{"id":421,"date":"2024-12-21T22:58:51","date_gmt":"2024-12-21T14:58:51","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=421"},"modified":"2024-12-21T22:58:51","modified_gmt":"2024-12-21T14:58:51","slug":"java%e9%87%8d%e6%9e%84%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2024\/12\/21\/java%e9%87%8d%e6%9e%84%e6%96%b9%e6%b3%95\/","title":{"rendered":"java\u91cd\u6784\u65b9\u6cd5"},"content":{"rendered":"\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u5728 Java \u4e2d\uff0c\u91cd\u6784\uff08Refactoring\uff09\u65b9\u6cd5\u662f\u6307\u5bf9\u73b0\u6709\u4ee3\u7801\u8fdb\u884c\u4fee\u6539\uff0c\u4ee5\u6539\u8fdb\u5176\u7ed3\u6784\u3001\u53ef\u8bfb\u6027\u548c\u53ef\u7ef4\u62a4\u6027\uff0c\u800c\u4e0d\u6539\u53d8\u5176\u529f\u80fd\u3002\u4e0b\u9762\u662f\u4e00\u4e9b\u5e38\u89c1\u7684 Java \u65b9\u6cd5\u91cd\u6784\u6280\u672f\uff0c\u5e2e\u52a9\u4f60\u63d0\u9ad8\u4ee3\u7801\u8d28\u91cf\uff1a<\/p>\n<\/blockquote>\n\n\n\n<h3 class=\"wp-block-heading\">1. <strong>\u63d0\u70bc\u65b9\u6cd5\uff08Extract Method\uff09<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u679c\u4e00\u4e2a\u65b9\u6cd5\u8fc7\u957f\uff0c\u6216\u8005\u5305\u542b\u591a\u4e2a\u804c\u8d23\uff0c\u53ef\u4ee5\u5c06\u5176\u4e2d\u4e00\u90e8\u5206\u4ee3\u7801\u63d0\u53d6\u5230\u4e00\u4e2a\u65b0\u7684\u65b9\u6cd5\u4e2d\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u6784\u524d<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public void printStatement() {\n    System.out.println(\"Customer Statement\");\n    System.out.println(\"Name: \" + customer.getName());\n    System.out.println(\"Balance: \" + customer.getBalance());\n    System.out.println(\"Transactions: \");\n    for (Transaction transaction : customer.getTransactions()) {\n        System.out.println(transaction.getDetails());\n    }\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u6784\u540e<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public void printStatement() {\n    printHeader();\n    printTransactions();\n}\n\nprivate void printHeader() {\n    System.out.println(\"Customer Statement\");\n    System.out.println(\"Name: \" + customer.getName());\n    System.out.println(\"Balance: \" + customer.getBalance());\n}\n\nprivate void printTransactions() {\n    System.out.println(\"Transactions: \");\n    for (Transaction transaction : customer.getTransactions()) {\n        System.out.println(transaction.getDetails());\n    }\n}<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">2. <strong>\u5185\u8054\u65b9\u6cd5\uff08Inline Method\uff09<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f53\u4e00\u4e2a\u65b9\u6cd5\u53ea\u8c03\u7528\u53e6\u4e00\u4e2a\u65b9\u6cd5\uff0c\u5e76\u4e14\u6ca1\u6709\u6dfb\u52a0\u8db3\u591f\u7684\u4ef7\u503c\u65f6\uff0c\u53ef\u4ee5\u8003\u8651\u5c06\u5176\u5408\u5e76\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u6784\u524d<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public void printStatement() {\n    printHeader();\n}\n\nprivate void printHeader() {\n    System.out.println(\"Customer Statement\");\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u6784\u540e<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public void printStatement() {\n    System.out.println(\"Customer Statement\");\n}<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">3. <strong>\u66ff\u6362\u4e34\u65f6\u53d8\u91cf\uff08Replace Temp with Query\uff09<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u679c\u4e00\u4e2a\u4e34\u65f6\u53d8\u91cf\u5728\u65b9\u6cd5\u4e2d\u88ab\u4f7f\u7528\u591a\u6b21\uff0c\u4e14\u8fd9\u4e2a\u503c\u4e0d\u4f1a\u53d1\u751f\u53d8\u5316\uff0c\u53ef\u4ee5\u76f4\u63a5\u7528\u5176\u8868\u8fbe\u5f0f\u66ff\u4ee3\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u6784\u524d<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public double getTotalCost(Order order) {\n    double basePrice = order.getBasePrice();\n    double discount = order.getDiscount();\n    return basePrice - discount;\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u6784\u540e<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public