5651.0, 5653.0, 5657.0, 5659.0, 5669.0, 5683.0, 5689.0, 5693.0, 5701.0, 5711.0, 5717.0, 5737.0, 5741.0, 5743.0, 5749.0, 5779.0, 5783.0, 5791.0, 5801.0, 5807.0, 5813.0, 5821.0, 5827.0, 5839.0, 5843.0, 5849.0, 5851.0, 5857.0, 5861.0, 5867.0, 5869.0, 5879.0, 5881.0, 5897.0, 5903.0, 5923.0, 5927.0, 5939.0, 5953.0, 5981.0, 5987.0, 6007.0, 6011.0, 6029.0, 6037.0, 6043.0, 6047.0, 6053.0, 6067.0, 6073.0, 6079.0, 6089.0, 6091.0, 6101.0, 6113.0, 6121.0, 6131.0, 6133.0, 6143.0, 6151.0, 6163.0, 6173.0, 6197.0, 6199.0, 6203.0, 6211.0, 6217.0, 6221.0, 6229.0, 6247.0, 6257.0, 6263.0, 6269.0, 6271.0, 6277.0, 6287.0, 6299.0, 6301.0, 6311.0, 6317.0, 6323.0, 6329.0, 6337.0, 6343.0, 6353.0, 6359.0, 6361.0, 6367.0, 6373.0, 6379.0, 6389.0, 6397.0, 6421.0, 6427.0, 6449.0, 6451.0, 6469.0, 6473.0, 6481.0, 6491.0, 6521.0, 6529.0, 6547.0, 6551.0, 6553.0, 6563.0, 6569.0, 6571.0, 6577.0, 6581.0, 6599.0, 6607.0, 6619.0, 6637.0, 6653.0, 6659.0, 6661.0, 6673.0, 6679.0, 6689.0, 6691.0, 6701.0, 6703.0, 6709.0, 6719.0, 6733.0, 6737.0, 6761.0, 6763.0, 6779.0, 6781.0, 6791.0, 6793.0, 6803.0, 6823.0, 6827.0, 6829.0, 6833.0, 6841.0, 6857.0, 6863.0, 6869.0, 6871.0, 6883.0, 6899.0, 6907.0, 6911.0, 6917.0, 6947.0, 6949.0, 6959.0, 6961.0, 6967.0, 6971.0, 6977.0, 6983.0, 6991.0, 6997.0, 7001.0, 7013.0, 7019.0, 7027.0, 7039.0, 7043.0, 7057.0, 7069.0, 7079.0, 7103.0, 7109.0, 7121.0, 7127.0, 7129.0, 7151.0, 7159.0, 7177.0, 7187.0, 7193.0, 7207.0, 7211.0, 7213.0, 7219.0, 7229.0, 7237.0, 7243.0, 7247.0, 7253.0, 7283.0, 7297.0, 7307.0, 7309.0, 7321.0, 7331.0, 7333.0, 7349.0, 7351.0, 7369.0, 7393.0, 7411.0, 7417.0, 7433.0, 7451.0, 7457.0, 7459.0, 7477.0, 7481.0, 7487.0, 7489.0, 7499.0, 7507.0, 7517.0, 7523.0, 7529.0, 7537.0, 7541.0, 7547.0, 7549.0, 7559.0, 7561.0, 7573.0, 7577.0, 7583.0, 7589.0, 7591.0, 7603.0, 7607.0, 7621.0, 7639.0, 7643.0, 7649.0, 7669.0, 7673.0, 7681.0, 7687.0, 7691.0, 7699.0, 7703.0, 7717.0, 7723.0, 7727.0, 7741.0, 7753.0, 7757.0, 7759.0, 7789.0, 7793.0, 7817.0, 7823.0, 7829.0, 7841.0, 7853.0, 7867.0, 7873.0, 7877.0, 7879.0, 7883.0, 7901.0, 7907.0, 7919.0]

在我正在读取的文本文件中，只显示与输出相同的所有素数。

Answer 1

  

无论我在参数中输入什么，都没有变化？

这是因为在filename方法的任何地方都没有使用ReadNumberFile(String filename)参数..

看起来，这个参数（filename）代表了应该读取的文件的名称（或者可能是完全限定的路径）。如果是这种情况，您应该将此行更改为：

r = new BufferedReader(new FileReader(filename));