只有txt文件的最后一行放入数组

Question

我的代码有问题。我试图从txt文件中逐行阅读，然后将这些行添加到列表中。我的问题是只有文件的最后一行被添加到列表中。

这是我的扫描仪代码：

public void readFile() throws FileNotFoundException, IOException { 
    BufferedReader br = new BufferedReader(new FileReader(file)); 

    String line; 

    while ((line = br.readLine()) != null) { 
     cyclistList = (List) Arrays.asList(line); 
     System.out.println(line); 
    } 
    br.close(); 
} 

我可以将清单打印出来就好了，但是当我试图通过线从txt文件到列表中添加行，它只是增加了最后的线。

这是txt文件包含并也打印出来与System.out.println方法：

[A.CONTADOR TCS ESP 00:09:48 2 45] 
[A.DELAPLACE BSE FRA 03:11:28 1 15] 
[A.DEMARE FDJ FRA 04:05:28 0 43] 
[A.FONSECA BSE FRA 03:53:13 0 18] 
[A.GENIEZ FDJ FRA 03:42:57 27 31] 
[A.GERARD BSE FRA 04:02:06 0 0] 
[A.GREIPEL LTS ALL 04:03:28 0 366] 
[A.GRIVKO AST UKR 02:38:06 0 51] 
[A.HANSEN LTS AUS 03:45:18 0 2] 
[A.KRISTOFF KAT NOR 04:01:06 0 90] 
[A.LOSADA KAT ESP 02:32:30 0 7] 
[A.MALORI MOV ITA 03:37:28 0 11] 
[A.TALANSKY TCG USA 00:22:06 22 32] 
[A.TIMMER TGA HOL 04:05:30 0 0] 
[A.TULIK EUC FRA 03:18:24 0 11] 
[A.VALVERDE MOV ESP 00:05:25 72 103] 
[A.VUILLERMOZ ALM FRA 01:28:29 2 52] 
[A.YATES OGE GBR 02:16:36 17 42] 
[B.COQUARD EUC FRA 03:42:36 0 152] 
[B.FEILLU BSE FRA 03:23:11 0 17] 
[B.HUZARSKI BOA POL 03:38:06 1 27] 
[B.JUNGELS TFR LUX 01:33:21 16 76] 
[B.MOLLEMA TFR HOL 00:15:14 0 38] 
[B.NAULEAU EUC FRA 04:40:12 0 2] 
[B.TANKINK TLJ HOL 02:30:12 0 0] 
[B.VAUGRENARD FDJ FRA 03:43:08 0 20] 
[C.FROOME SKY GBR 00:00:00 119 139] 
[C.GAUTIER EUC FRA 01:51:51 4 54] 
[C.LAPORTE COF FRA 03:59:10 0 17] 
[C.RIBLON ALM FRA 02:48:19 1 23] 
[D.CARUSO BMC ITA 02:26:32 8 21] 
[D.CIMOLAI LAM ITA 04:33:21 0 34] 
[D.GAUDIN ALM FRA 04:16:13 0 0] 
[D.GRUZDEV AST KAZ 04:01:12 0 0] 
[D.MARTIN TCG IRL 02:03:37 27 72] 
[D.NAVARR GARCIA COF ESP 02:43:34 0 9] 
[D.OSS  BMC ITA 03:22:14 0 16] 
[D.TEKLEHAIMANOT MTN ERY 02:16:15 8 51] 
[D.VAN BAARLE TCG HOL 04:18:40 0 13] 
[D.WYSS  BMC SUI 02:37:17 0 0] 
[E.BOASSON HAGEN MTN NOR 03:08:02 2 79] 
[E.BUCHMANN BOA ALL 03:08:47 16 15] 
[F.BRUN  BSE FRA 04:10:32 0 18] 
[F.POZZATO LAM ITA 03:58:20 1 0] 
