nl.tweeenveertig.openstack.headers.object.range.AbstractRange Maven / Gradle / Ivy

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Java Client library for OpenStack Storage (Swift)

There is a newer version: 0.7.0

package nl.tweeenveertig.openstack.headers.object.range;

import nl.tweeenveertig.openstack.headers.Header;

import java.util.Arrays;

/**
 * Offers the option to return not the entire object, but only a designated part. The various options are
 * 
 *     {@link ExcludeStartRange} - take the object starting from position x until the end

 *     {@link FirstPartRange} - take the first x bytes of the object, starting at position 0

 *     {@link MidPartRange} - take the object from offset for a certain length

 *     {@link LastPartRange} - take the last x bytes, starting at the end minus x until the end

 * 

 * Also see: http://docs.openstack.org/api/openstack-object-storage/1.0/content/retrieve-object.html
 */
public abstract class AbstractRange extends Header {

    public String RANGE_HEADER_NAME = "Range";
    public String RANGE_HEADER_VALUE_PREFIX = "bytes=";

    protected int offset;

    protected int length;

    protected AbstractRange(int offset, int length) {
        this.offset = offset;
        this.length = length;
    }

    public String getHeaderValue() {
        return
            RANGE_HEADER_VALUE_PREFIX+
                (offset >= 0 ? Long.toString(offset) : "") +
                "-" +
                (length >= 0 ? Long.toString(length) : "");
    }

    public String getHeaderName() {
        return RANGE_HEADER_NAME;
    }

    public abstract int getFrom(int byteArrayLength);

    public abstract int getTo(int byteArrayLength);

    public byte[] copy(byte[] original) {
        return Arrays.copyOfRange(original, getFrom(original.length), getTo(original.length));
    }
}