{"id":61873,"date":"2024-10-13T14:21:41","date_gmt":"2024-10-13T06:21:41","guid":{"rendered":"https:\/\/server.hk\/cnblog\/61873\/"},"modified":"2024-10-13T14:21:41","modified_gmt":"2024-10-13T06:21:41","slug":"javaweb%e4%b8%ad%e5%a6%82%e4%bd%95%e5%b0%87%e6%9e%9a%e8%88%89%e9%a1%9e%e5%ad%98%e5%84%b2%e5%88%b0%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%ef%bc%9f-javaweb-enum%e5%ad%98%e6%95%b8%e6%93%9a%e5%ba%ab","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/61873\/","title":{"rendered":"JavaWeb\u4e2d\u5982\u4f55\u5c07\u679a\u8209\u985e\u5b58\u5132\u5230\u6578\u64da\u5eab\u4e2d\uff1f (javaweb enum\u5b58\u6578\u64da\u5eab)"},"content":{"rendered":"<h1 id=\"javaweb%e4%b8%ad%e5%a6%82%e4%bd%95%e5%b0%87%e6%9e%9a%e8%88%89%e9%a1%9e%e5%ad%98%e5%84%b2%e5%88%b0%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%ef%bc%9f-rjxViIpQEz\">JavaWeb\u4e2d\u5982\u4f55\u5c07\u679a\u8209\u985e\u5b58\u5132\u5230\u6578\u64da\u5eab\u4e2d\uff1f<\/h1>\n<p>\u5728JavaWeb\u958b\u767c\u4e2d\uff0c\u679a\u8209\u985e\uff08Enum\uff09\u662f\u4e00\u7a2e\u975e\u5e38\u6709\u7528\u7684\u6578\u64da\u985e\u578b\uff0c\u80fd\u5920\u5e6b\u52a9\u958b\u767c\u8005\u5b9a\u7fa9\u4e00\u7d44\u56fa\u5b9a\u7684\u5e38\u91cf\u3002\u7576\u9700\u8981\u5c07\u9019\u4e9b\u679a\u8209\u985e\u7684\u503c\u5b58\u5132\u5230\u6578\u64da\u5eab\u4e2d\u6642\uff0c\u958b\u767c\u8005\u9700\u8981\u8003\u616e\u5982\u4f55\u5c07\u5176\u8f49\u63db\u70ba\u6578\u64da\u5eab\u80fd\u5920\u7406\u89e3\u7684\u683c\u5f0f\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5728JavaWeb\u4e2d\u5982\u4f55\u5c07\u679a\u8209\u985e\u5b58\u5132\u5230\u6578\u64da\u5eab\u4e2d\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u5be6\u7528\u7684\u793a\u4f8b\u548c\u4ee3\u78bc\u7247\u6bb5\u3002<\/p>\n<h2 id=\"1-%e4%bb%80%e9%ba%bc%e6%98%af%e6%9e%9a%e8%88%89%e9%a1%9e%ef%bc%9f-rjxViIpQEz\">1. \u4ec0\u9ebc\u662f\u679a\u8209\u985e\uff1f<\/h2>\n<p>\u679a\u8209\u985e\u662f\u4e00\u7a2e\u7279\u6b8a\u7684Java\u985e\u578b\uff0c\u7528\u65bc\u5b9a\u7fa9\u4e00\u7d44\u5e38\u91cf\u3002\u5b83\u53ef\u4ee5\u63d0\u9ad8\u4ee3\u78bc\u7684\u53ef\u8b80\u6027\u548c\u53ef\u7dad\u8b77\u6027\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u7c21\u55ae\u7684\u679a\u8209\u985e\u793a\u4f8b\uff1a<\/p>\n<pre><code>public enum UserRole {\n    ADMIN,\n    USER,\n    GUEST\n}\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u5b9a\u7fa9\u4e86\u4e00\u500b\u540d\u70baUserRole\u7684\u679a\u8209\u985e\uff0c\u5305\u542b\u4e09\u500b\u89d2\u8272\uff1aADMIN\u3001USER\u548cGUEST\u3002<\/p>\n<h2 