Fix some quality flaws

15 files changed, 122 insertions, 76 deletions

diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/batch/SquidUtils.java b/sonar-plugin-api/src/main/java/org/sonar/api/batch/SquidUtils.java
index 318868e15c2..dbb2e2e2132 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/batch/SquidUtils.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/batch/SquidUtils.java
@@ -25,14 +25,16 @@ import org.sonar.api.resources.JavaPackage;
 
 public final class SquidUtils {
 
+  private static final String JAVA_FILE_SUFFIX = ".java";
+
   private SquidUtils() {
     // only static methods
   }
 
   public static JavaFile convertJavaFileKeyFromSquidFormat(String key) {
-    boolean isJavaFile = key.endsWith(".java");
+    boolean isJavaFile = key.endsWith(JAVA_FILE_SUFFIX);
     if (isJavaFile) {
-      key = key.substring(0, key.length() - ".java".length());
+      key = key.substring(0, key.length() - JAVA_FILE_SUFFIX.length());
     }
 
     String convertedKey = key.replace('/', '.');
@@ -53,11 +55,11 @@ public final class SquidUtils {
 
   public static String convertToSquidKeyFormat(JavaFile file) {
     String key = file.getKey();
-    if (file.getParent()==null || file.getParent().isDefault()) {
+    if (file.getParent() == null || file.getParent().isDefault()) {
       key = StringUtils.substringAfterLast(file.getKey(), ".");
     } else {
       key = StringUtils.replace(key, ".", "/");
     }
-    return  key + ".java";
+    return key + JAVA_FILE_SUFFIX;
   }
 }
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/batch/maven/MavenPlugin.java b/sonar-plugin-api/src/main/java/org/sonar/api/batch/maven/MavenPlugin.java
index f8217841cbf..fad61ba028e 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/batch/maven/MavenPlugin.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/batch/maven/MavenPlugin.java
@@ -37,6 +37,7 @@ import java.util.List;
  */
 public class MavenPlugin {
 
+  private static final String CONFIGURATION_ELEMENT = "configuration";
   private Plugin plugin;
   private Xpp3Dom configuration;
 
@@ -49,7 +50,7 @@ public class MavenPlugin {
     this.plugin = plugin;
     this.configuration = (Xpp3Dom) plugin.getConfiguration();
     if (this.configuration == null) {
-      configuration = new Xpp3Dom("configuration");
+      configuration = new Xpp3Dom(CONFIGURATION_ELEMENT);
       plugin.setConfiguration(this.configuration);
     }
   }
@@ -66,7 +67,7 @@ public class MavenPlugin {
     plugin.setGroupId(groupId);
     plugin.setArtifactId(artifactId);
     plugin.setVersion(version);
-    configuration = new Xpp3Dom("configuration");
+    configuration = new Xpp3Dom(CONFIGURATION_ELEMENT);
     plugin.setConfiguration(this.configuration);
   }
 
@@ -163,7 +164,7 @@ public class MavenPlugin {
    * Removes all parameters from the maven plugin
    */
   public void removeParameters() {
-    configuration = new Xpp3Dom("configuration");
+    configuration = new Xpp3Dom(CONFIGURATION_ELEMENT);
     plugin.setConfiguration(this.configuration);
   }
 
@@ -200,7 +201,7 @@ public class MavenPlugin {
   }
 
   private static int getIndex(String key) {
-    //parsing index-syntax (e.g. item[1])
+    // parsing index-syntax (e.g. item[1])
     if (key.matches(".*?\\[\\d+\\]")) {
       return Integer.parseInt(StringUtils.substringBetween(key, "[", "]"));
     }
@@ -231,7 +232,7 @@ public class MavenPlugin {
     Xpp3Dom node = configuration;
     for (String keyPart : keyParts) {
 
-      if(node.getChildren(removeIndexSnippet(keyPart)).length <= getIndex(keyPart)) {
+      if (node.getChildren(removeIndexSnippet(keyPart)).length <= getIndex(keyPart)) {
         return null;
       }
 
