java - 按字母顺序对对象数组进行排序

Question

我有一个对象数组，每个对象都有一个给定的名称和姓氏。使用方法 getGivenName 和 getSurname 将这些名称写入对象。

我需要按姓氏的字母顺序对数组中的元素进行排序。我怎样才能做到这一点？

Answer 1

你的比较器

class SampleComparator implements Comparator<YourObject> {
    @Override
    public int compare(YourObject o1, YourObject o2) {

           return o1.getSurname().compareTo(o2.getSurname());
   }
}

你的排序

  Collections.sort(YourList, new SampleComparator())

如果您需要忽略大小写，请使用 like

  return o1.getSurname().compareToIgnoreCase(o2.getSurname()); 

Answer 2

在对自然语言文本进行排序时，建议使用Collat​​or和Collat​​ionKeys。其他答案提到的String.compareTo方法将根据字符串中每个字符的 Unicode 值比较字符串，这可能不是您想要/期望的，具体取决于您的输入字符串和语言环境。

请注意，我编写了一些实用方法来帮助对自然语言文本进行排序。

例如，您可以尝试以下操作：

public class PersonLocalizer implements Localizer<Person> {
    @Override
    public String getDisplayString(Person person, Locale inLocale) {
        return person.getSurname();
    }
} 

[...]

Localizables.sort(new PersonLocalizer (), persons);

马文：

<dependency>  
    <groupId>org.softsmithy.lib</groupId>  
    <artifactId>softsmithy-lib-core</artifactId>  
    <version>0.3</version>  
</dependency>  

Answer 3

使用List而不是使用数组。你的班级需要implements Comparable interface。请看代码，

通过实现 Comparable 接口

public class Person implements Comparable<Person>{

private String givenName;
private String surname;

public static void main(String[] args) {
    Person person1 = new Person("a","b");
    Person person2 = new Person("c","d");
    Person person3 = new Person("e","f");

    List<Person> personList = new ArrayList<Person>();
    personList.add(person1);
    personList.add(person2);
    personList.add(person3);
    Collections.sort(personList);
    System.out.println(personList);
}

@Override
public String toString() {
    return "WorkSheet [givenName=" + givenName + ", surname=" + surname
            + "]";
}
    public Person() {
        // TODO Auto-generated constructor stub
    }


public Person(String givenName , String surname) {
    this.givenName = givenName;
    this.surname = surname;
}

public String getGivenName() {
    return givenName;
}

public void setGivenName(String givenName) {
    this.givenName = givenName;
}

public String getSurname() {
    return surname;
}

public void setSurname(String surname) {
    this.surname = surname;
}

@Override
public int compareTo(Person o) {
    // TODO Auto-generated method stub
    return o.getSurname().compareTo(this.getSurname());
}
}   

通过实现比较器接口

public class Person implements Comparator<Person>{

private String givenName;
private String surname;

public static void main(String[] args) {
    Person person1 = new Person("a","b");
    Person person2 = new Person("c","d");
    Person person3 = new Person("e","f");

    List<Person> personList = new ArrayList<Person>();
    personList.add(person1);
    personList.add(person2);
    personList.add(person3);
    Collections.sort(personList , new Person());
    System.out.println(personList);
}

@Override
public String toString() {
    return "WorkSheet [givenName=" + givenName + ", surname=" + surname
            + "]";
}

public Person() {
    // TODO Auto-generated constructor stub
}

public Person(String givenName , String surname) {
    this.givenName = givenName;
    this.surname = surname;
}

public String getGivenName() {
    return givenName;
}

public void setGivenName(String givenName) {
    this.givenName = givenName;
}

public String getSurname() {
    return surname;
}

public void setSurname(String surname) {
    this.surname = surname;
}

@Override
public int compare(Person o1, Person o2) {
    // TODO Auto-generated method stub
    return o2.getSurname().compareTo(o1.getSurname());
}
}

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