如何將對象列表轉換爲java中的字符串數組列表？

Question

我有一個類，說所有人的字符串屬性。我有一個ArrayList < Person>。我想將此ArrayList < Person>轉換爲列表< String []>。我如何使用java轉換它？

Answer 1

假設人類的每個屬性是字符串數組中的一個項目，下面將做的工作：

Person類：

public class Person { 
private String title; 
private String firstName; 
private String lastName; 

public Person(String title, String firstName, String lastName) { 
    super(); 
    this.title = title; 
    this.firstName = firstName; 
    this.lastName = lastName; 
} 

public String getTitle() { 
    return title; 
} 

public void setTitle(String title) { 
    this.title = title; 
} 

public String getFirstName() { 
    return firstName; 
} 

public void setFirstName(String firstName) { 
    this.firstName = firstName; 
} 

public String getLastName() { 
    return lastName; 
} 

public void setLastName(String lastName) { 
    this.lastName = lastName; 
} 

} 

PersonConverter類別：

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

public class PersonConverter { 

public List<String[]> convertPersonList(List<Person> list) { 
    List<String[]> result = new ArrayList<>(); 

    for (Person p : list) { 
     result.add(convertPerson(p)); 
    } 

    return result; 
} 

private String[] convertPerson(Person p) { 
    String[] persontAttributes = new String[3]; 
    persontAttributes[0] = p.getTitle(); 
    persontAttributes[1] = p.getFirstName(); 
    persontAttributes[2] = p.getLastName(); 
    return persontAttributes; 
} 
} 

測試：

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

public class Main { 

public static void main(String[] args) { 
    //create a person list 
    List<Person> personList = new ArrayList<>(); 

    Person john = new Person("Mr.", "John", "Lenonn"); 
    Person paul = new Person("Sir", "Paul", "McCartney"); 

    personList.add(john); 
    personList.add(paul); 

    //create an instance of the person converter 
    PersonConverter pc = new PersonConverter(); 

    //perform the conversion 
    List<String[]> convertedList = pc.convertPersonList(personList); 

    //print the result to the console 
    for (String[] stringArray : convertedList) { 
     for (String s : stringArray) { 
      System.out.println(s); 
     } 
     System.out.println(); 
    } 
} 

} 

此打印出：

Mr. 
John 
Lenonn 

Sir 
Paul 
McCartney 

Answer 2

我不確定我是否清楚您要求的內容，但您始終可以對您的人員進行簡單循環。

ArrayList<Person> people = new ArrayList<Person>(); 
List<String[]> everyonesAtt = new ArrayList<String[]>(); 
for (Person person : people) { 
    everyonesAtt.add(person.getAttributes()); 
} 

和Person類的例子：

public class Person { 

private String name; 

private String surname; 

public String[] getAttributes(){ 
    String[] atts = {name, surname}; 
    return atts; 
} 
}