\/* MD \/ \u5bcc\u6587\u672c\u4e2d\u7684 .toc\uff08\u542b\u535a\u5ba2\u56ed\u642c\u5bb6\u7b49\u5d4c\u5957\u7ed3\u6784\uff09\uff1b.toc-box \u5728\u4fa7\u680f\uff0c\u4e0d\u53d7\u5f71\u54cd *\/
\n #content_views .toc,
\n \/* \u7f16\u8f91\u5668\u5e38\u5728\u76ee\u5f55\u524d\u540e\u63d2\u5165\u7a7a p\uff08:empty \u4ecd\u5360 20px\uff09\uff0c\u4e00\u5e76\u53bb\u6389\u907f\u514d\u9876\u7a7a\u9699 *\/
\n #content_views.markdown_views > p:empty:has(+ .toc),
\n #content_views.markdown_views > .toc + p:empty,
\n \/* \u5bcc\u6587\u672c\u65e7\u7248\u76ee\u5f55\u6807\u8bb0 *\/
\n #content_views.htmledit_views #main-toc,
\n #content_views.htmledit_views #hr-toc,
\n #content_views.htmledit_views p[id*=\\”-toc\\”] {
\n display: none !important;
\n }
\n \/* \u76ee\u5f55\u53bb\u6389\u540e\uff0c\u7d27\u8ddf\u7684\u9996\u4e2a\u6807\u9898\u4e0d\u518d\u591a\u51fa\u4e00\u5757\u4e0a\u8fb9\u8ddd *\/
\n #content_views.markdown_views > .toc + h1,
\n #content_views.markdown_views > .toc + h2,
\n #content_views.markdown_views > .toc + h3,
\n #content_views.markdown_views > .toc + h4,
\n #content_views.markdown_views > .toc + p:empty + h1,
\n #content_views.markdown_views > .toc + p:empty + h2,
\n #content_views.markdown_views > .toc + p:empty + h3,
\n #content_views.markdown_views > .toc + p:empty + h4 {
\n margin-top: 0 !important;
\n }<\/p>\n
\u601d\u8003：\u5b66\u4e60\u6d4b\u5f00\u77e5\u8bc6\u5e76\u642d\u4e00\u4e2a\u9879\u76ee，\u540e\u7eed\u5168\u6808，agent，\u6d4b\u5f00\u90fd\u80fd\u6295<\/p>\n
\u76db\u6700\u591a\u6c34\u7684\u5bb9\u5668<\/p>\n
\u7ed9\u5b9a\u4e00\u4e2a\u957f\u5ea6\u4e3a n \u7684\u6574\u6570\u6570\u7ec4\u00a0height\u00a0\u3002\u6709\u00a0n\u00a0\u6761\u5782\u7ebf，\u7b2c i \u6761\u7ebf\u7684\u4e24\u4e2a\u7aef\u70b9\u662f\u00a0(i, 0)\u00a0\u548c\u00a0(i, height[i])\u00a0\u3002<\/p>\n
\u627e\u51fa\u5176\u4e2d\u7684\u4e24\u6761\u7ebf，\u4f7f\u5f97\u5b83\u4eec\u4e0e\u00a0x\u00a0\u8f74\u5171\u540c\u6784\u6210\u7684\u5bb9\u5668\u53ef\u4ee5\u5bb9\u7eb3\u6700\u591a\u7684\u6c34\u3002<\/p>\n
\u8fd4\u56de\u5bb9\u5668\u53ef\u4ee5\u50a8\u5b58\u7684\u6700\u5927\u6c34\u91cf\u3002<\/p>\n
\u601d\u8def：\u53cc\u6307\u9488\u5f80\u4e2d\u95f4\u8d70，\u6bcf\u6b21\u8ba1\u7b97\u5f53\u524d\u5bb9\u79ef，\u8981\u6c42\u6700\u5927\u6c34\u5bb9\u91cf，\u5de6\u53f3\u54ea\u8fb9\u5c0f\u79fb\u52a8\u54ea\u8fb9
\nclass Solution {<\/p>\n
public int maxArea(int[] height) {<\/p>\n
int left=0;<\/p>\n
int right=height.length-1;<\/p>\n
int max=0;<\/p>\n
while(left<right){<\/p>\n
int cur=-1;<\/p>\n
if(height[left]<height[right]){<\/p>\n
cur=height[left]*(right-left);<\/p>\n
left++;<\/p>\n
}<\/p>\n
else{<\/p>\n
cur=height[right]*(right-left);<\/p>\n
right\u2013;<\/p>\n
}<\/p>\n
if(cur>max)max=cur;<\/p>\n
}<\/p>\n
return max;<\/p>\n
}<\/p>\n
}<\/p>\n
\u4e24\u6570\u4e4b\u548c<\/p>\n
\u7ed9\u5b9a\u4e00\u4e2a\u6574\u6570\u6570\u7ec4 nums\u00a0\u548c\u4e00\u4e2a\u6574\u6570\u76ee\u6807\u503c target，\u8bf7\u4f60\u5728\u8be5\u6570\u7ec4\u4e2d\u627e\u51fa \u548c\u4e3a\u76ee\u6807\u503c target\u00a0 \u7684\u90a3\u00a0\u4e24\u4e2a\u00a0\u6574\u6570，\u5e76\u8fd4\u56de\u5b83\u4eec\u7684\u6570\u7ec4\u4e0b\u6807\u3002<\/p>\n
