org.tsugi.basiclti

Class BasicLTIUtil

java.lang.Object

org.tsugi.basiclti.BasicLTIUtil

public class BasicLTIUtil
extends Object

Some Utility code for IMS LTI http://www.anyexample.com/programming/java /java_simple_class_to_compute_sha_1_hash.xml

Sample Descriptor

 <?xml version="1.0" encoding="UTF-8"?>
 <basic_lti_link xmlns="http://www.imsglobal.org/xsd/imsbasiclti_v1p0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <title>generated by tp+user</title>
   <description>generated by tp+user</description>
   <custom>
         <parameter key="keyname">value</parameter>
   </custom>
   <extensions platform="www.lms.com">
         <parameter key="keyname">value</parameter>
   </extensions>
   <launch_url>url to the basiclti launch URL</launch_url>
   <secure_launch_url>url to the basiclti launch URL</secure_launch_url>
   <icon>url to an icon for this tool (optional)</icon>
   <secure_icon>url to an icon for this tool (optional)</secure_icon>
   <cartridge_icon identifierref="BLTI001_Icon"/>
   <vendor>
         <code>vendor.com</code>
         <name>Vendor Name</name>
         <description>
            This is a Grade Book that supports many column types.
          </description>
         <contact>
           <email>support@vendor.com</email>
         </contact>
         <url>http://www.vendor.com/product</url>
   </vendor>
 </basic_lti_link>
 

Field Summary

Fields

Modifier and Type	Field and Description
static String	ISO_8601_FORMAT

Constructor Summary

Constructors

Constructor and Description
BasicLTIUtil()

Method Summary

Modifier and Type	Method and Description
static String	adaptToCustomPropertyName(String propertyName) A simple utility method which implements the specified semantics of custom properties.
static boolean	checkProperties(Map<String,String> postProp, String url, String method, String oauth_consumer_key, String oauth_consumer_secret) Check if the fields are properly signed
static boolean	checkProperties(Properties postProp, String url, String method, String oauth_consumer_key, String oauth_consumer_secret) Deprecated. See: checkProperties(Map, String, String, String, String)
static Map<String,String>	convertToMap(Properties properties) Simple utility method to help with the migration from Properties to Map.
static Properties	convertToProperties(Map<String,String> map) Deprecated. Should migrate to Map signatures.
static boolean	equals(String str1, String str2) Compares two Strings, returning true if they are equal.
static boolean	equalsIgnoreCase(String str1, String str2) Compares two Strings, returning true if they are equal ignoring the case.
static String	getISO8601() Return a ISO 8601 formatted date
static String	getISO8601(Date date) Return a ISO 8601 formatted date
static String	getOAuthURL(String method, String url, String oauth_consumer_key, String oauth_secret) getOAuthURL - Form a GET request signed by OAuth
static String	getOAuthURL(String method, String url, String oauth_consumer_key, String oauth_secret, String signature) getOAuthURL - Form a GET request signed by OAuth
static String	getRealPath(HttpServletRequest request, String extUrl)
static String	getRealPath(String servletUrl, String extUrl) Simple utility method deal with a request that has the wrong URL when behind a proxy.
static int	getResponseCode(HttpURLConnection connection) getResponseCode - Read the HTTP Response
static String	htmlspecialchars(String input)
static boolean	isBlank(String str) Checks if a String is whitespace, empty ("") or null.
static boolean	isNotBlank(String str) Checks if a String is not empty (""), not null and not whitespace only.
static boolean	isRequest(HttpServletRequest request)
static String	mapKeyName(String keyname) The parameter name is mapped to lower case and any character that is neither a number or letter is replaced with an "underscore".
static boolean	parseDescriptor(Map<String,String> launch_info, Map<String,String> postProp, String descriptor)
static boolean	parseDescriptor(Properties launch_info, Properties postProp, String descriptor) Deprecated. See: parseDescriptor(Map, Map, String)
static String	postLaunchHTML(Map<String,String> cleanProperties, String endpoint, String launchtext, boolean autosubmit, boolean debug, Map<String,String> extra) Create the HTML to render a POST form and then automatically submit it.
static String	postLaunchHTML(Map<String,String> cleanProperties, String endpoint, String launchtext, boolean debug, Map<String,String> extra) Create the HTML to render a POST form and then automatically submit it.
static String	postLaunchHTML(Properties cleanProperties, String endpoint, String launchtext, boolean autosubmit, boolean debug, Map<String,String> extra) Deprecated. Moved to postLaunchHTML(Map, String, String, boolean, boolean, Map)
static String	postLaunchHTML(Properties cleanProperties, String endpoint, String launchtext, boolean debug, Map<String,String> extra) Deprecated. Moved to postLaunchHTML(Map, String, String, boolean, Map)
static String	prepareForExport(String descriptor)
static String	readHttpResponse(HttpURLConnection connection) readHttpResponse - Read the HTTP Response
static HttpURLConnection	sendOAuthURL(String method, String url, String oauth_consumer_key, String oauth_secret) getOAuthURL - Form a GET request signed by OAuth
static void	setProperty(Map<String,String> map, String key, String value) Mutates the passed Map map variable.
static void	setProperty(Properties props, String key, String value) Deprecated. See: setProperty(Map, String, String)
static Map<String,String>	signProperties(Map<String,String> postProp, String url, String method, String oauth_consumer_key, String oauth_consumer_secret, String tool_consumer_instance_guid, String tool_consumer_instance_description, String tool_consumer_instance_url, String tool_consumer_instance_name, String tool_consumer_instance_contact_email, Map<String,String> extra) Add the necessary fields and sign.
static Properties	signProperties(Properties postProp, String url, String method, String oauth_consumer_key, String oauth_consumer_secret, String org_id, String org_desc, String org_url, Map<String,String> extra) Deprecated. See: signProperties(Map, String, String, String, String, String, String, String, String, String, Map)
static String	toNull(String str)
static String	validateDescriptor(String descriptor)
static Object	validateMessage(HttpServletRequest request, String URL, String oauth_secret, String expected_oauth_key)

