/*
* Copyright (c) 2002-2012 Alibaba Group Holding Limited.
* All rights reserved.
*
* 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 com.alibaba.citrus.service.resource.support;
import static com.alibaba.citrus.util.Assert.*;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import com.alibaba.citrus.service.resource.Resource;
import com.alibaba.citrus.util.ToStringBuilder;
/**
* 代表一个<code>byte[]</code>的资源。
*
* @author Michael Zhou
*/
public class ByteArrayResource implements Resource {
private final byte[] bytes;
private final int offset;
private final int length;
/** 创建一个<code>ByteArrayResource</code>。 */
public ByteArrayResource(byte[] bytes) {
this(assertNotNull(bytes, "bytes"), 0, bytes.length);
}
/** 创建一个<code>ByteArrayResource</code>。 */
public ByteArrayResource(byte[] bytes, int offset, int length) {
this.bytes = assertNotNull(bytes, "bytes");
if (offset < 0 || offset + length > bytes.length || length < 0) {
throw new IndexOutOfBoundsException();
}
this.offset = offset;
this.length = length;
}
/** 取得资源的<code>URL</code>。 */
public URL getURL() {
return null;
}
/** 取得资源的<code>File</code>。 */
public File getFile() {
return null;
}
/** 取得资源的<code>InputStream</code>。 */
public InputStream getInputStream() throws IOException {
return new ByteArrayInputStream(bytes, offset, length);
}
/** 判断资源是否存在。 */
public boolean exists() {
return bytes != null;
}
/**
* 取得资源最近修改时间。
*
* @return 资源的最近修改时间，如果不支持，则返回<code>0</code>
*/
public long lastModified() {
return 0;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + length;
result = prime * result + hashCode(bytes, offset, length);
return result;
}
private static int hashCode(byte bytes[], int offset, int length) {
int result = 1;
for (int i = offset, end = offset + length; i < end; i++) {
result = 31 * result + bytes[i];
}
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
ByteArrayResource other = (ByteArrayResource) obj;
if (length != other.length) {
return false;
}
for (int i = offset, j = other.offset, end = offset + length; i < end; i++, j++) {
if (bytes[i] != other.bytes[j]) {
return false;
}
}
return true;
}
/** 将resource转换成字符串表示。 */
@Override
public String toString() {
ToStringBuilder buf = new ToStringBuilder();
buf.append(getClass().getSimpleName());
buf.appendArray(bytes, offset, 128); // 最多打印128个字节
return buf.toString();
}
}