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POHow can this Java code be improved to find sub-string in a string?
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copied!<p>I was recently asked to submit a solution to a problem for a job. </p> <p><strong>Problem</strong>: Find a sub-string in a string.</p> <pre><code>Input: "Little star's deep dish pizza sure is fantastic." Search: "deep dish pizza" Output: "Little star's [[HIGHLIGHT]]deep dish pizza[[ENDHIGHLIGHT]] sure is fantastic." </code></pre> <p>Note that the highlighter doesn't have to have the exact same result on this example, since <em>you</em> are defining what a good snippet is and return the the most relevant snippet with the query terms highlighted.</p> <p>The most important requirement was to write it as I would write a <strong>production code</strong>.</p> <p>My solution was not accepted. How could I have improved it? I know, I could have used:</p> <ol> <li><a href="http://en.wikipedia.org/wiki/Knuth%E2%80%93Morris%E2%80%93Pratt_algorithm" rel="nofollow">Knuth–Morris–Pratt algorithm</a></li> <li>Regex (could I?)</li> </ol> <p><strong>My QUESTION:</strong> </p> <ol> <li><p>What do tech companies take into consideration when they review a code for a job. I submitted the code the same day, does that help in any way? </p></li> <li><p>In one of the comments, it pointed out, it looks like a school code than production code. How? Any suggestions?</p></li> </ol> <p>My solution:<br> <strong>FindSubString.java</strong></p> <pre><code>/** * FindSubString.java: Find sub-string in a given query * * @author zengr * @version 1.0 */ public class FindSubstring { private static final String startHighlight = "[[HIGHLIGHT]]"; private static final String endHighlight = "[[ENDHIGHLIGHT]]"; /** * Find sub-string in a given query * * @param inputQuery: A string data type (input Query) * @param highlightDoc: A string data type (pattern to match) * @return inputQuery: A String data type. */ public String findSubstringInQuery(String inputQuery, String highlightDoc) { try { highlightDoc = highlightDoc.trim(); if (inputQuery.toLowerCase().indexOf(highlightDoc.toLowerCase()) >= 0) { // update query if exact doc exists inputQuery = updateString(inputQuery, highlightDoc); } else { // If exact doc is not in the query then break it up String[] docArray = highlightDoc.split(" "); for (int i = 0; i < docArray.length; i++) { if (inputQuery.toLowerCase().indexOf(docArray[i].toLowerCase()) > 0) { inputQuery = updateString(inputQuery, docArray[i]); } } } } catch (NullPointerException ex) { // Ideally log this exception System.out.println("Null pointer exception caught: " + ex.toString()); } return inputQuery; } /** * Update the query with the highlighted doc * * @param inputQuery: A String data type (Query to update) * @param highlightDoc: A String data type (pattern around which to update) * @return inputQuery: A String data type. */ private String updateString(String inputQuery, String highlightDoc) { int startIndex = 0; int endIndex = 0; String lowerCaseDoc = highlightDoc.toLowerCase(); String lowerCaseQuery = inputQuery.toLowerCase(); // get index of the words to highlight startIndex = lowerCaseQuery.indexOf(lowerCaseDoc); endIndex = lowerCaseDoc.length() + startIndex; // Get the highlighted doc String resultHighlightDoc = highlightString(highlightDoc); // Update the original query return inputQuery = inputQuery.substring(0, startIndex - 1) + resultHighlightDoc + inputQuery.substring(endIndex, inputQuery.length()); } /** * Highlight the doc * * @param inputString: A string data type (value to be highlighted) * @return highlightedString: A String data type. */ private String highlightString(String inputString) { String highlightedString = null; highlightedString = " " + startHighlight + inputString + endHighlight; return highlightedString; } } </code></pre> <p><strong>TestClass.java</strong></p> <pre><code>/** * TestClass.java: jUnit test class to test FindSubString.java * * @author zengr * @version 1.0 */ import junit.framework.Test; import junit.framework.TestCase; import junit.framework.TestSuite; public class TestClass extends TestCase { private FindSubstring simpleObj = null; private String originalQuery = "I like fish. Little star's deep dish pizza sure is fantastic. Dogs are funny."; public TestClass(String name) { super(name); } public void setUp() { simpleObj = new FindSubstring(); } public static Test suite(){ TestSuite suite = new TestSuite(); suite.addTest(new TestClass("findSubstringtNameCorrect1Test")); suite.addTest(new TestClass("findSubstringtNameCorrect2Test")); suite.addTest(new TestClass("findSubstringtNameCorrect3Test")); suite.addTest(new TestClass("findSubstringtNameIncorrect1Test")); suite.addTest(new TestClass("findSubstringtNameNullTest")); return suite; } public void findSubstringtNameCorrect1Test() throws Exception { String expectedOutput = "I like fish. Little star's deep [[HIGHLIGHT]]dish pizza[[ENDHIGHLIGHT]] sure is fantastic. Dogs are funny."; assertEquals(expectedOutput, simpleObj.findSubstringInQuery(originalQuery, "dish pizza")); } public void findSubstringtNameCorrect2Test() throws Exception { String expectedOutput = "I like fish. Little star's [[HIGHLIGHT]]deep dish pizza[[ENDHIGHLIGHT]] sure is fantastic. Dogs are funny."; assertEquals(expectedOutput, simpleObj.findSubstringInQuery(originalQuery, "deep dish pizza")); } public void findSubstringtNameCorrect3Test() throws Exception { String expectedOutput = "Hello [[HIGHLIGHT]]how[[ENDHIGHLIGHT]] are [[HIGHLIGHT]]you[[ENDHIGHLIGHT]]r?"; assertEquals(expectedOutput, simpleObj.findSubstringInQuery("Hello how are your?", "how you")); } public void findSubstringtNameIncorrect1Test() throws Exception { String expectedOutput = "I like fish. Little star's deep dish pizza sure is fantastic. Dogs are funny."; assertEquals(expectedOutput, simpleObj.findSubstringInQuery(originalQuery, "I love Ruby too")); } public void findSubstringtNameNullTest() throws Exception { String expectedOutput = "I like fish. Little star's deep dish pizza sure is fantastic. Dogs are funny."; assertEquals(expectedOutput, simpleObj.findSubstringInQuery(originalQuery, null)); } } </code></pre>

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