java 读取当前项目根目录下所有后缀为obj的文件将这些Emp对象读取出来 并存入到一个List集合中然后按照员工工资从多到少的顺序依次输出员工信息

假设Emp对象的定义如下：

public class Emp {
    private String name;
    private int age;
    private double salary;

    public Emp(String name, int age, double salary) {
        this.name = name;
        this.age = age;
        this.salary = salary;
    }

    // getters and setters
}

可以使用如下代码读取当前项目根目录下所有后缀为.obj的文件：

List<Emp> empList = new ArrayList<>();

File dir = new File(".");
File[] files = dir.listFiles(new FilenameFilter() {
    @Override
    public boolean accept(File dir, String name) {
        return name.endsWith(".obj");
    }
});

for (File file : files) {
    try (ObjectInputStream in = new ObjectInputStream(new FileInputStream(file))) {
        Emp emp = (Emp) in.readObject();
        empList.add(emp);
    } catch (IOException | ClassNotFoundException e) {
        e.printStackTrace();
    }
}

然后可以使用如下代码按照员工工资从多到少的顺序输出员工信息：

Collections.sort(empList, new Comparator<Emp>() {
    @Override
    public int compare(Emp o1, Emp o2) {
        return Double.compare(o2.getSalary(), o1.getSalary());
    }
});

for (Emp emp : empList) {
    System.out.println(emp.getName() + ", " + emp.getAge() + ", " + emp.getSalary());
}
``