\u601d\u8def：Hashmap
\n\u6613\u9519：\u4e0d\u80fd\u4e00\u5f00\u59cb\u5c31\u5efa\u7acb\u6570\u5b57->\u7d22\u5f15，\u5f53target=2*nums[i]\u4f1a\u51fa\u91cd\u590d
\nclass Solution {<\/p>\n
public int[] twoSum(int[] nums, int target) {<\/p>\n
Map<Integer,Integer> map=new HashMap<>();<\/p>\n
for(int i=0;i<nums.length;i++){<\/p>\n
if(map.containsKey(target-nums[i])){<\/p>\n
return new int[]{i,map.get(target-nums[i])};<\/p>\n
}<\/p>\n
map.put(nums[i],i);<\/p>\n
}<\/p>\n
return null;<\/p>\n
}<\/p>\n
}<\/p>\n
5.Java\u8bbe\u8ba1\u6a21\u5f0f：\u8bb2\u4e00\u4e0b\u7b56\u7565\u6a21\u5f0f\u3002
\n\u662f\u4e00\u79cd\u4ee3\u7801\u8bbe\u8ba1\u6a21\u5f0f，\u4e3b\u8981\u76ee\u7684\u5c31\u662f\u4e3a\u4e86\u6d88\u9664\u5927\u91cf\u7684ifelse\u4ee3\u7801，\u6bd4\u5982\u4e00\u4e2a\u652f\u4ed8\u529f\u80fd，\u652f\u6301\u5fae\u4fe1\u652f\u4ed8\u5b9d\u7b49，\u6700\u7b80\u5355\u5199\u6cd5\u662f\u5229\u7528ifelse\u6839\u636e\u652f\u4ed8\u7c7b\u578b\u8d70\u5bf9\u5e94\u652f\u4ed8\u903b\u8f91，\u4f46\u5229\u7528\u7b56\u7565\u6a21\u5f0f，\u53ef\u4ee5\u5148\u5b9a\u4e49\u4e00\u4e2a\u652f\u4ed8\u63a5\u53e3，\u5bf9\u4e8e\u4e0d\u540c\u7684\u652f\u4ed8\u884c\u4e3a\u5b9e\u73b0\u4e0d\u540c\u7684\u652f\u4ed8\u7c7b，\u7136\u540e\u642d\u914d\u5de5\u5382\u6a21\u5f0f\u5199\u4e00\u4e2amap\u8fdb\u884c\u52a8\u6001\u7684\u652f\u4ed8\u7b56\u7565\u7684\u8def\u7531，\u5728\u8c03\u7528\u7684\u65f6\u5019\u4e1a\u52a1\u4ee3\u7801\u5c31\u53d8\u5f97\u5f88\u5e72\u51c0
\n\u597d\u5904：<\/p>\n
\u6d88\u706d\u4e86 if-else：\u4f60\u7684\u4e3b\u6d41\u7a0b\u4ee3\u7801\u53d8\u5f97\u975e\u5e38\u5e72\u51c0\u3001\u6e05\u6670\u3002<\/p>\n<\/li>\n
\u7b26\u5408\u201c\u5f00\u95ed\u539f\u5219\u201d：\u4e0b\u6b21\u52a0\u4e2a\u201c\u94f6\u8054\u652f\u4ed8\u201d\u3002\u4f60\u4e0d\u9700\u8981\u6539\u52a8\u4efb\u4f55\u73b0\u6709\u7684\u4ee3\u7801\u3002\u4f60\u53ea\u9700\u8981\u65b0\u5efa\u4e00\u4e2a UnionPayStrategy implements PayStrategy \u7c7b，\u6253\u4e0a @Service("UNION") \u6ce8\u89e3，Spring \u81ea\u52a8\u5c31\u628a\u5b83\u6ce8\u518c\u8fdb\u53bb\u4e86\u3002\u4e1a\u52a1\u7acb\u9a6c\u5c31\u80fd\u7528！<\/p>\n<\/li>\n
\u804c\u8d23\u5355\u4e00：\u5fae\u4fe1\u652f\u4ed8\u51fa Bug \u4e86，\u4f60\u53ea\u9700\u8981\u53bb WechatPayStrategy \u91cc\u627e，\u7edd\u5bf9\u4e0d\u4f1a\u78b0\u5230\u652f\u4ed8\u5b9d\u7684\u4ee3\u7801<\/p>\n<\/li>\n
6\u00a0.\u67b6\u6784\u8bbe\u8ba1：\u4e86\u89e3\u00a0DDD（Domain-Driven Design \u9886\u57df\u9a71\u52a8\u8bbe\u8ba1）\u5417？<\/p>\n
\u201cDDD \u5e76\u4e0d\u662f\u4e00\u5957\u6280\u672f\u6846\u67b6，\u800c\u662f\u4e00\u79cd\u5e94\u5bf9\u590d\u6742\u4e1a\u52a1\u67b6\u6784\u7684\u65b9\u6cd5\u8bba\u3002\u4f20\u7edf\u7684 MVC \u6a21\u5f0f\u628a\u6240\u6709\u7684\u903b\u8f91\u5806\u5728 Service \u91cc，\u5bb9\u6613\u4ea7\u751f\u2018\u4e0a\u5e1d\u7c7b\u2019\u3002<\/p>\n
