Java-从名称和地址的ArrayList返回“地址”

Question

I've been working on this AP Problem all day with no luck. If anyone can help, it would be appreciated.

I have an ArrayList of Strings composed of names and addresses. After the addresses, there is an empty String and the next name starts. The method getAddress takes a String parameter (a name) and returns the address of the pereson (the lines after the name including the empty String, but stopping there). I'm having trouble writing this method.

import java.util.ArrayList;

public class Recipients {
    ArrayList<String> lines = new ArrayList<String>();
    public String extractCity(String cityZip) {
        int pos = cityZip.indexOf(",");
        return cityZip.substring(0, pos);
    }
    public void printNames() {
        System.out.println(lines.get(0));
        for (int i = 0; i < lines.size()-1; i++) 
            if (lines.get(i).substring(0, lines.get(i).length()).equals("")) 
                System.out.println(lines.get(i+1));
    }
    public String getAddress(String name) {
        String address = "";
        int ct = 0;
        int place = 0;
        for (int i = 0; i < lines.size(); i++) {
            if (lines.get(i).substring(0, lines.get(i).length()).equals(name)) {
                place = i;
                for (int j = i+1; j < lines.size(); j++) {
                    ct = j;
                    if (!lines.get(i).substring(0, lines.get(i).length()).equals("")) {
                        ct++;
                    }
                }
                for (int k = place; k < ct; k++) {
                    address = address + lines.get(i);
                }
            }
        }

        return address;
    }
        public void main() {
            lines.add("Mr. J Adams");
            lines.add("Rose St.");
            lines.add("Ithaca, NY 14850");
            lines.add("");
            lines.add("Jack S. Smith");
            lines.add("12 Posy Way");
            lines.add("Suite #201");
            lines.add("Glendale, CA 91203");
            lines.add("");
            lines.add("Ms. M.K. Delgado");
            lines.add("2 River Dr.");
            lines.add("");
            System.out.println(getAddress("Jack S. Smith"));
            System.out.println("test line break");
            }
}

Thank you for your time.

EDIT: This method is supposed to be written in the Recipients class. It has an assumed constructor and I've written other methods inside the class. I've edited the class. I'm having trouble with the logic.

Worksheet says: Write the getAddress method of the Recipients class. This method should return a string that contains only the address of the corresponding name parameter. For example, if name is "Jack S. Smith", a string containing the three subsequent lines of his address should be returned. This string should contain line breaks in appropriate places, including after the last line of the address.

public String getAddress(String name)

Answer 1

You should create class for saving name and address. Please find below mentioned approach.

package hello;

import java.util.ArrayList;
import java.util.List;

class Employee {

    private String name;
    private String address;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

}

public class So3 {

    public static void main(String[] args) {
        List<String> lines = new ArrayList<String>();
        lines.add("Mr. J Adams");
        lines.add("Rose St.");
        lines.add("Ithaca, NY 14850");
        lines.add("");
        lines.add("Jack S. Smith");
        lines.add("12 Posy Way");
        lines.add("Suite #201");
        lines.add("Glendale, CA 91203");
        lines.add("");
        lines.add("Ms. M.K. Delgado");
        lines.add("2 River Dr.");
        lines.add("");

        List<Employee> employees = new ArrayList<Employee>();
        Employee employee = new Employee();
        for (String str : lines) {
            if (str.isEmpty()) {
                if (employee.getName() != null && employee.getAddress() != null) {
                    employees.add(employee);
                    employee = new Employee();
                }
            } else if (employee.getName() == null) {
                employee.setName(str);
            } else {
                if (employee.getAddress() == null) {
                    employee.setAddress(str);
                } else {
                    employee.setAddress(employee.getAddress() + " " + str);
                }
            }
        }

        if (employee.getName() != null && employee.getAddress() != null) {
            employees.add(employee);
        }

        System.out.println(getAddress(employees, "Ms. M.K. Delgado"));

    }

    private static String getAddress(List<Employee> employees, String name) {
        if (employees != null && name != null) {
            for (Employee employee : employees) {
                if (name.equals(employee.getName())) {
                    return employee.getAddress();
                }
            }
        }
        return null;
    }

}

Answer 2

If you have to use as you have wanted then you need to modify your getAddress method. Try the following getAddress method in your code:

public String getAddress(String name) {
    String address = "";
    boolean nameFound=false;
    for(String str:lines)
    {
        if(!nameFound && str.equals(name))
            nameFound=true;
        else if(nameFound && str.isEmpty())
            break;
        else if(nameFound && !str.isEmpty())
            address+=str;
    }
    return address;
}

Answer 3

You should use HashMap rather than an ArrayList for this. This is a perfect scenario to use HashMap instead.

public class APProblem {
    Map<String, List<String>> lines2 = new HashMap<>();

    public List<String> getAddress(String name) {
        return lines2.get(name);
    }

        public void main() {
            String name = "Mr. J Adams";
            List<String> address = Arrays.asList("Rose St.", "Ithaca, NY 14850");
            lines2.put(name, address);
            name = "Jack S. Smith";
            address = Arrays.asList("12 Posy Way", "Suite #201", "Glendale, CA 91203");
            lines2.put(name, address);

            System.out.println(getAddress("Jack S. Smith"));
            System.out.println("Testing line break.");
            }
}