Methods inherited from class java.lang.Object

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

Field Detail

ISO_8601_FORMAT

public static final String ISO_8601_FORMAT

See Also:

Constant Field Values

Constructor Detail

BasicLTIUtil

public BasicLTIUtil()

Method Detail

isRequest

public static boolean isRequest(HttpServletRequest request)

validateMessage

public static Object validateMessage(HttpServletRequest request,
                                     String URL,
                                     String oauth_secret,
                                     String expected_oauth_key)

validateDescriptor

public static String validateDescriptor(String descriptor)

adaptToCustomPropertyName

public static String adaptToCustomPropertyName(String propertyName)

A simple utility method which implements the specified semantics of custom properties.

i.e. The parameter names are mapped to lower case and any character that is neither a number nor letter in a parameter name is replaced with an "underscore".

e.g. Review:Chapter=1.2.56 would map to custom_review_chapter=1.2.56.

Parameters:

propertyName -

Returns:

signProperties

public static Properties signProperties(Properties postProp,
                                        String url,
                                        String method,
                                        String oauth_consumer_key,
                                        String oauth_consumer_secret,
                                        String org_id,
                                        String org_desc,
                                        String org_url,
                                        Map<String,String> extra)

Deprecated. See: signProperties(Map, String, String, String, String, String, String, String, String, String, Map)

Add the necessary fields and sign.

Parameters:

postProp -

url -

method -

oauth_consumer_key -

oauth_consumer_secret -

org_id - See: BasicLTIConstants.TOOL_CONSUMER_INSTANCE_GUID

org_desc - See: BasicLTIConstants.TOOL_CONSUMER_INSTANCE_DESCRIPTION

org_url - See: BasicLTIConstants.TOOL_CONSUMER_INSTANCE_URL

extra -

Returns:

signProperties

public static Map<String,String> signProperties(Map<String,String> postProp,
                                                String url,
                                                String method,
                                                String oauth_consumer_key,
                                                String oauth_consumer_secret,
                                                String tool_consumer_instance_guid,
                                                String tool_consumer_instance_description,
                                                String tool_consumer_instance_url,
                                                String tool_consumer_instance_name,
                                                String tool_consumer_instance_contact_email,
                                                Map<String,String> extra)

Add the necessary fields and sign.

Parameters:

postProp -

url -

method -

oauth_consumer_key -

oauth_consumer_secret -

tool_consumer_instance_guid - See: BasicLTIConstants.TOOL_CONSUMER_INSTANCE_GUID

tool_consumer_instance_description - See: BasicLTIConstants.TOOL_CONSUMER_INSTANCE_DESCRIPTION

tool_consumer_instance_url - See: BasicLTIConstants.TOOL_CONSUMER_INSTANCE_URL

tool_consumer_instance_name - See: BasicLTIConstants.TOOL_CONSUMER_INSTANCE_NAME

tool_consumer_instance_contact_email - See: BasicLTIConstants.TOOL_CONSUMER_INSTANCE_CONTACT_EMAIL

extra -

Returns:

checkProperties

public static boolean checkProperties(Properties postProp,
                                      String url,
                                      String method,
                                      String oauth_consumer_key,
                                      String oauth_consumer_secret)