\u5f15\u5165 DDD \u540e，\u6211\u4eec\u4f1a\u6839\u636e\u4e1a\u52a1\u8fb9\u754c\u5212\u5206\u51fa\u4e0d\u540c\u7684**\u2018\u9650\u754c\u4e0a\u4e0b\u6587\u2019（\u5fae\u670d\u52a1）\u3002\u5728\u4ee3\u7801\u5b9e\u73b0\u4e0a，\u6211\u4eec\u4f1a\u91c7\u7528\u56db\u5c42\u67b6\u6784，\u628a\u6838\u5fc3\u4e1a\u52a1\u903b\u8f91\u6c89\u6dc0\u5230\u2018\u9886\u57df\u5c42\u2019，\u901a\u8fc7\u2018\u805a\u5408\u6839\u2019\u4fdd\u8bc1\u6570\u636e\u4e00\u81f4\u6027，\u901a\u8fc7\u2018\u9886\u57df\u4e8b\u4ef6\u2019**\u5b9e\u73b0\u670d\u52a1\u95f4\u7684\u89e3\u8026\u3002<\/p>\n
\u6211\u66fe\u7ecf\u5728\u4e00\u4e2a\u7535\u5546\u9879\u76ee\u4e2d\u5e94\u7528\u8fc7 DDD，\u628a\u539f\u672c\u63c9\u5728\u4e00\u8d77\u7684\u8ba2\u5355\u3001\u5e93\u5b58\u3001\u8425\u9500\u7cfb\u7edf\u62c6\u5206，\u7528\u4e8b\u4ef6\u9a71\u52a8\u4e32\u8054，\u5927\u5927\u964d\u4f4e\u4e86\u7cfb\u7edf\u7684\u8026\u5408\u5ea6，\u63d0\u5347\u4e86\u4ee3\u7801\u7684\u53ef\u7ef4\u62a4\u6027\u3002\u201d<\/p>\n
MVC\u548cDDD\u533a\u522b<\/p>\n
\u5728 MVC \u4e2d，\u6240\u6709\u7684\u4e1a\u52a1\u903b\u8f91（\u8ba1\u7b97\u4ef7\u683c\u3001\u5224\u65ad\u5e93\u5b58\u3001\u6821\u9a8c\u72b6\u6001）\u90fd\u88ab\u585e\u8fdb\u4e86 Service \u5c42，\u800c Entity（\u6570\u636e\u5e93\u5b9e\u4f53）\u91cc\u53ea\u6709 getter \u548c setter\u3002<\/p>\n
\u5047\u8bbe\u4e1a\u52a1\u89c4\u5219\u662f：\u4e0b\u5355\u65f6，\u5fc5\u987b\u6821\u9a8c\u5e93\u5b58\u662f\u5426\u5145\u8db3，\u5982\u679c\u5145\u8db3\u5219\u6263\u51cf；\u5982\u679c\u8ba2\u5355\u603b\u91d1\u989d\u8d85\u8fc7 500 \u5143，\u8fd8\u9700\u8981\u6253 9 \u6298\u3002<\/p>\n
\u5728 MVC \u67b6\u6784\u4e0b，\u6211\u4eec\u7684\u5b9e\u4f53\u7c7b（Entity）\u901a\u5e38\u53ea\u662f\u4e2a\u201c\u6570\u636e\u888b\u201d，\u6240\u6709\u7684\u903b\u8f91\u5168\u5728 Service \u91cc\u3002<\/p>\n
java<\/p>\n
public class Order {
\nprivate Long id;
\nprivate Double totalAmount;
\nprivate Integer status;
\n\/\/ \u53ea\u6709 getter \u548c setter
\npublic Double getTotalAmount() { return totalAmount; }
\npublic void setTotalAmount(Double totalAmount) { this.totalAmount = totalAmount; }
\n\/\/ \u2026 \u5176\u4ed6 getter\/setter
\n}
\npublic class Product {
\nprivate Long id;
\nprivate Integer stock;
\n\/\/ \u53ea\u6709 getter \u548c setter
\npublic Integer getStock() { return stock; }
\npublic void setStock(Integer stock) { this.stock = stock; }
\n}<\/p>\n
\u6240\u6709\u7684\u4e1a\u52a1\u903b\u8f91\u3001\u5224\u65ad\u3001\u7b97\u94b1\u90fd\u5728\u8fd9\u91cc，\u968f\u7740\u9700\u6c42\u589e\u52a0，\u8fd9\u4e2a\u7c7b\u4f1a\u53d8\u5f97\u65e0\u6bd4\u81c3\u80bf\u3002<\/p>\n
java<\/p>\n
@Service
\npublic class OrderService {<\/p>\n
@Autowired
\nprivate ProductMapper productMapper;
\n@Autowired
\nprivate OrderMapper orderMapper;
\npublic void createOrder(Long productId, Integer quantity) {
\n \/\/ 1. \u67e5\u6570\u636e\u5e93
\n Product product = productMapper.selectById(productId);<\/p>\n
\/\/ 2. \u4e1a\u52a1\u5224\u65ad：\u6821\u9a8c\u5e93\u5b58
\n if (product.getStock() < quantity) {
