Flink Caused by: java.lang.ClassCastException: class java.lang.Integer cannot be cast to class java.lang.Long

 

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package com.example;

import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.java.typeutils.RowTypeInfo;
import org.apache.flink.connector.jdbc.JdbcExecutionOptions;
import org.apache.flink.connector.jdbc.JdbcInputFormat;
import org.apache.flink.connector.jdbc.JdbcSink;
import org.apache.flink.connector.jdbc.JdbcStatementBuilder;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.types.Row;
import org.apache.flink.streaming.api.datastream.DataStream;
import java.sql.PreparedStatement;
import java.sql.SQLException;

/**
 * first flink
 */
public class FlinkMySQLExampleMain
{
    public static void main( String[] args )
    {
        // 创建执行环境
        final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        // 从 MySQL 读取数据
        RowTypeInfo rowTypeInfo = new RowTypeInfo(
                TypeInformation.of(String.class), // user_name
                TypeInformation.of(Long.class),  // id
                TypeInformation.of(Long.class),  // age
                TypeInformation.of(Long.class)  // level
        );
        JdbcInputFormat jdbcInputFormat = JdbcInputFormat.buildJdbcInputFormat()
                .setDrivername("com.mysql.cj.jdbc.Driver")
                .setDBUrl("jdbc:mysql://192.168.0.211:3306/flink-test")
                .setQuery("SELECT `user_name`,`id`,`age`,`level` FROM flink_user")
                .setRowTypeInfo(rowTypeInfo)
                .setUsername("root")
                .setPassword("test123456")
                .finish();
        DataStream<Row> sourceStream = env.createInput(jdbcInputFormat);
        // 对数据进行简单处理（例如，转换名称为大写）
        DataStream<FlinkExchangeDto> processedStream = sourceStream.map(value -> {
            FlinkExchangeDto dto = new FlinkExchangeDto();
            // 确保类型正确，检查是否有那个字段
            if (value.getField(0) != null) {
                dto.setUserName(value.getField(0).toString().toUpperCase());
            } else {
                // 或者设置默认值
                dto.setUserName("no user name");
            }
            if (value.getField(1) != null) {
                Long id = (Long)value.getField(1);
                dto.setUserId(id);
            } else {
                // 或者设置默认值
                dto.setUserId(0L);
            }

            if (value.getField(2) != null&&value.getField(3) != null) {
                Long age = (Long) value.getField(2);
                Long level = (Long) value.getField(3);
                dto.setActivityType("FromUser-age:"+age.toString()+",level:"+level.toString());
            } else {
                // 或者设置默认值
                dto.setActivityType("FromUser");
            }
            return dto;
        });
        // 将数据写回 MySQL
        processedStream.addSink(JdbcSink.sink(
                "INSERT INTO activity_user (user_id,user_name,activity_type) VALUES ( ?,?,?) ",
                new JdbcStatementBuilder<FlinkExchangeDto>() {
                    @Override
                    public void accept(PreparedStatement ps, FlinkExchangeDto t) throws SQLException {
                        ps.setLong(1, t.getUserId());
                        ps.setString(2, t.getUserName());
                        ps.setString(3, t.getActivityType());
                    }
                },
                JdbcExecutionOptions.builder()
                        .withBatchSize(1000)
                        .withBatchIntervalMs(200)
                        .withMaxRetries(5)
                        .build(),
                new org.apache.flink.connector.jdbc.JdbcConnectionOptions.JdbcConnectionOptionsBuilder()
                        .withUrl("jdbc:mysql://192.168.0.211:3306/flink-test")
                        .withDriverName("com.mysql.cj.jdbc.Driver")
                        .withUsername("root")
                        .withPassword("test123456")
                        .build()
        ));

        // 执行 Flink 作业
        try {
            env.execute("Flink MySQL Example123");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static class FlinkExchangeDto {

        /**
         * 执行的用户 ID
         */
        private Long userId;

        private String userName;

        /**
         * 执行的活动类型
         */
        private String activityType;

        public Long getUserId() {
            return userId;
        }

        public void setUserId(Long userId) {
            this.userId = userId;
        }
        public String getUserName() {
            return userName;
        }
        public void setUserName(String userName) {
            this.userName = userName;
        }
        public String getActivityType() {
            return activityType;
        }

        public void setActivityType(String activityType) {
            this.activityType = activityType;
        }
    }
}
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数据表结构如下

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CREATE TABLE `flink_user`  (
  `id` int UNSIGNED NOT NULL AUTO_INCREMENT,
  `user_name` varchar(30) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL DEFAULT '',
  `age` int NOT NULL,
  `level` int NOT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 4 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Dynamic;

