Update logging in java-basic examples

- Use Context logger for all handlers, removing SLF4J dependency
- Unit testing still requires SLF4J dependency to show this logging option
- Tested all handlers manually, minor updates to README

Author: yualexan

sample-apps/blank-java/pom.xml

@@ -26,7 +26,7 @@
       <groupId>org.slf4j</groupId>
       <artifactId>slf4j-nop</artifactId>
       <version>2.0.6</version>
-  </dependency>
+    </dependency>
     <dependency>
       <groupId>software.amazon.awssdk</groupId>
       <artifactId>lambda</artifactId>
@@ -79,7 +79,7 @@
                     <exclude>META-INF/services/**</exclude>
                 </excludes>
             </filter>
-        </filters>
+          </filters>
         </configuration>
         <executions>
           <execution>

sample-apps/java-basic/README.md

@@ -95,7 +95,7 @@ To use a different handler, change the value of the Handler setting in the appli
       CodeUri: build/distributions/java-basic.zip
       Handler: example.HandlerList
 
-Deploy the change, and then use the invoke script to test the new configuration. For handlers, that don't take a JSON object as input, pass the type (`string`, `int` or `list`) as an argument to the invoke script.
+Deploy the change, and then use the invoke script to test the new configuration. For handlers, that don't take a JSON object as input, pass the type (`string`, `int`, `list`, or `divide`) as an argument to the invoke script.
 
     ./3-invoke.sh list
     {

sample-apps/java-basic/build.gradle

@@ -8,9 +8,9 @@ repositories {
 
 dependencies {
     implementation 'com.amazonaws:aws-lambda-java-core:1.2.1'
-    runtimeOnly 'org.apache.logging.log4j:log4j-slf4j18-impl:[2.17.1,)'
-    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.6.0'
-    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.6.0'
+    implementation 'org.slf4j:slf4j-nop:2.0.6'
+    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.8.2'
+    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.8.2'
 }
 
 test {

sample-apps/java-basic/pom.xml

@@ -18,32 +18,20 @@
       <version>1.2.1</version>
     </dependency>
     <dependency>
-      <groupId>org.apache.logging.log4j</groupId>
-      <artifactId>log4j-api</artifactId>
-      <version>[2.17.1,)</version>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.apache.logging.log4j</groupId>
-      <artifactId>log4j-core</artifactId>
-      <version>[2.17.1,)</version>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.apache.logging.log4j</groupId>
-      <artifactId>log4j-slf4j18-impl</artifactId>
-      <version>[2.17.1,)</version>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-nop</artifactId>
+      <version>2.0.6</version>
     </dependency>
     <dependency>
       <groupId>org.junit.jupiter</groupId>
       <artifactId>junit-jupiter-api</artifactId>
-      <version>5.6.0</version>
+      <version>5.8.2</version>
       <scope>test</scope>
     </dependency>
     <dependency>
       <groupId>org.junit.jupiter</groupId>
       <artifactId>junit-jupiter-engine</artifactId>
-      <version>5.6.0</version>
+      <version>5.8.2</version>
       <scope>test</scope>
     </dependency>
   </dependencies>
@@ -62,10 +50,13 @@
           <createDependencyReducedPom>false</createDependencyReducedPom>
           <filters>
             <filter>
-               <artifact>com.example:*</artifact>
-               <excludes>
-                  <exclude>META-INF/MANIFEST.MF</exclude>
-               </excludes>
+                <artifact>*:*</artifact>
+                <excludes>
+                    <exclude>module-info.class</exclude>
+                    <exclude>META-INF/*</exclude>
+                    <exclude>META-INF/versions/**</exclude>
+                    <exclude>META-INF/services/**</exclude>
+                </excludes>
             </filter>
           </filters>
         </configuration>

sample-apps/java-basic/src/main/java/example/Handler.java

@@ -1,24 +1,21 @@
 package example;
 
 import com.amazonaws.services.lambda.runtime.Context;
+import com.amazonaws.services.lambda.runtime.LambdaLogger;
 import com.amazonaws.services.lambda.runtime.RequestHandler;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import java.util.Map;
 
 // Handler value: example.Handler
 public class Handler implements RequestHandler<Map<String,String>, Void>{
 
-  private static final Logger logger = LoggerFactory.getLogger(Handler.class);
-
   @Override
   public Void handleRequest(Map<String,String> event, Context context)
   {
-    logger.info("ENVIRONMENT VARIABLES: " + System.getenv());
-    logger.info("EVENT: " + event);
-    logger.info("EVENT TYPE: " + event.getClass());
+    LambdaLogger logger = context.getLogger();
+    logger.log("ENVIRONMENT VARIABLES: " + System.getenv());
+    logger.log("EVENT: " + event);
+    logger.log("EVENT TYPE: " + event.getClass());
     return null;
   }
 }

sample-apps/java-basic/src/main/java/example/HandlerDivide.java

@@ -1,30 +1,27 @@
 package example;
 
 import com.amazonaws.services.lambda.runtime.Context;
+import com.amazonaws.services.lambda.runtime.LambdaLogger;
 import com.amazonaws.services.lambda.runtime.RequestHandler;
 
 import java.util.List;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 // Handler value: example.HandlerDivide
 public class HandlerDivide implements RequestHandler<List<Integer>, Integer>{
-
-  private static final Logger logger = LoggerFactory.getLogger(HandlerDivide.class);
   /*
    * Takes a list of two integers and divides them.
    */
   @Override
   public Integer handleRequest(List<Integer> event, Context context)
   {
+    LambdaLogger logger = context.getLogger();
     if ( event.size() != 2 )
     {
       throw new InputLengthException("Input must be an array that contains 2 numbers.");
     }
     int numerator = event.get(0);
     int denominator = event.get(1);
-    logger.info("EVENT: Numerator is " + event.get(0).toString() +
+    logger.log("EVENT: Numerator is " + event.get(0).toString() +
       "; Denominator is " + event.get(1).toString());
     return numerator/denominator;
   }

sample-apps/java-basic/src/main/java/example/HandlerInteger.java

@@ -1,24 +1,21 @@
 package example;
 
 import com.amazonaws.services.lambda.runtime.Context;
+import com.amazonaws.services.lambda.runtime.LambdaLogger;
 import com.amazonaws.services.lambda.runtime.RequestHandler;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 // Handler value: example.HandlerInteger
 public class HandlerInteger implements RequestHandler<Integer, Integer>{
 
