Java tutorial
/* * $URL: https://source.sakaiproject.org/svn/basiclti/trunk/basiclti-util/src/java/org/imsglobal/basiclti/BasicLTIUtil.java $ * $Id: BasicLTIUtil.java 98512 2011-09-22 17:59:08Z csev@umich.edu $ * * Copyright (c) 2008 IMS GLobal Learning Consortium * * 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.tls.basiclti; import static com.tls.basiclti.BasicLTIConstants.CUSTOM_PREFIX; import static com.tls.basiclti.BasicLTIConstants.LTI_MESSAGE_TYPE; import static com.tls.basiclti.BasicLTIConstants.LTI_VERSION; import static com.tls.basiclti.BasicLTIConstants.TOOL_CONSUMER_INSTANCE_CONTACT_EMAIL; import static com.tls.basiclti.BasicLTIConstants.TOOL_CONSUMER_INSTANCE_DESCRIPTION; import static com.tls.basiclti.BasicLTIConstants.TOOL_CONSUMER_INSTANCE_GUID; import static com.tls.basiclti.BasicLTIConstants.TOOL_CONSUMER_INSTANCE_NAME; import static com.tls.basiclti.BasicLTIConstants.TOOL_CONSUMER_INSTANCE_URL; import net.oauth.OAuthAccessor; import net.oauth.OAuthConsumer; import net.oauth.OAuthMessage; import java.util.HashMap; import java.util.List; import java.util.Locale; import java.util.Map; import java.util.Properties; import java.util.TreeMap; import java.util.Map.Entry; import java.util.logging.Logger; import java.util.regex.Pattern; import com.liferay.portal.kernel.language.LanguageUtil; /* Leave out until we have JTidy 0.8 in the repository import org.w3c.tidy.Tidy; import java.io.ByteArrayOutputStream; */ /** * Some Utility code for IMS Basic LTI * http://www.anyexample.com/programming/java * /java_simple_class_to_compute_sha_1_hash.xml * <p> * Sample Descriptor * * <pre> * <?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> * </pre> */ public class BasicLTIUtil { // We use the built-in Java logger because this code needs to be very generic private static Logger M_log = Logger.getLogger(BasicLTIUtil.class.toString()); /** To turn on really verbose debugging */ private static boolean verbosePrint = false; public static final String BASICLTI_SUBMIT = "ext_basiclti_submit"; private static final Pattern CUSTOM_REGEX = Pattern.compile("[^A-Za-z0-9]"); private static final String UNDERSCORE = "_"; // Simple Debug Print Mechanism public static void dPrint(String str) { if (verbosePrint) System.out.println(str); M_log.fine(str); } public static String validateDescriptor(String descriptor) { if (descriptor == null) return null; if (descriptor.indexOf("<basic_lti_link") < 0) return null; Map<String, Object> tm = XMLMap.getFullMap(descriptor.trim()); if (tm == null) return null; // We demand at least an endpoint String ltiSecureLaunch = XMLMap.getString(tm, "/basic_lti_link/secure_launch_url"); // We demand at least an endpoint if (ltiSecureLaunch != null && ltiSecureLaunch.trim().length() > 0) return ltiSecureLaunch; String ltiLaunch = XMLMap.getString(tm, "/basic_lti_link/launch_url"); if (ltiLaunch != null && ltiLaunch.trim().length() > 0) return ltiLaunch; return null; } /** * Any properties which are not well known (i.e. in * {@link BasicLTIConstants#validPropertyNames}) will be mapped to custom * properties per the specified semantics. NOTE: no blacklisting of keys is * performed. * * @param rawProperties * A set of properties that will be cleaned. * @return A cleansed version of rawProperties. */ public static Map<String, String> cleanupProperties(final Map<String, String> rawProperties) { return cleanupProperties(rawProperties, null); } /** * Any properties which are not well known (i.e. in * {@link BasicLTIConstants#validPropertyNames}) will be mapped to custom * properties per the specified semantics. * * @param rawProperties * A set of properties that will be cleaned. * @param blackList * An array of {@link String}s which are considered unsafe to be * included in launch data. Any matches will be removed from the * return. * @return A cleansed version of rawProperties. */ public static Map<String, String> cleanupProperties(final Map<String, String> rawProperties, final String[] blackList) { final Map<String, String> newProp = new HashMap<String, String>(rawProperties.size()); // roughly the same size for (String okey : rawProperties.keySet()) { final