Deprecated. See: checkProperties(Map, String, String, String, String)

Check if the properties are properly signed

Parameters:

postProp -

url -

method -

oauth_consumer_key -

oauth_consumer_secret -

Returns:

checkProperties

public static boolean checkProperties(Map<String,String> postProp,
                                      String url,
                                      String method,
                                      String oauth_consumer_key,
                                      String oauth_consumer_secret)

Check if the fields are properly signed

Parameters:

postProp -

url -

method -

oauth_consumer_key -

oauth_consumer_secret -

Returns:

postLaunchHTML

public static String postLaunchHTML(Properties cleanProperties,
                                    String endpoint,
                                    String launchtext,
                                    boolean debug,
                                    Map<String,String> extra)

Deprecated. Moved to postLaunchHTML(Map, String, String, boolean, Map)

Create the HTML to render a POST form and then automatically submit it.

Parameters:

cleanProperties -

endpoint - The LTI launch url.

launchtext - The LTI launch text. Used if javascript is turned off.

debug - Useful for viewing the HTML before posting to end point.

extra -

Returns:

the HTML ready for IFRAME src = inclusion.

postLaunchHTML

public static String postLaunchHTML(Properties cleanProperties,
                                    String endpoint,
                                    String launchtext,
                                    boolean autosubmit,
                                    boolean debug,
                                    Map<String,String> extra)

Deprecated. Moved to postLaunchHTML(Map, String, String, boolean, boolean, Map)

Create the HTML to render a POST form and then automatically submit it.

Parameters:

cleanProperties -

endpoint - The LTI launch url.

launchtext - The LTI launch text. Used if javascript is turned off.

autosubmit - Whether or not we want the form autosubmitted

debug - Useful for viewing the HTML before posting to end point.

extra -

Returns:

the HTML ready for IFRAME src = inclusion.

postLaunchHTML

public static String postLaunchHTML(Map<String,String> cleanProperties,
                                    String endpoint,
                                    String launchtext,
                                    boolean debug,
                                    Map<String,String> extra)

Create the HTML to render a POST form and then automatically submit it.

Parameters:

cleanProperties -

endpoint - The LTI launch url.

launchtext - The LTI launch text. Used if javascript is turned off.

debug - Useful for viewing the HTML before posting to end point.

extra - Useful for viewing the HTML before posting to end point.

Returns:

the HTML ready for IFRAME src = inclusion.

postLaunchHTML

public static String postLaunchHTML(Map<String,String> cleanProperties,
                                    String endpoint,
                                    String launchtext,
                                    boolean autosubmit,
                                    boolean debug,
                                    Map<String,String> extra)

Create the HTML to render a POST form and then automatically submit it.

Parameters:

cleanProperties -

endpoint - The LTI launch url.

launchtext - The LTI launch text. Used if javascript is turned off.

autosubmit - Whether or not we want the form autosubmitted

extra - Useful for viewing the HTML before posting to end point.

Returns:

the HTML ready for IFRAME src = inclusion.

getOAuthURL

public static String getOAuthURL(String method,
                                 String url,
                                 String oauth_consumer_key,
                                 String oauth_secret)

getOAuthURL - Form a GET request signed by OAuth

Parameters:

method -

url -

oauth_consumer_key -

oauth_secret -

getOAuthURL

public static String getOAuthURL(String method,
                                 String url,
                                 String oauth_consumer_key,
                                 String oauth_secret,
                                 String signature)

getOAuthURL - Form a GET request signed by OAuth

Parameters:

method -

url -

oauth_consumer_key -

oauth_secret -

signature -

sendOAuthURL

public static HttpURLConnection sendOAuthURL(String method,
                                             String url,
                                             String oauth_consumer_key,
                                             String oauth_secret)

getOAuthURL - Form a GET request signed by OAuth

Parameters:

method -

url -

oauth_consumer_key -

oauth_secret - HttpURLConnection connection = sendOAuthURL('GET', url, oauth_consumer_key, oauth_secret) int responseCode = connection.getResponseCode(); String data = readHttpResponse(connection)

getResponseCode

public static int getResponseCode(HttpURLConnection connection)

getResponseCode - Read the HTTP Response

Parameters:

connection -

readHttpResponse

public static String readHttpResponse(HttpURLConnection connection)

readHttpResponse - Read the HTTP Response

Parameters:

connection -

parseDescriptor

public static boolean parseDescriptor(Properties launch_info,
                                      Properties postProp,
                                      String descriptor)

Deprecated. See: parseDescriptor(Map, Map, String)

Parameters:

launch_info - Variable is mutated by this method.

postProp - Variable is mutated by this method.