id=\"2-%e5%b0%87%e6%9e%9a%e8%88%89%e9%a1%9e%e5%ad%98%e5%84%b2%e5%88%b0%e6%95%b8%e6%93%9a%e5%ba%ab%e7%9a%84%e6%96%b9%e5%bc%8f-rjxViIpQEz\">2. \u5c07\u679a\u8209\u985e\u5b58\u5132\u5230\u6578\u64da\u5eab\u7684\u65b9\u5f0f<\/h2>\n<p>\u5c07\u679a\u8209\u985e\u5b58\u5132\u5230\u6578\u64da\u5eab\u4e2d\uff0c\u901a\u5e38\u6709\u5169\u7a2e\u5e38\u898b\u7684\u65b9\u6cd5\uff1a<\/p>\n<ul>\n<li><strong>\u5b58\u5132\u679a\u8209\u7684\u540d\u7a31\uff1a<\/strong>\u5c07\u679a\u8209\u7684\u540d\u7a31\uff08\u5982&#8221;ADMIN&#8221;\uff09\u76f4\u63a5\u5b58\u5132\u5230\u6578\u64da\u5eab\u4e2d\u3002<\/li>\n<li><strong>\u5b58\u5132\u679a\u8209\u7684\u6578\u503c\uff1a<\/strong>\u5c07\u679a\u8209\u7684\u7d22\u5f15\u503c\uff08\u59820\u30011\u30012\uff09\u5b58\u5132\u5230\u6578\u64da\u5eab\u4e2d\u3002<\/li>\n<\/ul>\n<h3 id=\"2-1-%e5%ad%98%e5%84%b2%e6%9e%9a%e8%88%89%e7%9a%84%e5%90%8d%e7%a8%b1-rjxViIpQEz\">2.1 \u5b58\u5132\u679a\u8209\u7684\u540d\u7a31<\/h3>\n<p>\u9019\u7a2e\u65b9\u6cd5\u7684\u512a\u9ede\u662f\u53ef\u8b80\u6027\u9ad8\uff0c\u6578\u64da\u5eab\u4e2d\u7684\u6578\u64da\u80fd\u5920\u76f4\u63a5\u53cd\u6620\u51fa\u679a\u8209\u7684\u542b\u7fa9\u3002\u4ee5\u4e0b\u662f\u5982\u4f55\u5be6\u73fe\u9019\u7a2e\u65b9\u6cd5\u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>String sql = \"INSERT INTO users (username, role) VALUES (?, ?)\";\nPreparedStatement pstmt = connection.prepareStatement(sql);\npstmt.setString(1, \"john_doe\");\npstmt.setString(2, UserRole.ADMIN.name());\npstmt.executeUpdate();\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u5c07\u7528\u6236\u7684\u89d2\u8272\u5b58\u5132\u70ba\u5b57\u7b26\u4e32\u5f62\u5f0f\u7684\u679a\u8209\u540d\u7a31\u3002<\/p>\n<h3 id=\"2-2-%e5%ad%98%e5%84%b2%e6%9e%9a%e8%88%89%e7%9a%84%e6%95%b8%e5%80%bc-rjxViIpQEz\">2.2 \u5b58\u5132\u679a\u8209\u7684\u6578\u503c<\/h3>\n<p>\u9019\u7a2e\u65b9\u6cd5\u7684\u512a\u9ede\u662f\u7bc0\u7701\u5b58\u5132\u7a7a\u9593\uff0c\u4f46\u53ef\u8b80\u6027\u8f03\u5dee\u3002\u4ee5\u4e0b\u662f\u5982\u4f55\u5be6\u73fe\u9019\u7a2e\u65b9\u6cd5\u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>String sql = \"INSERT INTO users (username, role) VALUES (?, ?)\";\nPreparedStatement pstmt = connection.prepareStatement(sql);\npstmt.setString(1, \"john_doe\");\npstmt.setInt(2, UserRole.ADMIN.ordinal());\npstmt.executeUpdate();\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u5c07\u7528\u6236\u7684\u89d2\u8272\u5b58\u5132\u70ba\u679a\u8209\u7684\u7d22\u5f15\u503c\u3002<\/p>\n<h2 id=\"3-%e5%be%9e%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e8%ae%80%e5%8f%96%e6%9e%9a%e8%88%89%e9%a1%9e-rjxViIpQEz\">3. \u5f9e\u6578\u64da\u5eab\u4e2d\u8b80\u53d6\u679a\u8209\u985e<\/h2>\n<p>\u7121\u8ad6\u9078\u64c7\u54ea\u7a2e\u5b58\u5132\u65b9\u5f0f\uff0c\u5f9e\u6578\u64da\u5eab\u4e2d\u8b80\u53d6\u679a\u8209\u985e\u7684\u904e\u7a0b\u90fd\u662f\u76f8\u4f3c\u7684\u3002\u4ee5\u4e0b\u662f\u5f9e\u6578\u64da\u5eab\u4e2d\u8b80\u53d6\u679a\u8209\u985e\u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>String sql = \"SELECT role FROM users WHERE username = ?