\n throw new RuntimeException("\u5e93\u5b58\u4e0d\u8db3");
\n }<\/p>\n
\/\/ 3. \u4e1a\u52a1\u903b\u8f91：\u6263\u51cf\u5e93\u5b58 (\u76f4\u63a5\u4fee\u6539\u5c5e\u6027)
\n product.setStock(product.getStock() – quantity);
\n productMapper.updateById(product);<\/p>\n
\/\/ 4. \u4e1a\u52a1\u903b\u8f91：\u8ba1\u7b97\u91d1\u989d
\n Double amount = 100.0 * quantity;
\n if (amount > 500) {
\n amount = amount * 0.9; \/\/ \u6ee1500\u62539\u6298
\n }<\/p>\n
\/\/ 5. \u521b\u5efa\u8ba2\u5355
\n Order order = new Order();
\n order.setTotalAmount(amount);
\n order.setStatus(1);
\n orderMapper.insert(order);<\/p>\n
System.out.println("\u4e0b\u5355\u6210\u529f，\u91d1\u989d：" + amount);
\n}<\/p>\n
}<\/p>\n
\u75db\u70b9：\u672a\u6765\u5982\u679c\u4ea7\u54c1\u7ecf\u7406\u8bf4\u201cVIP\u7528\u6237\u79ef\u5206\u8d85\u8fc71000\u4e5f\u53ef\u4ee5\u6253\u6298\u201d，\u4f60\u5f97\u7ee7\u7eed\u5728\u8fd9\u4e2a createOrder \u91cc\u9762\u5199 if-else\u3002\u6570\u636e（Entity）\u548c\u64cd\u4f5c\u6570\u636e\u7684\u884c\u4e3a（Service）\u5206\u5bb6\u4e86，\u975e\u5e38\u5bb9\u6613\u6539\u51fa Bug\u3002<\/p>\n
\u5728 DDD \u4e2d，\u6211\u4eec\u5f3a\u8c03**\u201c\u8c01\u7684\u6570\u636e，\u8c01\u81ea\u5df1\u7ba1\u201d**\u3002\u6211\u4eec\u628a\u8ba1\u7b97\u91d1\u989d\u3001\u6263\u51cf\u5e93\u5b58\u7684\u884c\u4e3a，\u76f4\u63a5\u642c\u5230\u5b9e\u4f53\u5185\u90e8\u53bb\u3002<\/p>\n
\u5b9e\u4f53\u4e0d\u518d\u53ea\u662f\u6570\u636e\u888b，\u5b83\u6709\u4e86\u81ea\u5df1\u7684\u201c\u7075\u9b42\u201d（\u884c\u4e3a）\u3002<\/p>\n
java<\/p>\n
\/\/ \u5546\u54c1\u5b9e\u4f53：\u81ea\u5df1\u8d1f\u8d23\u6263\u5e93\u5b58
\npublic class Product {
\nprivate Long id;
\nprivate Integer stock;
\npublic Integer getStock() { return stock; }
\n\/\/ \u6838\u5fc3\u4e1a\u52a1\u903b\u8f91：\u6263\u51cf\u5e93\u5b58\u7531\u5546\u54c1\u81ea\u5df1\u8d1f\u8d23
\npublic void deductStock(int quantity) {
\nif (this.stock < quantity) {
\nthrow new BusinessException(\u201c\u5546\u54c1\u5e93\u5b58\u4e0d\u8db3\u201d);
\n}
\nthis.stock -= quantity;
\n}
\n}
\n\/\/ \u8ba2\u5355\u5b9e\u4f53：\u81ea\u5df1\u8d1f\u8d23\u7b97\u94b1
\npublic class Order {
\nprivate Long id;
\nprivate Double totalAmount;
\npublic Double getTotalAmount() { return totalAmount; }
\n\/\/ \u6838\u5fc3\u4e1a\u52a1\u903b\u8f91：\u8ba1\u7b97\u603b\u4ef7\u7531\u8ba2\u5355\u81ea\u5df1\u8d1f\u8d23
\npublic void calculateTotalAmount(Double unitPrice, int quantity) {
\ndouble amount = unitPrice * quantity;
\nif (amount > 500) {
\namount = amount * 0.9;
\n}
\nthis.totalAmount = amount;
\n}
\n}<\/p>\n
\u5e94\u7528\u670d\u52a1\u53d8\u6210\u4e86\u201c\u5149\u6746\u53f8\u4ee4\u201d，\u5b83\u53ea\u8d1f\u8d23\u8c03\u5ea6：\u62ff\u6570\u636e -> \u8c03\u9886\u57df\u6a21\u578b -> \u5b58\u6570\u636e\u3002\u6ca1\u6709\u5177\u4f53\u7684\u4e1a\u52a1\u5224\u65ad\u3002<\/p>\n
java<\/p>\n
@Service
\npublic class OrderApplicationService {
\n@Autowired
\nprivate ProductRepository productRepository;
\n@Autowired
\nprivate OrderRepository orderRepository;
