FlightSqlColumnMetadata.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.arrow.flight.sql;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
/**
* Metadata for a column in a Flight SQL query.
*
* <p>This can be used with FlightSqlClient to access column's metadata contained in schemas
* returned by GetTables and query execution as follows:
*
* <pre>
* FlightSqlColumnMetadata metadata = new FlightSqlColumnMetadata(field.getMetadata());
* Integer precision = metadata.getPrecision();
* </pre>
*
* FlightSqlProducer can use this to set metadata on a column in a schema as follows:
*
* <pre>
* FlightSqlColumnMetadata metadata = new FlightSqlColumnMetadata.Builder()
* .precision(10)
* .scale(5)
* .build();
* Field field = new Field("column", new FieldType(..., metadata.getMetadataMap()), null);
* </pre>
*/
public class FlightSqlColumnMetadata {
private static final String CATALOG_NAME = "ARROW:FLIGHT:SQL:CATALOG_NAME";
private static final String SCHEMA_NAME = "ARROW:FLIGHT:SQL:SCHEMA_NAME";
private static final String TABLE_NAME = "ARROW:FLIGHT:SQL:TABLE_NAME";
private static final String TYPE_NAME = "ARROW:FLIGHT:SQL:TYPE_NAME";
private static final String PRECISION = "ARROW:FLIGHT:SQL:PRECISION";
private static final String SCALE = "ARROW:FLIGHT:SQL:SCALE";
private static final String IS_AUTO_INCREMENT = "ARROW:FLIGHT:SQL:IS_AUTO_INCREMENT";
private static final String IS_CASE_SENSITIVE = "ARROW:FLIGHT:SQL:IS_CASE_SENSITIVE";
private static final String IS_READ_ONLY = "ARROW:FLIGHT:SQL:IS_READ_ONLY";
private static final String IS_SEARCHABLE = "ARROW:FLIGHT:SQL:IS_SEARCHABLE";
private static final String BOOLEAN_TRUE_STR = "1";
private static final String BOOLEAN_FALSE_STR = "0";
private final Map<String, String> metadataMap;
/** Creates a new instance of FlightSqlColumnMetadata. */
public FlightSqlColumnMetadata(Map<String, String> metadataMap) {
this.metadataMap = new HashMap<>(metadataMap);
}
/**
* Returns the metadata map.
*
* @return The metadata map.
*/
public Map<String, String> getMetadataMap() {
return Collections.unmodifiableMap(metadataMap);
}
/**
* Returns the catalog name.
*
* @return The catalog name.
*/
public String getCatalogName() {
return metadataMap.get(CATALOG_NAME);
}
/**
* Returns the schema name.
*
* @return The schema name.
*/
public String getSchemaName() {
return metadataMap.get(SCHEMA_NAME);
}
/**
* Returns the table name.
*
* @return The table name.
*/
public String getTableName() {
return metadataMap.get(TABLE_NAME);
}
/**
* Returns the type name.
*
* @return The type name.
*/
public String getTypeName() {
return metadataMap.get(TYPE_NAME);
}
/**
* Returns the precision / column size.
*
* @return The precision / column size.
*/
public Integer getPrecision() {
String value = metadataMap.get(PRECISION);
if (value == null) {
return null;
}
return Integer.valueOf(value);
}
/**
* Returns the scale / decimal digits.
*
* @return The scale / decimal digits.
*/
public Integer getScale() {
String value = metadataMap.get(SCALE);
if (value == null) {
return null;
}
return Integer.valueOf(value);
}
/**
* Returns if the column is auto incremented.
*
* @return True if the column is auto incremented, false otherwise.
*/
public Boolean isAutoIncrement() {
String value = metadataMap.get(IS_AUTO_INCREMENT);
if (value == null) {
return null;
}
return stringToBoolean(value);
}
/**
* Returns if the column is case-sensitive.
*
* @return True if the column is case-sensitive, false otherwise.