[F.SENECHAL COF FRA 04:04:06 0 -5] 
[F.VACHON BSE FRA 03:15:01 0 11] 
[G.CARUSO KAT ITA 03:17:03 0 1] 
[G.IZAGIRRE MOV ESP 01:41:34 28 26] 
[G.PREIDLER TGA AUT 03:14:14 15 14] 
[G.RAST  TFR SUI 03:29:00 0 0] 
[G.SOUPE COF FRA 03:55:35 0 34] 
[G.THOMAS SKY GBR 00:31:39 22 37] 
[H.ZUBELDIA TFR ESP 02:36:50 0 0] 
[I.ERVITI MOV ESP 03:47:14 0 6] 
[I.STANNARD SKY GBR 03:59:37 0 0] 
[J.ARREDO MORENO TFR COL 03:56:49 0 10] 
[J.BAKELANTS ALM BEL 01:16:36 2 50] 
[J.BARTA BOA RTC 01:26:56 20 47] 
[J.CASTROVIEJO MOV ESP 01:26:05 0 31] 
[J.DEBUSSCHERE LTS BEL 04:16:06 0 29] 
[J.DEGENKOLB TGA ALL 03:39:43 1 298] 
[J.FUGLSANG AST DAN 01:25:23 64 34] 
[J.GUARNIERI KAT ITA 04:22:20 0 24] 
[J.HERRADA MOV ESP 02:40:06 3 1] 
[J.JANS RENSBURG MTN AFS 02:18:16 0 0] 
[J.MENDES BOA POR 04:07:47 0 0] 
[J.PANTANO IAM COL 01:09:08 2 48] 
[J.PERAUD ALM FRA 02:35:10 0 -5] 
[J.RODRIGUEZ KAT ESP 01:36:07 78 71] 
[J.ROY  FDJ FRA 03:32:12 6 8] 
[J.SERPA PEREZ LAM COL 03:54:25 0 20] 
[J.SIMON COF FRA 03:19:53 12 18] 
[J.VAN EMDEN TLJ HOL 03:54:19 0 11] 
[J.VERMOTE EQS BEL 03:50:32 0 0] 
[K.DE KORT TGA HOL 02:57:05 0 30] 
[K.DURASEK LAM CRO 03:02:14 13 26] 
[K.KOREN TCG SLV 02:51:44 1 14] 
[K.VANBILSEN COF BEL 04:41:27 3 37] 
[L.BAK  LTS DAN 01:56:57 14 9] 
[L.DURBRIDGE OGE AUS 04:25:03 0 11] 
[L.KONIG SKY RTC 02:53:09 0 0] 
[L.MATE MARDONES COF ESP 02:10:12 0 29] 
[L.ROWE  SKY GBR 04:04:45 0 3] 
[L.TEN DAM TLJ HOL 03:18:43 0 -5] 
[L.WESTRA AST HOL 03:03:09 3 25] 
[M.BONO  LAM ITA 03:52:17 0 0] 
[M.BRANDLE IAM AUT 04:37:36 0 9] 
[M.CAVENDISH EQS GBR 04:12:05 0 206] 
[M.CHEREL ALM FRA 01:05:00 24 8] 
[M.ELMIGER IAM SUI 03:26:47 0 0] 
[M.FRANK IAM SUI 00:15:39 4 24] 
[M.GOLAS EQS POL 03:21:17 0 9] 
[M.HALLER KAT AUT 03:59:04 1 13] 
[M.IRIZAR TFR ESP 03:19:44 0 0] 
[M.GHEBREMEDHIN MTN ERY 03:10:36 0 26] 
[M.LADAGNOUS FDJ FRA 02:53:22 9 13] 
[M.MATTHEWS OGE AUS 04:26:33 0 25] 
[M.QUINZIATO BMC ITA 03:53:21 0 0] 
[M.ROGERS TCS AUS 01:56:13 1 32] 
[M.SCARPONI AST ITA 02:05:03 0 0] 
[M.SCHAR BMC SUI 02:31:13 1 1] 