\n@Transactional
\npublic void createOrder(Long productId, Integer quantity) {
\n\/\/ 1. \u83b7\u53d6\u805a\u5408\u6839（\u901a\u8fc7 Repository \u67e5\u51fa\u6765）
\nProduct product = productRepository.findById(productId);<\/p>\n
\/\/ 2. \u59d4\u6258\u7ed9\u9886\u57df\u6a21\u578b\u81ea\u5df1\u53bb\u6263\u5e93\u5b58（\u5b83\u5185\u90e8\u6709\u6821\u9a8c\u903b\u8f91）
\n product.deductStock(quantity);<\/p>\n
\/\/ 3. \u521b\u5efa\u8ba2\u5355\u5e76\u59d4\u6258\u9886\u57df\u6a21\u578b\u81ea\u5df1\u7b97\u94b1
\n Order order = new Order();
\n order.calculateTotalAmount(100.0, quantity);<\/p>\n
\/\/ 4. \u6301\u4e45\u5316
\n productRepository.save(product);
\n orderRepository.save(order);
\n}<\/p>\n
}<\/p>\n
\u5bf9\u6bd4\u4e00\u4e0b\u4e0a\u9762\u4e24\u6bb5\u4ee3\u7801：<\/p>\n
\u5728 MVC \u4e2d：OrderService \u50cf\u4e2a\u64cd\u788e\u4e86\u5fc3\u7684\u8001\u6bcd\u4eb2，\u4e0d\u4f46\u8981\u67e5\u6570\u636e\u5e93，\u8fd8\u8981\u7ba1\u7b97\u8d26\u3001\u7ba1\u6263\u5e93\u5b58\u3002\u5982\u679c\u7b97\u8d26\u903b\u8f91\u51fa\u9519\u4e86，\u4f60\u9700\u8981\u5728\u4e00\u4e2a\u51e0\u5343\u884c\u7684 Service \u91cc\u627e\u534a\u5929\u3002<\/p>\n<\/li>\n
\u5728 DDD \u4e2d：OrderApplicationService \u5c31\u50cf\u4e2a\u9879\u76ee\u7ecf\u7406，\u5b83\u53ea\u8bf4\u4e00\u53e5：order.calculateTotalAmount(…) \u548c product.deductStock(…)\u3002\u5177\u4f53\u600e\u4e48\u7b97\u3001\u600e\u4e48\u6263，\u8ba9 Order \u548c Product \u8fd9\u4e24\u4e2a\u201c\u4e13\u5bb6（\u5b9e\u4f53）\u201d\u81ea\u5df1\u53bb\u641e\u5b9a\u3002<\/p>\n<\/li>\n
\u201c\u8c08\u8c08\u4f60\u5bf9 DDD\u3001MVC \u548c\u5fae\u670d\u52a1\u7684\u7406\u89e3？\u201d<\/p>\n
\u201c\u6211\u8ba4\u4e3a\u8fd9\u4e09\u8005\u662f\u4e0d\u540c\u7ef4\u5ea6\u7684\u6982\u5ff5\u3002<\/p>\n
MVC \u662f\u4e00\u79cd\u6280\u672f\u5b9e\u73b0\u67b6\u6784，\u5b83\u901a\u8fc7 Controller\u3001Service\u3001DAO \u5b9e\u73b0\u4ee3\u7801\u5206\u5c42，\u4f46\u5728\u590d\u6742\u4e1a\u52a1\u4e2d，\u5bb9\u6613\u5bfc\u81f4 Service \u5c42\u53d8\u6210\u2018\u4e0a\u5e1d\u7c7b\u2019（\u8d2b\u8840\u6a21\u578b）\u3002<\/p>\n
DDD \u662f\u4e00\u79cd\u5e94\u5bf9\u590d\u6742\u4e1a\u52a1\u7684\u65b9\u6cd5\u8bba\u3002\u5b83\u7684\u6838\u5fc3\u662f\u628a\u4e1a\u52a1\u903b\u8f91\u6536\u62e2\u5230\u9886\u57df\u6a21\u578b\u4e2d（\u5145\u8840\u6a21\u578b），\u5e76\u901a\u8fc7\u5212\u5206\u2018\u9650\u754c\u4e0a\u4e0b\u6587\u2019\u548c\u2018\u805a\u5408\u6839\u2019\u6765\u4fdd\u8bc1\u4e1a\u52a1\u7684\u9ad8\u5185\u805a\u3002<\/p>\n
\u5fae\u670d\u52a1 \u662f\u4e00\u79cd\u7269\u7406\u90e8\u7f72\u67b6\u6784\u3002，\u5982\u679c\u6ca1\u6709 DDD \u7684\u6307\u5bfc，\u5fae\u670d\u52a1\u5f88\u5bb9\u6613\u62c6\u6210\u2018\u5206\u5e03\u5f0f\u5355\u4f53\u2019\u3002<\/p>\n
\u6240\u4ee5，\u5b9e\u9645\u5de5\u7a0b\u4e2d，\u6211\u4eec\u901a\u5e38\u7528 DDD \u7684\u601d\u60f3\u6765\u5212\u5206\u5fae\u670d\u52a1\u7684\u8fb9\u754c，\u628a\u6bcf\u4e2a\u9650\u754c\u4e0a\u4e0b\u6587\u843d\u5730\u4e3a\u4e00\u4e2a\u5fae\u670d\u52a1，\u7136\u540e\u7528 MVC \u6216\u516d\u8fb9\u5f62\u67b6\u6784\u5728\u5fae\u670d\u52a1\u5185\u90e8\u5b9e\u73b0\u4ee3\u7801\u5206\u5c42\u3002\u8fd9\u6837\u65e2\u6709\u5b8f\u89c2\u7684\u4e1a\u52a1\u89e3\u8026，\u53c8\u6709\u5fae\u89c2\u7684\u6280\u672f\u5b9e\u73b0\u3002\u201d<\/p>\n