String key = okey.trim(); if (blackList != null) { boolean blackListed = false; for (String blackKey : blackList) { if (blackKey.equals(key)) { blackListed = true; break; } } if (blackListed) { continue; } } final String value = rawProperties.get(key); if (value == null || "".equals(value)) { // remove null or empty values continue; } if (isSpecifiedPropertyName(key)) { // a well known property name newProp.put(key, value); } else { // convert to a custom property name newProp.put(adaptToCustomPropertyName(key), value); } } return newProp; } /** * Any properties which are not well known (i.e. in * {@link BasicLTIConstants#validPropertyNames}) will be mapped to custom * properties per the specified semantics. * * @deprecated See {@link #cleanupProperties(Map)} * @param rawProperties * A set of {@link Properties} that will be cleaned. Keys must be of * type {@link String}. * @return A cleansed version of {@link Properties}. */ public static Properties cleanupProperties(final Properties rawProperties) { final Map<String, String> map = cleanupProperties(convertToMap(rawProperties), null); return convertToProperties(map); } /** * Checks to see if the passed propertyName is equal to one of the Strings * contained in {@link BasicLTIConstants#validPropertyNames}. String matching * is case sensitive. * * @param propertyName * @return true if propertyName is equal to one of the Strings contained in * {@link BasicLTIConstants#validPropertyNames} * or is a custom parameter oe extension parameter ; * else return false. */ public static boolean isSpecifiedPropertyName(final String propertyName) { boolean found = false; if (propertyName.startsWith(BasicLTIConstants.CUSTOM_PREFIX)) return true; if (propertyName.startsWith(BasicLTIConstants.EXTENSION_PREFIX)) return true; if (propertyName.startsWith(BasicLTIConstants.OAUTH_PREFIX)) return true; for (String key : BasicLTIConstants.validPropertyNames) { if (key.equals(propertyName)) { found = true; break; } } return found; } /** * A simple utility method which implements the specified semantics of custom * properties. * <p> * 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". * <p> * e.g. Review:Chapter=1.2.56 would map to custom_review_chapter=1.2.56. * * @param propertyName * @return */ public static String adaptToCustomPropertyName(final String propertyName) { if (propertyName == null || "".equals(propertyName)) { throw new IllegalArgumentException("propertyName cannot be null"); } String customName = propertyName.toLowerCase(); customName = CUSTOM_REGEX.matcher(customName).replaceAll(UNDERSCORE); if (!customName.startsWith(CUSTOM_PREFIX)) { customName = CUSTOM_PREFIX + customName; } return customName; } /** * Add the necessary fields and sign. * * @deprecated See: * {@link BasicLTIUtil#signProperties(Map, String, String, String, String, String, String, String, String, String)} * * @param postProp * @param url * @param method * @param oauth_consumer_key * @param oauth_consumer_secret * @param org_id * See: {@link BasicLTIConstants#TOOL_CONSUMER_INSTANCE_GUID} * @param org_desc * See: {@link BasicLTIConstants#TOOL_CONSUMER_INSTANCE_DESCRIPTION} * @param org_url * See: {@link BasicLTIConstants#TOOL_CONSUMER_INSTANCE_URL} * @return */ 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) { final Map<String, String> signedMap = signProperties(convertToMap(postProp), url, method, oauth_consumer_key, oauth_consumer_secret, org_id, org_desc, org_url, null, null); return convertToProperties(signedMap); } /** * Add the necessary fields and sign. * * @param postProp * @param url * @param method * @param oauth_consumer_key * @param oauth_consumer_secret * @param tool_consumer_instance_guid * See: {@link BasicLTIConstants#TOOL_CONSUMER_INSTANCE_GUID} * @param tool_consumer_instance_description * See: {@link BasicLTIConstants#TOOL_CONSUMER_INSTANCE_DESCRIPTION} * @param tool_consumer_instance_url * See: {@link BasicLTIConstants#TOOL_CONSUMER_INSTANCE_URL} * @param tool_consumer_instance_name * See: {@link BasicLTIConstants#TOOL_CONSUMER_INSTANCE_NAME} * @param tool_consumer_instance_contact_email * See: * {@link