com.akamai.netstorage

Class Utils

java.lang.Object

com.akamai.netstorage.Utils

public class Utils
extends Object

General utility functions needed to implement the HTTP SDK. Many of these functions are also available as standard parts of other libraries, but this package strives to operate without any external dependencies.

Author:

colinb@akamai.com (Colin Bendell)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Utils.HashAlgorithm An enum of the hash algorithms supported by computeHash(java.io.InputStream, com.akamai.netstorage.Utils.HashAlgorithm) Currently supported hashes include MD5; SHA1; SHA256 The string representation matches the java MessageDigest.getInstance(String) canonical names.
static class	Utils.KeyedHashAlgorithm An enum of the keyed-hash algorithms supported by computeKeyedHash(byte[], String, com.akamai.netstorage.Utils.KeyedHashAlgorithm) Currently supported hashes include HMAC-MD5; HMAC-SHA1; HMAC-SHA256 The string representation matches the java Mac.getInstance(String)} cononical names.

Constructor Summary

Constructors

Constructor and Description
Utils()

Method Summary

Modifier and Type	Method and Description
static byte[]	computeHash(InputStream srcStream, Utils.HashAlgorithm hashAlgorithm) Computes the hash of a given InputStream.
static byte[]	computeKeyedHash(byte[] data, String key, Utils.KeyedHashAlgorithm hashType) Computes the HMAC hash of a given byte[].
static String	convertMapAsQueryParams(Map<String,String> data) Convert Map<String, String> into a name=value query params string.
static Map<String,String>	convertObjectAsMap(Object srcObj) Convert a POJO object into a primitive name-value pair or Map<String, String>.
static String	encodeBase64(byte[] value) Base64-encode a byte array.
static String	encodeHex(byte[] value) Hex encoding wrapper for a byte array.
static Properties	readIniSection(File srcFile, String section) Convenience method to read Properties in Ini format
static Properties	readIniSection(InputStream inputStream, String section) Convenience method to read Properties in Ini format
static void	readToEnd(InputStream stream) Simple utility to read to the end of a stream when you don't particularly care for the contents of the stream.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Utils

public Utils()

Method Detail

computeHash

public static byte[] computeHash(InputStream srcStream,
                                 Utils.HashAlgorithm hashAlgorithm)
                          throws IOException

Computes the hash of a given InputStream. This is a wrapper over the MessageDigest crypto functions.

Parameters:

srcStream - a source stream. This will be wrapped in a BufferedInputStream in case the source stream is not buffered

hashAlgorithm - the Algorithm to use to compute the hash

Returns:

a byte[] representation of the hash. If the InputStream is a null object then null will be returned. If the InputStream is empty an empty byte[] {} will be returned.

Throws:

IOException - If there is a problem with the InputStream during the compute of the hash

computeKeyedHash

public static byte[] computeKeyedHash(byte[] data,
                                      String key,
                                      Utils.KeyedHashAlgorithm hashType)

Computes the HMAC hash of a given byte[]. This is a wrapper over the Mac crypto functions.

Parameters:

data - byte[] of content to hash

key - secret key to salt the hash

hashType - determines which alogirthm to use. The recommendation is to use HMAC-SHA256

Returns:

a byte[] presenting the HMAC hash of the source data.

encodeHex

public static String encodeHex(byte[] value)

Hex encoding wrapper for a byte array. The output will be 2 character padded string in lower case.

Parameters:

value - a byte array to encode. The assumption is that the string to encode is small enough to be held in memory without streaming the encoding

Returns:

a 2 character zero padded string in lower case

encodeBase64

public static String encodeBase64(byte[] value)

Base64-encode a byte array.

Parameters:

value - byte array to encode.

Returns:

Encoded string.

convertObjectAsMap

public static Map<String,String> convertObjectAsMap(Object srcObj)

Convert a POJO object into a primitive name-value pair or Map<String, String>. Field names or parameter names are used to construct the output

Parameters:

srcObj - source pojo object

Returns:

a name-value presentation of the object

convertMapAsQueryParams

public static String convertMapAsQueryParams(Map<String,String> data)

Convert Map<String, String> into a name=value query params string.

NB: This uses URLEncoding - not URI Encoding for escaping name and values. This shouldn't be an issue for most uses of this function for the Netstorage API, but could impact non-ascii usernames in the future.

Parameters:

data - a Key-Value map

Returns:

a query params encoded string in the form of name=value&name2=value2...

readToEnd

public static void readToEnd(InputStream stream)
                      throws IOException

Simple utility to read to the end of a stream when you don't particularly care for the contents of the stream. This is useful when you want to re-use URLConnections but need to make sure that the streams are properly flushed.

Parameters:

stream - the open InputStream

Throws:

IOException - inputs tream read exception

readIniSection

public static Properties readIniSection(File srcFile,
                                        String section)
                                 throws IOException

Convenience method to read Properties in Ini format

Parameters:

srcFile - File of the inputstream

section - the ini [section] name to read the properties from

Returns:

the Properties for the section

Throws:

IOException - inputs tream read exception

readIniSection

public static Properties readIniSection(InputStream inputStream,
                                        String section)
                                 throws IOException

Convenience method to read Properties in Ini format

Parameters:

inputStream - stream

section - the ini [section] name to read the properties from

Returns:

the Properties for the section

Throws:

IOException - inputs tream read exception