7.\u00a0Redis：Redis\u00a0\u4e3a\u4ec0\u4e48\u90a3\u4e48\u5feb？<\/p>\n
\u7eaf\u5185\u5b58\u64cd\u4f5c：\u57fa\u4e8e\u5185\u5b58，\u8bfb\u5199\u901f\u5ea6\u6781\u5feb，\u907f\u514d\u4e86\u78c1\u76d8 I\/O\u3002<\/p>\n<\/li>\n
\u5355\u7ebf\u7a0b\u6a21\u578b（\u9488\u5bf9\u547d\u4ee4\u6267\u884c）：\u907f\u514d\u4e86\u591a\u7ebf\u7a0b\u7684\u4e0a\u4e0b\u6587\u5207\u6362\u548c\u9501\u7ade\u4e89，\u4fdd\u8bc1\u4e86\u539f\u5b50\u6027（6.0 \u4e4b\u540e\u7f51\u7edc I\/O \u662f\u591a\u7ebf\u7a0b，\u4f46\u6838\u5fc3\u547d\u4ee4\u6267\u884c\u4ecd\u662f\u5355\u7ebf\u7a0b）\u3002<\/p>\n<\/li>\n
I\/O \u591a\u8def\u590d\u7528（epoll）：\u4e00\u4e2a\u7ebf\u7a0b\u53ef\u4ee5\u540c\u65f6\u5904\u7406\u5927\u91cf\u7f51\u7edc\u8fde\u63a5，\u8ba9 CPU \u59cb\u7ec8\u5904\u4e8e\u9ad8\u5229\u7528\u7387\u3002<\/p>\n<\/li>\n
\u9ad8\u6548\u7684\u6570\u636e\u7ed3\u6784：\u5982 SDS\u3001\u8df3\u8868（ZSet）\u3001\u54c8\u5e0c\u8868（\u6e10\u8fdb\u5f0f rehash）\u7b49，\u90fd\u7ecf\u8fc7\u6781\u81f4\u4f18\u5316\u3002<\/p>\n<\/li>\n
\u201c\u6bd4\u5982\u5728\u9ad8\u5e76\u53d1\u79d2\u6740\u573a\u666f\u4e0b，\u6bcf\u79d2\u51e0\u4e07\u6b21\u7684\u5e93\u5b58\u8bfb\u53d6\u548c\u6263\u51cf，\u4f20\u7edf\u6570\u636e\u5e93\u4f1a\u56e0\u4e3a\u884c\u9501\u548c\u78c1\u76d8 IO \u76f4\u63a5\u5d29\u6e83\u3002\u5229\u7528 Redis \u7684\u539f\u5b50\u547d\u4ee4（\u5982 DECR）\u5728\u5185\u5b58\u4e2d\u77ac\u95f4\u5b8c\u6210，\u6548\u7387\u6781\u9ad8\u3002\u201d<\/p>\n
8.\u00a0Spring：Spring\u00a0\u4e8b\u52a1\u5931\u6548\u7684\u573a\u666f\u6709\u54ea\u4e9b？<\/p>\n
\u201cSpring \u4e8b\u52a1\u5931\u6548\u7684\u672c\u8d28\u662f\u56e0\u4e3a AOP \u52a8\u6001\u4ee3\u7406\u6ca1\u6709\u751f\u6548\u3002\u5e38\u89c1\u573a\u666f\u6709 5 \u79cd：<\/p>\n
\u65b9\u6cd5\u975e public：Spring \u4e8b\u52a1\u9ed8\u8ba4\u53ea\u80fd\u62e6\u622a public \u65b9\u6cd5\u3002<\/p>\n<\/li>\n
\u81ea\u8c03\u7528：\u540c\u4e00\u4e2a\u7c7b\u4e2d，A \u65b9\u6cd5（\u65e0\u4e8b\u52a1）\u8c03\u7528 B \u65b9\u6cd5（\u6709\u4e8b\u52a1），\u56e0\u4e3a\u8d70\u7684\u662f this \u5f15\u7528，\u4e0d\u7ecf\u8fc7\u4ee3\u7406\u7c7b\u3002<\/p>\n<\/li>\n
\u5f02\u5e38\u88ab catch \u541e\u6389：\u6216\u8005\u629b\u51fa\u7684\u662f\u53d7\u68c0\u5f02\u5e38（Checked Exception），\u9ed8\u8ba4\u4e0d\u56de\u6eda\u3002<\/p>\n<\/li>\n
\u7c7b\u672a\u88ab Spring \u7ba1\u7406：\u6ca1\u6709\u52a0 @Service \u7b49\u6ce8\u89e3\u3002<\/p>\n<\/li>\n
\u6570\u636e\u5e93\u5f15\u64ce\u4e0d\u652f\u6301：\u5982 MySQL \u7684 MyISAM\u3002\u201d<\/p>\n<\/li>\n
9.\u00a0Java\u5e76\u53d1：CAS\u00a0\u7684\u539f\u7406\u662f\u4ec0\u4e48？<\/p>\n