BasicLTIConstants#TOOL_CONSUMER_INSTANCE_CONTACT_EMAIL} * @return */ 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) { postProp = BasicLTIUtil.cleanupProperties(postProp); postProp.put(LTI_VERSION, "LTI-1p0"); postProp.put(LTI_MESSAGE_TYPE, "basic-lti-launch-request"); // Allow caller to internationalize this for us... if (postProp.get(BASICLTI_SUBMIT) == null) { postProp.put(BASICLTI_SUBMIT, "Launch Endpoint with BasicLTI Data"); } if (tool_consumer_instance_guid != null) postProp.put(TOOL_CONSUMER_INSTANCE_GUID, tool_consumer_instance_guid); if (tool_consumer_instance_description != null) postProp.put(TOOL_CONSUMER_INSTANCE_DESCRIPTION, tool_consumer_instance_description); if (tool_consumer_instance_url != null) postProp.put(TOOL_CONSUMER_INSTANCE_URL, tool_consumer_instance_url); if (tool_consumer_instance_name != null) postProp.put(TOOL_CONSUMER_INSTANCE_NAME, tool_consumer_instance_name); if (tool_consumer_instance_contact_email != null) postProp.put(TOOL_CONSUMER_INSTANCE_CONTACT_EMAIL, tool_consumer_instance_contact_email); if (postProp.get("oauth_callback") == null) postProp.put("oauth_callback", "about:blank"); if (oauth_consumer_key == null || oauth_consumer_secret == null) { dPrint("No signature generated in signProperties"); return postProp; } OAuthMessage oam = new OAuthMessage(method, url, postProp.entrySet()); OAuthConsumer cons = new OAuthConsumer("about:blank", oauth_consumer_key, oauth_consumer_secret, null); OAuthAccessor acc = new OAuthAccessor(cons); try { oam.addRequiredParameters(acc); // System.out.println("Base Message String\n"+OAuthSignatureMethod.getBaseString(oam)+"\n"); List<Map.Entry<String, String>> params = oam.getParameters(); Map<String, String> nextProp = new HashMap<String, String>(); // Convert to Map<String, String> for (final Map.Entry<String, String> entry : params) { nextProp.put(entry.getKey(), entry.getValue()); } return nextProp; } catch (net.oauth.OAuthException e) { M_log.warning("BasicLTIUtil.signProperties OAuth Exception " + e.getMessage()); throw new Error(e); } catch (java.io.IOException e) { M_log.warning("BasicLTIUtil.signProperties IO Exception " + e.getMessage()); throw new Error(e); } catch (java.net.URISyntaxException e) { M_log.warning("BasicLTIUtil.signProperties URI Syntax Exception " + e.getMessage()); throw new Error(e); } } /** * Create the HTML to render a POST form and then automatically submit it. * Make sure to call {@link #cleanupProperties(Properties)} before signing. * * @deprecated Moved to {@link #postLaunchHTML(Map, String, boolean)} * @param cleanProperties * Assumes you have called {@link #cleanupProperties(Properties)} * beforehand. * @param endpoint * The LTI launch url. * @param debug * Useful for viewing the HTML before posting to end point. * @return the HTML ready for IFRAME src = inclusion. */ public static String postLaunchHTML(final Properties cleanProperties, String endpoint, boolean debug) { Map<String, String> map = convertToMap(cleanProperties); return postLaunchHTML(map, endpoint, debug, LanguageUtil.getLocale("es_ES"), false); } /** * Create the HTML to render a POST form and then automatically submit it. * Make sure to call {@link #cleanupProperties(Properties)} before signing. * * @param cleanProperties * Assumes you have called {@link #cleanupProperties(Properties)} * beforehand. * @param endpoint * The LTI launch url. * @param debug * Useful for viewing the HTML before posting to end point. * @return the HTML ready for IFRAME src = inclusion. */ public static String postLaunchHTML(final Map<String, String> cleanProperties, String endpoint, boolean debug, Locale locale, boolean iframe) { if (cleanProperties == null || cleanProperties.isEmpty()) { throw new IllegalArgumentException("cleanProperties == null || cleanProperties.isEmpty()"); } if (endpoint == null) { throw new IllegalArgumentException("endpoint == null"); } Map<String, String> newMap = null; if (debug) { // sort the properties for readability newMap = new TreeMap<String, String>(cleanProperties); } else { newMap = cleanProperties; } StringBuilder text = new StringBuilder(); // paint form text.append("<div