\";\nPreparedStatement pstmt = connection.prepareStatement(sql);\npstmt.setString(1, \"john_doe\");\nResultSet rs = pstmt.executeQuery();\nif (rs.next()) {\n    String roleName = rs.getString(\"role\");\n    UserRole role = UserRole.valueOf(roleName);\n    System.out.println(\"User role: \" + role);\n}\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u5f9e\u6578\u64da\u5eab\u4e2d\u8b80\u53d6\u7528\u6236\u7684\u89d2\u8272\uff0c\u4e26\u4f7f\u7528`UserRole.valueOf()`\u65b9\u6cd5\u5c07\u5b57\u7b26\u4e32\u8f49\u63db\u56de\u679a\u8209\u985e\u578b\u3002<\/p>\n<h2 id=\"4-%e7%b8%bd%e7%b5%90-rjxViIpQEz\">4. \u7e3d\u7d50<\/h2>\n<p>\u5728JavaWeb\u958b\u767c\u4e2d\uff0c\u5c07\u679a\u8209\u985e\u5b58\u5132\u5230\u6578\u64da\u5eab\u4e2d\u662f\u4e00\u500b\u5e38\u898b\u7684\u9700\u6c42\u3002\u958b\u767c\u8005\u53ef\u4ee5\u9078\u64c7\u5c07\u679a\u8209\u7684\u540d\u7a31\u6216\u7d22\u5f15\u503c\u5b58\u5132\u5230\u6578\u64da\u5eab\u4e2d\uff0c\u6839\u64da\u5177\u9ad4\u9700\u6c42\u9078\u64c7\u5408\u9069\u7684\u65b9\u6cd5\u3002\u7121\u8ad6\u9078\u64c7\u54ea\u7a2e\u65b9\u5f0f\uff0c\u7406\u89e3\u5982\u4f55\u5c07\u679a\u8209\u985e\u8207\u6578\u64da\u5eab\u9032\u884c\u4ea4\u4e92\u90fd\u662f\u63d0\u5347\u958b\u767c\u6548\u7387\u7684\u91cd\u8981\u6280\u80fd\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4f86\u652f\u6301\u60a8\u7684JavaWeb\u61c9\u7528\uff0cServer.HK\u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u4e0d\u540c\u9700\u6c42\u7684\u5ba2\u6236\u3002\u7121\u8ad6\u662f <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u9084\u662f\u5176\u4ed6\u670d\u52d9\uff0c\u6211\u5011\u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3\u5982\u4f55\u5728JavaWeb\u4e2d\u5c07\u679a\u8209\u985e\u5b58\u5132\u5230\u6578\u64da\u5eab\uff0c\u7c21\u5316\u6578\u64da\u7ba1\u7406\u4e26\u63d0\u9ad8\u4ee3\u78bc\u53ef\u8b80\u6027\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-61873","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/61873","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=61873"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/61873\/revisions"}],"predecessor-version":[{"id":61874,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/61873\/revisions\/61874"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=61873"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=61873"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=61873"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}