springboot 使用yml配置文件给静态变量赋值教程

谁践踏了优雅 2021-07-25 00:08 454阅读 0赞

声明：

> 此处需求是修改封装的clickhouseUtil数据查询引擎连接工具类。由于此类中的方法都是静态方法。连接地址等参数需要根据不同环境改变。例如开发下地址，测试下地址，生产地址等，所有通过配置文件来获取不同环境下的配置参数，但是使用的方法是静态的，所有不能使用一般情况下的@value直接给变量赋值，需要用到spring 属性的set方法来给静态变量赋值，然后静态方法使用静态变量即可

方法：

**第一步：在yml文件中配置需要的参数**

clickhouse:
     address: jdbc:clickhouse://172.20.xxx.xxx:8123
     username: default
     password: xxxxx
     db: marketing
     socketTimeout: 600000

第二步：

类上一定要先注明@Component注解，在程序启动是自动加载，否则静态参数仍旧获取不到配置文件的值

## 创建静态变量 ##

给静态变量set方法上添加@Value()

@Value("${clickhouse.address}")
    public void setClickhouseAddress(String address) { 
    ClickHouseUtil.clickhouseAddress = address;
    }

最后在静态方法中使用即可

@Component
    public class ClickHouseUtil { 
      
     private static String clickhouseAddress;
      
     private static String clickhouseUsername;
      
     private static String clickhousePassword;
      
     private static String clickhouseDB;
      
     private static Integer clickhouseSocketTimeout;
      
     @Value("${clickhouse.address}")
     public void setClickhouseAddress(String address) { 
     ClickHouseUtil.clickhouseAddress = address;
     }
     @Value("${clickhouse.username}")
     public void setClickhouseUsername(String username) { 
     ClickHouseUtil.clickhouseUsername = username;
     }
     @Value("${clickhouse.password}")
     public void setClickhousePassword(String password) { 
     ClickHouseUtil.clickhousePassword = password;
     }//加入Java开发交流君样：756584822一起吹水聊天
     @Value("${clickhouse.db}")
     public void setClickhouseDB(String db) { 
     ClickHouseUtil.clickhouseDB = db;
     }
     @Value("${clickhouse.socketTimeout}")
     public void setClickhouseSocketTimeout(Integer socketTimeout) { 
     ClickHouseUtil.clickhouseSocketTimeout = socketTimeout;
     }
      
      
     public static Connection getConn() { 
      
     ClickHouseConnection conn = null;
     ClickHouseProperties properties = new ClickHouseProperties();
     properties.setUser(clickhouseUsername);
     properties.setPassword(clickhousePassword);
     properties.setDatabase(clickhouseDB);
     properties.setSocketTimeout(clickhouseSocketTimeout);
     ClickHouseDataSource clickHouseDataSource = new ClickHouseDataSource(clickhouseAddress,properties);
     try { //加入Java开发交流君样：756584822一起吹水聊天
      conn = clickHouseDataSource.getConnection();
      return conn;
     } catch (SQLException e) { 
      e.printStackTrace();
     }
      
     return null;
     }
      
     public static List<JSONObject> exeSql(String sql){ 
     log.info("cliockhouse 执行sql：" + sql);
     Connection connection = getConn();
     try { 
      Statement statement = connection.createStatement();
      ResultSet results = statement.executeQuery(sql);
      ResultSetMetaData rsmd = results.getMetaData();
      List<JSONObject> list = new ArrayList();
      while(results.next()){ 
      JSONObject row = new JSONObject();
      for(int i = 1;i<=rsmd.getColumnCount();i++){ 
       row.put(rsmd.getColumnName(i),results.getString(rsmd.getColumnName(i)));
      }
      list.add(row);
      }
      //加入Java开发交流君样：756584822一起吹水聊天
      return list;
     } catch (SQLException e) { 
      e.printStackTrace();
     }
     return null;
     }
      
    }

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