Upgrade the project to Java7+

.gitignore

@@ -0,0 +1,3 @@
+.gradle
+.idea
+build

build.gradle

@@ -0,0 +1,19 @@
+apply plugin: 'java'
+
+repositories {
+  mavenCentral()
+  maven {
+      url 'https://repository.jboss.org/nexus/content/repositories/thirdparty-releases/'
+  }
+}
+
+dependencies {
+  compile 'net.sf:jargs:1.0'
+  testCompile 'junit:junit:4.11'
+}
+
+compileJava {
+  sourceCompatibility = 1.7
+  targetCompatibility = 1.7
+  options.compilerArgs = ['-Xlint:all']
+}

settings.gradle

@@ -0,0 +1 @@
+rootProject.name = "csscompressor"

andyr/csscompressor/CssCompressor.java → src/main/java/andyr/csscompressor/CssCompressor.java

@@ -71,8 +71,8 @@ public CssCompressor(Reader in) throws IOException {
 
     protected String mergeRules(String inputCss) {
 
-        Map ruleMap = new HashMap();
-        StringBuffer mergedCss = new StringBuffer();
+        Map<String, String> ruleMap = new HashMap<String, String>();
+        StringBuilder mergedCss = new StringBuilder();
 
         Pattern p = Pattern.compile("([^\\{]*)\\{(.*?)\\}");
         Matcher m = p.matcher(inputCss);
@@ -84,30 +84,28 @@ protected String mergeRules(String inputCss) {
             rules = compressDimensions(rules);
 
             if (ruleMap.containsKey(rules)) {
-                ruleMap.put(rules, ruleMap.get(rules) + "," + selectors);
+                ruleMap.put(rules, ruleMap.get(rules) + ',' + selectors);
             }
             else {
                 ruleMap.put(rules, selectors);
             }
         }
 
-        String rule;
-        for (Iterator i = ruleMap.keySet().iterator(); i.hasNext();) {
-            rule = (String)i.next();
-            mergedCss.append(ruleMap.get(rule)+"{"+rule+"}");
+        for (String rule : ruleMap.keySet()) {
+            mergedCss.append(ruleMap.get(rule)).append('{').append(rule).append('}');
         }
 
         return mergedCss.toString();
     }
 
     protected String removeDuplicateProperties(String inputCssRule) {
 
-        StringBuffer cssRule = new StringBuffer();
+        StringBuilder cssRule = new StringBuilder();
 
-        Set ruleSet = new HashSet(Arrays.asList(inputCssRule.split(";")));
+        Set<String> ruleSet = new HashSet<String>(Arrays.asList(inputCssRule.split(";")));
 
-        for (Iterator i = ruleSet.iterator(); i.hasNext();) {
-            cssRule.append((String)i.next() + ";");
+        for (String aRuleSet : ruleSet) {
+            cssRule.append(aRuleSet).append(";");
         }
 
         return cssRule.toString();
@@ -117,18 +115,18 @@ protected String compressDimensions(String inputCssRule) {
         Pattern p = Pattern.compile("(border|margin):(\\d+(?:\\p{Alpha}*))(\\2){3}");
         Matcher m;
 
-        StringBuffer cssRule = new StringBuffer();
+        StringBuilder cssRule = new StringBuilder();
 
         for (String rule: inputCssRule.split(";")) {
 
             String condensedRule = rule.replaceAll(" +", "");
             m = p.matcher(condensedRule);
             if (m.find()) {
                 cssRule.append(condensedRule.substring(0, m.start()));
-                cssRule.append(m.group(1) + ':' + m.group(2) + ';');
+                cssRule.append(m.group(1)).append(':').append(m.group(2)).append(';');
             }
             else {
-                cssRule.append(rule + ';');
+                cssRule.append(rule).append(';');
             }
         }
 
@@ -223,9 +221,9 @@ public void compress(Writer out, int linebreakpos)
         sb = new StringBuffer();
         while (m.find()) {
             String[] rgbcolors = m.group(1).split(",");
-            StringBuffer hexcolor = new StringBuffer("#");
-            for (int i = 0; i < rgbcolors.length; i++) {
-                int val = Integer.parseInt(rgbcolors[i]);
+            StringBuilder hexcolor = new StringBuilder("#");
+            for (String rgbcolor : rgbcolors) {
+                int val = Integer.parseInt(rgbcolor);
                 if (val < 16) {
                     hexcolor.append("0");
                 }
@@ -246,7 +244,7 @@ public void compress(Writer out, int linebreakpos)
         m = p.matcher(css);
         sb = new StringBuffer();
 
-        Map colorMap = new HashMap();
+        Map<String, String> colorMap = new HashMap<String, String>();
         colorMap.put("C0C0C0", "silver");
         colorMap.put("800000", "maroon");
         colorMap.put("800080", "purple");

src/test/java/andyr/csscompressor/CssCompressorTest.java

@@ -0,0 +1,65 @@
+package andyr.csscompressor;
+
+import org.junit.Test;
+
+import java.io.*;
+
+import static org.junit.Assert.*;
+
+public class CssCompressorTest {
+
+    @Test
+    public void testCompressionMergesDuplicates() throws Exception {
+        checkCompression(".myclassA { font-style: bold; }\n.myclassB { font-style: bold; }", ".myclassA,\n.myclassB{font-style:bold}");
+    }
+
+    @Test
+    public void testCompressionCompressesDimensions() throws Exception {
+        checkCompression(".myclass { border: 4px 4px 4px 4px; } ", ".myclass{border:4px}");
+    }
+
+    @Test
+    public void testCompressionRemovesLastSemiColon() throws Exception {
+        checkCompression(".myclass { font-style: bold; color: red; }", ".myclass{font-style:bold;color:red}");
+    }
+
+    @Test
+    public void testCompressionRemovesWhitespaces() throws Exception {
+        checkCompression(".myclass { font-style: bold; }", ".myclass{font-style:bold}");
+    }
+
+    @Test
+    public void testCompressionStripsUnitValuesOnZeros() throws Exception {
+        checkCompression(".myclass { margin-left: 0px; }", ".myclass{margin-left:0}");
+    }
+
+    @Test
+    public void testCompressionCompressesColors() throws Exception {
+        checkCompression(".myclass { color: rgb(51,102,153); }", ".myclass{color:#369}");
+        checkCompression(".myclass { color: #AABBCC; }", ".myclass{color:#ABC}");
+    }
+
+    @Test
+    public void testCompressionRemovesComments() throws Exception {
+        checkCompression(".myclass { font-style: bold; /* comment */ }", ".myclass{font-style:bold}");
+    }
+
+    @Test
+    public void testCompressionRemovesEmptyRules() throws Exception {
+        checkCompression(".myclass { }", "");
+    }
+
+    @Test
+    public void testCompressionAcceptsBlankInputs() throws Exception {
+        checkCompression("", "");
+        checkCompression("\n\n", "");
+    }
+
+    private void checkCompression(String cssIn, String cssOut) throws IOException {
+        Reader in = new StringReader(cssIn);
+        Writer out = new StringWriter();
+        new CssCompressor(in).compress(out, 4);
+        assertEquals(cssOut, out.toString());
+    }
+
+}