@@ -258,7 +259,7 @@ public class MavenPlugin {
    * @return whether the maven plugin has got configuration
    */
   public boolean hasConfiguration() {
-    return configuration.getChildCount()>0;
+    return configuration.getChildCount() > 0;
   }
 
   private static void checkKeyArgument(String key) {
@@ -416,13 +417,12 @@ public class MavenPlugin {
     }
   }
 
-
   @Override
   public String toString() {
     return new ToStringBuilder(this)
-        .append("groupId", plugin.getGroupId())
-        .append("artifactId", plugin.getArtifactId())
-        .append("version", plugin.getVersion())
-        .toString();
+      .append("groupId", plugin.getGroupId())
+      .append("artifactId", plugin.getArtifactId())
+      .append("version", plugin.getVersion())
+      .toString();
   }
 }
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/batch/maven/MavenUtils.java b/sonar-plugin-api/src/main/java/org/sonar/api/batch/maven/MavenUtils.java
index 16806f1d7a6..3b4c9120f55 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/batch/maven/MavenUtils.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/batch/maven/MavenUtils.java
@@ -30,11 +30,12 @@ import java.util.Collection;
 
 /**
  * An utility class to manipulate Maven concepts
- * 
+ *
  * @since 1.10
  */
 public final class MavenUtils {
 
+  private static final String MAVEN_COMPILER_PLUGIN = "maven-compiler-plugin";
   public static final String GROUP_ID_APACHE_MAVEN = "org.apache.maven.plugins";
   public static final String GROUP_ID_CODEHAUS_MOJO = "org.codehaus.mojo";
 
@@ -44,12 +45,12 @@ public final class MavenUtils {
 
   /**
    * Returns the version of Java used by the maven compiler plugin
-   * 
+   *
    * @param pom the project pom
    * @return the java version
    */
   public static String getJavaVersion(MavenProject pom) {
-    MavenPlugin compilerPlugin = MavenPlugin.getPlugin(pom, GROUP_ID_APACHE_MAVEN, "maven-compiler-plugin");
+    MavenPlugin compilerPlugin = MavenPlugin.getPlugin(pom, GROUP_ID_APACHE_MAVEN, MAVEN_COMPILER_PLUGIN);
     if (compilerPlugin != null) {
       return compilerPlugin.getParameter("target");
     }
@@ -57,7 +58,7 @@ public final class MavenUtils {
   }
 
   public static String getJavaSourceVersion(MavenProject pom) {
-    MavenPlugin compilerPlugin = MavenPlugin.getPlugin(pom, GROUP_ID_APACHE_MAVEN, "maven-compiler-plugin");
+    MavenPlugin compilerPlugin = MavenPlugin.getPlugin(pom, GROUP_ID_APACHE_MAVEN, MAVEN_COMPILER_PLUGIN);
     if (compilerPlugin != null) {
       return compilerPlugin.getParameter("source");
     }
@@ -66,7 +67,7 @@ public final class MavenUtils {
 
   /**
    * Queries a collection of plugins based on a group id and an artifact id and returns the plugin if it exists
-   * 
+   *
    * @param plugins the plugins collection
    * @param groupId the group id
    * @param artifactId the artifact id
@@ -85,7 +86,7 @@ public final class MavenUtils {
 
   /**
    * Tests whether a plugin has got a given artifact id and group id
-   * 
+   *
    * @param plugin the plugin to test
    * @param groupId the group id
    * @param artifactId the artifact id
@@ -103,7 +104,7 @@ public final class MavenUtils {
 
   /**
    * Tests whether a ReportPlugin has got a given artifact id and group id
-   * 
+   *
    * @param plugin the ReportPlugin to test
    * @param groupId the group id
    * @param artifactId the artifact id
@@ -128,7 +129,7 @@ public final class MavenUtils {
 
   /**
    * Returns the charset of a pom
-   * 
+   *
    * @param pom the project pom
    * @return the charset
    */
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/checks/AnnotationCheckFactory.java b/sonar-plugin-api/src/main/java/org/sonar/api/checks/AnnotationCheckFactory.java
index b231829e8f5..e706da53015 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/checks/AnnotationCheckFactory.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/checks/AnnotationCheckFactory.java
@@ -40,6 +40,7 @@ import java.util.Map;
  */
 public final class AnnotationCheckFactory extends CheckFactory {
 
