{"id":185840,"date":"2024-11-11T00:56:20","date_gmt":"2024-11-10T16:56:20","guid":{"rendered":"https:\/\/server.hk\/cnblog\/185840\/"},"modified":"2024-11-11T00:56:21","modified_gmt":"2024-11-10T16:56:21","slug":"%e6%95%b8%e6%93%9a%e7%9a%84%e6%96%b9%e6%b3%95map%e5%af%a6%e7%8f%be%e5%8f%96%e5%87%ba%e6%95%b8%e6%93%9a%e5%ba%ab%e6%95%b8%e6%93%9a%e6%96%b9%e6%b3%95%e4%bb%8b%e7%b4%b9%ef%bc%88%e5%be%9emap%e4%b8%ad","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/185840\/","title":{"rendered":"\u6578\u64da\u7684\u65b9\u6cd5Map\u5be6\u73fe\u53d6\u51fa\u6578\u64da\u5eab\u6578\u64da\u65b9\u6cd5\u4ecb\u7d39\uff08\u5f9emap\u4e2d\u53d6\u51fa\u6578\u64da\u5eab\uff09"},"content":{"rendered":"

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\u4ec0\u9ebc\u662fMap\uff1f<\/h2>\n

\u5728Java\u4e2d\uff0cMap\u662f\u4e00\u7a2e\u7528\u65bc\u5b58\u5132\u9375\u503c\u5c0d\u7684\u6578\u64da\u7d50\u69cb\u3002\u5b83\u5141\u8a31\u958b\u767c\u8005\u901a\u904e\u9375\u4f86\u5feb\u901f\u67e5\u627e\u5c0d\u61c9\u7684\u503c\u3002Map\u7684\u5be6\u73fe\u985e\u578b\u6709\u5f88\u591a\uff0c\u5982HashMap\u3001TreeMap\u7b49\u3002\u9019\u4e9b\u985e\u578b\u5404\u6709\u7279\u9ede\uff0c\u9069\u7528\u65bc\u4e0d\u540c\u7684\u5834\u666f\u3002<\/p>\n

\u5f9e\u6578\u64da\u5eab\u4e2d\u63d0\u53d6\u6578\u64da<\/h2>\n

\u5728\u63d0\u53d6\u6578\u64da\u4e4b\u524d\uff0c\u6211\u5011\u9700\u8981\u78ba\u4fdd\u5df2\u7d93\u5efa\u7acb\u4e86\u8207\u6578\u64da\u5eab\u7684\u9023\u63a5\u3002\u4ee5\u4e0b\u662f\u4f7f\u7528JDBC\uff08Java Database Connectivity\uff09\u4f86\u9023\u63a5\u6578\u64da\u5eab\u7684\u57fa\u672c\u6b65\u9a5f\uff1a<\/p>\n

import java.sql.Connection;\nimport java.sql.DriverManager;\nimport java.sql.ResultSet;\nimport java.sql.Statement;\n\npublic class DatabaseConnection {\n    public static Connection connect() {\n        Connection connection = null;\n        try {\n            \/\/ \u52a0\u8f09JDBC\u9a45\u52d5\n            Class.forName(\"com.mysql.cj.jdbc.Driver\");\n            \/\/ \u5efa\u7acb\u9023\u63a5\n            connection = DriverManager.getConnection(\"jdbc:mysql:\/\/localhost:3306\/your_database\", \"username\", \"password\");\n        } catch (Exception e) {\n            e.printStackTrace();\n        }\n        return connection;\n    }\n}\n<\/code><\/pre>\n
\u4f7f\u7528Map\u5b58\u5132\u6578\u64da<\/h2>\n
\u4e00\u65e6\u6210\u529f\u9023\u63a5\u5230\u6578\u64da\u5eab\uff0c\u6211\u5011\u53ef\u4ee5\u4f7f\u7528Map\u4f86\u5b58\u5132\u5f9e\u6578\u64da\u5eab\u4e2d\u63d0\u53d6\u7684\u6578\u64da\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u793a\u4f8b\uff0c\u5c55\u793a\u5982\u4f55\u5f9e\u6578\u64da\u5eab\u4e2d\u67e5\u8a62\u6578\u64da\u4e26\u5c07\u5176\u5b58\u5132\u5230Map\u4e2d\uff1a<\/p>\n
import java.sql.Connection;\nimport java.sql.ResultSet;\nimport java.sql.Statement;\nimport java.util.HashMap;\nimport java.util.Map;\n\npublic class DataRetrieval {\n    public static Map getData() {\n        Map dataMap = new HashMap();\n        Connection connection = DatabaseConnection.connect();\n        try {\n            Statement statement = connection.createStatement();\n            ResultSet resultSet = statement.executeQuery(\"SELECT id, name FROM users\");\n            while (resultSet.next()) {\n                int id = resultSet.getInt(\"id\");\n                String name = resultSet.getString(\"name\");\n                dataMap.put(id, name);\n            }\n        } catch (Exception e) {\n            e.printStackTrace();\n        } finally {\n            try {\n                if (connection != null) {\n                    connection.close();\n                }\n            } catch (Exception e) {\n                e.printStackTrace();\n            }\n        }\n        return dataMap;\n    }\n}\n<\/code><\/pre>\n
\u5f9eMap\u4e2d\u53d6\u51fa\u6578\u64da<\/h2>\n
\u4e00\u65e6\u6578\u64da\u88ab\u5b58\u5132\u5728Map\u4e2d\uff0c\u6211\u5011\u53ef\u4ee5\u901a\u904e\u9375\u4f86\u8f15\u9b06\u5730\u53d6\u51fa\u76f8\u61c9\u7684\u503c\u3002\u4ee5\u4e0b\u662f\u5982\u4f55\u5f9eMap\u4e2d\u53d6\u51fa\u6578\u64da\u7684\u793a\u4f8b\uff1a<\/p>\n
public class Main {\n    public static void main(String[] args) {\n        Map users = DataRetrieval.getData();\n        \/\/ \u53d6\u51fa\u7279\u5b9aID\u7684\u7528\u6236\u540d\n        String userName = users.get(1); \/\/ \u5047\u8a2d\u6211\u5011\u8981\u53d6\u51faID\u70ba1\u7684\u7528\u6236\u540d\n        System.out.println(\"\u7528\u6236\u540d: \" + userName);\n    }\n}\n<\/code><\/pre>\n
\u7e3d\u7d50<\/h2>\n
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\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4f86\u652f\u6301\u60a8\u7684\u61c9\u7528\u958b\u767c\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u4e0d\u540c\u9700\u6c42\u7684\u5ba2\u6236\u3002\u7121\u8ad6\u662f \u9999\u6e2fVPS<\/a> \u9084\u662f\u5176\u4ed6\u985e\u578b\u7684 \u4f3a\u670d\u5668<\/a>\uff0c\u6211\u5011\u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u7684\u670d\u52d9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
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