com.firefly.utils.io.EncodedResource Maven / Gradle / Ivy
package com.firefly.utils.io;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.nio.charset.Charset;
import com.firefly.utils.Assert;
import com.firefly.utils.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}.
*
* @see java.io.Reader
* @see java.nio.charset.Charset
*/
public class EncodedResource implements InputStreamSource {
private final Resource resource;
private final String encoding;
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, 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, Charset charset) {
this(resource, null, charset);
}
private EncodedResource(Resource resource, String encoding, 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.
*/
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.
*/
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 a {@code java.io.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(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();
}
}