eliminated maven warnings by providing plugin version

pom.xml

@@ -1,45 +1,48 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-	<modelVersion>4.0.0</modelVersion>
-
-	<groupId>edu.uoc.elc.lti</groupId>
-	<artifactId>lti-1.3-core</artifactId>
-	<version>0.0.2</version>
-	<packaging>jar</packaging>
-
-	<name>lti-1.3-core</name>
-	<description>Shared interfaces and beans for using in LTI libraries</description>
-
-	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
-		<java.version>1.8</java.version>
-	</properties>
-
-	<dependencies>
-		<dependency>
-			<groupId>org.projectlombok</groupId>
-			<artifactId>lombok</artifactId>
-			<version>1.16.10</version>
-			<scope>provided</scope>
-		</dependency>
-		<dependency>
-			<groupId>com.fasterxml.jackson.core</groupId>
-			<artifactId>jackson-databind</artifactId>
-			<version>2.9.10.1</version>
-		</dependency>
-	</dependencies>
-
-	<build>
-		<plugins>
-			<plugin>
-				<groupId>org.apache.maven.plugins</groupId>
-				<artifactId>maven-compiler-plugin</artifactId>
-				<configuration>
-					<source>1.8</source>
-					<target>1.8</target>
-				</configuration>
-			</plugin>
-		</plugins>
-	</build>
-</project>
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+
+	<groupId>edu.uoc.elc.lti</groupId>
+	<artifactId>lti-1.3-core</artifactId>
+	<version>0.0.2</version>
+	<packaging>jar</packaging>
+
+	<name>lti-1.3-core</name>
+	<description>Shared interfaces and beans for using in LTI libraries</description>
+
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+		<java.version>1.8</java.version>
+	</properties>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.projectlombok</groupId>
+			<artifactId>lombok</artifactId>
+			<version>1.18.12</version>
+			<scope>provided</scope>
+		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-databind</artifactId>
+			<version>2.9.10.1</version>
+		</dependency>
+	</dependencies>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-compiler-plugin</artifactId>
+				<version>3.8.1</version>
+				<configuration>
+					<source>${java.version}</source>
+					<target>${java.version}</target>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+</project>

src/main/java/edu/uoc/lti/accesstoken/AccessTokenRequest.java

@@ -1,16 +1,16 @@
-package edu.uoc.lti.accesstoken;
-
-import lombok.Builder;
-import lombok.Getter;
-
-/**
- * @author Created by [email protected]
- */
-@Getter
-@Builder
-public class AccessTokenRequest {
-	private String grant_type;
-	private String client_assertion_type;
-	private String scope;
-	private String client_assertion;
-}
+package edu.uoc.lti.accesstoken;
+
+import lombok.Builder;
+import lombok.Value;
+
+/**
+ * @author Created by [email protected]
+ */
+@Value
+@Builder
+public class AccessTokenRequest {
+	private String grant_type;
+	private String client_assertion_type;
+	private String scope;
+	private String client_assertion;
+}

src/main/java/edu/uoc/lti/accesstoken/UrlEncodedFormAccessTokenRequestBuilderImpl.java

@@ -1,50 +1,51 @@
-package edu.uoc.lti.accesstoken;
-
-import java.io.IOException;
-import java.io.UnsupportedEncodingException;
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
-import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
-import java.util.Arrays;
-import java.util.stream.Collectors;
-
-public class UrlEncodedFormAccessTokenRequestBuilderImpl implements AccessTokenRequestBuilder {
-
-  @Override
-  public String build(final AccessTokenRequest request) throws IOException {
-    final Method[] methods = request.getClass().getDeclaredMethods();
-
-		return Arrays.stream(methods)
-						.map(method -> {
-							try {
-                if (!method.getName().startsWith("get")) {
-                  return null;
-                }                
-								final Object value = method.invoke(request, null);
-								String valueAsString = null;
-								if (method.getReturnType().getSimpleName().equals("String")) {
-									valueAsString = (String) value;
-								}
-								else if (method.getReturnType().isPrimitive()) {
-									valueAsString = String.valueOf(value);
-								}
-								return valueAsString != null && valueAsString.length() > 0
-												? method.getName().substring(3, 4).toLowerCase() + method.getName().substring(4) + "=" + URLEncoder.encode(valueAsString, StandardCharsets.UTF_8.toString())
-												: null;
-							} catch (IllegalArgumentException | InvocationTargetException | UnsupportedEncodingException
-              | IllegalAccessException e) {
-								e.printStackTrace();
-              }
-							return null;
-						})
-						.filter(value -> value != null)
-						.collect(Collectors.joining("&"));
-  }
-
-  @Override
-  public String getContentType() {
-    return "application/x-www-form-urlencoded";
-  }
-
+package edu.uoc.lti.accesstoken;
+
+import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
+import java.util.stream.Collectors;
+
+import lombok.extern.java.Log;
+
+@Log
+public class UrlEncodedFormAccessTokenRequestBuilderImpl implements AccessTokenRequestBuilder {
+
+	@Override
+	public String build(final AccessTokenRequest request) throws IOException {
+		final Method[] methods = request.getClass().getDeclaredMethods();
+
+		return Arrays.stream(methods).map(method -> {
+			try {
+				if (!method.getName().startsWith("get")) {
+					return null;
+				}
+				final Object value = method.invoke(request, (Object[]) null);
+				String valueAsString = null;
+				if (method.getReturnType().getSimpleName().equals("String")) {
+					valueAsString = (String) value;
+				} else if (method.getReturnType().isPrimitive()) {
+					valueAsString = String.valueOf(value);
+				}
+				return valueAsString != null && valueAsString.length() > 0
+						? method.getName().substring(3, 4).toLowerCase() + method.getName().substring(4) + "="
+								+ URLEncoder.encode(valueAsString, StandardCharsets.UTF_8.toString())
+						: null;
+			} catch (IllegalArgumentException | InvocationTargetException | UnsupportedEncodingException
+					| IllegalAccessException e) {
+				log.warning("Cannot build UrlEncodedFormAccessTokenRequest. " + e.getClass().getName() + " - "
+						+ e.getMessage());
+			}
+			return null;
+		}).filter(value -> value != null).collect(Collectors.joining("&"));
+	}
+
+	@Override
+	public String getContentType() {
+		return "application/x-www-form-urlencoded";
+	}
+
 }