+  private static final String CAN_NOT_INSTANTIATE_THE_CHECK_RELATED_TO_THE_RULE = "Can not instantiate the check related to the rule ";
   private Map<String, Object> checksByKey = Maps.newHashMap();
 
   private AnnotationCheckFactory(RulesProfile profile, String repositoryKey, Collection checks) {
@@ -81,10 +82,10 @@ public final class AnnotationCheckFactory extends CheckFactory {
       return check;
 
     } catch (InstantiationException e) {
-      throw new SonarException("Can not instantiate the check related to the rule " + activeRule, e);
+      throw new SonarException(CAN_NOT_INSTANTIATE_THE_CHECK_RELATED_TO_THE_RULE + activeRule, e);
 
     } catch (IllegalAccessException e) {
-      throw new SonarException("Can not instantiate the check related to the rule " + activeRule, e);
+      throw new SonarException(CAN_NOT_INSTANTIATE_THE_CHECK_RELATED_TO_THE_RULE + activeRule, e);
     }
   }
 
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/measures/Measure.java b/sonar-plugin-api/src/main/java/org/sonar/api/measures/Measure.java
index c08ad379867..f286c28790f 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/measures/Measure.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/measures/Measure.java
@@ -36,6 +36,8 @@ import java.util.Date;
  * @since 1.10
  */
 public class Measure {
+  private static final String INDEX_SHOULD_BE_IN_RANGE_FROM_1_TO_5 = "Index should be in range from 1 to 5";
+
   protected static final int MAX_TEXT_SIZE = 96;
 
   /**
@@ -531,7 +533,7 @@ public class Measure {
       case 5:
         return variation5;
       default:
-        throw new IndexOutOfBoundsException("Index should be in range from 1 to 5");
+        throw new IndexOutOfBoundsException(INDEX_SHOULD_BE_IN_RANGE_FROM_1_TO_5);
     }
   }
 
@@ -558,7 +560,7 @@ public class Measure {
         variation5 = d;
         break;
       default:
-        throw new IndexOutOfBoundsException("Index should be in range from 1 to 5");
+        throw new IndexOutOfBoundsException(INDEX_SHOULD_BE_IN_RANGE_FROM_1_TO_5);
     }
     return this;
   }
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/profiles/XMLProfileParser.java b/sonar-plugin-api/src/main/java/org/sonar/api/profiles/XMLProfileParser.java
index 2a42997edf2..ea6f038e4f3 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/profiles/XMLProfileParser.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/profiles/XMLProfileParser.java
@@ -45,7 +45,7 @@ import java.util.Map;
 
 /**
  * TODO should be an interface
- * 
+ *
  * @since 2.3
  */
 public final class XMLProfileParser implements ServerComponent {
@@ -55,7 +55,7 @@ public final class XMLProfileParser implements ServerComponent {
 
   /**
    * For backward compatibility.
-   * 
+   *
    * @deprecated since 2.5. Plugins shouldn't directly instantiate this class,
    *             because it should be retrieved as an IoC dependency.
    */
@@ -163,14 +163,13 @@ public final class XMLProfileParser implements ServerComponent {
 
       Rule rule = ruleFinder.findByKey(repositoryKey, key);
       if (rule == null) {
-        messages.addWarningText("Rule not found: [repository=" + repositoryKey + ", key=" + key + "]");
+        messages.addWarningText("Rule not found: " + ruleToString(repositoryKey, key));
 
       } else {
         ActiveRule activeRule = profile.activateRule(rule, priority);
         for (Map.Entry<String, String> entry : parameters.entrySet()) {
           if (rule.getParam(entry.getKey()) == null) {
-            messages.addWarningText("The parameter '" + entry.getKey() + "' does not exist in the rule: [repository=" + repositoryKey
-              + ", key=" + key + "]");
+            messages.addWarningText("The parameter '" + entry.getKey() + "' does not exist in the rule: " + ruleToString(repositoryKey, key));
           } else {
             activeRule.setParameter(entry.getKey(), entry.getValue());
           }
@@ -179,6 +178,10 @@ public final class XMLProfileParser implements ServerComponent {
     }
   }
 
+  private String ruleToString(String repositoryKey, String key) {
+    return "[repository=" + repositoryKey + ", key=" + key + "]";
+  }
+
   private void processParameters(SMInputCursor propsCursor, Map<String, String> parameters) throws XMLStreamException {
     while (propsCursor.getNext() != null) {
       SMInputCursor propCursor = propsCursor.childElementCursor();
@@ -222,7 +225,7 @@ public final class XMLProfileParser implements ServerComponent {
           if (StringUtils.isNotBlank(periodParameter)) {
             period = Integer.parseInt(periodParameter);
           }
-        }else if (StringUtils.equals("operator", nodeName)) {
+        } else if (StringUtils.equals("operator", nodeName)) {
           operator = StringUtils.trim(alertCursor.collectDescendantText(false));
 
         } else if (StringUtils.equals("warning", nodeName)) {
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/resources/Project.java b/sonar-plugin-api/src/main/java/org/sonar/api/resources/Project.java
index 0e93c6a00b8..68c9b62e7fb 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/resources/Project.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/resources/Project.java
@@ -34,11 +34,14 @@ import java.util.List;
 
 /**
  * A class that manipulates Projects in the Sonar way.
- * 
+ *
  * @since 1.10
  */
 public class Project extends Resource implements Component {
 
+  private static final String MAVEN_KEY_FORMAT = "%s:%s";
+  private static final String BRANCH_KEY_FORMAT = "%s:%s";
+
   public static final String SCOPE = Scopes.PROJECT;
 
   /**
@@ -86,7 +89,7 @@ public class Project extends Resource implements Component {
 
   public Project(String key, String branch, String name) {
     if (StringUtils.isNotBlank(branch)) {
-      setKey(String.format("%s:%s", key, branch));
+      setKey(String.format(BRANCH_KEY_FORMAT, key, branch));
       this.name = String.format("%s %s", name, branch);
     } else {
       setKey(key);
@@ -158,7 +161,7 @@ public class Project extends Resource implements Component {
 
   /**
    * For internal use only.
-   * 
+   *
    * @deprecated in 2.8. See http://jira.codehaus.org/browse/SONAR-2341
    */
   @Deprecated
@@ -199,7 +202,7 @@ public class Project extends Resource implements Component {
 
   /**
    * whether it's the latest analysis done on this project (displayed in sonar dashboard) or an analysis on a past revision.
-   * 
+   *
    * @since 2.0
    * @deprecated in 3.6. The analysis is now always the latest one (past analysis must be done in a chronological order). See http://jira.codehaus.org/browse/SONAR-4334
    */
@@ -396,7 +399,7 @@ public class Project extends Resource implements Component {
 
   /**
    * For internal use only.
-   * 
+   *
    * @deprecated since 2.6. See http://jira.codehaus.org/browse/SONAR-2126
    */
   @Deprecated
@@ -457,7 +460,7 @@ public class Project extends Resource implements Component {
   }
 
   public static Project createFromMavenIds(String groupId, String artifactId) {
-    return new Project(String.format("%s:%s", groupId, artifactId));
+    return new Project(String.format(MAVEN_KEY_FORMAT, groupId, artifactId));
   }
 
   @Override
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/resources/ResourceType.java b/sonar-plugin-api/src/main/java/org/sonar/api/resources/ResourceType.java
index d5aa6d2e402..3d7f4f6b8fa 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/resources/ResourceType.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/resources/ResourceType.java
@@ -59,6 +59,7 @@ public class ResourceType {
    * Builder used to create {@link ResourceType} objects.
    */
   public static class Builder {
+    private static final String SUPPORTS_MEASURE_FILTERS = "supportsMeasureFilters";
     private String qualifier;
     private String iconPath;
     private boolean hasSourceCode = false;
@@ -88,7 +89,7 @@ public class ResourceType {
      */
     @Deprecated
     public Builder availableForFilters() {
-      setProperty("supportsMeasureFilters", "true");
+      setProperty(SUPPORTS_MEASURE_FILTERS, "true");
       return this;
     }
 