*/
public Boolean isCaseSensitive() {
String value = metadataMap.get(IS_CASE_SENSITIVE);
if (value == null) {
return null;
}
return stringToBoolean(value);
}
/**
* Returns if the column is read only.
*
* @return True if the column is read only, false otherwise.
*/
public Boolean isReadOnly() {
String value = metadataMap.get(IS_READ_ONLY);
if (value == null) {
return null;
}
return stringToBoolean(value);
}
/**
* Returns if the column is searchable.
*
* @return True if the column is searchable, false otherwise.
*/
public Boolean isSearchable() {
String value = metadataMap.get(IS_SEARCHABLE);
if (value == null) {
return null;
}
return stringToBoolean(value);
}
/** Builder of FlightSqlColumnMetadata, used on FlightSqlProducer implementations. */
public static class Builder {
private final Map<String, String> metadataMap;
/** Creates a new instance of FlightSqlColumnMetadata.Builder. */
public Builder() {
this.metadataMap = new HashMap<>();
}
/**
* Sets the catalog name.
*
* @param catalogName the catalog name.
* @return This builder.
*/
public Builder catalogName(String catalogName) {
metadataMap.put(CATALOG_NAME, catalogName);
return this;
}
/**
* Sets the schema name.
*
* @param schemaName The schema name.
* @return This builder.
*/
public Builder schemaName(String schemaName) {
metadataMap.put(SCHEMA_NAME, schemaName);
return this;
}
/**
* Sets the table name.
*
* @param tableName The table name.
* @return This builder.
*/
public Builder tableName(String tableName) {
metadataMap.put(TABLE_NAME, tableName);
return this;
}
/**
* Sets the type name.
*
* @param typeName The type name.
* @return This builder.
*/
public Builder typeName(String typeName) {
metadataMap.put(TYPE_NAME, typeName);
return this;
}
/**
* Sets the precision / column size.
*
* @param precision The precision / column size.
* @return This builder.
*/
public Builder precision(int precision) {
metadataMap.put(PRECISION, Integer.toString(precision));
return this;
}
/**
* Sets the scale / decimal digits.
*
* @param scale The scale / decimal digits.
* @return This builder.
*/
public Builder scale(int scale) {
metadataMap.put(SCALE, Integer.toString(scale));
return this;
}
/**
* Sets if the column is auto incremented.
*
* @param isAutoIncrement True if the column is auto incremented.
* @return This builder.
*/
public Builder isAutoIncrement(boolean isAutoIncrement) {
metadataMap.put(IS_AUTO_INCREMENT, booleanToString(isAutoIncrement));
return this;
}
/**
* Sets if the column is case-sensitive.
*
* @param isCaseSensitive If the column is case-sensitive.
* @return This builder.
*/
public Builder isCaseSensitive(boolean isCaseSensitive) {
metadataMap.put(IS_CASE_SENSITIVE, booleanToString(isCaseSensitive));
return this;
}
/**
* Sets if the column is read only.
*
* @param isReadOnly If the column is read only.
* @return This builder.
*/
public Builder isReadOnly(boolean isReadOnly) {
metadataMap.put(IS_READ_ONLY, booleanToString(isReadOnly));
return this;
}
/**
* Sets if the column is searchable.
*
* @param isSearchable If the column is searchable.
* @return This builder.
*/
public Builder isSearchable(boolean isSearchable) {
metadataMap.put(IS_SEARCHABLE, booleanToString(isSearchable));
return this;
}
/**
* Builds a new instance of FlightSqlColumnMetadata.
*
* @return A new instance of FlightSqlColumnMetadata.
*/
public FlightSqlColumnMetadata build() {
return new FlightSqlColumnMetadata(metadataMap);
}
}
private static String booleanToString(boolean boolValue) {
return boolValue ? BOOLEAN_TRUE_STR : BOOLEAN_FALSE_STR;
}
private static boolean stringToBoolean(String value) {
return value.equals(BOOLEAN_TRUE_STR);
}
}