Question

我正在处理一个项目，我想从一个名为＆＃34; stars.txt＆＃34;的文本文件中读取数据，为文件中的所有销售代表创建对象，加载将对象放到ArrayList上，并使用增强的for循环将它们显示到我的JTextField中，并使用toString方法进行格式化。我已经在这几天了，无法获得在JTextField中显示的stars.txt数据！它在NetBeans中编译并显示我想要stars.txt文件中的数据的格式，但不显示实际数据（即salesID，firstName，lastName，osField，bsField，psField，buttonGroup1，buttonGroup2）。这都属于类（JButton）displayActionButtonPerformed。我创建了另一个名为SalesReps的类来存储变量，集合/获取和构造函数（我在主类下创建它，在NetBeans中是否重要，我没有创建新类，即主要的新TAB？）我很想我能得到任何帮助。谢谢。继承我的代码：

private void displayButtonActionPerformed(java.awt.event.ActionEvent evt) { 

File file = new File("stars.txt"); 
SalesReps rep = new SalesReps(); 
ArrayList<SalesReps> aList = new ArrayList<>(); 

  try { 

    Scanner sc = new Scanner(file); 

    int sID = 0; 
    String fName = null; 
    String lName = null; 
    double oSupp = 0; 
    double bSupp = 0; 
    double pSupp = 0; 
    String button1 = null; 
    String button2 = null; 
    //SalesReps rep = null; 

    for (SalesReps aList1 : aList) { 
    System.out.println(aList1); 
    sID = sc.nextInt(); 
    fName = sc.next(); 
    lName = sc.next(); 
    oSupp = sc.nextDouble(); 
    bSupp = sc.nextDouble(); 
    pSupp = sc.nextDouble(); 
    button1 = sc.next(); 
    button2 = sc.next(); 
    rep = new SalesReps(sID, fName, lName, oSupp, bSupp, pSupp, 
          button1, button2); 
    aList.add(rep); 


 } 

      while (sc.hasNextLine()) { 
        String line = sc.nextLine(); 
        System.out.println(line); 
 } 

      sc.close(); 

  } catch (FileNotFoundException e) { 
 } 

   resultsTextArea.append(rep.toString());

}

 public class SalesReps { 

 private int salesID = 0; 
 private String firstName = null; 
 private String lastName= null ; 
 private double osField = 0; 
 private double bsField = 0; 
 private double psField = 0; 
 private String buttonGroup1 = null; 
 private String buttonGroup2 = null; 


 public int getSalesID() { 
 return salesID; 
} 

 public void setSalesID(int sID) { 
 salesID = sID; 
} 

 public String getFirstName() { 
 return firstName; 
} 

 public void setFirstName(String fName) { 
 firstName = fName; 
} 

 public String getLastName() { 
 return lastName; 
} 

 public void setLastName(String lName) { 
 lastName = lName; 
} 

 public double getOsField() { 
 return osField; 
} 

 public void setOsField(double oSupp) { 
 osField = oSupp; 
} 

 public double getBsField() { 
 return bsField; 
} 

 public void setBsField(double bSupp) { 
 bsField = bSupp; 
} 

 public double getPsField() { 
 return psField; 
} 

 public void setPsField(double pSupp) { 
 psField = pSupp; 
} 

 public String getButtonGroup1() { 
 return buttonGroup1; 
} 

 public void setButtonGroup1(String button1) { 
 buttonGroup1 = button1; 
} 

 public String getButtonGroup2() { 
 return buttonGroup2; 
} 

 public void setButtonGroup2(String button2) { 
 buttonGroup2 = button2; 
} 

 public SalesReps(int sID, String fName, String lName, 
                 double oSupp, double bSupp, double pSupp, String button1, 
                 String button2){ 

} 

 public SalesReps() { 
} 

 @Override 
 public String toString(){ 
 return String.format(" %s %s %s\n SUPPLIES" 
 + " %.2f \n BOOKS %.2f \n PAPER %.2f \n %s \n %s \n",salesID, 
 firstName, lastName, osField, bsField, psField, 
 buttonGroup1, buttonGroup2); 
  } 
}

Answer 1

您永远不会解析文件中的行，此循环for (SalesReps aList1 : aList)循环遍历空数组，因此无法构建列表。这段代码在这里说是一个空列表，对于空列表中的所有东西都做这个东西（当然从未发生过）然后你只是遍历文件。当您的扫描仪有更多行时，该逻辑应该继续。 while (sc.hasNextLine())你可以在这个循环中完成所有的解析，通过在那里分割线。此外，您最多只会像这样显示一个解析。

Answer 2

使用StringBuilder连接数据并在JTextField中显示它。

StringBuilder s = new StringBuilder();

 .
 .
 .

  for (SalesReps aList1 : aList) { 
    System.out.println(aList1); 
    sID = sc.nextInt(); 
    fName = sc.next(); 
    lName = sc.next(); 
    oSupp = sc.nextDouble(); 
    bSupp = sc.nextDouble(); 
    pSupp = sc.nextDouble(); 
    button1 = sc.next(); 
    button2 = sc.next(); 
    rep = new SalesReps(sID, fName, lName, oSupp, bSupp, pSupp, 
          button1, button2);
    aList.add(rep); 
    s.append(rep.toString());
 }
 .
 .
 .
 resultsTextArea.append(s.toString());

希望是你的帮助

需要将对象加载到从文本文件中读取的ArrayList并输出到JTextField吗？

2 个答案: