org.springframework.core.io.support.EncodedResource Maven / Gradle / Ivy
/*
* Copyright 2002-2014 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
*
* http://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.Resource;
import org.springframework.util.Assert;
import org.springframework.util.ObjectUtils;
/**
* Holder that combines a {@link org.springframework.core.io.Resource}
* with a specific encoding to be used for reading from the resource.
*
* Used as argument for operations that support to read content with
* a specific encoding (usually through a {@code java.io.Reader}).
*
* @author Juergen Hoeller
* @since 1.2.6
* @see java.io.Reader
*/
public class EncodedResource {
private final Resource resource;
private String encoding;
private Charset charset;
/**
* Create a new EncodedResource for the given Resource,
* not specifying a specific encoding.
* @param resource the Resource to hold
*/
public EncodedResource(Resource resource) {
Assert.notNull(resource, "Resource must not be null");
this.resource = resource;
}
/**
* Create a new EncodedResource for the given Resource,
* using the specified encoding.
* @param resource the Resource to hold
* @param encoding the encoding to use for reading from the resource
*/
public EncodedResource(Resource resource, String encoding) {
Assert.notNull(resource, "Resource must not be null");
this.resource = resource;
this.encoding = encoding;
}
/**
* Create a new EncodedResource for the given Resource,
* using the specified encoding.
* @param resource the Resource to hold
* @param charset the charset to use for reading from the resource
*/
public EncodedResource(Resource resource, Charset charset) {
Assert.notNull(resource, "Resource must not be null");
this.resource = resource;
this.charset = charset;
}
/**
* Return the Resource held.
*/
public final Resource getResource() {
return this.resource;
}
/**
* Return the encoding to use for reading from the resource,
* or {@code null} if none specified.
*/
public final String getEncoding() {
return this.encoding;
}
/**
* Return the charset to use for reading from the resource,
* or {@code null} if none specified.
*/
public final Charset getCharset() {
return this.charset;
}
/**
* Determine whether a {@link Reader} is required as opposed to an {@link InputStream},
* i.e. whether an encoding or a 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 encoding (if any).
* @throws IOException if opening the Reader failed
* @see #requiresReader()
*/
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 java.io.InputStream} for the specified resource,
* typically assuming that there is no specific encoding to use.
* @throws IOException if opening the InputStream failed
* @see #requiresReader()
*/
public InputStream getInputStream() throws IOException {
return this.resource.getInputStream();
}
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (obj instanceof EncodedResource) {
EncodedResource otherRes = (EncodedResource) obj;
return (this.resource.equals(otherRes.resource) &&
ObjectUtils.nullSafeEquals(this.encoding, otherRes.encoding));
}
return false;
}
@Override
public int hashCode() {
return this.resource.hashCode();
}
@Override
public String toString() {
return this.resource.toString();
}
}