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    <p>Welcome to SO.</p> <p>First of all, there are Java conventions to name the variables. Have a look at the <a href="http://java.sun.com/docs/codeconv/html/CodeConventions.doc8.html" rel="nofollow noreferrer"> Naming conventions</a></p> <p>Secondly, Java is an Object Oriented Language, so you have to change your mind a little bit about how you approach problems.</p> <p>In this particular case, you want all the data scattered among 3 arrays to be together. Well, create a class for it.</p> <pre><code>public class Data implements Comparable{ private String title; private String desc; private int num; public Data(String title, String desc, int num){ //set the private fields here } //You may want to write some setters and getters here for individual fields. public int compareTo(Object o){ //here you compare an item with other item. Remember to cast the object o to Data. // Read http://java.sun.com/j2se/1.4.2/docs/api/java/lang/Comparable.html to know what to return } } </code></pre> <p>And then in your main class:</p> <pre><code>int item = 0; do { Data group = new Data(arr_title.get(item),arr_desc.get(item),arr_num.get(item); groupData.add(group); item++; } while (item &lt; arr_num.size()); Collections.sort(groupData); </code></pre> <p>Last but not least, there are better ways to iterate through a set in Java. Read about <a href="http://java.sun.com/j2se/1.4.2/docs/api/java/util/Iterator.html" rel="nofollow noreferrer">Iterators</a>. It's a much secure and cleaner way to go through an array or a set.</p>
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    1. POJava: Sorting multiple ArrayLists synchronously or a single mapped ArrayList
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    1. COWhile I have very basic knowledge of several languages, I consider Java to be the first language I've learned, so I'm not really taking much as far as skills from another language into Java. I remember touching on the object-oriented topic when I first started getting into Java, but I guess I didn't spend enough time on it to fully understand it or build the habit of using it properly. I guess that's a typical problem with going at it alone instead of taking classes. I'll give your example a spin and let you know how it goes. Thanks!
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    2. COUnfortunately I still seem to be having trouble. There are a number of warnings and at first were some errors, but after changing the first line to List<Data> groupData = new ArrayList<Data>();, removing Map<String, String> group;, then casting groupData in SimpleAdapter to (List<? extends Map<String, ?>>) as Eclipse suggested, I managed to get rid of the errors and compile, but I get a ClassCastException at runtime. It appears to be caused by the type of list that the SimpleAdapter accepts. I'll keep crunching on this, but any more tips would be appreciated.
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    3. COYeah that's normal because Java is a strict typed language. You changed the type of the data, so it complains :). What you have to do now is modify SimpleAdapter to receive a List of Data (List<Data>) instead of the old groupData.
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