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JDBC wrapper of the Java Driver for Apache Cassandra®.
/*
*
* 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.ing.data.cassandra.jdbc;
import com.datastax.oss.driver.api.core.type.DataType;
import org.apache.commons.lang3.StringUtils;
import javax.annotation.Nonnull;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
/**
* Metadata describing the columns returned in a {@link CassandraResultSet} or a {@link CassandraPreparedStatement}.
*
* A {@code ColumnDefinitions} instance is mainly a list of {@link Definition}. The definitions or metadata for a
* column can be accessed either by:
*
* - index (indexed from 0)
* - name
*
*
*
* When accessed by name, column selection is case insensitive. In case multiple columns only differ by the case of
* their name, then the column returned will be the first column that has been defined in CQL without forcing case
* sensitivity (that is, it has either been defined without quotes or is fully lowercase). If none of the columns
* have been defined in this manner, the first column matching (with case insensitivity) is returned. You can force
* the case of a selection by using double quotes (") around the name.
*
*
* For example, considering {@code cd} an instance of {@code ColumnDefinitions}:
*
* - if {@code cd} contains column {@code bAR}, then {@code cd.contains("bar")}, {@code cd.contains("bAR")}
* and {@code cd.contains("Bar")} will return {@code true}
* - if {@code cd} contains both {@code foo} and {@code FOO} then:
*
* - {@code cd.getType("foo")}, {@code cd.getType("fOO")} and {@code cd.getType("FOO")} will all match
* the column {@code foo}
* - {@code cd.getType("\"FOO\"")} will match the column {@code FOO}
*
*
* Note that the preceding rules mean that if a {@code ColumnDefinitions} object contains multiple occurrences of
* the exact same name (either the same column multiple times or columns from different tables with the same name),
* you will have to use selection by index to disambiguate.
*
*/
public class ColumnDefinitions implements Iterable {
private final Definition[] byIdx;
private final Map byName;
/**
* Constructor.
*
* @param definitions Array of columns definitions.
*/
public ColumnDefinitions(final Definition[] definitions) {
this.byIdx = definitions;
this.byName = new HashMap<>(definitions.length);
for (int i = 0; i < definitions.length; i++) {
// Be optimistic, 99% of the time, previous will be null.
final int[] previous = this.byName.put(definitions[i].name.toLowerCase(), new int[]{i});
if (previous != null) {
final int[] indexes = new int[previous.length + 1];
System.arraycopy(previous, 0, indexes, 0, previous.length);
indexes[indexes.length - 1] = i;
this.byName.put(definitions[i].name.toLowerCase(), indexes);
}
}
}
/**
* Returns the number of columns described by this {@code ColumnDefinitions} instance.
*
* @return The number of columns described by these metadata.
*/
public int size() {
return this.byIdx.length;
}
/**
* Returns whether these metadata contains a given name.
*
* @param name The name to check.
* @return {@code true} if these metadata contains the column named {@code name}, {@code false} otherwise.
*/
public boolean contains(final String name) {
return findAllIdx(name) != null;
}
/**
* Returns the first index in these metadata of the provided column name, if present.
*
* @param name The name of the column.
* @return The index of the first occurrence of the column name in these metadata if present, -1 otherwise.
*/
public int getIndexOf(final String name) {
return findFirstIdx(name);
}
/**
* Returns an iterator over the {@link Definition} contained in these metadata.
*
* The order of the iterator will be the one of these metadata.
*
*
* @return An iterator over the {@link Definition} contained in these metadata.
*/
@Override
@Nonnull
public Iterator iterator() {
return Arrays.asList(this.byIdx).iterator();
}
/**
* Returns a list containing all the definitions of these metadata ordered by index.
*
* @return A list of the {@link Definition} contained in these metadata.
*/
public List asList() {
return Arrays.asList(this.byIdx);
}
/**
* Returns the name of the {@code i}th column in these metadata.
*
* @param i The index of the column in these metadata (the first column is 0).
* @return The name of the {@code i}th column in these metadata.
* @throws IndexOutOfBoundsException if {@code i < 0} or {@code i >= size()}.
*/
public String getName(final int i) {
return this.byIdx[i].name;
}
/**
* Returns the type of the {@code i}th column in these metadata.
*
* @param i The index of the column in these metadata (the first column is 0).
* @return The type of the {@code i}th column in these metadata.
* @throws IndexOutOfBoundsException if {@code i < 0} or {@code i >= size()}.
*/
public DataType getType(final int i) {
return byIdx[i].type;
}
/**
* Returns the type of the first occurrence of the column {@code name} in these metadata.
*
* @param name The name of the column.
* @return The type of (the first occurrence of) the column {@code name} in these metadata.
* @throws IllegalArgumentException if {@code name} is not in these metadata.