id=\"ltiLaunchFormSubmitArea\">\n"); text.append("<form action=\""); text.append(endpoint); text.append("\" name=\"ltiLaunchForm\" id=\"ltiLaunchForm\" method=\"post\" "); if (iframe) text.append("target=\"output_frame\""); text.append(" encType=\"application/x-www-form-urlencoded\" accept-charset=\"utf-8\">\n"); for (Entry<String, String> entry : newMap.entrySet()) { String key = entry.getKey(); String value = entry.getValue(); if (value == null) continue; // This will escape the contents pretty much - at least // we will be safe and not generate dangerous HTML key = htmlspecialchars(key); value = htmlspecialchars(value); if (!key.equals(BASICLTI_SUBMIT)) { //text.append("<input type=\"submit\" name=\""); text.append("<input type=\"hidden\" name=\""); text.append(key); text.append("\" value=\""); text.append(value); text.append("\"/>\n"); } /*else { } text.append(key); text.append("\" value=\""); text.append(value); text.append("\"/>\n");*/ } text.append("</form>\n"); text.append("</div>\n"); // paint debug output if (debug) { text.append("<pre>\n"); text.append("<b>BasicLTI Endpoint</b>\n"); text.append(endpoint); text.append("\n\n"); text.append("<b>BasicLTI Parameters:</b>\n"); for (Entry<String, String> entry : newMap.entrySet()) { String key = entry.getKey(); String value = entry.getValue(); if (value == null) continue; text.append(key); text.append("="); text.append(value); text.append("\n"); } text.append("</pre>\n"); } else { // paint auto submit script text.append("<div class='ltimessage'>"); if (iframe) { text.append(" <a href='#content' onclick='javascript:goto();' >"); text.append(LanguageUtil.format(locale, "learningactivity.lti.goiframe", null)); } else { text.append(LanguageUtil.format(locale, "learningactivity.lti.outplataform", null)); text.append(" <a href='#' onclick='javascript:goto();' >"); text.append(LanguageUtil.format(locale, "learningactivity.lti.go", null)); } text.append("</a>"); text.append( "<script language=\"javascript\">function goto(){" + "nei = document.createElement('input');" + "nei.setAttribute('type', 'hidden');" + "nei.setAttribute('name', '" + BASICLTI_SUBMIT + "');" + " nei.setAttribute('value', '" + newMap.get(BASICLTI_SUBMIT) + "');" + "document.getElementById(\"ltiLaunchForm\").appendChild(nei);" + "document.ltiLaunchForm.submit();"); if (iframe) { text.append("f = document.getElementById(\"output_frame\");" + "f.style.display = \"block\";"); } text.append("}</script>"); text.append("</div>"); /*text .append(" <script language=\"javascript\"> \n" + " document.getElementById(\"ltiLaunchFormSubmitArea\").style.display = \"none\";\n" + " nei = document.createElement('input');\n" + " nei.setAttribute('type', 'hidden');\n" + " nei.setAttribute('name', '" + BASICLTI_SUBMIT + "');\n" + " nei.setAttribute('value', '" + newMap.get(BASICLTI_SUBMIT) + "');\n" + " document.getElementById(\"ltiLaunchForm\").appendChild(nei);\n" + " document.ltiLaunchForm.submit(); \n" + " </script> \n");*/ } String htmltext = text.toString(); return htmltext; } /** * @deprecated See: {@link #parseDescriptor(Map, Map, String)} * @param launch_info * Variable is mutated by this method. * @param postProp * Variable is mutated by this method. * @param descriptor * @return */ public static boolean parseDescriptor(Properties launch_info, Properties postProp, String descriptor) { // this is an ugly copy/paste of the non-@deprecated method // could not convert data types as they variables get mutated (ugh) Map<String, Object> tm = null; try { tm = XMLMap.getFullMap(descriptor.trim()); } catch (Exception e) { M_log.warning("BasicLTIUtil exception parsing BasicLTI descriptor: " + e.getMessage()); return false; } if (tm == null) { M_log.warning("Unable to parse XML in parseDescriptor"); return false; } String launch_url = toNull(XMLMap.getString(tm, "/basic_lti_link/launch_url")); String secure_launch_url = toNull(XMLMap.getString(tm, "/basic_lti_link/secure_launch_url")); if (launch_url == null && secure_launch_url == null) return false; setProperty(launch_info, "launch_url", launch_url); setProperty(launch_info, "secure_launch_url", secure_launch_url); // Extensions