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Utility classes for Jetty
//
// ========================================================================
// Copyright (c) 1995-2021 Mort Bay Consulting Pty Ltd and others.
//
// This program and the accompanying materials are made available under the
// terms of the Eclipse Public License v. 2.0 which is available at
// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
// which is available at https://www.apache.org/licenses/LICENSE-2.0.
//
// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
// ========================================================================
//
package org.eclipse.jetty.util;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
/**
* A container for name/value pairs, known as fields.
* A {@link Field} is composed of a name string that can be case-sensitive
* or case-insensitive (by specifying the option at the constructor) and
* of a case-sensitive set of value strings.
* The implementation of this class is not thread safe.
*/
public class Fields implements Iterable
{
private final boolean caseSensitive;
private final Map fields;
/**
* Creates an empty, modifiable, case insensitive {@link Fields} instance.
*
* @see #Fields(Fields, boolean)
*/
public Fields()
{
this(false);
}
/**
* Creates an empty, modifiable, case insensitive {@link Fields} instance.
*
* @param caseSensitive whether this {@link Fields} instance must be case sensitive
* @see #Fields(Fields, boolean)
*/
public Fields(boolean caseSensitive)
{
this.caseSensitive = caseSensitive;
fields = new LinkedHashMap<>();
}
/**
* Creates a {@link Fields} instance by copying the fields from the given
* {@link Fields} and making it (im)mutable depending on the given {@code immutable} parameter
*
* @param original the {@link Fields} to copy fields from
* @param immutable whether this instance is immutable
*/
public Fields(Fields original, boolean immutable)
{
this.caseSensitive = original.caseSensitive;
Map copy = new LinkedHashMap<>();
copy.putAll(original.fields);
fields = immutable ? Collections.unmodifiableMap(copy) : copy;
}
@Override
public boolean equals(Object obj)
{
if (this == obj)
return true;
if (obj == null || getClass() != obj.getClass())
return false;
Fields that = (Fields)obj;
if (getSize() != that.getSize())
return false;
if (caseSensitive != that.caseSensitive)
return false;
for (Map.Entry entry : fields.entrySet())
{
String name = entry.getKey();
Field value = entry.getValue();
if (!value.equals(that.get(name), caseSensitive))
return false;
}
return true;
}
@Override
public int hashCode()
{
return fields.hashCode();
}
/**
* @return a set of field names
*/
public Set getNames()
{
Set result = new LinkedHashSet<>();
for (Field field : fields.values())
{
result.add(field.getName());
}
return result;
}
private String normalizeName(String name)
{
return caseSensitive ? name : name.toLowerCase(Locale.ENGLISH);
}
/**
* @param name the field name
* @return the {@link Field} with the given name, or null if no such field exists
*/
public Field get(String name)
{
return fields.get(normalizeName(name));
}
/**
* Inserts or replaces the given name/value pair as a single-valued {@link Field}.
*
* @param name the field name
* @param value the field value
*/
public void put(String name, String value)
{
// Preserve the case for the field name
Field field = new Field(name, value);
fields.put(normalizeName(name), field);
}
/**
* Inserts or replaces the given {@link Field}, mapped to the {@link Field#getName() field's name}
*
* @param field the field to put
*/
public void put(Field field)
{
if (field != null)
fields.put(normalizeName(field.getName()), field);
}
/**
* Adds the given value to a field with the given name,
* creating a {@link Field} is none exists for the given name.
*
* @param name the field name
* @param value the field value to add
*/
public void add(String name, String value)
{
String key = normalizeName(name);
Field field = fields.get(key);
if (field == null)
{
// Preserve the case for the field name
field = new Field(name, value);
fields.put(key, field);
}
else
{
field = new Field(field.getName(), field.getValues(), value);
fields.put(key, field);
}
}
/**
* Removes the {@link Field} with the given name
*
* @param name the name of the field to remove
* @return the removed field, or null if no such field existed
*/
public Field remove(String name)
{
return fields.remove(normalizeName(name));
}
/**
* Empties this {@link Fields} instance from all fields
*
* @see #isEmpty()
*/
public void clear()
{
fields.clear();
}
/**
* @return whether this {@link Fields} instance is empty
*/
public boolean isEmpty()
{
return fields.isEmpty();
}
/**
* @return the number of fields
*/
public int getSize()
{
return fields.size();
}
/**
* @return an iterator over the {@link Field}s present in this instance
*/
@Override
public Iterator iterator()
{
return fields.values().iterator();
}
@Override
public String toString()
{
return fields.toString();
}
/**
* A named list of string values.
* The name is case-sensitive and there must be at least one value.
*/
public static class Field
{
private final String name;
private final List values;
public Field(String name, String value)
{
this(name, Collections.singletonList(value));
}
private Field(String name, List values, String... moreValues)
{
this.name = name;
List list = new ArrayList<>(values.size() + moreValues.length);
list.addAll(values);
list.addAll(Arrays.asList(moreValues));
this.values = Collections.unmodifiableList(list);
}
@SuppressWarnings("ReferenceEquality")
public boolean equals(Field that, boolean caseSensitive)
{
if (this == that)
return true;
if (that == null)
return false;
if (caseSensitive)
return equals(that);
return name.equalsIgnoreCase(that.name) && values.equals(that.values);
}
@Override
public boolean equals(Object obj)
{
if (this == obj)
return true;
if (obj == null || getClass() != obj.getClass())
return false;
Field that = (Field)obj;
return name.equals(that.name) && values.equals(that.values);
}
@Override
public int hashCode()
{
int result = name.hashCode();
result = 31 * result + values.hashCode();
return result;
}
/**
* @return the field's name
*/
public String getName()
{
return name;
}
/**
* @return the first field's value
*/
public String getValue()
{
return values.get(0);
}
/**
* Attempts to convert the result of {@link #getValue()} to an integer,
* returning it if the conversion is successful; returns null if the
* result of {@link #getValue()} is null.
*
* @return the result of {@link #getValue()} converted to an integer, or null
* @throws NumberFormatException if the conversion fails
*/
public Integer getValueAsInt()
{
final String value = getValue();
return value == null ? null : (Integer)Integer.parseInt(value);
}
/**
* @return the field's values
*/
public List getValues()
{
return values;
}
/**
* @return whether the field has multiple values
*/
public boolean hasMultipleValues()
{
return values.size() > 1;
}
@Override
public String toString()
{
return String.format("%s=%s", name, values);
}
}
}