利用spark将mysql同步数据到hudi提供详细java代码案例

以下是一个基本的Java代码示例，用于将MySQL中的数据同步到Hudi：

import org.apache.hudi.DataSourceWriteOptions;
import org.apache.hudi.HoodieSparkUtils;
import org.apache.hudi.OverwriteWithLatestAvroPayload;
import org.apache.hudi.QuickstartUtils;
import org.apache.hudi.api.HoodieWriteClient;
import org.apache.hudi.common.model.HoodieTableType;
import org.apache.hudi.config.HoodieWriteConfig;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.sql.Dataset;
import org.apache.spark.sql.Row;
import org.apache.spark.sql.SparkSession;

import java.util.Collections;
import java.util.Properties;

public class MySQLToHudiSync {

  public static void main(String[] args) {

    String tableName = "hudi_table";
    String basePath = "file:///tmp/hudi_table";
    String jdbcUrl = "jdbc:mysql://<mysql_host>:<mysql_port>/<mysql_db>";
    String username = "<mysql_username>";
    String password = "<mysql_password>";
    String partitionKey = "id";
    String hudiTableType = HoodieTableType.COPY_ON_WRITE.name();

    SparkSession spark = SparkSession.builder().appName("MySQLToHudiSync").config("spark.serializer", "org.apache.spark.serializer.KryoSerializer").getOrCreate();
    JavaSparkContext jsc = new JavaSparkContext(spark.sparkContext());

    Properties connectionProperties = new Properties();
    connectionProperties.put("user", username);
    connectionProperties.put("password", password);

    Dataset<Row> jdbcDF = spark.read().jdbc(jdbcUrl, tableName, connectionProperties);
    JavaRDD<Row> rowsRDD = jdbcDF.javaRDD();

    HoodieWriteConfig hoodieWriteConfig = HoodieWriteConfig.newBuilder().withPath(basePath)
        .withSchema(QuickstartUtils.getSchema()).withParallelism(2, 2)
        .withBulkInsertParallelism(3).withFinalizeWriteParallelism(2)
        .withStorageConfig(HoodieSparkUtils.getDefaultHoodieConf(jsc.hadoopConfiguration()))
        .withAutoCommit(false).withTableType(hudiTableType)
        .forTable(tableName).withIndexConfig(HoodieIndexConfig.newBuilder().withIndexType(HoodieIndex.IndexType.BLOOM).build())
        .withProps(Collections.singletonMap(DataSourceWriteOptions.RECORDKEY_FIELD_OPT_KEY().key(), partitionKey)).build();

    HoodieWriteClient hoodieWriteClient = new HoodieWriteClient<>(jsc, hoodieWriteConfig);

    hoodieWriteClient.upsert(rowsRDD.map(row -> {
      String key = row.getAs(partitionKey).toString();
      return new UpsertPOJO(key, row);
    }), hoodieWriteConfig.getBasePath(), hoodieWriteConfig.getTableType(), OverwriteWithLatestAvroPayload.class.getName());

    hoodieWriteClient.commit();
  }

  public static class UpsertPOJO implements Serializable {

    private String key;
    private Row row;

    public UpsertPOJO(String key, Row row) {
      this.key = key;
      this.row = row;
    }

    public String getKey() {
      return key;
    }

    public void setKey(String key) {
      this.key = key;
    }

    public Row getRow() {
      return row;
    }

    public void setRow(Row row) {
      this.row = row;
    }
  }
}

代码中的`tableName`是要同步的MySQL表的名称，`basePath`是Hudi表的根路径。`jdbcUrl`，`username`和`password`是连接MySQL所需的凭据。`partitionKey`是Hudi表中用作分区键的字段名称。`hudiTableType`是Hudi表的类型，可以是`COPY_ON_WRITE`或`MERGE_ON_READ`。

代码中使用`HoodieWriteConfig`对象配置Hudi写入选项，例如`withPath`，`withSchema`，`withParallelism`，`withBulkInsertParallelism`等。`forTable`方法指定Hudi表的名称。`withIndexConfig`方法配置Hudi索引选项，例如索引类型和配置。`withProps`方法设置自定义属性。`withAutoCommit`方法用于控制提交方式，可以是自动提交或手动提交。

最后，使用`HoodieWriteClient`对象将MySQL数据插入Hudi表，使用`upsert`方法进行插入。`UpsertPOJO`类是自定义的POJO类，用于将MySQL中的行转换为要插入到Hudi表中的数据。`commit`方法用于提交更改。

请注意，此代码示例仅用于演示目的，并且可能需要进行修改以适应您的特定需求。