for hand-authored placements - The export process should scrub // these setProperty(launch_info, "key", toNull(XMLMap.getString(tm, "/basic_lti_link/x-secure/launch_key"))); setProperty(launch_info, "secret", toNull(XMLMap.getString(tm, "/basic_lti_link/x-secure/launch_secret"))); List<Map<String, Object>> theList = XMLMap.getList(tm, "/basic_lti_link/custom/parameter"); for (Map<String, Object> setting : theList) { dPrint("Setting=" + setting); String key = XMLMap.getString(setting, "/!key"); // Get the key attribute String value = XMLMap.getString(setting, "/"); // Get the value if (key == null || value == null) continue; key = "custom_" + mapKeyName(key); dPrint("key=" + key + " val=" + value); postProp.setProperty(key, value); } return true; } /** * * @param launch_info * Variable is mutated by this method. * @param postProp * Variable is mutated by this method. * @param descriptor * @return */ public static boolean parseDescriptor(Map<String, String> launch_info, Map<String, String> postProp, String descriptor) { Map<String, Object> tm = null; try { tm = XMLMap.getFullMap(descriptor.trim()); } catch (Exception e) { M_log.warning("BasicLTIUtil exception parsing BasicLTI descriptor: " + e.getMessage()); return false; } if (tm == null) { M_log.warning("Unable to parse XML in parseDescriptor"); return false; } String launch_url = toNull(XMLMap.getString(tm, "/basic_lti_link/launch_url")); String secure_launch_url = toNull(XMLMap.getString(tm, "/basic_lti_link/secure_launch_url")); if (launch_url == null && secure_launch_url == null) return false; setProperty(launch_info, "launch_url", launch_url); setProperty(launch_info, "secure_launch_url", secure_launch_url); // Extensions for hand-authored placements - The export process should scrub // these setProperty(launch_info, "key", toNull(XMLMap.getString(tm, "/basic_lti_link/x-secure/launch_key"))); setProperty(launch_info, "secret", toNull(XMLMap.getString(tm, "/basic_lti_link/x-secure/launch_secret"))); List<Map<String, Object>> theList = XMLMap.getList(tm, "/basic_lti_link/custom/parameter"); for (Map<String, Object> setting : theList) { dPrint("Setting=" + setting); String key = XMLMap.getString(setting, "/!key"); // Get the key attribute String value = XMLMap.getString(setting, "/"); // Get the value if (key == null || value == null) continue; key = "custom_" + mapKeyName(key); dPrint("key=" + key + " val=" + value); postProp.put(key, value); } return true; } // Remove fields that should not be exported public static String prepareForExport(String descriptor) { Map<String, Object> tm = null; try { tm = XMLMap.getFullMap(descriptor.trim()); } catch (Exception e) { M_log.warning("BasicLTIUtil exception parsing BasicLTI descriptor" + e.getMessage()); return null; } if (tm == null) { M_log.warning("Unable to parse XML in prepareForExport"); return null; } XMLMap.removeSubMap(tm, "/basic_lti_link/x-secure"); String retval = XMLMap.getXML(tm, true); return retval; } /** * 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: * * <parameter name="Vendor:Chapter">1.2.56</parameter> * * Would map to: custom_vendor_chapter=1.2.56 */ public static String mapKeyName(String keyname) { StringBuffer sb = new StringBuffer(); if (keyname == null) return null; keyname = keyname.trim(); if (keyname.length() < 1) return null; for (int i = 0; i < keyname.length(); i++) { Character ch = Character.toLowerCase(keyname.charAt(i)); if (Character.isLetter(ch) || Character.isDigit(ch)) { sb.append(ch); } else { sb.append('_'); } } return sb.toString(); } public static String toNull(String str) { if (str == null) return null; if (str.trim().length() < 1) return null; return str; } /** * Mutates the passed Map<String, String> map variable. Puts the key,value * into the Map if the value is not null and is not empty. * * @param map * Variable is mutated by this method. * @param key * @param value */ public static void setProperty(final Map<String, String> map, final String key, final String value) { if (value != null && !"".equals(value)) { map.put(key, value); } } /** * Mutates the passed Properties props variable. Puts the