Java 8 Stream API 查找与属性值匹配的唯一对象

使用Java 8的Stream API可以轻松地查找与属性值匹配的唯一对象。Stream API是Java 8引入的一个强大的功能，它提供了一种流式处理数据的方式，可以简化代码，并且使代码更具可读性和可维护性。

java
public class Student {
    private int id;
    private String name;
    public Student(int id, String name) {
        this.id = id;
        this.name = name;
    }
    public int getId() {
        return id;
    }
    public String getName() {
        return name;
    }
}

java
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
public class Main {
    public static void main(String[] args) {
        List students = new ArrayList<>();
        students.add(new Student(1, "Alice"));
        students.add(new Student(2, "Bob"));
        students.add(new Student(3, "Charlie"));
        Optional student = students.stream()
                .filter(s -> s.getId() == 2)
                .findFirst();
        if (student.isPresent()) {
            System.out.println("找到了匹配的学生对象：");
            System.out.println("ID: " + student.get().getId());
            System.out.println("名字: " + student.get().getName());
        } else {
            System.out.println("未找到匹配的学生对象");
        }
    }
}

java
Optional student = students.stream()
        .filter(s -> s.getId() == 2)
        .findFirst();
if (student.isPresent()) {
    System.out.println("找到了匹配的学生对象：");
    System.out.println("ID: " + student.get().getId());
    System.out.println("名字: " + student.get().getName());
} else {
    System.out.println("未找到匹配的学生对象");
}