使用For-Each循环时发生类型转换错误

Question

我的for-each循环中出现了这个错误：

private static HashMap<Integer,Employee> employeeDatabase = new HashMap<Integer,Employee>();

public HashMap getEmployeeDatabase() {
    return employeeDatabase;
}

for(Employee e: c.getEmployeeDatabase().values()) 
    {
        e.print();
    }

Company c = new Company();

Answer 1

方法返回类型是raw类型。不要使用原始类型。

private static HashMap<Integer,Employee> employeeDatabase = new HashMap<Integer,Employee>();

public HashMap getEmployeeDatabase() {
    return employeeDatabase;
}

应该是像

private static Map<Integer, Employee> employeeDatabase = new HashMap<>();

public Map<Integer, Employee> getEmployeeDatabase() {
    return employeeDatabase;
}