001/* 002 * nimbus-jose-jwt 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.jose.util; 019 020 021import java.io.*; 022import java.nio.charset.Charset; 023 024 025/** 026 * Input / output utilities. 027 * 028 * @author Vladimir Dzhuvinov 029 * @version 2020-02-23 030 */ 031public class IOUtils { 032 033 034 /** 035 * Reads the specified input stream into a string using UTF-8 character 036 * set encoding. 037 * 038 * @param stream The input stream. Must not be {@code null}. 039 * 040 * @return The string. 041 * 042 * @throws IOException If an input exception is encountered. 043 */ 044 public static String readInputStreamToString(final InputStream stream) 045 throws IOException { 046 047 return readInputStreamToString(stream, StandardCharset.UTF_8); 048 } 049 050 051 /** 052 * Reads the specified input stream into a string. 053 * 054 * @param stream The input stream. Must not be {@code null}. 055 * @param charset The expected character set. Must not be {@code null}. 056 * 057 * @return The string. 058 * 059 * @throws IOException If an input exception is encountered. 060 */ 061 public static String readInputStreamToString(final InputStream stream, final Charset charset) 062 throws IOException { 063 064 final int bufferSize = 1024; 065 final char[] buffer = new char[bufferSize]; 066 final StringBuilder out = new StringBuilder(); 067 068 Reader in = new InputStreamReader(stream, charset); 069 try { 070 while (true) { 071 int rsz = in.read(buffer, 0, buffer.length); 072 if (rsz < 0) 073 break; 074 out.append(buffer, 0, rsz); 075 } 076 return out.toString(); 077 } finally { 078 in.close(); 079 } 080 } 081 082 083 /** 084 * Reads the content of the specified file into a string using UTF-8 085 * character set encoding. 086 * 087 * @param file The file. Must not be {@code null}. 088 * 089 * @return The string. 090 * 091 * @throws IOException If an input exception is encountered. 092 */ 093 public static String readFileToString(final File file) 094 throws IOException { 095 096 return readInputStreamToString(new FileInputStream(file)); 097 } 098 099 100 /** 101 * Reads the content of the specified file into a string. 102 * 103 * @param file The file. Must not be {@code null}. 104 * @param charset The expected character set. Must not be {@code null}. 105 * 106 * @return The string. 107 * 108 * @throws IOException If an input exception is encountered. 109 */ 110 public static String readFileToString(final File file, final Charset charset) 111 throws IOException { 112 113 return readInputStreamToString(new FileInputStream(file), charset); 114 } 115 116 117 /** 118 * Prevents public instantiation. 119 */ 120 private IOUtils() {} 121}