key,value into the * Map if the value is not null and is not empty. * * @deprecated See: {@link #setProperty(Map, String, String)} * @param props * Variable is mutated by this method. * @param key * @param value */ public static void setProperty(Properties props, String key, String value) { if (value == null) return; if (value.trim().length() < 1) return; props.setProperty(key, value); } // Basic utility to encode form text - handle the "safe cases" public static String htmlspecialchars(String input) { if (input == null) return null; String retval = input.replace("&", "&"); retval = retval.replace("\"", """); retval = retval.replace("<", "<"); retval = retval.replace(">", ">"); retval = retval.replace(">", ">"); retval = retval.replace("=", "="); return retval; } /** * Simple utility method to help with the migration from Properties to * Map<String, String>. * * @param properties * @return */ @SuppressWarnings("unchecked") public static Map<String, String> convertToMap(final Properties properties) { final Map<String, String> map = new HashMap(properties); return map; } /** * Simple utility method to help with the migration from Map<String, String> * to Properties. * * @deprecated Should migrate to Map<String, String> signatures. * @param map * @return */ public static Properties convertToProperties(final Map<String, String> map) { final Properties properties = new Properties(); if (map != null) { for (Entry<String, String> entry : map.entrySet()) { properties.setProperty(entry.getKey(), entry.getValue()); } } return properties; } /** * <p> * Checks if a String is whitespace, empty ("") or null. * </p> * * <pre> * StringUtils.isBlank(null) = true * StringUtils.isBlank("") = true * StringUtils.isBlank(" ") = true * StringUtils.isBlank("bob") = false * StringUtils.isBlank(" bob ") = false * </pre> * * @param str * the String to check, may be null * @return <code>true</code> if the String is null, empty or whitespace * @since 2.0 */ public static boolean isBlank(String str) { int strLen; if (str == null || (strLen = str.length()) == 0) { return true; } for (int i = 0; i < strLen; i++) { if ((Character.isWhitespace(str.charAt(i)) == false)) { return false; } } return true; } /** * <p> * Checks if a String is not empty (""), not null and not whitespace only. * </p> * * <pre> * StringUtils.isNotBlank(null) = false * StringUtils.isNotBlank("") = false * StringUtils.isNotBlank(" ") = false * StringUtils.isNotBlank("bob") = true * StringUtils.isNotBlank(" bob ") = true * </pre> * * @param str * the String to check, may be null * @return <code>true</code> if the String is not empty and not null and not * whitespace * @since 2.0 */ public static boolean isNotBlank(String str) { return !isBlank(str); } /** * <p> * Compares two Strings, returning <code>true</code> if they are equal. * </p> * * <p> * <code>null</code>s are handled without exceptions. Two <code>null</code> * references are considered to be equal. The comparison is case sensitive. * </p> * * <pre> * 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 * </pre> * * @see java.lang.String#equals(Object) * @param str1 * the first String, may be null * @param str2 * the second String, may be null * @return <code>true</code> if the Strings are equal, case sensitive, or both * <code>null</code> */ public static boolean equals(String str1, String str2) { return str1 == null ? str2 == null : str1.equals(str2); } /** * <p> * Compares two Strings, returning <code>true</code> if they are equal * ignoring the case. * </p> * * <p> * <code>null</code>s are handled without exceptions. Two <code>null</code> * references are considered equal. Comparison is case insensitive. * </p> * * <pre> * 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 * </pre> * * @see java.lang.String#equalsIgnoreCase(String) * @param str1 * the first String, may be null * @param str2 * the second String, may be null * @return <code>true</code> if the Strings are equal, case insensitive, or * both <code>null</code> */ public static boolean equalsIgnoreCase(String str1, String str2) { return str1 == null ? str2 == null : str1.equalsIgnoreCase(str2); } }