-  private static final Logger logger = LoggerFactory.getLogger(HandlerInteger.class);
-
   @Override
   /*
    * Takes an Integer as input, adds 1, and returns it.
    */
   public Integer handleRequest(Integer event, Context context)
   {
-    logger.info("EVENT: " + event);
-    logger.info("EVENT TYPE: " + event.getClass().toString());
+    LambdaLogger logger = context.getLogger();
+    logger.log("EVENT: " + event);
+    logger.log("EVENT TYPE: " + event.getClass().toString());
     return event + 1;
   }
 }

sample-apps/java-basic/src/main/java/example/HandlerList.java

@@ -1,26 +1,23 @@
 package example;
 
 import com.amazonaws.services.lambda.runtime.Context;
+import com.amazonaws.services.lambda.runtime.LambdaLogger;
 import com.amazonaws.services.lambda.runtime.RequestHandler;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import java.util.List;
 
 // Handler value: example.HandlerList
 public class HandlerList implements RequestHandler<List<Integer>, Integer>{
 
-  private static final Logger logger = LoggerFactory.getLogger(HandlerList.class);
-
   @Override
   /*
    * Takes a list of Integers and returns its sum.
    */
   public Integer handleRequest(List<Integer> event, Context context)
   {
-    logger.info("EVENT: " + event);
-    logger.info("EVENT TYPE: " + event.getClass().toString());
+    LambdaLogger logger = context.getLogger();
+    logger.log("EVENT: " + event);
+    logger.log("EVENT TYPE: " + event.getClass().toString());
     return event.stream().mapToInt(Integer::intValue).sum();
   }
 }

sample-apps/java-basic/src/main/java/example/HandlerStream.java

@@ -1,27 +1,24 @@
 package example;
 
 import com.amazonaws.services.lambda.runtime.Context;
+import com.amazonaws.services.lambda.runtime.LambdaLogger;
 import com.amazonaws.services.lambda.runtime.RequestStreamHandler;
 
 import java.io.InputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 // Handler value: example.HandlerStream
 public class HandlerStream implements RequestStreamHandler {
 
-  private static final Logger logger = LoggerFactory.getLogger(HandlerStream.class);
-
   @Override
   /*
    * Takes an InputStream and an OutputStream. Reads from the InputStream,
    * and copies all characters to the OutputStream.
    */
   public void handleRequest(InputStream inputStream, OutputStream outputStream, Context context) throws IOException
   {
+    LambdaLogger logger = context.getLogger();
     int nextChar;
     try {
       while ((nextChar = inputStream.read()) != -1) {
@@ -32,7 +29,7 @@ public void handleRequest(InputStream inputStream, OutputStream outputStream, Co
     } finally {
       inputStream.close();
       String finalString = outputStream.toString();
-      logger.info("Final string result: " + finalString);
+      logger.log("Final string result: " + finalString);
       outputStream.close();
     }
   }

sample-apps/java-basic/src/main/java/example/HandlerString.java

@@ -1,24 +1,21 @@
 package example;
 
 import com.amazonaws.services.lambda.runtime.Context;
+import com.amazonaws.services.lambda.runtime.LambdaLogger;
 import com.amazonaws.services.lambda.runtime.RequestHandler;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 // Handler value: example.HandlerString
 public class HandlerString implements RequestHandler<String, String>{
 
-  private static final Logger logger = LoggerFactory.getLogger(HandlerString.class);
-
   @Override
   /*
    * Takes a String as input, and converts all characters to lowercase.
    */
   public String handleRequest(String event, Context context)
   {
-    logger.info("EVENT: " + event);
-    logger.info("EVENT TYPE: " + event.getClass().toString());
+    LambdaLogger logger = context.getLogger();
+    logger.log("EVENT: " + event);
+    logger.log("EVENT TYPE: " + event.getClass().toString());
     return event.toLowerCase();
   }
 }

sample-apps/java-basic/src/main/java/example/HandlerWeatherData.java

@@ -1,25 +1,22 @@
 package example;
 
 import com.amazonaws.services.lambda.runtime.Context;
+import com.amazonaws.services.lambda.runtime.LambdaLogger;
 import com.amazonaws.services.lambda.runtime.RequestHandler;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 // Handler value: example.HandlerWeatherData
 public class HandlerWeatherData implements RequestHandler<WeatherData, WeatherData>{
 
-  private static final Logger logger = LoggerFactory.getLogger(WeatherData.class);
-
   @Override
   /*
    * Takes in a WeatherData event object and updates its attributes with dummy values.
    * Returns the updated WeatherData object.
    */
   public WeatherData handleRequest(WeatherData event, Context context)
   {
-    logger.info("EVENT: " + event);
-    logger.info("EVENT TYPE: " + event.getClass().toString());
+    LambdaLogger logger = context.getLogger();
+    logger.log("EVENT: " + event);
+    logger.log("EVENT TYPE: " + event.getClass().toString());
 
     event.setHumidityPct(50.5);
     event.setPressureHPa(1005);