/**  * 获取schema信息  * @throws IOException  */ @Test public void testGetSchema() throws IOException {
      Configuration configuration = new Configuration(true);     configuration.set("fs.defaultFS","hdfs://10.0.1.xx:9000");     ParquetMetadata readFooter = null;     Path parquetFilePath = new Path("/user/yanglei/parquet/douban.parquet");     readFooter = ParquetFileReader.readFooter(configuration, parquetFilePath, ParquetMetadataConverter.NO_FILTER);     MessageType schema =readFooter.getFileMetaData().getSchema();     System.out.println(schema.toString()); } public static final MessageType FILE_SCHEMA = Types.buildMessage()         .required(PrimitiveType.PrimitiveTypeName.BINARY).named("user_name")         .required(PrimitiveType.PrimitiveTypeName.INT64).named("bookid")         .required(PrimitiveType.PrimitiveTypeName.INT32).named("bookscore")         .named("douban"); /**  * 写parquet文件  * @throws Exception  */ @Test public void testWriteParquet() throws Exception {
      Configuration conf = new Configuration(true);     conf.set("fs.defaultFS","hdfs://10.0.1.xx:9000");     String file = "/user/yanglei/parquet/douban.parquet";     Path path = new Path(file);     FileSystem fs = path.getFileSystem(conf);     if (fs.exists(path)) {
          fs.delete(path, true);     }     GroupWriteSupport.setSchema(FILE_SCHEMA, conf);     SimpleGroupFactory f = new SimpleGroupFactory(FILE_SCHEMA);     ParquetWriter
    
      writer = new ParquetWriter<>(path, new GroupWriteSupport(),             CompressionCodecName.GZIP, 1024, 1024, 512, true, false, ParquetProperties.WriterVersion.PARQUET_2_0, conf);     for (int i = 0; i < 1000; i++) {
          writer.write(                 f.newGroup()                         .append("user_name", String.valueOf(i))                         .append("bookid", 64l)                         .append("bookscore",i));     }     writer.close(); }