从文件读取的字符串没有得到解析到本地日期

问题描述：

public class Loan { 

private Borrower Borrower; 
private Book Book; 
private LocalDate issueDate; 
private LocalDate returnDate; 
private int status; 

public Loan(Borrower Borrower, Book Book, LocalDate issueDate, LocalDate returnDate, int status) { 
    this.Borrower = Borrower; 
    this.Book = Book; 
    this.issueDate = issueDate; 
    this.returnDate = returnDate; 
    this.status = status; 
} 

public LocalDate getIssueDate() { 
    return issueDate; 
} 

public void setIssueDate(LocalDate issueDate) { 
    this.issueDate = issueDate; 
} 

public LocalDate getReturnDate() { 
    return returnDate; 
} 

public void setReturnDate(LocalDate returnDate) { 
    this.returnDate = returnDate; 
} 

public int getStatus() { 
    return status; 
} 

public void setStatus(int status) { 
    this.status = status; 
} 

public Borrower getBorrower() { 
    return Borrower; 
} 

public void setBorrower(Borrower Borrower) { 
    this.Borrower = Borrower; 
} 

public Book getBook() { 
    return Book; 
} 

public void setBook(Book Book) { 
    this.Book = Book; 
} 

}  

ArrayList<Loan> Loans= new ArrayList(); 

try { 
    BufferedReader reader = new BufferedReader(new FileReader("C:\\Users\\NimraArif\\Documents\\NetBeansProjects\\ooad1\\src\\ooad1\\Loans.txt")); 
    String line = null; 

    int bookid, status, borrowerid; 

    line = reader.readLine(); 

    while (line!= null) { 

     String[] values = line.split(","); 

     bookid = Integer.valueOf(values[0]); 
     borrowerid=Integer.valueOf(values[1]); 
     DateTimeFormatter formatter= DateTimeFormatter.ofPattern("dd/MM/yy"); 
     LocalDate issueDate=LocalDate.parse(values[2],formatter); 
     LocalDate returnDate=LocalDate.parse(values[3],formatter); 
     status=Integer.valueOf(values[4]); 
     Book temp = null; 
     Borrower temp2 = null; 

     for (int i = 0; i < Books.size(); i++) { 
     if (Books.get(i).getBookid()==bookid) { 
      temp=Books.get(i); 
     } 
     } 

     for (int i = 0; i < borrowers.size(); i++) { 
     if (borrowers.get(i).getRollno()==borrowerid) { 
      temp2=borrowers.get(i); 
     } 
     } 

     Loan temp3 = new Loan(temp2, temp, issueDate, returnDate, status); 
     Loans.add(temp3); 
     line = reader.readLine(); 
    } 
    reader.close(); 

    } 
    catch (Exception e) { 
    System.err.format("Exception occurred trying to read '%s'.", "Loans.txt"); 
    e.printStackTrace(); 
    }

当我执行此代码时，它会在包含解析函数的同时在该行引发异常。但是，如果我自己硬编码字符串，它工作正常。我不明白为什么会发生这种情况。从文件读取的字符串没有得到解析到本地日期

这是e.printStackTrace();获得的输出：从文件中读取

'Loans.txt'.java.time.format.DateTimeParseException: Text '2017/11/01' could not be parsed at index 2 
     at java.time.format.DateTimeFormatter.parseResolved0(DateTimeFormatter.java:1949) 
     at java.time.format.DateTimeFormatter.parse(DateTimeFormatter.java:1851) 
     at java.time.LocalDate.parse(LocalDate.java:400) 
     at ooad1.Ooad1.main(Ooad1.java:119) 
Exception occurred trying to read 'Holder.txt'.

您可以更新您的异常打印堆栈跟踪 – 2017-10-13 14:15:02

问题总是记录或打印未链接到另一个异常捕获异常的堆栈跟踪。在你的情况下，你的'catch'块需要包含'e.printStackTrace（）;'。一旦你完成了，编辑你的问题，并添加完整的堆栈跟踪。 – VGR

你是否目测检查了loans.txt中的数据？也许文件中有一个无效的日期？ –

答

字符串不获取解析到LOCALDATE的

LOCALDATE的是表示与默认格式日期的不可变类YYYY-MM-DD。我们可以使用now（）方法获取当前日期。我们还可以提供年，月和日的输入参数来创建LocalDate实例。

使用格式化解析单个字符日/月字段java.time.LocalDate

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy/MM/dd"); 
LocalDate ldate = LocalDate.parse("2017/11/01", formatter);

然后你可以使用LocalDate您setter方法，你会得到后也不例外。

例如

setIssueDate(ldate); 
setReturnDate(ldate);

谢谢。它为我工作。 –

从文件读取的字符串没有得到解析到本地日期

相关推荐