/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.shiro.util;
import java.io.File;
import java.io.InputStream;
/**
* A {@code ByteSource} wraps a byte array and provides additional encoding operations. Most users will find the
* {@link Util} inner class sufficient to construct ByteSource instances.
*
* @since 1.0
*/
public interface ByteSource {
/**
* Returns the wrapped byte array.
*
* @return the wrapped byte array.
*/
byte[] getBytes();
/**
* Returns the <a href="http://en.wikipedia.org/wiki/Hexadecimal">Hex</a>-formatted String representation of the
* underlying wrapped byte array.
*
* @return the <a href="http://en.wikipedia.org/wiki/Hexadecimal">Hex</a>-formatted String representation of the
* underlying wrapped byte array.
*/
String toHex();
/**
* Returns the <a href="http://en.wikipedia.org/wiki/Base64">Base 64</a>-formatted String representation of the
* underlying wrapped byte array.
*
* @return the <a href="http://en.wikipedia.org/wiki/Base64">Base 64</a>-formatted String representation of the
* underlying wrapped byte array.
*/
String toBase64();
/**
* Returns {@code true} if the underlying wrapped byte array is null or empty (zero length), {@code false}
* otherwise.
*
* @return {@code true} if the underlying wrapped byte array is null or empty (zero length), {@code false}
* otherwise.
* @since 1.2
*/
boolean isEmpty();
/**
* Utility class that can construct ByteSource instances. This is slightly nicer than needing to know the
* {@code ByteSource} implementation class to use.
*
* @since 1.2
*/
public static final class Util {
/**
* Returns a new {@code ByteSource} instance representing the specified byte array.
*
* @param bytes the bytes to represent as a {@code ByteSource} instance.
* @return a new {@code ByteSource} instance representing the specified byte array.
*/
public static ByteSource bytes(byte[] bytes) {
return new SimpleByteSource(bytes);
}
/**
* Returns a new {@code ByteSource} instance representing the specified character array's bytes. The byte
* array is obtained assuming {@code UTF-8} encoding.
*
* @param chars the character array to represent as a {@code ByteSource} instance.
* @return a new {@code ByteSource} instance representing the specified character array's bytes.
*/
public static ByteSource bytes(char[] chars) {
return new SimpleByteSource(chars);
}
/**
* Returns a new {@code ByteSource} instance representing the specified string's bytes. The byte
* array is obtained assuming {@code UTF-8} encoding.
*
* @param string the string to represent as a {@code ByteSource} instance.
* @return a new {@code ByteSource} instance representing the specified string's bytes.
*/
public static ByteSource bytes(String string) {
return new SimpleByteSource(string);
}
/**
* Returns a new {@code ByteSource} instance representing the specified ByteSource.
*
* @param source the ByteSource to represent as a new {@code ByteSource} instance.
* @return a new {@code ByteSource} instance representing the specified ByteSource.
*/
public static ByteSource bytes(ByteSource source) {
return new SimpleByteSource(source);
}
/**
* Returns a new {@code ByteSource} instance representing the specified File's bytes.
*
* @param file the file to represent as a {@code ByteSource} instance.
* @return a new {@code ByteSource} instance representing the specified File's bytes.
*/
public static ByteSource bytes(File file) {
return new SimpleByteSource(file);
}
/**
* Returns a new {@code ByteSource} instance representing the specified InputStream's bytes.
*
* @param stream the InputStream to represent as a {@code ByteSource} instance.
* @return a new {@code ByteSource} instance representing the specified InputStream's bytes.
*/
public static ByteSource bytes(InputStream stream) {
return new SimpleByteSource(stream);
}
/**
* Returns {@code true} if the specified object can be easily represented as a {@code ByteSource} using
* the {@link ByteSource.Util}'s default heuristics, {@code false} otherwise.
* <p/>
* This implementation merely returns {@link SimpleByteSource}.{@link SimpleByteSource#isCompatible(Object) isCompatible(source)}.
*
* @param source the object to test to see if it can be easily converted to ByteSource instances using default
* heuristics.
* @return {@code true} if the specified object can be easily represented as a {@code ByteSource} using
* the {@link ByteSource.Util}'s default heuristics, {@code false} otherwise.
*/
public static boolean isCompatible(Object source) {
return SimpleByteSource.isCompatible(source);
}
/**
* Returns a {@code ByteSource} instance representing the specified byte source argument. If the argument
* <em>cannot</em> be easily converted to bytes (as is indicated by the {@link #isCompatible(Object)} JavaDoc),
* this method will throw an {@link IllegalArgumentException}.
*
* @param source the byte-backed instance that should be represented as a {@code ByteSource} instance.
* @return a {@code ByteSource} instance representing the specified byte source argument.
* @throws IllegalArgumentException if the argument <em>cannot</em> be easily converted to bytes
* (as indicated by the {@link #isCompatible(Object)} JavaDoc)
*/
public static ByteSource bytes(Object source) throws IllegalArgumentException {
if (source == null) {
return null;
}
if (!isCompatible(source)) {
String msg = "Unable to heuristically acquire bytes for object of type [" +
source.getClass().getName() + "]. If this type is indeed a byte-backed data type, you might " +
"want to write your own ByteSource implementation to extract its bytes explicitly.";
throw new IllegalArgumentException(msg);
}
if (source instanceof byte[]) {
return bytes((byte[]) source);
} else if (source instanceof ByteSource) {
return (ByteSource) source;
} else if (source instanceof char[]) {
return bytes((char[]) source);
} else if (source instanceof String) {
return bytes((String) source);
} else if (source instanceof File) {
return bytes((File) source);
} else if (source instanceof InputStream) {
return bytes((InputStream) source);
} else {
throw new IllegalStateException("Encountered unexpected byte source. This is a bug - please notify " +
"the Shiro developer list asap (the isCompatible implementation does not reflect this " +
"method's implementation).");
}
}
}
}