double getTotalCost(Order order) {\n    return order.getBasePrice() - order.getDiscount();\n}<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">4. <strong>\u5f15\u5165\u89e3\u91ca\u6027\u53d8\u91cf\uff08Introduce Explaining Variable\uff09<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u679c\u8868\u8fbe\u5f0f\u8fc7\u4e8e\u590d\u6742\uff0c\u53ef\u4ee5\u7528\u4e00\u4e2a\u6709\u610f\u4e49\u7684\u53d8\u91cf\u540d\u6765\u63d0\u53d6\u8868\u8fbe\u5f0f\uff0c\u4f7f\u4ee3\u7801\u66f4\u5bb9\u6613\u7406\u89e3\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u6784\u524d<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>if (a &gt; b * 2 &amp;&amp; c &lt; d \/ 3) {\n    \/\/ Do something\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u6784\u540e<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>boolean isComplexConditionMet = (a &gt; b * 2) &amp;&amp; (c &lt; d \/ 3);\nif (isComplexConditionMet) {\n    \/\/ Do something\n}<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">5. <strong>\u66ff\u6362\u9b54\u6cd5\u6570\u5b57\uff08Replace Magic Number with Constant\uff09<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5c06\u4ee3\u7801\u4e2d\u4f7f\u7528\u7684\u6570\u5b57\u66ff\u6362\u4e3a\u5177\u540d\u5e38\u91cf\uff0c\u4ee5\u63d0\u9ad8\u53ef\u8bfb\u6027\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u6784\u524d<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public double calculateDiscount(double price) {\n    if (price &gt; 1000) {\n        return price * 0.1;\n    } else {\n        return price * 0.05;\n    }\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u6784\u540e<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>private static final double HIGH_PRICE_THRESHOLD = 1000;\nprivate static final double HIGH_DISCOUNT = 0.1;\nprivate static final double LOW_DISCOUNT = 0.05;\n\npublic double calculateDiscount(double price) {\n    if (price &gt; HIGH_PRICE_THRESHOLD) {\n        return price * HIGH_DISCOUNT;\n    } else {\n        return price * LOW_DISCOUNT;\n    }\n}<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">6. <strong>\u53c2\u6570\u5bf9\u8c61\u5316\uff08Introduce Parameter Object\uff09<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u679c\u4e00\u4e2a\u65b9\u6cd5\u6709\u591a\u4e2a\u53c2\u6570\uff0c\u5e76\u4e14\u8fd9\u4e9b\u53c2\u6570\u901a\u5e38\u4e00\u8d77\u51fa\u73b0\uff0c\u53ef\u4ee5\u5c06\u5b83\u4eec\u5305\u88c5\u5230\u4e00\u4e2a\u5bf9\u8c61\u4e2d\uff0c\u4ece\u800c\u7b80\u5316\u65b9\u6cd5\u7b7e\u540d\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u6784\u524d<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public void processOrder(int customerId, String product, int quantity, double price) {\n    \/\/ Process the order\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u6784\u540e<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Order {\n    private int customerId;\n    private String product;\n    private int quantity;\n    private double price;\n\n    \/\/ Constructor, getters, setters\n}\n\npublic void processOrder(Order order) {\n    \/\/ Process the order\n}<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">7. <strong>\u79fb\u52a8\u65b9\u6cd5\uff08Move Method\uff09<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u679c\u65b9\u6cd5\u548c\u5b83\u6240\u5728\u7684\u7c7b\u5173\u7cfb\u4e0d\u5927\uff0c\u53ef\u4ee5\u8003\u8651\u5c06\u8be5\u65b9\u6cd5\u79fb\u5230\u66f4\u76f8\u5173\u7684\u7c7b\u4e2d\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u6784\u524d<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Order {\n    private Customer customer;\n\n    public void processOrder() {\n        \/\/ process order for the customer\n    }\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u6784\u540e<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Customer {\n    public void processOrder(Order order) {\n        \/\/ process order for the customer\n    }\n}<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">8. <strong>\u7b80\u5316\u6761\u4ef6\u8868\u8fbe\u5f0f\uff08Simplify Conditional