使用flink将数据流写入到Clickhouse的工具类

快来打我* 2022-11-12 10:54 201阅读 0赞

## 使用flink将数据流写入到Clickhouse的工具类 ##

package com.gmall.realtime.util;
    
    import com.gmall.realtime.bean.VisitorStats;
    import org.apache.flink.connector.jdbc.JdbcConnectionOptions;
    import org.apache.flink.connector.jdbc.JdbcSink;
    import org.apache.flink.connector.jdbc.JdbcStatementBuilder;
    import org.apache.flink.streaming.api.functions.sink.SinkFunction;
    
    import java.lang.reflect.Field;
    import java.lang.reflect.Modifier;
    import java.sql.PreparedStatement;
    import java.sql.SQLException;
    
    public class MySinkUtil { 
    
        public static void main(String[] args) { 
            getClickHouseSink("abc","a", VisitorStats.class);
        }
    
        public static <T> SinkFunction<VisitorStats> getClickHouseSink(String db,
                                                                   String table,
                                                                  Class<T> tClass) { 
            String url = "jdbc:clickhouse://hadoop162:8123/"+db;
            String driver = "ru.yandex.clickhouse.ClickHouseDriver";
    
            //构建插入语句的SQL
            final StringBuilder sql = new StringBuilder();
            sql.append("insert into ").append(table).append("(");
            //通过反射获取字段名，拼接
            final Field[] fields = tClass.getDeclaredFields();
            for (Field field : fields) { 
                //如果属性被transient修饰，则不会写入到clickhouse中
                if (!Modifier.isTransient(field.getModifiers())){ 
                    final String fieldName = field.getName();
                    sql.append(fieldName).append(",");
                }
            }
            //去掉最后多拼接的一个逗号
            sql.deleteCharAt(sql.length()-1);
    
            sql.append(" ) values ( ");
    
            for (Field field : fields) { 
               if (!Modifier.isTransient(field.getModifiers())){ 
                   sql.append("?,");
               }
            }
            sql.deleteCharAt(sql.length()-1);
    
            sql.append(" )");
    
           // System.out.println(sql.toString());
    
            return getJDBCSink(url,driver,sql.toString());
        }
    
        private static <T> SinkFunction<T> getJDBCSink(String url,
                                                              String driver,
                                                              String sql) { 
    
            return JdbcSink.<T>sink(sql,
                    new JdbcStatementBuilder<T>() { 
                        @Override
                        public void accept(PreparedStatement ps,
                                           T t) throws SQLException { 
                            final Field[] fields = t.getClass().getDeclaredFields();
                            try { 
                                for (int i = 0,position=1; i < fields.length; i++) { 
                                    if (!Modifier.isTransient(fields[i].getModifiers())){ 
                                        fields[i].setAccessible(true);
                                        ps.setObject(position++,fields[i].get(t));
                                    }
                                }
    
                            }catch (Exception e){ 
                                e.printStackTrace();
                            }
                        }
                    },
                    new JdbcConnectionOptions.JdbcConnectionOptionsBuilder()
                            .withUrl(url)
                            .withDriverName(driver)
                            .build());
    
        }
    
    
    }