org.springframework.core.io.support.EncodedResource Maven / Gradle / Ivy
/*
* Copyright 2002-2017 the original author or authors.
*
* 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
*
* https://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 org.springframework.core.io.support;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.nio.charset.Charset;
import org.springframework.core.io.InputStreamSource;
import org.springframework.core.io.Resource;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ObjectUtils;
/**
* Holder that combines a {@link Resource} descriptor with a specific encoding
* or {@code Charset} to be used for reading from the resource.
*
* Used as an argument for operations that support reading content with
* a specific encoding, typically via a {@code java.io.Reader}.
*
* @author Juergen Hoeller
* @author Sam Brannen
* @since 1.2.6
* @see Resource#getInputStream()
* @see java.io.Reader
* @see java.nio.charset.Charset
*/
public class EncodedResource implements InputStreamSource {
private final Resource resource;
@Nullable
private final String encoding;
@Nullable
private final Charset charset;
/**
* Create a new {@code EncodedResource} for the given {@code Resource},
* not specifying an explicit encoding or {@code Charset}.
* @param resource the {@code Resource} to hold (never {@code null})
*/
public EncodedResource(Resource resource) {
this(resource, null, null);
}
/**
* Create a new {@code EncodedResource} for the given {@code Resource},
* using the specified {@code encoding}.
* @param resource the {@code Resource} to hold (never {@code null})
* @param encoding the encoding to use for reading from the resource
*/
public EncodedResource(Resource resource, @Nullable String encoding) {
this(resource, encoding, null);
}
/**
* Create a new {@code EncodedResource} for the given {@code Resource},
* using the specified {@code Charset}.
* @param resource the {@code Resource} to hold (never {@code null})
* @param charset the {@code Charset} to use for reading from the resource
*/
public EncodedResource(Resource resource, @Nullable Charset charset) {
this(resource, null, charset);
}
private EncodedResource(Resource resource, @Nullable String encoding, @Nullable Charset charset) {
super();
Assert.notNull(resource, "Resource must not be null");
this.resource = resource;
this.encoding = encoding;
this.charset = charset;
}
/**
* Return the {@code Resource} held by this {@code EncodedResource}.
*/
public final Resource getResource() {
return this.resource;
}
/**
* Return the encoding to use for reading from the {@linkplain #getResource() resource},
* or {@code null} if none specified.
*/
@Nullable
public final String getEncoding() {
return this.encoding;
}
/**
* Return the {@code Charset} to use for reading from the {@linkplain #getResource() resource},
* or {@code null} if none specified.
*/
@Nullable
public final Charset getCharset() {
return this.charset;
}
/**
* Determine whether a {@link Reader} is required as opposed to an {@link InputStream},
* i.e. whether an {@linkplain #getEncoding() encoding} or a {@link #getCharset() Charset}
* has been specified.
* @see #getReader()
* @see #getInputStream()
*/
public boolean requiresReader() {
return (this.encoding != null || this.charset != null);
}
/**
* Open a {@code java.io.Reader} for the specified resource, using the specified
* {@link #getCharset() Charset} or {@linkplain #getEncoding() encoding}
* (if any).
* @throws IOException if opening the Reader failed
* @see #requiresReader()
* @see #getInputStream()
*/
public Reader getReader() throws IOException {
if (this.charset != null) {
return new InputStreamReader(this.resource.getInputStream(), this.charset);
}
else if (this.encoding != null) {
return new InputStreamReader(this.resource.getInputStream(), this.encoding);
}
else {
return new InputStreamReader(this.resource.getInputStream());
}
}
/**
* Open an {@code InputStream} for the specified resource, ignoring any specified
* {@link #getCharset() Charset} or {@linkplain #getEncoding() encoding}.
* @throws IOException if opening the InputStream failed
* @see #requiresReader()
* @see #getReader()
*/
@Override
public InputStream getInputStream() throws IOException {
return this.resource.getInputStream();
}
@Override
public boolean equals(@Nullable Object other) {
if (this == other) {
return true;
}
if (!(other instanceof EncodedResource)) {
return false;
}
EncodedResource otherResource = (EncodedResource) other;
return (this.resource.equals(otherResource.resource) &&
ObjectUtils.nullSafeEquals(this.charset, otherResource.charset) &&
ObjectUtils.nullSafeEquals(this.encoding, otherResource.encoding));
}
@Override
public int hashCode() {
return this.resource.hashCode();
}
@Override
public String toString() {
return this.resource.toString();
}
}