001/* 002 * oauth2-oidc-sdk 003 * 004 * Copyright 2012-2016, Connect2id Ltd and contributors. 005 * 006 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use 007 * this file except in compliance with the License. You may obtain a copy of the 008 * License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software distributed 013 * under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR 014 * CONDITIONS OF ANY KIND, either express or implied. See the License for the 015 * specific language governing permissions and limitations under the License. 016 */ 017 018package com.nimbusds.oauth2.sdk.id; 019 020 021import com.nimbusds.oauth2.sdk.util.StringUtils; 022import net.jcip.annotations.Immutable; 023 024 025/** 026 * Opaque value used to maintain state between a request and a callback. Also 027 * serves as a protection against XSRF attacks, among other uses. 028 */ 029@Immutable 030public final class State extends Identifier { 031 032 033 /** 034 * Creates a new state with the specified value. 035 * 036 * @param value The state value. Must not be {@code null} or empty 037 * string. 038 */ 039 public State(final String value) { 040 041 super(value); 042 } 043 044 045 /** 046 * Creates a new state with a randomly generated value of the specified 047 * byte length, Base64URL-encoded. 048 * 049 * @param byteLength The byte length of the value to generate. Must be 050 * greater than one. 051 */ 052 public State(final int byteLength) { 053 054 super(byteLength); 055 } 056 057 058 /** 059 * Creates a new state with a randomly generated 256-bit (32-byte) 060 * value, Base64URL-encoded. 061 */ 062 public State() { 063 064 super(); 065 } 066 067 068 @Override 069 public boolean equals(final Object object) { 070 071 return object instanceof State && 072 this.toString().equals(object.toString()); 073 } 074 075 076 /** 077 * Parses a state from the specified string. 078 * 079 * @param s The string to parse, {@code null} or empty if no state is 080 * specified. 081 * 082 * @return The state, {@code null} if the parsed string was 083 * {@code null} or empty. 084 */ 085 public static State parse(final String s) { 086 087 if (StringUtils.isBlank(s)) 088 return null; 089 090 return new State(s); 091 } 092}