src/main/java/edu/uoc/lti/ags/LineItem.java

@@ -2,6 +2,7 @@
 
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonInclude;
+
 import lombok.Data;
 import lombok.NoArgsConstructor;
 import lombok.NonNull;

src/main/java/edu/uoc/lti/ags/Result.java

@@ -2,6 +2,7 @@
 
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonInclude;
+
 import lombok.Getter;
 import lombok.Setter;
 

src/main/java/edu/uoc/lti/ags/Score.java

@@ -1,13 +1,14 @@
 package edu.uoc.lti.ags;
 
+import java.time.Instant;
+
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonInclude;
+
 import lombok.Builder;
 import lombok.Getter;
 import lombok.Setter;
 
-import java.time.Instant;
-
 /**
  * @author Created by [email protected]
  */

src/main/java/edu/uoc/lti/ags/Submission.java

@@ -1,10 +1,11 @@
 package edu.uoc.lti.ags;
 
+import java.time.Instant;
+
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonInclude;
-import lombok.Setter;
 
-import java.time.Instant;
+import lombok.Setter;
 
 /**
  * @author Created by [email protected]

src/main/java/edu/uoc/lti/deeplink/DeepLinkingResponse.java

@@ -1,12 +1,11 @@
 package edu.uoc.lti.deeplink;
 
-import lombok.Getter;
-import lombok.RequiredArgsConstructor;
-import lombok.Setter;
-
 import java.util.List;
 
 import edu.uoc.lti.deeplink.content.Item;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import lombok.Setter;
 
 /**
  * @author Created by [email protected]

src/main/java/edu/uoc/lti/deeplink/content/DataItem.java

@@ -1,6 +1,7 @@
 package edu.uoc.lti.deeplink.content;
 
 import com.fasterxml.jackson.annotation.JsonInclude;
+
 import lombok.Builder;
 import lombok.Getter;
 import lombok.Setter;

src/main/java/edu/uoc/lti/deeplink/content/Duration.java

@@ -1,12 +1,13 @@
 package edu.uoc.lti.deeplink.content;
 
+import java.time.Instant;
+
 import com.fasterxml.jackson.annotation.JsonInclude;
+
 import lombok.Builder;
 import lombok.Setter;
 import lombok.ToString;
 
-import java.time.Instant;
-
 /**
  * @author Created by [email protected]
  */

src/main/java/edu/uoc/lti/deeplink/content/FileItem.java

@@ -1,12 +1,12 @@
 package edu.uoc.lti.deeplink.content;
 
+import java.time.Instant;
+
 import lombok.Builder;
 import lombok.Getter;
 import lombok.Setter;
 import lombok.ToString;
 
-import java.time.Instant;
-
 /**
  * @author Created by [email protected]
  */

src/main/java/edu/uoc/lti/deeplink/content/HtmlItem.java

@@ -1,6 +1,7 @@
 package edu.uoc.lti.deeplink.content;
 
 import com.fasterxml.jackson.annotation.JsonInclude;
+
 import lombok.Builder;
 import lombok.Getter;
 import lombok.Setter;

src/main/java/edu/uoc/lti/deeplink/content/IFrame.java

@@ -1,6 +1,7 @@
 package edu.uoc.lti.deeplink.content;
 
 import com.fasterxml.jackson.annotation.JsonInclude;
+
 import lombok.Builder;
 import lombok.Getter;
 import lombok.Setter;

src/main/java/edu/uoc/lti/deeplink/content/Image.java

@@ -1,6 +1,7 @@
 package edu.uoc.lti.deeplink.content;
 
 import com.fasterxml.jackson.annotation.JsonInclude;
+
 import lombok.Builder;
 import lombok.Getter;
 import lombok.Setter;

src/main/java/edu/uoc/lti/deeplink/content/ImageItem.java

@@ -1,6 +1,7 @@
 package edu.uoc.lti.deeplink.content;
 
 import com.fasterxml.jackson.annotation.JsonInclude;
+
 import lombok.Builder;
 import lombok.Getter;
 import lombok.Setter;

src/main/java/edu/uoc/lti/deeplink/content/Item.java

@@ -1,15 +1,16 @@
 package edu.uoc.lti.deeplink.content;
 
+import java.util.HashMap;
+import java.util.Map;
+
 import com.fasterxml.jackson.annotation.JsonAnyGetter;
 import com.fasterxml.jackson.annotation.JsonAnySetter;
 import com.fasterxml.jackson.annotation.JsonInclude;
+
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.ToString;
 
-import java.util.HashMap;
-import java.util.Map;
-
 /**
  * @author Created by [email protected]
  */

src/main/java/edu/uoc/lti/deeplink/content/LineItem.java

@@ -1,6 +1,7 @@
 package edu.uoc.lti.deeplink.content;
 
 import com.fasterxml.jackson.annotation.JsonInclude;
+
 import lombok.Builder;
 import lombok.Getter;
 import lombok.Setter;