SpringBoot 项目中使用 spring-boot-starter-amqp 依赖实现 RabbitMQ

一、区别

• dup

• deep_dup

• clone

二、示例

• 浅复制的意思是只复制对象的第一层属性，不会递归复制嵌套的对象。
• 深复制的意思是递归复制嵌套对象

require 'active_support/core_ext/object/deep_dup'

# 使用 dup
# 这里 original 是一个包含嵌套哈希的哈希。dup 方法只复制了 original 的第一层属性，因此 dup_copy[:b] 和 original[:b] 仍然引用同一个嵌套哈希 { c: 4 }。所以修改 dup_copy[:b][:c] 也会影响 original[:b][:c]
original = { a: [1, 2, 3], b: { c: 4 } }
dup_copy = original.dup
dup_copy[:b][:c] = 5
puts original[:b][:c] # => 5 (浅复制)

original = "hello".freeze
copy = original.dup
copy.frozen? # => false (不复制冻结状态)

# 使用 deep_dup
original = { a: [1, 2, 3], b: { c: 4 } }
deep_dup_copy = original.deep_dup
deep_dup_copy[:b][:c] = 6
puts original[:b][:c] # => 4 (深复制)

# 使用 clone
original = { a: [1, 2, 3], b: { c: 4 } }
clone_copy = original.clone
clone_copy[:b][:c] = 7
puts original[:b][:c] # => 7 (浅复制)

original_str = "hello".freeze
clone_copy = original_str.clone
puts clone_copy.frozen? # => true (复制冻结状态)

三、dup 方法常用场景：通常用于创建对象的浅复制

# 避免修改原始对象
original_array = [1, 2, 3]
copy_array = original_array.dup
copy_array << 4
puts original_array.inspect # => [1, 2, 3]
puts copy_array.inspect     # => [1, 2, 3, 4]

# 复制可变对象
original_hash = { a: 1, b: 2 }
copy_hash = original_hash.dup
copy_hash[:c] = 3
puts original_hash.inspect # => {:a=>1, :b=>2}
puts copy_hash.inspect     # => {:a=>1, :b=>2, :c=>3}

# 复制对象的状态
class MyClass
  attr_accessor :value
end

original = MyClass.new
original.value = 10
copy = original.dup
copy.value = 20
puts original.value # => 10
puts copy.value     # => 20

# 复制 ActiveRecord 对象
original_user = User.find(1)
copy_user = original_user.dup
copy_user.email = "new_email@example.com"
copy_user.save