001/* 002 * Copyright 2002-2017 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.core.io.support; 018 019import java.io.IOException; 020import java.io.InputStream; 021import java.io.InputStreamReader; 022import java.io.Reader; 023import java.nio.charset.Charset; 024 025import org.springframework.core.io.InputStreamSource; 026import org.springframework.core.io.Resource; 027import org.springframework.lang.Nullable; 028import org.springframework.util.Assert; 029import org.springframework.util.ObjectUtils; 030 031/** 032 * Holder that combines a {@link Resource} descriptor with a specific encoding 033 * or {@code Charset} to be used for reading from the resource. 034 * 035 * <p>Used as an argument for operations that support reading content with 036 * a specific encoding, typically via a {@code java.io.Reader}. 037 * 038 * @author Juergen Hoeller 039 * @author Sam Brannen 040 * @since 1.2.6 041 * @see Resource#getInputStream() 042 * @see java.io.Reader 043 * @see java.nio.charset.Charset 044 */ 045public class EncodedResource implements InputStreamSource { 046 047 private final Resource resource; 048 049 @Nullable 050 private final String encoding; 051 052 @Nullable 053 private final Charset charset; 054 055 056 /** 057 * Create a new {@code EncodedResource} for the given {@code Resource}, 058 * not specifying an explicit encoding or {@code Charset}. 059 * @param resource the {@code Resource} to hold (never {@code null}) 060 */ 061 public EncodedResource(Resource resource) { 062 this(resource, null, null); 063 } 064 065 /** 066 * Create a new {@code EncodedResource} for the given {@code Resource}, 067 * using the specified {@code encoding}. 068 * @param resource the {@code Resource} to hold (never {@code null}) 069 * @param encoding the encoding to use for reading from the resource 070 */ 071 public EncodedResource(Resource resource, @Nullable String encoding) { 072 this(resource, encoding, null); 073 } 074 075 /** 076 * Create a new {@code EncodedResource} for the given {@code Resource}, 077 * using the specified {@code Charset}. 078 * @param resource the {@code Resource} to hold (never {@code null}) 079 * @param charset the {@code Charset} to use for reading from the resource 080 */ 081 public EncodedResource(Resource resource, @Nullable Charset charset) { 082 this(resource, null, charset); 083 } 084 085 private EncodedResource(Resource resource, @Nullable String encoding, @Nullable Charset charset) { 086 super(); 087 Assert.notNull(resource, "Resource must not be null"); 088 this.resource = resource; 089 this.encoding = encoding; 090 this.charset = charset; 091 } 092 093 094 /** 095 * Return the {@code Resource} held by this {@code EncodedResource}. 096 */ 097 public final Resource getResource() { 098 return this.resource; 099 } 100 101 /** 102 * Return the encoding to use for reading from the {@linkplain #getResource() resource}, 103 * or {@code null} if none specified. 104 */ 105 @Nullable 106 public final String getEncoding() { 107 return this.encoding; 108 } 109 110 /** 111 * Return the {@code Charset} to use for reading from the {@linkplain #getResource() resource}, 112 * or {@code null} if none specified. 113 */ 114 @Nullable 115 public final Charset getCharset() { 116 return this.charset; 117 } 118 119 /** 120 * Determine whether a {@link Reader} is required as opposed to an {@link InputStream}, 121 * i.e. whether an {@linkplain #getEncoding() encoding} or a {@link #getCharset() Charset} 122 * has been specified. 123 * @see #getReader() 124 * @see #getInputStream() 125 */ 126 public boolean requiresReader() { 127 return (this.encoding != null || this.charset != null); 128 } 129 130 /** 131 * Open a {@code java.io.Reader} for the specified resource, using the specified 132 * {@link #getCharset() Charset} or {@linkplain #getEncoding() encoding} 133 * (if any). 134 * @throws IOException if opening the Reader failed 135 * @see #requiresReader() 136 * @see #getInputStream() 137 */ 138 public Reader getReader() throws IOException { 139 if (this.charset != null) { 140 return new InputStreamReader(this.resource.getInputStream(), this.charset); 141 } 142 else if (this.encoding != null) { 143 return new InputStreamReader(this.resource.getInputStream(), this.encoding); 144 } 145 else { 146 return new InputStreamReader(this.resource.getInputStream()); 147 } 148 } 149 150 /** 151 * Open an {@code InputStream} for the specified resource, ignoring any specified 152 * {@link #getCharset() Charset} or {@linkplain #getEncoding() encoding}. 153 * @throws IOException if opening the InputStream failed 154 * @see #requiresReader() 155 * @see #getReader() 156 */ 157 @Override 158 public InputStream getInputStream() throws IOException { 159 return this.resource.getInputStream(); 160 } 161 162 163 @Override 164 public boolean equals(@Nullable Object other) { 165 if (this == other) { 166 return true; 167 } 168 if (!(other instanceof EncodedResource)) { 169 return false; 170 } 171 EncodedResource otherResource = (EncodedResource) other; 172 return (this.resource.equals(otherResource.resource) && 173 ObjectUtils.nullSafeEquals(this.charset, otherResource.charset) && 174 ObjectUtils.nullSafeEquals(this.encoding, otherResource.encoding)); 175 } 176 177 @Override 178 public int hashCode() { 179 return this.resource.hashCode(); 180 } 181 182 @Override 183 public String toString() { 184 return this.resource.toString(); 185 } 186 187}