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POJava compile-time error: Compiler not recognizing method override
 

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  1. POJava compile-time error: Compiler not recognizing method override
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    <p>I am working on modifying a fairly basic linked list implementation of a log in Java to use generics. My project has 3 .java files: </p> <ul> <li>GenericLogInterface.java -> Interface that defines the log</li> <li>LLGenericNode.java -> Class that defines the LL's nodes</li> <li>LinkedGenericLog.java -> Extension of interface that defines the LL</li> </ul> <p>Unfortunately, I am receiving a compile-time error from LinkedGenericLog.java:</p> <blockquote> <p>ch02/genericStringLogs/LinkedGenericLog.java:10: ch02.genericStringLogs.LinkedGenericLog is not abstract and does not override abstract method contains(java.lang.Object) in ch02.genericStringLogs.GenericLogInterface </p> </blockquote> <p>This would seemingly be easily solved by overriding the contains() method from GenericLogInterface.java in LinkedGenericLog.java. </p> <p>There is one huge hangup, however: I have already overridden it.</p> <p>Here is the source for the three .java files:</p> <p><strong>GenericLogInterface.java</strong></p> <pre><code>package ch02.genericStringLogs; public interface GenericLogInterface&lt;T&gt; { void insert(T element); // Precondition: This GenericLog is not full. // // Places element into this GenericLog. boolean isFull(); // Returns true if this GenericLog is full, otherwise returns false. int size(); // Returns the number of Strings in this GenericLog. boolean contains(T element); // Returns true if element is in this GenericLog, // otherwise returns false. // Ignores case differences when doing string comparison. void clear(); // Makes this GenericLog empty. String getName(); // Returns the name of this GenericLog. String toString(); // Returns a nicely formatted string representing this GenericLog. } </code></pre> <p><strong>LLGenericNode.java</strong></p> <pre><code>package ch02.genericStringLogs; public class LLGenericNode&lt;T&gt; { private T info; private LLGenericNode link; public LLGenericNode(T info) { this.info = info; link = null; } public void setInfo(T info) // Sets info of this LLGenericNode. { this.info = info; } public T getInfo() // Returns info of this LLGenericNode. { return info; } public void setLink(LLGenericNode link) // Sets link of this LLGenericNode. { this.link = link; } public LLGenericNode getLink() // Returns link of this LLGenericNode. { return link; } } </code></pre> <p><strong>LinkedGenericLog.java</strong></p> <pre><code>package ch02.genericStringLogs; public class LinkedGenericLog&lt;T&gt; implements GenericLogInterface { protected LLGenericNode log; // reference to first node of linked // list that holds the GenericLog items protected String name; // name of this GenericLog public LinkedGenericLog(String name) // Instantiates and returns a reference to an empty GenericLog object // with name "name". { log = null; this.name = name; } public void insert(T element) // Precondition: This GenericLog is not full. // // Places element into this GenericLog. { LLGenericNode newNode = new LLGenericNode(element); newNode.setLink(log); log = newNode; } public boolean isFull() // Returns true if this GenericLog is full, false otherwise. { return false; } public int size() // Returns the number of items in this GenericLog. { int count = 0; LLGenericNode node; node = log; while (node != null) { count++; node = node.getLink(); } return count; } public boolean contains(T element) // Returns true if element is in this GenericLog, // otherwise returns false. // Ignores case difference when doing comparison. { LLGenericNode node; node = log; while (node != null) { if (element.equals(node.getInfo())) // if they match return true; else node = node.getLink(); } return false; } public void clear() // Makes this GenericLog empty. { log = null; } public String getName() // Returns the name of this GenericLog. { return name; } public String toString() // Returns a nicely formatted string representing this GenericLog. { String logString = "Log: " + name + "\n\n"; LLGenericNode node; node = log; int count = 0; while (node != null) { count++; logString = logString + count + ". " + node.getInfo() + "\n"; node = node.getLink(); } return logString; } } </code></pre> <p>As you can clearly, see, I have overridden contains() in LinkedGenericLog.java Yet, the compiler still throws me this error. I am thinking it has to do with my use of generics in the argument of the contains() method, but I am new to generics and can't understand the problem.</p> <p>Can anyone help me?</p> <p>(Btw I am running java version "1.6.0_15" and compiling with the command line)</p>
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    1. This table or related slice is empty.
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    1. COWhat is the T in LinkedGenericLog?
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    2. COT represents the type of item that the LinkedGenericLog is meant to store. In other words, you could instantiate a LinkedGenericLog where T is replaced by String, and then use the Log to store String objects.
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    3. COsee my answer then
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