Solution avec SortedMap + ...

src/ch/genevaJug/fooBarQix/FooBarQix.java

@@ -0,0 +1,36 @@
+package ch.genevaJug.fooBarQix;
+
+
+import org.apache.log4j.Logger;
+
+public class FooBarQix {
+
+    private final static Logger logger = Logger.getLogger(FooBarQix.class);
+
+    /**
+     * @param args
+     */
+    public static void main(String[] args) {
+        logger.debug("START FooBarQix");
+        FooBarQix fooBarQix = new FooBarQix();
+        fooBarQix.display(100);
+        logger.debug("END FooBarQix");
+    }
+
+    public void display(int nbLine) {
+        Window window = new Window();
+
+        FooBarQixConverter converter = FooBarQixConverter.getInstance();
+        for (int number = 1; number <= nbLine; number++) {
+            try {
+                String value = converter.convert(number);
+                window.addValue(value);
+            } catch (Exception e) {
+                logger.error("Unable to convert value "+number, e);
+                // Error policy, continue and hope user will not see the error
+                // => we display the number. But we send by mail the error so know they are a error.
+                window.addValue(String.valueOf(number));
+            }
+        }
+    }
+}

src/ch/genevaJug/fooBarQix/FooBarQixConverter.java

@@ -0,0 +1,62 @@
+package ch.genevaJug.fooBarQix;
+
+import java.util.Collections;
+import java.util.Map.Entry;
+import java.util.SortedMap;
+import java.util.TreeMap;
+
+
+/**
+ * 
+ * @author Daniel
+ *
+ */
+public class FooBarQixConverter {
+
+
+    // Unmodifiable SortedMap.
+    private final SortedMap<Integer, String> specialValues;
+    private FooBarQixConverter () {
+        SortedMap<Integer, String> specialValuesTmp = new TreeMap<Integer, String>();
+        specialValuesTmp.put(5, "Bar");
+        specialValuesTmp.put(3, "Foo");
+        specialValuesTmp.put(7, "Qix");
+        specialValues = Collections.unmodifiableSortedMap(specialValuesTmp);
+    }
+
+    // Singleton with static solution
+    private final static FooBarQixConverter instance = new FooBarQixConverter();
+    public static FooBarQixConverter getInstance() {
+        return instance; 
+    } 
+
+    /**
+     * Convert with following rules:
+     *  if number can be divided by 3,5,7 add special Values
+     *  if number contain char 3,5,7 add special Values
+     *  if no special Values return the number
+     * @param number
+     * @return
+     */
+    public String convert(int number) {
+        final String numberStr = String.valueOf(number);
+        StringBuilder result = new StringBuilder();
+
+        // if number can be divided by 3,5,7 add special Values 
+        for (Entry<Integer, String> entry : specialValues.entrySet()) {
+            if (number % entry.getKey() == 0) {
+                result.append(entry.getValue());
+            }
+        }
+
+        // if number contain char 3,5,7 add special Values 
+        for (char ch : numberStr.toCharArray()) {
+            int key = Character.digit(ch, 10);
+            if (specialValues.containsKey(key)) {
+                result.append(specialValues.get(key));
+            }
+        }
+
+        return result.length() == 0 ? numberStr : result.toString();
+    }
+}

src/ch/genevaJug/fooBarQix/Window.java

@@ -0,0 +1,28 @@
+package ch.genevaJug.fooBarQix;
+
+import javax.swing.JFrame;
+import javax.swing.JScrollPane;
+import javax.swing.JTextPane;
+import javax.swing.text.Document;
+
+public class Window extends JFrame {
+    private static final long serialVersionUID = 1L;
+
+    private JTextPane textPane = new JTextPane();
+
+    public Window () {
+        this.setTitle("FooBarQix");
+        this.setSize(300,500);
+        this.setLocationRelativeTo(null);
+        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        this.getContentPane().add(new JScrollPane(textPane));
+        this.setVisible(true);
+    }
+
+    public void addValue(String value) {
+        Document doc = textPane.getDocument();
+        textPane.setCaretPosition(doc.getLength());
+        textPane.replaceSelection(value + "\n");
+    }
+
+}

