Add PMD for static analysis

config/pmd.xml

@@ -0,0 +1,72 @@
+<?xml version="1.0"?>
+
+<ruleset name="Basic"
+    xmlns="http://pmd.sourceforge.net/ruleset/2.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://pmd.sourceforge.net/ruleset/2.0.0 https://pmd.sourceforge.io/ruleset_2_0_0.xsd">
+  <description>
+The Basic ruleset contains a collection of good practices which should be followed.
+  </description>
+
+    <rule ref="category/java/errorprone.xml">
+      <exclude name="AvoidBranchingStatementAsLastInLoop" />
+      <exclude name="AvoidMultipleUnaryOperators"/>
+      <exclude name="AvoidUsingOctalValues"/>
+      <exclude name="BrokenNullCheck"/>
+      <exclude name="CheckSkipResult"/>
+      <exclude name="ClassCastExceptionWithToArray"/>
+      <exclude name="DontUseFloatTypeForLoopIndices"/>
+      <exclude name="JumbledIncrementer"/>
+      <exclude name="MisplacedNullCheck"/>
+      <exclude name="OverrideBothEqualsAndHashcode"/>
+      <exclude name="ReturnFromFinallyBlock"/>
+      <exclude name="UnconditionalIfStatement"/>
+      <exclude name="DataflowAnomalyAnalysis"/>
+    </rule>
+
+    <rule ref="category/java/multithreading.xml">
+      <exclude name="AvoidThreadGroup" />
+      <exclude name="DontCallThreadRun"/>
+      <exclude name="DoubleCheckedLocking"/>
+      <exclude name="BrokenNullCheck"/>
+    </rule>
+
+    <rule ref="category/java/bestpractices.xml">
+      <exclude name="AvoidUsingHardCodedIP" />
+      <exclude name="CheckResultSet"/>
+      <exclude name="GuardLogStatement"/>
+    </rule>
+
+    <rule ref="category/java/codestyle.xml">
+      <exclude name="ExtendsObject" />
+      <exclude name="ForLoopShouldBeWhileLoop"/>
+      <exclude name="AtLeastOneConstructor"/>
+      <exclude name="UnnecessaryAnnotationValueElement"/>
+      <exclude name="OnlyOneReturn"/>
+    </rule>
+
+    <rule ref="category/java/codestyle.xml/ClassNamingConventions">
+      <properties>
+        <property name="classPattern" value="[A-Z][a-zA-Z0-9]*" />
+        <property name="abstractClassPattern" value="[A-Z][a-zA-Z0-9]*" />
+        <property name="interfacePattern" value="[A-Z][a-zA-Z0-9]*" />
+        <property name="enumPattern" value="[A-Z][a-zA-Z0-9]*" />
+        <property name="annotationPattern" value="[A-Z][a-zA-Z0-9]*" />
+        <property name="utilityClassPattern" value="[A-Z][a-zA-Z0-9]+" />
+      </properties>
+    </rule>
+
+    <rule ref="category/java/performance.xml">
+      <exclude name="BigIntegerInstantiation" />
+      <exclude name="BooleanInstantiation"/>
+      <exclude name="AvoidInstantiatingObjectsInLoops" />
+    </rule>
+
+    <rule ref="category/java/design.xml">
+      <exclude name="UseUtilityClass"/>
+      <exclude name="CollapsibleIfStatements" />
+      <exclude name="SimplifiedTernary"/>
+      <exclude name="LawOfDemeter"/>
+    </rule>
+
+</ruleset>

pom.xml

@@ -95,6 +95,25 @@
 	<build>
 		<plugins>
 			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-pmd-plugin</artifactId>
+				<version>3.13.0</version>
+				<configuration>
+				<rulesets>
+					<ruleset>/config/pmd.xml</ruleset>
+				</rulesets>
+				</configuration>
+				<executions>
+					<execution>
+						<phase>compile</phase>
+						<goals>
+							<goal>check</goal>
+							<goal>cpd-check</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+				<plugin>
 				<groupId>org.jacoco</groupId>
 				<artifactId>jacoco-maven-plugin</artifactId>
 				<version>0.8.3</version>
@@ -271,5 +290,4 @@
 		  <url>https://repo.jenkins-ci.org/public/</url>
 		</pluginRepository>
 	</pluginRepositories>
-
-</project>
+</project>

src/main/java/com/org/jenkins/custom/jenkins/distribution/service/CustomJenkinsDistributionServiceApplication.java

