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POsorting class content according to few parameters
 

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    <p>I need implement sorting for content of file.</p> <p>Every line of File contain next data: <code>Instructor, Course, Group, Student, Result</code> And can contain few results for the same student.</p> <p><em><strong>for example:</em></strong></p> <pre><code>Paul Schwartz,Introduction to Computer Architecture,I1,Ben Dunkin,88 Muhamed Olji,Object Oriented Programming,I4,Mike Brown,73 ... Paul Schwartz,Introduction to Computer Architecture,I1,Ben Dunkin,96 </code></pre> <p>I need to implement for every instructor </p> <ul> <li>course that is leaded by him; </li> <li>all groups that listened this course (ascending order); </li> <li>for every group <code>Student - Result</code> (descending order); </li> <li>and top 5 <code>Student</code> with higher result from this course. </li> </ul> <p>I made reading from file and created class <code>Item</code>:</p> <pre><code>class Item { private String instructor; private String course; private String group; private String student; private int result; // and add appropriate public getters/setters } </code></pre> <p>In java, we can sort all the elements of this class using one of the two options: class implementing <code>Comparable</code> interface and overriding the <code>compareTo() method</code> or using external <code>Comparator</code> interface with <code>compare() method</code>. But how can we sort different querys of sorting using these options.</p> <ul> <li>how to use <code>compareTo()</code> to satisfy this requirements (or better <code>compare()</code>)?</li> </ul>
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    1. USAnkur Shanbhag
    1. USnazar_art
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    1. COAre you sorting or extracting?
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      1. USSotirios Delimanolis
    2. CO@Sotirios Delimanolis I extracted and don't know how to so sorting.
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      1. USnazar_art
    3. COYou can't do one sort that will give you all the results you want (4 bullet points). They each need different information.
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      1. USSotirios Delimanolis
 

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