[M.SIEBERG LTS ALL 04:24:52 0 11] 
[M.TOSATTO TCS ITA 04:01:15 0 0] 
[M.TRENTIN EQS ITA 03:50:59 1 44] 
[M.WYSS  IAM SUI 02:34:38 0 0] 
[N.EDET  COF FRA 03:42:42 16 34] 
[N.OLIVEIRA LAM POR 02:15:32 0 10] 
[N.QUINTANA MOV COL 00:01:12 108 80] 
[N.ROCHE SKY IRL 01:54:08 0 16] 
[P.FEDRIGO BSE FRA 02:22:54 0 37] 
[P.MARTENS TLJ ALL 03:04:52 0 20] 
[P.PERICHON BSE FRA 03:05:48 0 61] 
[P.QUEMENEUR EUC FRA 02:57:19 0 46] 
[P.ROLLAND EUC FRA 00:17:30 74 73] 
[P.SAGAN TCS SLQ 02:14:55 3 432] 
[P.VOSS  BOA ALL 03:24:53 0 7] 
[P.WEENING OGE HOL 04:15:20 0 -5] 
[R.BARDET ALM FRA 00:16:00 90 74] 
[R.CURVERS TGA HOL 03:35:40 0 46] 
[R.DENNIS BMC AUS 03:27:34 1 36] 
[R.GESINK TLJ HOL 00:10:47 32 53] 
[R.HESJEDAL TCG CAN 02:04:37 41 43] 
[R.HOLLENSTEIN IAM SUI 02:58:30 0 0] 
[R.JANS RENSBURG MTN AFS 03:21:30 0 14] 
[R.KREUZIGER TCS RTC 01:02:51 12 17] 
[R.MAJKA TCS POL 01:35:06 40 28] 
[R.NAVARDAUSKAS TCG LIT 04:14:40 20 44] 
[R.PLAZA LAM ESP 01:38:22 11 86] 
[R.PORTE SKY AUS 02:16:05 58 38] 
[R.SICARD EUC FRA 01:51:32 23 32] 
[R.URAN  EQS COL 02:08:20 5 55] 
[R.VALLS FERRI LAM ESP 03:03:11 0 5] 
[S.CHAVANEL FDJ FRA 04:56:59 2 39] 
[S.CLEMENT IAM HOL 02:33:42 0 37] 
[S.CUMMINGS MTN GBR 03:12:23 2 49] 
[S.DEVOLDER TFR BEL 04:21:31 0 0] 
[S.GESCHKE TGA ALL 01:58:14 22 78] 
[S.KRUIJSWIJK TLJ HOL 01:21:27 10 10] 
[S.PAUWELS MTN BEL 00:31:03 55 43] 
[S.SANCHEZ BMC ESP 00:22:50 0 10] 
[S.TUFT  OGE CAN 04:48:08 0 0] 
[S.VANMARCKE TLJ BEL 03:31:15 8 5] 
[S.YATES OGE GBR 03:16:04 0 40] 
[T.DE GENDT LTS BEL 02:48:02 6 90] 
[T.FARRAR MTN USA 04:32:32 0 12] 
[T.GALLOPIN LTS FRA 01:40:44 8 85] 
[T.KANGERT AST EST 01:24:58 0 0] 
[T.LEEZER TLJ HOL 04:26:47 0 0] 
[T.MACHADO KAT POR 02:54:31 0 0] 
[T.PINOT FDJ FRA 00:38:52 82 113] 
[T.VOECKLER EUC FRA 02:14:08 23 28] 
[T.WELLENS LTS BEL 03:59:39 0 -1] 
[V.NIBALI AST ITA 00:08:36 53 49] 
[W.ANACONA MOV COL 02:31:14 33 29] 
[W.BARGUIL TGA FRA 00:31:15 0 25] 
[W.KELDERMAN TLJ HOL 03:04:07 1 20] 
[W.POELS SKY HOL 02:12:44 18 9] 
[Y.GENE  EUC FRA 04:04:56 0 0] 
[Z.STYBAR EQS RTC 03:30:13 0 78] 