@@ -112,7 +113,7 @@ public class ResourceType {
 
       // for backward-compatibility since version 3.4
       if ("availableForFilters".equals(key)) {
-        properties.put("supportsMeasureFilters", value);
+        properties.put(SUPPORTS_MEASURE_FILTERS, value);
       }
       return this;
     }
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/rules/Rule.java b/sonar-plugin-api/src/main/java/org/sonar/api/rules/Rule.java
index 02612902def..afa876940d6 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/rules/Rule.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/rules/Rule.java
@@ -34,7 +34,19 @@ import org.sonar.check.Cardinality;
 
 import javax.annotation.CheckForNull;
 import javax.annotation.Nullable;
-import javax.persistence.*;
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.EnumType;
+import javax.persistence.Enumerated;
+import javax.persistence.FetchType;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.ManyToOne;
+import javax.persistence.OneToMany;
+import javax.persistence.Table;
+import javax.persistence.Temporal;
+import javax.persistence.TemporalType;
 
 import java.util.ArrayList;
 import java.util.Date;
@@ -70,7 +82,6 @@ public final class Rule {
    */
   private static final Set<String> STATUS_LIST = ImmutableSet.of(STATUS_READY, STATUS_BETA, STATUS_DEPRECATED, STATUS_REMOVED);
 
-
   @Id
   @Column(name = "id")
   @GeneratedValue
@@ -282,7 +293,7 @@ public final class Rule {
   }
 
   public Boolean isEnabled() {
-    return !"REMOVED".equals(status);
+    return !STATUS_REMOVED.equals(status);
   }
 
   public List<RuleParam> getParams() {
@@ -450,7 +461,6 @@ public final class Rule {
     return this;
   }
 
-
   /**
    * @since 3.6
    */
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/rules/RulePriority.java b/sonar-plugin-api/src/main/java/org/sonar/api/rules/RulePriority.java
index f62d342a0eb..faf640d4ac1 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/rules/RulePriority.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/rules/RulePriority.java
@@ -32,6 +32,9 @@ public enum RulePriority {
    */
   INFO, MINOR, MAJOR, CRITICAL, BLOCKER;
 
+  private static final String UNKNOWN_PRIORITY = "Unknown priority ";
+
+
   /**
    * A class to map priority level prior to Sonar 1.10 to the new ones
    *
@@ -52,7 +55,7 @@ public enum RulePriority {
         return RulePriority.INFO;
       }
     }
-    throw new IllegalArgumentException("Unknown priority " + level);
+    throw new IllegalArgumentException(UNKNOWN_PRIORITY + level);
   }
 
 
@@ -72,6 +75,6 @@ public enum RulePriority {
     if (checkPriority == Priority.INFO) {
       return RulePriority.INFO;
     }
-    throw new IllegalArgumentException("Unknown priority " + checkPriority);
+    throw new IllegalArgumentException(UNKNOWN_PRIORITY + checkPriority);
   }
-}
\ No newline at end of file
+}
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/utils/HttpDownloader.java b/sonar-plugin-api/src/main/java/org/sonar/api/utils/HttpDownloader.java
index 00fa4c82678..bfcb689b2c7 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/utils/HttpDownloader.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/utils/HttpDownloader.java
@@ -143,9 +143,13 @@ public class HttpDownloader extends UriReader.SchemeProcessor implements BatchCo
   }
 
   public static class BaseHttpDownloader {
+
+    private static final String HTTP_PROXY_USER = "http.proxyUser";
+    private static final String HTTP_PROXY_PASSWORD = "http.proxyPassword";
+
     private static final List<String> PROXY_SETTINGS = ImmutableList.of(
-        "http.proxyHost", "http.proxyPort", "http.nonProxyHosts",
-        "http.auth.ntlm.domain", "socksProxyHost", "socksProxyPort");
+      "http.proxyHost", "http.proxyPort", "http.nonProxyHosts",
+      "http.auth.ntlm.domain", "socksProxyHost", "socksProxyPort");
 
     private String userAgent;
 