CAS（Compare and Swap）\u662f\u4e00\u79cd\u65e0\u9501\u5e76\u53d1\u673a\u5236，\u5305\u542b\u4e09\u4e2a\u64cd\u4f5c\u6570：\u5185\u5b58\u4f4d\u7f6e V\u3001\u9884\u671f\u539f\u503c A\u3001\u65b0\u503c B\u3002\u5f53\u4e14\u4ec5\u5f53 V \u7684\u503c\u7b49\u4e8e A \u65f6，\u624d\u4f1a\u5c06 V \u66f4\u65b0\u4e3a B，\u5426\u5219\u4e0d\u505a\u4efb\u4f55\u64cd\u4f5c，\u901a\u5e38\u914d\u5408\u81ea\u65cb\u5faa\u73af\u91cd\u8bd5\u3002
\n\u4f46\u5728\u9ad8\u5e76\u53d1\u4e0b，CAS \u6709\u4e09\u5927\u95ee\u9898：ABA \u95ee\u9898（\u52a0\u7248\u672c\u53f7\u89e3\u51b3）\u3001\u81ea\u65cb\u5f00\u9500\u5927\u3001\u53ea\u80fd\u4fdd\u8bc1\u4e00\u4e2a\u53d8\u91cf\u539f\u5b50\u6027\u3002<\/p>\n
10.\u00a0Java\u5e76\u53d1：synchronized\u00a0\u7684\u9501\u5347\u7ea7\u8fc7\u7a0b\u662f\u600e\u6837\u7684？<\/p>\n
\u201c\u4e3a\u4e86\u51cf\u5c11\u9501\u5e26\u6765\u7684\u6027\u80fd\u5f00\u9500，JDK 1.6 \u5f15\u5165\u4e86\u9501\u5347\u7ea7\u673a\u5236\u3002\u9501\u7684\u72b6\u6001\u4fdd\u5b58\u5728\u5bf9\u8c61\u5934\u7684 Mark Word \u4e2d，\u8fc7\u7a0b\u4e3a：<\/p>\n
\u65e0\u9501：\u5bf9\u8c61\u521a\u521b\u5efa\u3002<\/p>\n<\/li>\n
\u504f\u5411\u9501：\u53ea\u6709\u4e00\u4e2a\u7ebf\u7a0b\u8bbf\u95ee\u65f6，\u76f4\u63a5\u5728\u5bf9\u8c61\u5934\u8bb0\u5f55\u7ebf\u7a0b ID，\u4e0b\u6b21\u8fdb\u6765\u76f4\u63a5\u653e\u884c，\u65e0\u9501\u5316\u5f00\u9500\u3002<\/p>\n<\/li>\n
\u8f7b\u91cf\u7ea7\u9501：\u5f53\u6709\u591a\u4e2a\u7ebf\u7a0b\u4ea4\u66ff\u8bbf\u95ee\u65f6，\u504f\u5411\u9501\u5347\u7ea7\u4e3a\u8f7b\u91cf\u7ea7\u9501\u3002\u7ebf\u7a0b\u901a\u8fc7 CAS \u81ea\u65cb\u83b7\u53d6\u9501，\u4e0d\u4f1a\u963b\u585e\u3002<\/p>\n<\/li>\n
\u91cd\u91cf\u7ea7\u9501：\u5982\u679c\u81ea\u65cb\u5931\u8d25（\u5e76\u53d1\u51b2\u7a81\u4e25\u91cd），\u5347\u7ea7\u4e3a\u91cd\u91cf\u7ea7\u9501，\u6ca1\u62a2\u5230\u9501\u7684\u7ebf\u7a0b\u8fdb\u5165 Monitor \u7684 EntryList \u963b\u585e\u7b49\u5f85，\u7531\u64cd\u4f5c\u7cfb\u7edf\u5524\u9192\u3002\u201d<\/p>\n<\/li>\n
11.\u00a0\u573a\u666f\u9898：\u5982\u679c\u63a5\u624b\u4e86\u4e00\u5806\u00a0if-else\u00a0\u5d4c\u5957，\u91cc\u9762\u8fd8\u6709\u4e00\u5806\u00a0try-catch\u00a0\u7684\u4ee3\u7801，\u4f60\u4f1a\u600e\u4e48\u4f18\u5316\u91cd\u6784？<\/p>\n
\u4f7f\u7528\u8bbe\u8ba1\u6a21\u5f0f：\u5982\u679c if-else \u662f\u4e1a\u52a1\u7c7b\u578b\u5224\u65ad，\u5f15\u5165\u7b56\u7565\u6a21\u5f0f + \u5de5\u5382\u6a21\u5f0f；\u5982\u679c\u662f\u72b6\u6001\u6d41\u8f6c，\u4f7f\u7528\u72b6\u6001\u6a21\u5f0f；\u5982\u679c\u662f\u53c2\u6570\u6821\u9a8c，\u4f7f\u7528\u8d23\u4efb\u94fe\u6a21\u5f0f\u3002<\/p>\n
| \u7b56\u7565 + \u5de5\u5382<\/td>\n | \u6d88\u9664\u5e73\u7ea7\u7684\u4e1a\u52a1\u7c7b\u578b\u5224\u65ad<\/td>\n | \u9009\u51fa\u552f\u4e00\u7684\u7b97\u6cd5\u53bb\u6267\u884c<\/td>\n | \u652f\u4ed8\u65b9\u5f0f\u3001\u767b\u5f55\u65b9\u5f0f\u3001\u6253\u6298\u8ba1\u7b97<\/td>\n<\/tr>\n |
| \u72b6\u6001\u6a21\u5f0f<\/td>\n | \u6d88\u9664\u968f\u72b6\u6001\u6539\u53d8\u7684\u5927\u91cf\u5206\u652f<\/td>\n | \u5185\u90e8\u72b6\u6001\u6539\u53d8\u5f15\u53d1\u884c\u4e3a\u6539\u53d8<\/td>\n | \u8ba2\u5355\u6d41\u8f6c\u3001\u7535\u68af\u8fd0\u884c\u3001\u7ea2\u7eff\u706f<\/td>\n<\/tr>\n |