src/log4j.properties

@@ -0,0 +1,29 @@
+log4j.rootLogger=ERROR, console, file
+#log4j.rootLogger=ERROR, console, file, mail
+
+log4j.appender.console=org.apache.log4j.ConsoleAppender
+log4j.appender.console.layout=org.apache.log4j.PatternLayout
+log4j.appender.console.layout.ConversionPattern=[%d{ISO8601}] %t %-5p %C{1}:%-4L %n%m %n
+
+#log4j.appender.logfile.Threshold=INFO
+log4j.appender.file=org.apache.log4j.RollingFileAppender
+log4j.appender.file.layout=org.apache.log4j.PatternLayout
+log4j.appender.file.layout.ConversionPattern=[%d{ISO8601}] %t %-5p [%c{1}] - %n%m%n
+log4j.appender.file.File=log/FooBarQixLogger.log
+log4j.appender.file.MaxFileSize=512KB
+log4j.appender.file.MaxBackupIndex=1
+
+log4j.appender.mail=org.apache.log4j.net.SMTPAppender
+log4j.appender.mail.Threshold=ERROR
+log4j.appender.mail.SMTPHost=smtp.server
+log4j.appender.mail.SMTPUsername=mail Authenticated by stmp server 
+log4j.appender.mail.SMTPPassword=password from Authenticated mail
+log4j.appender.mail.Subject=Error!
+log4j.appender.mail.To=to mail
+log4j.appender.mail.From=from mail
+log4j.appender.mail.layout=org.apache.log4j.PatternLayout
+log4j.appender.mail.layout.ConversionPattern=Date : %d{ISO8601}%nThread : %t%nLevel : %-5p%nLogger : %c%n%m%n%n
+log4j.appender.mail.BufferSize=10
+
+# limit categories
+log4j.logger.ch.genevaJug.fooBarQix.FooBarQix=DEBUG

src/test/ch/genevaJug/fooBarQix/FooBarQixConverterTestJunit.java

@@ -0,0 +1,53 @@
+package test.ch.genevaJug.fooBarQix;
+
+import org.fest.assertions.Assertions;
+import org.testng.annotations.DataProvider;
+import org.testng.annotations.Test;
+
+import ch.genevaJug.fooBarQix.FooBarQixConverter;
+
+
+public class FooBarQixConverterTestJunit {
+    @DataProvider(name = "intToValue")
+    public Object[][] getIntValueArray(){
+        return new Object[][] {
+                {1,"1"},
+                {2,"2"},
+                {3,"FooFoo"},
+                {4,"4"},
+                {5,"BarBar"},
+                {6,"Foo"},
+                {7,"QixQix"},
+                {8,"8"},
+                {9,"Foo"},
+                {10,"Bar"},
+                {11,"11"},
+                {12,"Foo"},
+                {13,"Foo"},
+                {14,"Qix"},
+                {15,"FooBarBar"},
+                {16,"16"},
+                {17,"Qix"},
+                {18,"Foo"},
+                {19,"19"},
+                {20,"Bar"},
+                {21,"FooQix"},
+                {22,"22"},
+                {23,"Foo"},
+                {30,"FooBarFoo"},
+                {33,"FooFooFoo"},
+                {35,"BarQixFooBar"},
+                {51,"FooBar"},
+                {53,"BarFoo"},
+                {55,"BarBarBar"},
+                {57,"FooBarQix"},
+                {75,"FooBarQixBar"},
+        };
+    }
+
+    @Test(dataProvider = "intToValue")
+    public void shouldReturnValue(int i, String value) {
+        FooBarQixConverter converter = FooBarQixConverter.getInstance();
+        Assertions.assertThat(converter.convert(i)).isEqualTo(value);
+    }
+}