java - 使用 bufferedread 和 hashset 检查文件中的行

Question

我的问题是我必须编写代码来检查客户名称是否已在我的 txt 文件 (Customers.txt) 中。

问题是我用哈希集检查客户是否在文件中，而他说他不在文件中。(手动检查)请帮我解决这个问题。

我已经拥有的代码如下。

    public class Customer {
    //declaration
    public static String S;
    private String line ;
    public String nameCustomer;


/**
 * constructor
 */
public Klant(){}

/**Checking of the customer is in the file
 */
public void getCustomer() {
    // make SimpleInOutDialog      
        SimpleInOutDialog  input = new SimpleInOutDialog("Customers");
        nameCustomer = input.readString("Give in the name");
    try{
    BufferedReader br = new BufferedReader(new FileReader("L:\\Documents/Informatica/6de jaar/GIP/Customers.txt"));
    HashSet<String> hs = new HashSet<String>();
    int i = 0;
    while ((line = br.readLine()) != null)
    {
        i++;
        if (i == 1){hs.add(br.readLine());}

        if (i % 4 == 0){hs.add(br.readLine());}

    }
    if(hs.contains(nameCustomer)){
        //the customer exists
     input.showString("The customer exists", "");
     }else{input.showString("The customer does not exist, we will make a new one", "");
         setNieuweKlant();}


    }catch (Exception e){//Catch when there are errors
        System.err.println("Error: " + e.getMessage());}

}


/**
 * make a new customer
 */

public void Make new customer(){
    // make SimpleInOutDialog     
    SimpleInOutDialog  input = new SimpleInOutDialog("A new customer");
    //input
    S = "Name customer: " + input.readString("Give in your name:");
WriteToFile();
S = "Adress: " + input.readString("Give your adress");
WriteToFile();
S = "Telephonenummber: " + input.readString("Give your telephonenumber");
WriteToFile();
//making a customerID
  UUID idCustomer = UUID.randomUUID();  
S = "CustomerID: " + customerID.toString();
WriteToFile();

}


/**
 * Schrijft de gegevens weg naar het bestand
 */


 public void WriteToFile(){
try{

FileWriter writer = new FileWriter("L:\\Documents/Informatica/6de jaar/GIP/Customer.txt", true);
BufferedWriter out = new BufferedWriter(writer);
//Wrting away your data
out.write(S);

//Closing the writer
out.close();


}catch (Exception e){//Catch when there are errors
    System.err.println("Error: " + e.getMessage());
    }
    }

荷兰代码

public class Klant {
    //declaratie van de variabele die de tekst voorsteld
    public static String S;
    private String line ;
    public String naamklant;


/**
 * constructor
 */
public Klant(){}

/**Controleerd of de klant al bestaat
 */
public void getKlant() {
    // SimpleInOutDialog aanmaken     
        SimpleInOutDialog  input = new SimpleInOutDialog("Klanten");
        naamklant = input.readString("Geef de volledige naam in");
    try{
    BufferedReader br = new BufferedReader(new FileReader("L:\\Documents/Informatica/6de jaar/GIP/Klanten.txt"));
    HashSet<String> hs = new HashSet<String>();
    int i = 0;
    while ((line = br.readLine()) != null)
    {
        i++;
        if (i == 1){hs.add(br.readLine());}

        if (i % 4 == 0){hs.add(br.readLine());}

    }
    if(hs.contains(naamklant)){
        //klant bestaat
     input.showString("De klant bestaat", "");
     }else{input.showString("De klant bestaat niet, er wordt een nieuwe klant aangemaakt", "");
         setNieuweKlant();}


    }catch (Exception e){//Catch wanneer er errors zijn
        System.err.println("Error: " + e.getMessage());}

}


/**
 * Maakt een nieuwe klant aan 
 */

public void setNieuweKlant(){
    // SimpleInOutDialog aanmaken     
    SimpleInOutDialog  input = new SimpleInOutDialog("Een nieuwe klant");
    //input
    S = input.readString("Geef de volledige naam in");
    WriteToFile();
    S = "Adres: " + input.readString("Geef het adres op");
    WriteToFile();
    S = "Telefoonummer: " + input.readString("Geef het telefoonnummer op");
    WriteToFile();
    //een klantennummer aanmaken 
      UUID idKlant = UUID.randomUUID();  
    S = "Klantnummer: " + idKlant.toString();
    WriteToFile();

}


/**
 * Schrijft de gegevens weg naar het bestand
 */
public void WriteToFile(){

    try{

        FileWriter writer = new FileWriter("L:\\Documents/Informatica/6de jaar/GIP/Klanten.txt", true);
        BufferedWriter out = new BufferedWriter(writer);
        //uw gegevens wegschrijven
        out.write(S);
        out.newLine();
        //de writer sluiten
        out.close();


    }catch (Exception e){//Catch wanneer er errors zijn
        System.err.println("Error: " + e.getMessage());}



    }


}

Answer 1

这个:

    while ((line = br.readLine()) != null)
    {
        i++;
        if (i == 1){hs.add(br.readLine());}

        if (i % 4 == 0){hs.add(br.readLine());}

    }

可能应该是这样的:

    while ((line = br.readLine()) != null)
    {
        i++;
        if (i == 1)
            hs.add(line);
        if (i % 4 == 0)
            hs.add(line);
    }

也就是说，您可能想添加刚刚读过的行，而不是读取新行并添加它。