| \u8d23\u4efb\u94fe\u6a21\u5f0f<\/td>\n | \u6d88\u9664\u4e32\u884c\u7684\u524d\u7f6e\u6821\u9a8c\u6216\u5ba1\u6279<\/td>\n | \u50cf\u94fe\u6761\u4e00\u6837\u4f9d\u6b21\u4f20\u9012\u5904\u7406<\/td>\n | \u53c2\u6570\u6821\u9a8c\u3001\u5ba1\u6279\u6d41\u3001\u62e6\u622a\u5668<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n 12.\u00a0\u573a\u666f\u9898：\u5982\u679c\u6309\u7167\u4ea7\u54c1\u7ecf\u7406\u7684\u65b9\u6848\u505a\u51fa\u4e86\u6280\u672f\u65b9\u6848\u5e76\u4e0a\u7ebf，\u7ed3\u679c\u53d1\u73b0\u7cfb\u7edf\u51fa\u73b0\u4e86\u5f88\u4e25\u91cd\u7684\u95ee\u9898，\u8fd9\u4e2a\u65f6\u5019\u4f60\u8be5\u600e\u4e48\u89e3\u51b3？<\/p>\n \u201c\u9047\u5230\u7ebf\u4e0a\u4e8b\u6545，\u7b2c\u4e00\u539f\u5219\u662f**\u300e\u5148\u6062\u590d，\u540e\u6392\u67e5，\u518d\u590d\u76d8\u300f**：<\/p>\n \u5feb\u901f\u6b62\u635f：\u7acb\u5373\u56de\u6eda\u6700\u8fd1\u7684\u4e0a\u7ebf\u7248\u672c（\u524d\u63d0\u662f\u56de\u6eda\u5b89\u5168），\u6216\u8005\u901a\u8fc7\u914d\u7f6e\u4e2d\u5fc3\u964d\u7ea7\u8be5\u529f\u80fd\u5f00\u5173，\u4f18\u5148\u4fdd\u8bc1\u6838\u5fc3\u4e1a\u52a1\u53ef\u7528\u3002<\/p>\n<\/li>\n \u5b9a\u4f4d\u95ee\u9898：\u67e5\u770b APM \u76d1\u63a7（\u5982 SkyWalking）\u3001\u65e5\u5fd7\u9519\u8bef\u7387\u3001\u6570\u636e\u5e93\u6162\u67e5\u8be2，\u6392\u67e5\u662f\u5426\u56e0\u4e3a\u6d41\u91cf\u7a81\u589e\u3001\u8d44\u6e90\u6b7b\u9501\u6216\u65b0\u4ee3\u7801\u7684 Bug\u3002<\/p>\n<\/li>\n \u9ad8\u6548\u4fee\u590d：\u5b9a\u4f4d\u5230 Bug \u540e，\u7d27\u6025\u62c9\u5206\u652f\u4fee\u590d，\u8d70\u7eff\u8272\u901a\u9053\u5feb\u901f\u6d4b\u8bd5\u4e0a\u7ebf\u3002<\/p>\n<\/li>\n \u4e8b\u540e\u590d\u76d8：\u5199\u4e8b\u6545\u62a5\u544a（RCA），\u5206\u6790\u6839\u56e0，\u5e76\u8865\u5145\u76d1\u63a7\u544a\u8b66\u3001\u5b8c\u5584\u6d4b\u8bd5\u7528\u4f8b（\u7279\u522b\u662f\u6f0f\u6d4b\u7684\u8fb9\u754c\u573a\u666f），\u4f18\u5316\u53d1\u5e03\u6d41\u7a0b（\u5f15\u5165\u7070\u5ea6\u53d1\u5e03）\u3002\u201d<\/p>\n<\/li>\n 14.\u00a0\u7f13\u5b58\u8bbe\u8ba1：\u600e\u4e48\u4fdd\u8bc1\u00a0Redis\u00a0\u548c\u6570\u636e\u5e93\u7684\u6570\u636e\u4e00\u81f4\u6027？<\/p>\n \u5199\u64cd\u4f5c：\u5148\u66f4\u65b0\u6570\u636e\u5e93，\u518d\u5220\u9664\u7f13\u5b58 \/* MD \/ \u5bcc\u6587\u672c\u4e2d\u7684 .toc\uff08\u542b\u535a\u5ba2\u56ed\u642c\u5bb6\u7b49\u5d4c\u5957\u7ed3\u6784\uff09\uff1b.toc-box \u5728\u4fa7\u680f\uff0c\u4e0d\u53d7\u5f71\u54cd *\/#content_views .toc,\/* \u7f16\u8f91\u5668\u5e38\u5728\u76ee\u5f55\u524d\u540e\u63d2\u5165\u7a7a p\uff08:empty \u4ecd\u5360 20px\uff09\uff0c\u4e00\u5e76\u53bb\u6389\u907f\u514d\u9876\u7a7a\u9699 *\/#content_views.markdown_views > p:empty:has(+ .toc),#content_views.markdown_views > .toc + p:empty,\/* \u5bcc\u6587\u672c\u65e7\u7248\u76ee\u5f55\u6807\u8bb0 *\/#content<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[11820,99,2692,427],"topic":[],"class_list":["post-123289","post","type-post","status-publish","format-standard","hentry","category-server","tag-atomgit","tag-java","tag-leetcode","tag-427"],"yoast_head":"\n |