Expressions\uff09<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u901a\u8fc7\u7b80\u5316 <code>if<\/code> \u8bed\u53e5\u6216\u4f7f\u7528 <code>return<\/code> \u63d0\u524d\u9000\u51fa\uff0c\u53ef\u4ee5\u4f7f\u4ee3\u7801\u66f4\u7b80\u6d01\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u6784\u524d<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public void calculate(int value) {\n    if (value &gt; 0) {\n        doSomething();\n    } else {\n        doSomethingElse();\n    }\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u6784\u540e<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public void calculate(int value) {\n    if (value &gt; 0) {\n        doSomething();\n        return;\n    }\n    doSomethingElse();\n}<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">9. <strong>\u4f7f\u7528\u591a\u6001\uff08Replace Conditional with Polymorphism\uff09<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f53\u65b9\u6cd5\u4e2d\u6709\u5927\u91cf\u7684 <code>if<\/code> \u6216 <code>switch<\/code> \u8bed\u53e5\u65f6\uff0c\u53ef\u4ee5\u901a\u8fc7\u5f15\u5165\u591a\u6001\u6765\u91cd\u6784\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u6784\u524d<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public double calculateDiscount(Customer customer) {\n    if (customer.getType() == CustomerType.VIP) {\n        return 0.2;\n    } else if (customer.getType() == CustomerType.REGULAR) {\n        return 0.1;\n    } else {\n        return 0.05;\n    }\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u6784\u540e<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public interface DiscountStrategy {\n    double calculateDiscount(Customer customer);\n}\n\npublic class VIPDiscount implements DiscountStrategy {\n    public double calculateDiscount(Customer customer) {\n        return 0.2;\n    }\n}\n\npublic class RegularDiscount implements DiscountStrategy {\n    public double calculateDiscount(Customer customer) {\n        return 0.1;\n    }\n}\n\npublic class DefaultDiscount implements DiscountStrategy {\n    public double calculateDiscount(Customer customer) {\n        return 0.05;\n    }\n}\n\npublic class Customer {\n    private DiscountStrategy discountStrategy;\n\n    public double getDiscount() {\n        return discountStrategy.calculateDiscount(this);\n    }\n}<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u603b\u7ed3<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u65b9\u6cd5\u91cd\u6784\u662f\u4e3a\u4e86\u4f7f\u4ee3\u7801\u66f4\u7b80\u6d01\u3001\u53ef\u8bfb\u6027\u66f4\u5f3a\u3001\u6613\u4e8e\u7ef4\u62a4\u3002\u901a\u8fc7\u63d0\u70bc\u3001\u5185\u8054\u3001\u7b80\u5316\u6761\u4ef6\u548c\u5229\u7528\u591a\u6001\u7b49\u65b9\u6cd5\uff0c\u53ef\u4ee5\u6709\u6548\u5730\u63d0\u5347\u4ee3\u7801\u8d28\u91cf\u3002\u5728\u8fdb\u884c\u91cd\u6784\u65f6\uff0c\u8981\u786e\u4fdd\u65b9\u6cd5\u529f\u80fd\u4e0d\u53d1\u751f\u53d8\u5316\uff0c\u540c\u65f6\u52a0\u5f3a\u4ee3\u7801\u7684\u8868\u8fbe\u80fd\u529b\u3002\u66f4\u591a\u8be6\u7ec6\u5185\u5bb9\u8bf7\u5173\u6ce8\u5176\u4ed6\u76f8\u5173\u6587\u7ae0\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728 Java \u4e2d\uff0c\u91cd\u6784\uff08Refactoring\uff09\u65b9\u6cd5\u662f\u6307\u5bf9\u73b0\u6709\u4ee3\u7801\u8fdb\u884c\u4fee\u6539\uff0c\u4ee5\u6539\u8fdb\u5176\u7ed3\u6784\u3001\u53ef\u8bfb\u6027\u548c\u53ef\u7ef4\u62a4\u6027\uff0c\u800c [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[68],"tags":[],"class_list":["post-421","post","type-post","status-publish","format-standard","hentry","category-java"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/421","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/comments?post=421"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/421\/revisions"}],"predecessor-version":[{"id":422,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/421\/revisions\/422"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=421"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=421"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=421"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}