@@ -189,12 +193,12 @@ public class HttpDownloader extends UriReader.SchemeProcessor implements BatchCo
 
     private void registerProxyCredentials(Map<String, String> settings) {
       Authenticator.setDefault(new ProxyAuthenticator(
-          settings.get("http.proxyUser"),
-          settings.get("http.proxyPassword")));
+        settings.get(HTTP_PROXY_USER),
+        settings.get(HTTP_PROXY_PASSWORD)));
     }
 
     private boolean requiresProxyAuthentication(Map<String, String> settings) {
-      return settings.containsKey("http.proxyUser");
+      return settings.containsKey(HTTP_PROXY_USER);
     }
 
     private void propagateProxySystemProperties(Map<String, String> settings) {
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/utils/TimeProfiler.java b/sonar-plugin-api/src/main/java/org/sonar/api/utils/TimeProfiler.java
index 0b156cd2c48..d451aad884c 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/utils/TimeProfiler.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/utils/TimeProfiler.java
@@ -25,7 +25,7 @@ import org.slf4j.LoggerFactory;
 /**
  * A very simple profiler to log the time elapsed performing some tasks.
  * This implementation is not thread-safe.
- * 
+ *
  * @since 2.0
  */
 public class TimeProfiler {
@@ -80,10 +80,11 @@ public class TimeProfiler {
 
   public TimeProfiler stop() {
     if (start > 0) {
+      String format = "{} done: {} ms";
       if (debug) {
-        logger.debug("{} done: {} ms", name, System.currentTimeMillis() - start);
+        logger.debug(format, name, System.currentTimeMillis() - start);
       } else {
-        logger.info("{} done: {} ms", name, System.currentTimeMillis() - start);
+        logger.info(format, name, System.currentTimeMillis() - start);
       }
     }
     start = 0;
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/utils/XpathParser.java b/sonar-plugin-api/src/main/java/org/sonar/api/utils/XpathParser.java
index 65487c327a3..f48cd8e450e 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/utils/XpathParser.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/utils/XpathParser.java
@@ -28,18 +28,29 @@ import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;
 import org.xml.sax.SAXException;
 
-import java.io.*;
+import javax.xml.namespace.QName;
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.xpath.XPath;
+import javax.xml.xpath.XPathConstants;
+import javax.xml.xpath.XPathExpression;
+import javax.xml.xpath.XPathExpressionException;
+import javax.xml.xpath.XPathFactory;
+
+import java.io.BufferedReader;
+import java.io.ByteArrayInputStream;
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
-import javax.xml.namespace.QName;
-import javax.xml.parsers.DocumentBuilder;
-import javax.xml.parsers.DocumentBuilderFactory;
-import javax.xml.parsers.ParserConfigurationException;
-import javax.xml.xpath.*;
 
 /**
  * XML Parsing tool using XPATH. It's recommended to use StaxParser when parsing big XML files.
@@ -48,6 +59,7 @@ import javax.xml.xpath.*;
  */
 public class XpathParser {
 
+  private static final String CAN_NOT_PARSE_XML = "can not parse xml : ";
   private Element root = null;
   private Document doc = null;
   private DocumentBuilder builder;
@@ -120,9 +132,9 @@ public class XpathParser {
       xpath = factory.newXPath();
 
     } catch (SAXException e) {
-      throw new XmlParserException("can not parse xml : " + xml, e);
+      throw new XmlParserException(CAN_NOT_PARSE_XML + xml, e);
     } catch (IOException e) {
-      throw new XmlParserException("can not parse xml : " + xml, e);
+      throw new XmlParserException(CAN_NOT_PARSE_XML + xml, e);
     }
   }
 
