com.hazelcast.sql.SqlRowMetadata Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2021, Hazelcast, Inc. All Rights Reserved.
*
* Licensed 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 com.hazelcast.sql;
import com.hazelcast.internal.util.Preconditions;
import com.hazelcast.spi.annotation.PrivateApi;
import javax.annotation.Nonnull;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
/**
* SQL row metadata.
*/
public final class SqlRowMetadata {
/** Constant indicating that the column is not found. */
public static final int COLUMN_NOT_FOUND = -1;
private final List columns;
private final Map nameToIndex;
@PrivateApi
@SuppressWarnings("ConstantConditions")
public SqlRowMetadata(@Nonnull List columns) {
assert columns != null && !columns.isEmpty();
this.columns = Collections.unmodifiableList(columns);
nameToIndex = new HashMap<>(columns.size());
for (int i = 0; i < columns.size(); i++) {
nameToIndex.put(columns.get(i).getName(), i);
}
}
/**
* Gets the number of columns in the row.
*
* @return the number of columns in the row
*/
public int getColumnCount() {
return columns.size();
}
/**
* Gets column metadata.
*
* @param index column index, zero-based
* @return column metadata
* @throws IndexOutOfBoundsException If the column index is out of bounds
*/
@Nonnull
public SqlColumnMetadata getColumn(int index) {
if (index < 0 || index >= columns.size()) {
throw new IndexOutOfBoundsException("Column index is out of bounds: " + index);
}
return columns.get(index);
}
/**
* Gets columns metadata.
*
* @return columns metadata
*/
@Nonnull
public List getColumns() {
return columns;
}
/**
* Find index of the column with the given name. Returned index can be used to get column value
* from {@link SqlRow}.
*
* @param columnName column name (case sensitive)
* @return column index or {@link #COLUMN_NOT_FOUND} if a column with the given name is not found
* @throws NullPointerException if column name is null
*
* @see SqlRow
*/
public int findColumn(@Nonnull String columnName) {
Preconditions.checkNotNull(columnName, "Column name cannot be null");
return nameToIndex.getOrDefault(columnName, COLUMN_NOT_FOUND);
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
SqlRowMetadata that = (SqlRowMetadata) o;
return columns.equals(that.columns);
}
@Override
public int hashCode() {
return columns.hashCode();
}
@Override
public String toString() {
return columns.stream()
.map((column) -> column.getName() + ' ' + column.getType())
.collect(Collectors.joining(", ", "[", "]"));
}
}