Springg boot Demo : https://github.com/xkcoding/spring-boot-demo

https://www.liaoxuefeng.com/wiki/1016959663602400 廖雪峰

python-面试通关宝典：https://www.cnblogs.com/duanming/p/11830267.html

PEP8 Python 编码规范整理：http://blog.sae.sina.com.cn/archives/4781

https://www.javanav.com/interview/b5d9e1d5736642f78ffd528d14070617.html

序号	内容	链接地址
1	Java基础知识面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/104390612
2	Java集合容器面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/104588551
3	Java异常面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/104390689
4	并发编程面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/104863992
5	JVM面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/104390752
6	Spring面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/104397516
7	Spring MVC面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/104397427
8	Spring Boot面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/104397299
9	Spring Cloud面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/104397367
10	MyBatis面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/101292950
11	Redis面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/103522351
12	MySQL数据库面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/104778621
13	消息中间件MQ与RabbitMQ面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/104588612
14	Dubbo面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/104390006
15	Linux面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/104588679
16	Tomcat面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/104397665
17	ZooKeeper面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/104397719
18	Netty面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/104391081
19	架构设计&分布式&数据结构与算法面试题（2020最新版）	https://thinkwon.blog.csdn.net/article/details/105870730

安全

跨站脚本漏洞(XSS)基础讲解:https://www.jianshu.com/p/4fcb4b411a66

https://blog.csdn.net/qq_41637554/article/details/80844386

算法

数值交换

a = 2 
b = 3

# 方法一
a,b = b,a

# 方法二
tmp = a
a = b
b = tmp

# 方法三
a = a+b
b = a - b
a = a - b

# 方法四
a = a^b   # a = 10 ^ 11 = 01 = 1
b = a^b   # b = 01 ^ 11 = 10 = 2
a = a^b   # a = 01 ^ 10 = 11 = 3

经典排序算法：https://zhuanlan.zhihu.com/p/37430943

堆排序：

https://www.jianshu.com/p/0d383d294a80

https://www.jianshu.com/p/d174f1862601

class HeapSort(object):

    def build_max_heap(self, array):
        for i in range(len(array) // 2 - 1, -1, -1):
            self.heap_adjust(array, i, len(array))

    def heap_adjust(self, array, index, array_len):
        left = 2 * index + 1
        right = 2 * index + 2
        largest = index
        if left < array_len and array[left] > array[largest]:
            largest = left
        if right < array_len and array[right] > array[largest]:
            largest = right
        if largest != index:
            array[largest], array[index] = array[index], array[largest]
            self.heap_adjust(array, largest, array_len)

    def heap_sort(self, array):
        self.build_max_heap(array)
        for i in range(len(array) - 1, -1, -1):
            array[0], array[i] = array[i], array[0]
            self.heap_adjust(array, 0, i)


if __name__ == "__main__":
    array = [50, 16, 30, 10, 60, 90, 2, 80, 70]
    heap_sort = HeapSort()
    heap_sort.heap_sort(array)
    print(array)

View Code

快排：

# 方法一
def quick_sort(arr):
    if len(arr) < 2:
        return arr
    pivot = arr[0]
    less = [x for x in arr[1:] if x <= pivot]
    more = [x for x in arr[1:] if x > pivot]
    return quick_sort(less) + [pivot] + quick_sort(more)


# 方法二
class QuickSort(object):
    def quick_sort(self, arr, low, high):
        if low < high:
            i = self.partition(arr, low, high)
            self.quick_sort(arr, low, i - 1)
            self.quick_sort(arr, i + 1, high)

    def swap(self, arr, i, j):
        arr[i], arr[j] = arr[j], arr[i]

    def partition(self, arr, low, high):
        pivot = arr[low]
        index = low
        while low < high:
            while low < high and arr[high] >= pivot:
                high -= 1
            while low < high and arr[low] <= pivot:
                low += 1
            self.swap(arr, low, high)
        self.swap(arr, index, low)
        return low