*/
public DataType getType(final String name) {
return getType(getFirstIdx(name));
}
/**
* Returns the keyspace of the {@code i}th column in these metadata.
*
* @param i The index of the column in these metadata (the first column is 0).
* @return The keyspace of the {@code i}th column in these metadata.
* @throws IndexOutOfBoundsException if {@code i < 0} or {@code i >= size()}.
*/
public String getKeyspace(final int i) {
return this.byIdx[i].keyspace;
}
/**
* Returns the keyspace of the first occurrence of the column {@code name} in these metadata.
*
* @param name The name of the column.
* @return The keyspace of (the first occurrence of) the column {@code name} in these metadata.
* @throws IllegalArgumentException if {@code name} is not in these metadata.
*/
public String getKeyspace(final String name) {
return getKeyspace(getFirstIdx(name));
}
/**
* Returns the table name of the {@code i}th column in these metadata.
*
* @param i The index of the column in these metadata (the first column is 0).
* @return The table name of the {@code i}th column in these metadata.
* @throws IndexOutOfBoundsException if {@code i < 0} or {@code i >= size()}.
*/
public String getTable(final int i) {
return this.byIdx[i].table;
}
/**
* Returns the table name of the first occurrence of the column {@code name} in these metadata.
*
* @param name The name of the column.
* @return The table name of (the first occurrence of) the column {@code name} in these metadata.
* @throws IllegalArgumentException if {@code name} is not in these metadata.
*/
public String getTable(final String name) {
return getTable(getFirstIdx(name));
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder();
sb.append("Columns[");
for (int i = 0; i < size(); i++) {
if (i != 0) {
sb.append(", ");
}
final Definition def = byIdx[i];
sb.append(def.name).append('(').append(def.type).append(')');
}
sb.append(']');
return sb.toString();
}
int findFirstIdx(final String name) {
final int[] indexes = findAllIdx(name);
if (indexes == null) {
return -1;
} else {
return indexes[0];
}
}
int[] findAllIdx(final String name) {
boolean caseSensitive = false;
String columnName = name;
if (name.length() >= 2 && name.charAt(0) == '"' && name.charAt(name.length() - 1) == '"') {
columnName = name.substring(1, name.length() - 1);
caseSensitive = true;
}
final int[] indexes = this.byName.get(columnName.toLowerCase());
if (!caseSensitive || indexes == null) {
return indexes;
}
// First, optimistic and assume all are matching.
int nbMatch = 0;
for (final int index : indexes) {
if (columnName.equals(this.byIdx[index].name)) {
nbMatch++;
}
}
if (nbMatch == indexes.length) {
return indexes;
}
final int[] result = new int[nbMatch];
int j = 0;
for (final int idx : indexes) {
if (columnName.equals(this.byIdx[idx].name)) {
result[j++] = idx;
}
}
return result;
}
int[] getAllIdx(final String name) {
final int[] indexes = findAllIdx(name);
if (indexes == null) {
throw new IllegalArgumentException(name + " is not a column defined in these metadata.");
}
return indexes;
}
int getFirstIdx(final String name) {
return getAllIdx(name)[0];
}
/**
* A column definition.
*/
public static class Definition {
private final String keyspace;
private final String table;
private final String name;
private final DataType type;
/**
* Constructor.
*
* @param keyspace The Cassandra keyspace.
* @param table The Cassandra table name.
* @param name The column name.
* @param type The column type.
*/
public Definition(final String keyspace, final String table, final String name, final DataType type) {
this.keyspace = keyspace;
this.table = table;
this.name = name;
this.type = type;
}
/**
* Builds a column definition in an anonymous table (useful for metadata result sets built programmatically).
*
* @param name The column name.
* @param type The column type.
* @return A new column definition instance.
*/
public static Definition buildDefinitionInAnonymousTable(final String name, final DataType type) {
return new Definition(StringUtils.EMPTY, StringUtils.EMPTY, name, type);
}
/**
* Gets the name of the keyspace this column is part of.
*
* @return The name of the keyspace this column is part of.
*/
public String getKeyspace() {
return this.keyspace;
}
/**
* Gets the name of the table this column is part of.
*
* @return The name of the table this column is part of.
*/
public String getTable() {
return this.table;
}
/**
* Gets the name of the column.
*
* @return The name of the column.
*/
public String getName() {
return this.name;
}
/**
* Gets the type of the column.
*
* @return The type of the column.
*/
public DataType getType() {
return this.type;
}
@Override
public final int hashCode() {
return Arrays.hashCode(new Object[]{this.keyspace, this.table, this.name, this.type});
}
@Override
public final boolean equals(final Object o) {
if (!(o instanceof Definition)) {
return false;
}
final Definition other = (Definition) o;
return this.keyspace.equals(other.keyspace)
&& this.table.equals(other.table)
&& this.name.equals(other.name)
&& this.type.equals(other.type);
}
}
}