将字符串添加到另一个类的Array List中

Question

I'm having some trouble with adding a String in my "Row" class to my "Table" class. So every time i create a class called row it will add the submitted string to the same instance of the class "Table". Here is my Row class:

public class Row extends ArrayList<Table>{
public ArrayList<String> applicant;
public String row;
/**
 * Constructor for objects of class Row
 */
public Row()
{
    applicant = new ArrayList<String>();
    convertToString();
    applicants(row) //<------ This is the arrayList in the Table class that i wish to           add the row to
}

private void convertToString()
{
    for(int i = 0; i<applicant.size(); i++)
        {
            row = applicant.toString();
        }
}
}

Here is my "Row" class:

public class Table {

    public ArrayList<String> applicants;

    public String appArray[];

    /**
     * Constructor for objects of class Table
     */
    public Table() {
        applicants = new ArrayList<String>();
    }

    public void addApplicant(String app) {
        applicants.add(app);
        toArray();
    }

    public void toArray() {
        int x = applicants.size();
        appArray = applicants.toArray(new String[x]);
    }

    public void list() // Lists the arrayList
    {
        for(int i = 0; i < applicants.size(); i++) {
            System.out.println(applicants.get(i));
        }
    }

    public void listArray() // Lists the Array[]
    {
        for(int i = 0; i < appArray.length; i++) {
            System.out.println(appArray[i]);
        }
    }
}

Any help would be really appreciated.

Answer 1

applicants(row) is not a method in the Row/Table class.

If you wish to add the row to the Arrraylist in the Row class then use the add method

applicant.add(row) method.

Also you should note that Table and Row relationship does not require you to create a Row class extending the Table class. It should be two separate classes. So Table and Row class will have a one to Many relationship. So modify the Table class such that it is able to add several instances of Row class.

I dont know what you are trying to do but lets say you a Row class should contain two things a rowID and applicantName. And a table class which will have many rows representing each Applicant.

so Row class will somewhat look like this:

public class Row extends ArrayList<Table>{
String applicantName;
int applicantID;


/**
 * Constructor for objects of class Row
 */
public Row(int appID, String appName)
{
applicantName = appName;
applicantID = appID;

}

public getApplicantName(){
return applicantName;
}

public getApplicantID(){
return applicantID; 
}


}

And the table class will look like this:

public class Table {

    public ArrayList<Row> applicants;

    public String appArray[];

    /**
     * Constructor for objects of class Table
     */
    public Table() {
    applicants = new ArrayList<String>();
    }

    public void addApplicant(Row app) {
    applicants.add(app);

    }


    public void list() // Lists the arrayList
    {
    for(int i = 0; i < applicants.size(); i++) {
        Row row = (Row) applicants.get(i);  
        System.out.println("Applicant ID: "+ row.getApplicantID() +
        "  Applicant Name: " + row.getApplicantName());
    }
    }

}

so use the above classes in below manner:

Row r1 = new Row(1, "Tom");
Row r2 = new Row(2, "Hoggie");
Row r3 = new Row(3, "Julie");

Table table = new Table();

table.addApplicant(r1);
table.addApplicant(r2);
table.addApplicant(r3);

//So now when you will call the below method list it will print all the applicants with //their ids

table.list();