sparksql各种数据源

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sparksql各种数据源的测试:
大致的有json文件parquet文件,和常用的文件,jdbc等
还有hbase的数据源(还没有贴出,可能要等几天贴出来了)
代码:

一般过程:
第一步创建:利用SparkSeesion进行创建,一般是sparkSeesion.read.format(“格式”).load(“文件路径”)
第二部:进行一般操作
第三部:保存文件,或者保存到其他的地方:一般是sparkSeesion.write.format(“格式”).save(“文件路径”)

package sqlimport org.apache.spark.sql.SparkSessionobject SQLDataSourceExample {  case class Person(name: String, age: Long)  def main(args: Array[String]) {    val spark = SparkSession      .builder()      .master("local[*]")      .appName("Spark SQL data sources example")      .config("spark.some.config.option", "some-value")      .getOrCreate()    /*runBasicDataSourceExample(spark)    runBasicParquetExample(spark)*/    runParquetSchemaMergingExample(spark)    /* runJsonDatasetExample(spark)    runJdbcDatasetExample(spark)*/    spark.stop()  }  private def runBasicDataSourceExample(spark: SparkSession): Unit = {    println("--------------------      runBasicDataSourceExample  start    -----------------")    // $example on:generic_load_save_functions$    val usersDF = spark.read.load("spark_sql/src/main/resources/users.parquet")    println("--------------------parquet-----------------")    usersDF.printSchema()    usersDF.show()    usersDF.select("name", "favorite_color").write.save("spark_sql/src/main/resources/result/namesAndFavColors.parquet1")    // $example off:generic_load_save_functions$    // $example on:manual_load_options$    println("--------------------json-----------------")    val peopleDF = spark.read.format("json").load("spark_sql/src/main/resources/people.json")    peopleDF.show()    peopleDF.select("name", "age").write.format("parquet").save("spark_sql/src/main/resources/result/namesAndAges.parquet1")    println("--------------------直接使用sql-----------------")    val sqlDF = spark.sql("SELECT * FROM parquet.`spark_sql/src/main/resources/users.parquet`")    sqlDF.show()    println("--------------------      runBasicDataSourceExample  end    -----------------")  }  private def runBasicParquetExample(spark: SparkSession): Unit = {    println("--------------------      runBasicParquetExample  start    -----------------")    import spark.implicits._    val peopleDF = spark.read.json("spark_sql/src/main/resources/people.json")    peopleDF.write.parquet("spark_sql/src/main/resource/result/people.parquet")    val parquetFileDF = spark.read.parquet("spark_sql/src/main/resource/result/people.parquet")    println("-------创建临时表进行sql-------")    parquetFileDF.createOrReplaceTempView("parquetFile")    val namesDF = spark.sql("SELECT name FROM parquetFile WHERE age BETWEEN 13 AND 19")    namesDF.map(attributes => "Name: " + attributes(0)).show()    println("--------------------      runBasicParquetExample  end    -----------------")  }  private def runParquetSchemaMergingExample(spark: SparkSession): Unit = {    println("--------------------      runParquetSchemaMergingExample  start    -----------------")    import spark.implicits._println("---------创建一个普通的dataframe,然后保存为一个square文件------")    // Create a simple DataFrame, store into a partition directory    val squaresDF = spark.sparkContext.makeRDD(1 to 5).map(i => (i, i * i)).toDF("value", "square")    squaresDF.write.parquet("spark_sql/src/main/resource/result/data/test_table_key=1")    // Create another DataFrame in a new partition directory,    // adding a new column and dropping an existing column    val cubesDF = spark.sparkContext.makeRDD(6 to 10).map(i => (i, i * i * i)).toDF("value", "cube")    cubesDF.write.parquet("spark_sql/src/main/resource/result/data/test_table_key=2")    // Read the partitioned table    val mergedDF = spark.read.option("mergeSchema", "true").parquet("data/test_table")    mergedDF.printSchema()    // The final schema consists of all 3 columns in the Parquet files together    // with the partitioning column appeared in the partition directory paths    // root    //  |-- value: int (nullable = true)    //  |-- square: int (nullable = true)    //  |-- cube: int (nullable = true)    //  |-- key: int (nullable = true)    // $example off:schema_merging$  }  private def runJsonDatasetExample(spark: SparkSession): Unit = {    // $example on:json_dataset$    // A JSON dataset is pointed to by path.    // The path can be either a single text file or a directory storing text files    val path = "examples/src/main/resources/people.json"    val peopleDF = spark.read.json(path)    // The inferred schema can be visualized using the printSchema() method    peopleDF.printSchema()    // root    //  |-- age: long (nullable = true)    //  |-- name: string (nullable = true)    // Creates a temporary view using the DataFrame    peopleDF.createOrReplaceTempView("people")    // SQL statements can be run by using the sql methods provided by spark    val teenagerNamesDF = spark.sql("SELECT name FROM people WHERE age BETWEEN 13 AND 19")    teenagerNamesDF.show()    // +------+    // |  name|    // +------+    // |Justin|    // +------+    // Alternatively, a DataFrame can be created for a JSON dataset represented by    // an RDD[String] storing one JSON object per string    val otherPeopleRDD = spark.sparkContext.makeRDD(      """{"name":"Yin","address":{"city":"Columbus","state":"Ohio"}}""" :: Nil)    val otherPeople = spark.read.json(otherPeopleRDD)    otherPeople.show()    // +---------------+----+    // |        address|name|    // +---------------+----+    // |[Columbus,Ohio]| Yin|    // +---------------+----+    // $example off:json_dataset$  }  private def runJdbcDatasetExample(spark: SparkSession): Unit = {    val jdbcDF = spark.read      .format("jdbc")      .option("url", "jdbc:postgresql:dbserver")      .option("dbtable", "schema.tablename")      .option("user", "username")      .option("password", "password")      .load()    // $example off:jdbc_dataset$  }}

hbase作为源:稍后补上

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