@@ -6,7 +6,7 @@
 @SpringBootApplication
 public class CustomJenkinsDistributionServiceApplication {
 
-	public static void main(String[] args) {
+	public static void main(final String[] args) {
 		SpringApplication.run(CustomJenkinsDistributionServiceApplication.class, args);
 	}
 }

src/main/java/com/org/jenkins/custom/jenkins/distribution/service/IndexController.java

@@ -5,11 +5,11 @@
 import org.springframework.web.bind.annotation.RestController;
 
 @RestController
+@RequestMapping(value = "/error")
 public class IndexController implements ErrorController {
 
     private static final String PATH = "/error";
 
-    @RequestMapping(value = PATH)
     public String error() {
         return "This is the backend of the custom distribution service application. If you see this message the service is up and running";
     }

src/main/java/com/org/jenkins/custom/jenkins/distribution/service/PackagerController.java

@@ -3,6 +3,7 @@
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.org.jenkins.custom.jenkins.distribution.service.services.PackagerDownloadService;
 import com.org.jenkins.custom.jenkins.distribution.service.util.Util;
+import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.Map;
 import java.io.ByteArrayInputStream;
@@ -22,7 +23,6 @@
 @RestController
 @CrossOrigin
 @RequestMapping("/package")
-
 public class PackagerController {
 
     private static Util util = new Util();
@@ -42,15 +42,18 @@ public class PackagerController {
      * @return a ResponseEntity instance with a body containing the package configuration as a YAML string.
      */
     @PostMapping(path = "/getPackageConfiguration")
-    public ResponseEntity<?> getPackageConfig(@RequestBody String postPayload) {
+    public ResponseEntity<?> getPackageConfig(@RequestBody final String postPayload) {
         LOGGER.info("Request Received for packaging configuration with params" + postPayload);
+        String yamlResponse = "";
+        HttpStatus httpStatus;
         try {
-            String yamlResponse = generatePackageConfig(new JSONObject(postPayload));
-            return new ResponseEntity<>(yamlResponse, HttpStatus.OK);
-        } catch (Exception e) {
+            yamlResponse = generatePackageConfig(new JSONObject(postPayload));
+            httpStatus = HttpStatus.OK;
+        } catch (IOException e) {
             LOGGER.severe(e.toString());
-            return new ResponseEntity(HttpStatus.NOT_FOUND);
+            httpStatus = HttpStatus.NOT_FOUND;
         }
+        return new ResponseEntity<>(yamlResponse, httpStatus);
     }
 
