扫描仪和管道分隔文件Java

我正在使用管道分隔的

.txt

文件处理预定航班。我需要将每一行分成三个独立的部分，

scheduledTime

，

eventType

和

flightID

文件中的一个航班示例如下所示：

12:00 |到达| A001

我有一个单一的航班工作，但当我添加更多，我得到这个错误

完整跟踪：

java.time.format.DateTimeParseException: Text 'ARRIVAL' could not be parsed at index 0
at java.time.format.DateTimeFormatter.parseResolved0(Unknown Source)
at java.time.format.DateTimeFormatter.parse(Unknown Source)
at java.time.LocalTime.parse(Unknown Source)
at java.time.LocalTime.parse(Unknown Source)
at edu.metrostate.ics240.p4.gaw886.sim.AirportSimulator.processEventFile(AirportSimulator.java:49)
at edu.metrostate.ics240.p4.gaw886.sim.tests.AirportSimTests.testScenarioOne(AirportSimTests.java:22)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

现在我明白了这里发生的事情，当我有多个航班时，它会跳过第二行中的scheduledTime片段，并尝试解析eventType。我想不出怎么解决这个问题。以下是我的方法：

方法创建事件文件：

public static final double DEPARTURE_PROB = 0.20;
public static final double ARRIVAL_PROB = 0.15;
public static final int ARR_RESERVE_TIME = 2;
public static final int DEP_RESERVE_TIME = 3;
public static final int SIM_MINUTES = 60;
public static final long SEED = 20170620001L;
public static final Random RAND = new Random(SEED);
public static final String DELIM = "\\|";

public static void genEventFile(String fileName, double arrivalProbability, double departureProbability,
        int minutes) {
    int arrFlightId = 1;
    int depFlightId = 1;
    try (PrintWriter simFile = new PrintWriter(fileName);) {
        LocalTime time = LocalTime.parse("00:00");

        for (int i = 0; i < minutes; i++) {
            if (RAND.nextDouble() <= arrivalProbability) {
                simFile.printf("%s|%s|%s\n", time.plusMinutes(i), Event.EventType.ARRIVAL,
                        String.format("A%03d", arrFlightId++));
            }
            if (RAND.nextDouble() <= departureProbability) {
                simFile.printf("%s|%s|%s\n", time.plusMinutes(i), Event.EventType.DEPARTURE,
                        String.format("D%03d", depFlightId++));
            }
        }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }
}

    public void processEventFile(String filename) {
    LocalTime scheduledTime = null;
    EventType eventType;
    String flightID;
    try (Scanner scanner = new Scanner(new File(filename)).useDelimiter(DELIM);) {
        while (scanner.hasNext()) {
            scheduledTime = LocalTime.parse(scanner.next());
            eventType = EventType.valueOf(scanner.next());
            flightID = scanner.next();
            flight = new Flight(scheduledTime, eventType, flightID);
            flightQueue.add(flight);
        }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }
}

因此，我的问题是，如何在读取

flightId

后使扫描仪移动到下一行，而不认为第1行的

flightId

和第2行的

scheduledTime

在同一行

飞行数据样本：

00:02|DEPARTURE|D001
00:03|ARRIVAL|A001
00:03|DEPARTURE|D002
00:04|DEPARTURE|D003
00:06|DEPARTURE|D004
00:09|DEPARTURE|D005
00:12|ARRIVAL|A002
00:14|ARRIVAL|A003
00:16|DEPARTURE|D006
00:18|ARRIVAL|A004
00:21|DEPARTURE|D007
00:22|ARRIVAL|A005
00:24|DEPARTURE|D008
00:28|ARRIVAL|A006
00:28|DEPARTURE|D009
00:30|ARRIVAL|A007
00:41|ARRIVAL|A008
00:44|DEPARTURE|D010
00:47|DEPARTURE|D011
00:48|DEPARTURE|D012
00:53|DEPARTURE|D013
00:54|ARRIVAL|A009
00:54|DEPARTURE|D014
00:56|DEPARTURE|D015
00:57|DEPARTURE|D016

---

Scanner

对象仅基于

DELIM

变量

|

解析文件。它也不会按新行字符分割文件

您可以使用

BufferedReader

对象逐行读取文件，然后稍后拆分文本。大概是这样的：

public void processEventFile(String fileName) {
     String line;
     String[] split;
     BufferedReader reader = null;
     try {
          reader = new BufferedReader(new FileReader(fileName));
          while((line = reader.readLine()) != null) {
               split = line.split("\\|");
               flightQueue.add(new Flight(split[0], split[1], split[2]));
          }
     } catch(IOException e) {
          e.printStackTrace();
     } finally {
          if(reader != null) {
               try {
                    reader.close();
               } catch(IOException e) {
                    e.printStackTrace();
               }
          }
     }
}

---

Scanner

对象仅基于

DELIM

变量

|

解析文件。它也不会按新行字符分割文件

您可以使用

BufferedReader

对象逐行读取文件，然后稍后拆分文本。大概是这样的：

public void processEventFile(String fileName) {
     String line;
     String[] split;
     BufferedReader reader = null;
     try {
          reader = new BufferedReader(new FileReader(fileName));
          while((line = reader.readLine()) != null) {
               split = line.split("\\|");
               flightQueue.add(new Flight(split[0], split[1], split[2]));
          }
     } catch(IOException e) {
          e.printStackTrace();
     } finally {
          if(reader != null) {
               try {
                    reader.close();
               } catch(IOException e) {
                    e.printStackTrace();
               }
          }
     }
}

---

您可以将分隔符更改为使用或条件

public static final String DELIM = "[\\||\n]+"; 

---

您可以将分隔符更改为使用或条件

public static final String DELIM = "[\\||\n]+"; 

---

您可以使用

java.util.Scanner

逐行读取文件。在示例中，我使用

try with resources

块确保

扫描仪

已关闭。方法

forEachRemaining

返回输入文件的下一行：

public static void main(String[] args) throws ParseException {
        try (Scanner sc = new Scanner(NewMain.class.getResourceAsStream("airport.txt"))) {
            sc.forEachRemaining(s -> {
                System.out.println(s.length() + " " + s);
            });
        }
    }

---

您可以使用

java.util.Scanner

逐行读取文件。在示例中，我使用

try with resources

块确保

扫描仪

已关闭。方法

forEachRemaining

返回输入文件的下一行：

public static void main(String[] args) throws ParseException {
        try (Scanner sc = new Scanner(NewMain.class.getResourceAsStream("airport.txt"))) {
            sc.forEachRemaining(s -> {
                System.out.println(s.length() + " " + s);
            });
        }
    }

---

你能用一个缓冲读取器吗？然后您可以一次读取一行，并使用String.split（regex）将每行拆分为其组件扫描您发布带有航班id和时间的示例txt文件您可以使用BufferedReader吗？然后你可以一次读取一行，然后使用String.split（regex）将每行拆分为其组件扫描你发布的带有航班id和timeAwesome的示例txt文件，这就解决了问题。Awesome，这就解决了问题。