方法三：
def quick_sort(arr, low, high):
    if low < high:
        i = partition(arr, low, high)
        quick_sort(arr, low, i - 1)
        quick_sort(arr, i + 1, high)


def partition(arr, low, high):
    pivot = low
    while low < high:
        while low < high and arr[high] >= arr[pivot]:
            high -= 1
        while low < high and arr[low] <= arr[pivot]:
            low += 1
        arr[low], arr[high] = arr[high], arr[low]
    arr[pivot], arr[low] = arr[low], arr[pivot]
    return low


test_arr = [9, 1, 5, 2, 98, 23]
quick_sort(test_arr, 0, len(test_arr) - 1)
print(test_arr)

View Code

开发模式

单例模式

https://zhuanlan.zhihu.com/p/37534850

https://www.cnblogs.com/huchong/p/8244279.html

线程安全的单例：

https://blog.csdn.net/chichu261/article/details/84347305

https://www.jianshu.com/p/6a1690f0dd00

import threading

"""
线程安全的单利模式

紧跟with后面的语句被求值后，返回对象的 __enter__() 方法被调用，这个方法的返回值将被赋值给as后面的变量。
当with后面的代码块全部被执行完之后，将调用前面返回对象的 __exit__()方法
"""
def synchronized(func):
    func.__lock__ = threading.Lock()

    def lock_func(*args, **kwargs):
        with func.__lock__:
            return func(*args, **kwargs)

    return lock_func

class Singleton(object):
    instance = None

    @synchronized
    def __new__(cls):
        # 关键在于这，每一次实例化的时候，我们都只会返回这同一个instance对象
        if not cls.instance:
            cls.instance = super(Singleton, cls).__new__(cls)
        return cls.instance

View Code

import threading


class Singleton(object):
    _instance_lock = threading.Lock()

    def __init__(self, *args, **kwargs):
        pass

    def __new__(cls, *args, **kwargs):
        if not hasattr(cls, '_instance'):
            with Singleton._instance_lock:
                if not hasattr(cls, '_instance'):
                    Singleton._instance = super().__new__(cls)

            return Singleton._instance


obj1 = Singleton()
obj2 = Singleton()
print(obj1, obj2)


def task(arg):
    obj = Singleton()
    print(obj)


for i in range(10):
    t = threading.Thread(target=task, args=[i, ])
    t.start()

View Code

import threading
import time


class SingletonSafe(object):
    """线程不安全单例模式"""
    lock = threading.Lock()

    def __new__(cls, *args, **kwargs):
        if not hasattr(SingletonSafe, '_instance'):
            with SingletonSafe.lock:
                if not hasattr(SingletonSafe, "_instance"):
                    time.sleep(2)
                    SingletonSafe._instance = super(SingletonSafe, cls).__new__(cls)
        return SingletonSafe._instance


class SingletonUnsafe(object):
    """线程安全单例模式"""

    def __new__(cls, *args, **kwargs):
        if not hasattr(SingletonUnsafe, '_instance'):
            time.sleep(2)
            SingletonUnsafe._instance = super(SingletonUnsafe, cls).__new__(cls)
        return SingletonUnsafe._instance


def test_singleton(clz):
    def task(arg):
        obj = clz(arg)
        print(obj)

    for i in range(10):
        t = threading.Thread(target=task, args=[i, ])
        t.start()


if __name__ == "__main__":
    test_singleton(SingletonUnsafe)
    test_singleton(SingletonSafe)

View Code

Python基础

赋值、浅拷贝和深拷贝：https://zhuanlan.zhihu.com/p/54011712

iter函数解释

菜鸟教程： https://www.runoob.com/python/python-func-iter.html

class Counter:

    def __init__(self, _start, _end):
        self.start = _start
        self.end = _end

    def get_next(self):
        s = self.start
        if self.start < self.end:
            self.start += 1
        else:
            raise StopIteration

        return s


c = Counter(1, 5)
iterator = iter(c.get_next, 4)
print(type(iterator))
for i in iterator:
    print(i)