SET FOREIGN_KEY_CHECKS = 1;
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 当 MySQL 表中的字段被定义为  int 时，使用Integer 类型

 当 MySQL 表中的字段被定义为 int UNSIGNED 时，使用 Long 类型

 修改代码

复制代码
package com.example;

import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.java.typeutils.RowTypeInfo;
import org.apache.flink.connector.jdbc.JdbcExecutionOptions;
import org.apache.flink.connector.jdbc.JdbcInputFormat;
import org.apache.flink.connector.jdbc.JdbcSink;
import org.apache.flink.connector.jdbc.JdbcStatementBuilder;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.types.Row;
import org.apache.flink.streaming.api.datastream.DataStream;
import java.sql.PreparedStatement;
import java.sql.SQLException;

/**
 * first flink
 */
public class FlinkMySQLExampleMain
{
    public static void main( String[] args )
    {
        // 创建执行环境
        final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        // 从 MySQL 读取数据
        RowTypeInfo rowTypeInfo = new RowTypeInfo(
                TypeInformation.of(String.class), // user_name
                TypeInformation.of(Long.class),  // id
                TypeInformation.of(Integer.class),  // age
                TypeInformation.of(Integer.class)  // level
        );
        JdbcInputFormat jdbcInputFormat = JdbcInputFormat.buildJdbcInputFormat()
                .setDrivername("com.mysql.cj.jdbc.Driver")
                .setDBUrl("jdbc:mysql://192.168.0.211:3306/flink-test")
                .setQuery("SELECT `user_name`,`id`,`age`,`level` FROM flink_user")
                .setRowTypeInfo(rowTypeInfo)
                .setUsername("root")
                .setPassword("test123456")
                .finish();
        DataStream<Row> sourceStream = env.createInput(jdbcInputFormat);
        // 对数据进行简单处理（例如，转换名称为大写）
        DataStream<FlinkExchangeDto> processedStream = sourceStream.map(value -> {
            FlinkExchangeDto dto = new FlinkExchangeDto();
            // 确保类型正确，检查是否有那个字段
            if (value.getField(0) != null) {
                dto.setUserName(value.getField(0).toString().toUpperCase());
            } else {
                // 或者设置默认值
                dto.setUserName("no user name");
            }
            if (value.getField(1) != null) {
                Long id = (Long)value.getField(1);
                dto.setUserId(id);
            } else {
                // 或者设置默认值
                dto.setUserId(0L);
            }

            if (value.getField(2) != null&&value.getField(3) != null) {
                Integer age = (Integer) value.getField(2);
                Integer level = (Integer) value.getField(3);
                dto.setActivityType("FromUser-age:"+age.toString()+",level:"+level.toString());
            } else {
                // 或者设置默认值
                dto.setActivityType("FromUser");
            }
            return dto;
        });
        // 将数据写回 MySQL
        processedStream.addSink(JdbcSink.sink(
                "INSERT INTO activity_user (user_id,user_name,activity_type) VALUES ( ?,?,?) ",
                new JdbcStatementBuilder<FlinkExchangeDto>() {
                    @Override
                    public void accept(PreparedStatement ps, FlinkExchangeDto t) throws SQLException {
                        ps.setLong(1, t.getUserId());
                        ps.setString(2, t.getUserName());
                        ps.setString(3, t.getActivityType());
                    }
                },
                JdbcExecutionOptions.builder()
                        .withBatchSize(1000)
                        .withBatchIntervalMs(200)
                        .withMaxRetries(5)
                        .build(),
                new org.apache.flink.connector.jdbc.JdbcConnectionOptions.JdbcConnectionOptionsBuilder()
                        .withUrl("jdbc:mysql://192.168.0.211:3306/flink-test")
                        .withDriverName("com.mysql.cj.jdbc.Driver")
                        .withUsername("root")
                        .withPassword("test123456")
                        .build()
        ));

        // 执行 Flink 作业
        try {
            env.execute("Flink MySQL Example123");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static class FlinkExchangeDto {

        /**
         * 执行的用户 ID
         */
        private Long userId;

        private String userName;

        /**
         * 执行的活动类型
         */
        private String activityType;

        public Long getUserId() {
            return userId;
        }

        public void setUserId(Long userId) {
            this.userId = userId;
        }
        public String getUserName() {
            return userName;
        }
        public void setUserName(String userName) {
            this.userName = userName;
        }
        public String getActivityType() {
            return activityType;
        }

        public void setActivityType(String activityType) {
            this.activityType = activityType;
        }
    }
}
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