@@ -265,4 +277,4 @@ public class XpathParser {
     }
     return replace.toString();
   }
-}
\ No newline at end of file
+}
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/utils/ZipUtils.java b/sonar-plugin-api/src/main/java/org/sonar/api/utils/ZipUtils.java
index 0b6dfae9842..e367fcc2435 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/utils/ZipUtils.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/utils/ZipUtils.java
@@ -39,6 +39,8 @@ import java.util.zip.ZipOutputStream;
  */
 public final class ZipUtils {
 
+  private static final String ERROR_CREATING_DIRECTORY = "Error creating directory: ";
+
   private ZipUtils() {
     // only static methods
   }
@@ -86,12 +88,12 @@ public final class ZipUtils {
           File to = new File(toDir, entry.getName());
           if (entry.isDirectory()) {
             if (!to.exists() && !to.mkdirs()) {
-              throw new IOException("Error creating directory: " + to);
+              throw new IOException(ERROR_CREATING_DIRECTORY + to);
             }
           } else {
             File parent = to.getParentFile();
             if (parent != null && !parent.exists() && !parent.mkdirs()) {
-              throw new IOException("Error creating directory: " + parent);
+              throw new IOException(ERROR_CREATING_DIRECTORY + parent);
             }
 
             FileOutputStream fos = new FileOutputStream(to);
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/web/Criterion.java b/sonar-plugin-api/src/main/java/org/sonar/api/web/Criterion.java
index a1e8cba29fa..1eaf10eb920 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/web/Criterion.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/web/Criterion.java
@@ -20,7 +20,6 @@
 package org.sonar.api.web;
 
 import com.google.common.base.Joiner;
-
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableSortedSet;
 
@@ -32,6 +31,8 @@ import java.util.Set;
  * @since 3.1
  */
 public final class Criterion {
+  private static final String METRIC_FAMILY = "metric";
+  private static final String QUALIFIER_FAMILY = "qualifier";
   public static final String EQ = "eq";
   public static final String GT = "gt";
   public static final String GTE = "gte";
@@ -87,7 +88,7 @@ public final class Criterion {
    * @throws IllegalArgumentException if {@code operator} is not valid
    */
   public static Criterion createForMetric(String key, String operator, Float value, boolean variation) {
-    return new Criterion("metric", key, operator, value, null, variation);
+    return new Criterion(METRIC_FAMILY, key, operator, value, null, variation);
   }
 
   /**
@@ -98,19 +99,19 @@ public final class Criterion {
    * @throws IllegalArgumentException if {@code operator} is not valid
    */
   public static Criterion createForMetric(String key, String operator, String textValue, boolean variation) {
-    return new Criterion("metric", key, operator, null, textValue, variation);
+    return new Criterion(METRIC_FAMILY, key, operator, null, textValue, variation);
   }
 
   /**
    * Creates a new {@link Criterion} on a qualifier.
    */
   public static Criterion createForQualifier(Object... values) {
-    return new Criterion("qualifier", null, EQ, null, Joiner.on(',').join(values), false);
+    return new Criterion(QUALIFIER_FAMILY, null, EQ, null, Joiner.on(',').join(values), false);
   }
 
   /**
    * Get the the criterion's family.
-   * 
+   *
    * @return the family
    */
   public String getFamily() {
@@ -119,7 +120,7 @@ public final class Criterion {
 
   /**
    * Get the the criterion's key.
-   * 
+   *
    * @return the key
    */
   public String getKey() {
@@ -139,7 +140,7 @@ public final class Criterion {
 
   /**
    * Get the the criterion's value.
-   * 
+   *
    * @return the value
    */
   public Float getValue() {
@@ -148,7 +149,7 @@ public final class Criterion {
 
   /**
    * Get the the criterion's value as text.
-   * 
+   *
    * @return the value as text
    */
   public String getTextValue() {
@@ -157,7 +158,7 @@ public final class Criterion {
 
   /**
    * A criterion can be based on the varation of a value rather than on the value itself.
-   * 
+   *
    * @return <code>true</code> when the variation is used rather than the value
    */
   public boolean isVariation() {