这是输出我与cyclistList = (List) Arrays.asList(sc.nextLine());代码得到：

[Z.STYBAR EQS RTC 03:30:13 0 78] 

编辑： 我的不好，我忘了补充一些东西。我已经在类的列表：

private List<RacingCyclist> cyclistList = new ArrayList<>(); 

这个列表实现可比：

public class RacingCyclist implements Comparable<RacingCyclist> { 
//... 
} 

所以cyclistList.add();不起作用，该方法我收到以下错误：

"No suitable method found for add(String) Method Collection.add(RacingCyclist) is not applicable (argument mismatch; String cannot be converted to RacingCyclist)"

Answer 1

问题是，您正在循环中每创建一个新的List。

问题出在这里：cyclistList = (List) Arrays.asList(line);。在这一行上，你创建一个新的List，这就是为什么你只保留最后一个元素，因为在最后一次迭代中，你已经创建了一个只有该元素的列表。

为了解决这个问题，改变这种：

public void readFile() throws FileNotFoundException, IOException { 
    BufferedReader br = new BufferedReader(new FileReader(file)); 

    String line; 

    while ((line = br.readLine()) != null) { 
     cyclistList = (List) Arrays.asList(line); 
     System.out.println(line); 
    } 
    br.close(); 
} 

要这样：

public void readFile() throws FileNotFoundException, IOException { 
    BufferedReader br = new BufferedReader(new FileReader(file)); 

    String line; 
    ArrayList<String> list = new ArrayList<String>(); 

    while ((line = br.readLine()) != null) { 
     list.add(line); 
     System.out.println(line); 
    } 
    br.close(); 
} 

这样，你将有一个单一的与ArrayList您的所有数据，而不是创建一个新的List每迭代。

---

编辑：从您的编辑，你想一个String添加到您的自定义对象，而你的情况是RacingCyclist（或者这是一个自定义列表如果它是你的ArrayList”重新尝试创建列表清单）。

如果这个对象可以容纳一个String，那么它也许应该有一个getter和setter方法，所以用他们你的循环内，如：（？为什么）

customObject.setLine(line); 
cyclistList.add(customObject); 

现在，如果您的自定义对象是另一个列表那么它应该可以保存其他可以保存String的对象，或者它可以保存String本身。但我的猜测是，你可能不应该这样做，使用一个简单的ArrayList而不是持有者对象实现Comparable，这样ArrayList将能够排序你的元素。

---

第二个编辑：好吧，我在你的自定义类做了一些修改。在这里。

RacingCyclist.java

package opg3_tour; 

/** 
* 
* @author erso 
*/ 
public class RacingCyclist implements Comparable<RacingCyclist> { 

    private String name; 
    private String team; 
    private String country; 

    private String time; 
    private int mountains; 
    private int points; 

    public RacingCyclist(String name, String team, String country, String time, int mountains, int points) { 
     this.name = name; 
     this.team = team; 
     this.country = country; 
     this.time = time; 
     this.mountains = mountains; 
     this.points = points; 
    } 

    // Empty constructor. 
    public RacingCyclist() { } 

    // Getters 

    public String getName() { 
     return name; 
    } 

    public String getTeam() { 
     return team; 
    } 

    public String getCountry() { 
     return country; 
    } 

    public String getTime() { 
     return time; 
    } 

    public int getMountains() { 
     return mountains; 
    } 

    public int getPoints() { 
     return points; 
    } 

    // Setters - They update the data on your Object. 

    public void setName(String name) { 
     this.name = name; 
    } 

    public void setTeam(String team) { 
     this.team = team; 
    } 

    public void setCountry(String country) { 
     this.country = country; 
    } 

    public void setTime(String time) { 
     this.time = time; 
    } 

    public void setMountains(int mountains) { 
     this.mountains = mountains; 
    } 

    public void setPoints(int points) { 
     this.points = points; 
    } 

// This method parses lines on the following format: [A.CONTADOR TCS ESP 00:09:48 2 45] 
    public void parseLine(String str) { 
     str = str.replaceAll("^ +| +$| (?=)", ""); // Removing extra spaces between words. 
     str = str.replace("[",""); 
     str = str.replace("]",""); 
     String[] lines = str.split(" "); // Breaking the String into lines. 

     setName(lines[0]); 
     setTeam(lines[1]); 
     setCountry(lines[2]); 
     setTime(lines[3]); 
     setMountains(Integer.parseInt(lines[4])); 
     setPoints(Integer.parseInt(lines[5])); 
    } 

    @Override 
    public String toString() { 
     return name + " " + team + " " + country + " " + time + " " + mountains + " " + points + "\n"; 
    } 

    @Override 
    public int compareTo(RacingCyclist o) { 
     if (Integer.parseInt(getTime()) > Integer.parseInt(o.getTime())){ 
      return 1; 
     } 
     else if (Integer.parseInt(getTime()) < Integer.parseInt(o.getTime())){ 
      return -1; 
     } 
     else { 
      return this.name.compareTo(o.name); 
     } 
    } 
} 

我创建了一个空construtor和一个名为parseLine(String line)方法，它可以采取行的文件，并指定值以您的自定义对象RacingCyclist。

然后，你的循环应该是这样的：

while ((line = br.readLine()) != null) { 
    RacingCyclist obj = new RacingCyclist(); 
    obj.parseLine(line); 
    cyclistList.add(obj); 
    System.out.println(line); 
} 

您将创建您的RacingCyclist对象的新实例的方式，和parseLine方法将打破串下来，并得到它的价值和它分配到你的对象的内部变量。

Answer 2

这是因为您没有添加到列表中（使用“添加”方法），而是始终创建一个新列表。