public void initExplicitSchema(Random r, List<String> explicitTypeNameList, int maxComplexDepth,
      boolean allowNull, boolean isUnicodeOk,
      List<DataTypePhysicalVariation> explicitDataTypePhysicalVariationList) {
    this.r = r;
    this.allowNull = allowNull;
    this.isUnicodeOk = isUnicodeOk;

    List<GenerationSpec> generationSpecList = new ArrayList<GenerationSpec>();
    for (String explicitTypeName : explicitTypeNameList) {
      TypeInfo typeInfo =
          TypeInfoUtils.getTypeInfoFromTypeString(explicitTypeName);
      generationSpecList.add(
          GenerationSpec.createSameType(typeInfo));
    }

    chooseSchema(
        SupportedTypes.ALL, null, generationSpecList, explicitDataTypePhysicalVariationList,
        maxComplexDepth);
  }
Generate object inspector and random row object[].
ql/src/test/org/apache/hadoop/hive/ql/exec/vector/VectorRandomRowSource.java