     /**
@@ -61,11 +64,11 @@ public ResponseEntity<?> getPackageConfig(@RequestBody String postPayload) {
      * @return a ResponseEntity instance with a body containing the generated jenkins.war package.
      */
     @PostMapping (path = "/downloadWarPackage")
-    public ResponseEntity<?> downloadWAR(@RequestBody String postPayload) {
+    public ResponseEntity<?> downloadWAR(@RequestBody final String postPayload) {
         LOGGER.info("Request Received for downloading war file with configuration" + postPayload);
         try {
             return new PackagerDownloadService().downloadWAR(getWarVersion(), postPayload);
-        } catch (Exception e) {
+        } catch (IOException | InterruptedException e) {
             LOGGER.severe(e.toString());
             return new ResponseEntity(HttpStatus.NOT_FOUND);
         }
@@ -78,24 +81,21 @@ public ResponseEntity<?> downloadWAR(@RequestBody String postPayload) {
      * @return The content of the browser's text editor in an HTTP response (download from the server).
      */
     @PostMapping (path = "/downloadPackageConfiguration")
-    public ResponseEntity<?> downloadPackageConfig(@RequestBody String postPayload) {
-        try {
+    public ResponseEntity<?> downloadPackageConfig(@RequestBody final String postPayload) {
             LOGGER.info(postPayload);
-            InputStreamResource resource = new InputStreamResource(new ByteArrayInputStream(postPayload.getBytes(
-                StandardCharsets.UTF_8)));
-            String headerValue = "attachment; filename=packager-config.yml";
+            final InputStreamResource resource = new InputStreamResource(new ByteArrayInputStream(postPayload.getBytes(StandardCharsets.UTF_8)));
+            final String headerValue = "attachment; filename=packager-config.yml";
             LOGGER.info("Returning packager-config.yml");
             return Util.returnResource(Util.returnHeaders(headerValue), postPayload.getBytes(StandardCharsets.UTF_8).length, resource);
-        } catch (Exception e) {
-            LOGGER.severe(e.toString());
-            return new ResponseEntity(HttpStatus.NOT_FOUND);
-        }
     }
 
-    private String getWarVersion() throws Exception {
-        Yaml yaml = new Yaml();
-        Map<String , Map<String,String>> yamlMaps = (Map<String, Map<String,String>>) yaml.load(util.readStringFromFile("packager-config.yml"));
-        JSONObject json = new JSONObject(new ObjectMapper().writeValueAsString(yamlMaps.get("war")));
+    private String getWarVersion() throws IOException {
+        final Yaml yaml = new Yaml();
+        final JSONObject json;
+
+        final Map<String, Map<String, String>> yamlMaps = (Map<String, Map<String, String>>) yaml.load(util.readStringFromFile("packager-config.yml"));
+        json = new JSONObject(new ObjectMapper().writeValueAsString(yamlMaps.get("war")));
+
         return json.getJSONObject("source").get("version").toString();
     }
 }

src/main/java/com/org/jenkins/custom/jenkins/distribution/service/PluginController.java

@@ -1,6 +1,7 @@
 package com.org.jenkins.custom.jenkins.distribution.service;
 
 import com.org.jenkins.custom.jenkins.distribution.service.services.UpdateCenterService;
+import java.util.Map;
 import java.util.logging.Logger;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
@@ -13,14 +14,15 @@
 @RestController
 @CrossOrigin("*")
 @RequestMapping("api/plugin")
+@SuppressWarnings("PMD.AvoidCatchingGenericException")
 public class PluginController {
 
-    private final static Logger LOGGER = Logger.getLogger(PluginController.class.getName());
-    private final UpdateCenterService updateCenterService;
+    private transient final static Logger LOGGER = Logger.getLogger(PluginController.class.getName());
+    private transient final UpdateCenterService updateService;
 
     @Autowired
-    public PluginController(UpdateCenterService updateCenterService) {
-        this.updateCenterService = updateCenterService;
+    public PluginController(final UpdateCenterService updaterService) {
+        this.updateService = updaterService;
     }
 
     /*
@@ -30,11 +32,15 @@ public PluginController(UpdateCenterService updateCenterService) {
     @GetMapping(path = "/getPluginList")
     public ResponseEntity<?> getPlugins() {
         LOGGER.info("Request Received");
+        Map updateMap = null;
+        HttpStatus status;
         try {
-            return new ResponseEntity<>(updateCenterService.downloadUpdateCenterJSON().toMap(), HttpStatus.OK);
+            updateMap = updateService.downloadUpdateCenterJSON().toMap();
+            status = HttpStatus.OK;
         } catch (Exception e) {
             LOGGER.severe(e.toString());
-            return new ResponseEntity(HttpStatus.NOT_FOUND);
+            status = HttpStatus.NOT_FOUND;
         }
+        return new ResponseEntity(updateMap, status);
     }
 }