descriptor -

Returns:

parseDescriptor

public static boolean parseDescriptor(Map<String,String> launch_info,
                                      Map<String,String> postProp,
                                      String descriptor)

Parameters:

launch_info - Variable is mutated by this method.

postProp - Variable is mutated by this method.

descriptor -

Returns:

prepareForExport

public static String prepareForExport(String descriptor)

mapKeyName

public static String mapKeyName(String keyname)

The parameter name is mapped to lower case and any character that is neither a number or letter is replaced with an "underscore". So if a custom entry was as follows: 1.2.56 Would map to: custom_vendor_chapter=1.2.56

toNull

public static String toNull(String str)

setProperty

public static void setProperty(Map<String,String> map,
                               String key,
                               String value)

Mutates the passed Map map variable. Puts the key,value into the Map if the value is not null and is not empty.

Parameters:

map - Variable is mutated by this method.

key -

value -

setProperty

public static void setProperty(Properties props,
                               String key,
                               String value)

Deprecated. See: setProperty(Map, String, String)

Mutates the passed Properties props variable. Puts the key,value into the Map if the value is not null and is not empty.

Parameters:

props - Variable is mutated by this method.

key -

value -

htmlspecialchars

public static String htmlspecialchars(String input)

getRealPath

public static String getRealPath(String servletUrl,
                                 String extUrl)

Simple utility method deal with a request that has the wrong URL when behind a proxy.

Parameters:

servletUrl -

extUrl - The url that the external world sees us as responding to. This needs to be up to but not including the last slash like and not include any path information http://www.sakaiproject.org - although we do compensate for extra stuff at the end.

Returns:

The full path of the request with extUrl in place of whatever the request thinks is the current URL.

getRealPath

public static String getRealPath(HttpServletRequest request,
                                 String extUrl)

convertToMap

public static Map<String,String> convertToMap(Properties properties)

Simple utility method to help with the migration from Properties to Map.

Parameters:

properties -

Returns:

convertToProperties

public static Properties convertToProperties(Map<String,String> map)

Deprecated. Should migrate to Map signatures.

Simple utility method to help with the migration from Map to Properties.

Parameters:

map -

Returns:

isBlank

public static boolean isBlank(String str)

Checks if a String is whitespace, empty ("") or null.

 StringUtils.isBlank(null)        = true
 StringUtils.isBlank("")                = true
 StringUtils.isBlank(" ")          = true
 StringUtils.isBlank("bob")      = false
 StringUtils.isBlank("  bob  ") = false
 

Parameters:

str - the String to check, may be null

Returns:

true if the String is null, empty or whitespace

Since:

2.0

isNotBlank

public static boolean isNotBlank(String str)

Checks if a String is not empty (""), not null and not whitespace only.

 StringUtils.isNotBlank(null)     = false
 StringUtils.isNotBlank("")             = false
 StringUtils.isNotBlank(" ")       = false
 StringUtils.isNotBlank("bob")   = true
 StringUtils.isNotBlank("  bob  ") = true
 

Parameters:

str - the String to check, may be null

Returns:

true if the String is not empty and not null and not whitespace

Since:

2.0

equals

public static boolean equals(String str1,
                             String str2)

Compares two Strings, returning true if they are equal.

nulls are handled without exceptions. Two null references are considered to be equal. The comparison is case sensitive.

 StringUtils.equals(null, null)   = true
 StringUtils.equals(null, "abc")  = false
 StringUtils.equals("abc", null)  = false
 StringUtils.equals("abc", "abc") = true
 StringUtils.equals("abc", "ABC") = false
 

Parameters:

str1 - the first String, may be null

str2 - the second String, may be null

Returns:

true if the Strings are equal, case sensitive, or both null

See Also:

String.equals(Object)

equalsIgnoreCase

public static boolean equalsIgnoreCase(String str1,
                                       String str2)

Compares two Strings, returning true if they are equal ignoring the case.

nulls are handled without exceptions. Two null references are considered equal. Comparison is case insensitive.

 StringUtils.equalsIgnoreCase(null, null)   = true
 StringUtils.equalsIgnoreCase(null, "abc")  = false
 StringUtils.equalsIgnoreCase("abc", null)  = false
 StringUtils.equalsIgnoreCase("abc", "abc") = true
 StringUtils.equalsIgnoreCase("abc", "ABC") = true
 

Parameters:

str1 - the first String, may be null

str2 - the second String, may be null

Returns:

true if the Strings are equal, case insensitive, or both null

See Also:

String.equalsIgnoreCase(String)

getISO8601

public static String getISO8601()

Return a ISO 8601 formatted date

getISO8601

public static String getISO8601(Date date)

Return a ISO 8601 formatted date