Remove GSON dependencies from blank-java, java-basic examples

- This commit removes GSON dependencies from blank-java and java-basic examples.
- Removed logging the context as this isn't a common operation.
- Refactored the java-basic Stream example, and manually tested with an input string.
- Tested and verified that all samples still work.

Author: yualexan

sample-apps/blank-java/build.gradle

@@ -16,7 +16,6 @@ dependencies {
     implementation 'com.amazonaws:aws-xray-recorder-sdk-aws-sdk-v2-instrumentor'
     implementation 'com.amazonaws:aws-lambda-java-core:1.2.1'
     implementation 'com.amazonaws:aws-lambda-java-events:2.2.9'
-    implementation 'com.fasterxml.jackson.core:jackson-databind:[2.14.0,)'
     implementation 'org.apache.logging.log4j:log4j-api:[2.17.1,)'
     implementation 'org.apache.logging.log4j:log4j-core:[2.17.1,)'
     runtimeOnly 'org.apache.logging.log4j:log4j-slf4j18-impl:[2.17.1,)'

sample-apps/blank-java/pom.xml

@@ -27,11 +27,6 @@
       <artifactId>aws-lambda-java-log4j2</artifactId>
       <version>1.5.0</version>
     </dependency>
-    <dependency>
-      <groupId>com.fasterxml.jackson.core</groupId>
-      <artifactId>jackson-databind</artifactId>
-      <version>[2.14.0,)</version>
-    </dependency>
     <dependency>
       <groupId>org.apache.logging.log4j</groupId>
       <artifactId>log4j-api</artifactId>

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

@@ -28,7 +28,6 @@ public String handleRequest(Map<String,String> event, Context context) {
         // log execution details
         logger.info("ENVIRONMENT VARIABLES: " + System.getenv());
         logger.info("EVENT: " + event);
-        logger.info("CONTEXT: " + context);
 
         // process event
         GetAccountSettingsResponse response;

sample-apps/java-basic/build.gradle

@@ -8,7 +8,6 @@ repositories {
 
 dependencies {
     implementation 'com.amazonaws:aws-lambda-java-core:1.2.1'
-    implementation 'com.google.code.gson:gson:2.8.6'
     testImplementation 'org.apache.logging.log4j:log4j-api:[2.17.1,)'
     testImplementation 'org.apache.logging.log4j:log4j-core:[2.17.1,)'
     testImplementation 'org.apache.logging.log4j:log4j-slf4j18-impl:[2.17.1,)'

sample-apps/java-basic/pom.xml

@@ -17,11 +17,6 @@
       <artifactId>aws-lambda-java-core</artifactId>
       <version>1.2.1</version>
     </dependency>
-    <dependency>
-      <groupId>com.google.code.gson</groupId>
-      <artifactId>gson</artifactId>
-      <version>2.8.6</version>
-    </dependency>
     <dependency>
       <groupId>org.apache.logging.log4j</groupId>
       <artifactId>log4j-api</artifactId>

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

@@ -4,24 +4,21 @@
 import com.amazonaws.services.lambda.runtime.RequestHandler;
 import com.amazonaws.services.lambda.runtime.LambdaLogger;
 
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-
 import java.util.Map;
 
 // Handler value: example.Handler
 public class Handler implements RequestHandler<Map<String,String>, String>{
-  Gson gson = new GsonBuilder().setPrettyPrinting().create();
+
   @Override
   public String handleRequest(Map<String,String> event, Context context)
   {
     LambdaLogger logger = context.getLogger();
     String response = "200 OK";
     // log execution details
-    logger.log("ENVIRONMENT VARIABLES: " + gson.toJson(System.getenv()));
-    logger.log("CONTEXT: " + gson.toJson(context));
+    logger.log("ENVIRONMENT VARIABLES: " + System.getenv());
+
     // process event
-    logger.log("EVENT: " + gson.toJson(event));
+    logger.log("EVENT: " + event);
     logger.log("EVENT TYPE: " + event.getClass());
     return response;
   }

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

@@ -4,14 +4,11 @@
 import com.amazonaws.services.lambda.runtime.RequestHandler;
 import com.amazonaws.services.lambda.runtime.LambdaLogger;
 
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-
 import java.util.List;
 
 // Handler value: example.HandlerDivide
 public class HandlerDivide implements RequestHandler<List<Integer>, Integer>{
-  Gson gson = new GsonBuilder().setPrettyPrinting().create();
+
   @Override
   public Integer handleRequest(List<Integer> event, Context context)
   {
@@ -23,7 +20,7 @@ public Integer handleRequest(List<Integer> event, Context context)
     }
     int numerator = event.get(0);
     int denominator = event.get(1);
-    logger.log("EVENT: " + gson.toJson(event));
+    logger.log("EVENT: " + event);
     logger.log("EVENT TYPE: " + event.getClass().toString());
     return numerator/denominator;
   }

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

@@ -4,18 +4,15 @@
 import com.amazonaws.services.lambda.runtime.RequestHandler;
 import com.amazonaws.services.lambda.runtime.LambdaLogger;
 
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-
 // Handler value: example.HandlerInteger
 public class HandlerInteger implements RequestHandler<Integer, Integer>{
-  Gson gson = new GsonBuilder().setPrettyPrinting().create();
+
   @Override
   public Integer handleRequest(Integer event, Context context)
   {
     LambdaLogger logger = context.getLogger();
     // process event
-    logger.log("EVENT: " + gson.toJson(event));
+    logger.log("EVENT: " + event);
     logger.log("EVENT TYPE: " + event.getClass().toString());
     // return amount of time remaining before timeout
     return context.getRemainingTimeInMillis();

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

@@ -4,20 +4,17 @@
 import com.amazonaws.services.lambda.runtime.RequestHandler;
 import com.amazonaws.services.lambda.runtime.LambdaLogger;
 
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-
 import java.util.List;
 
 // Handler value: example.HandlerList
 public class HandlerList implements RequestHandler<List<Integer>, Integer>{
-  Gson gson = new GsonBuilder().setPrettyPrinting().create();
+
   @Override
   public Integer handleRequest(List<Integer> event, Context context)
   {
     LambdaLogger logger = context.getLogger();
     // process event
-    logger.log("EVENT: " + gson.toJson(event));
+    logger.log("EVENT: " + event);
     logger.log("EVENT TYPE: " + event.getClass().toString());
     return context.getRemainingTimeInMillis() ;
   }

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

@@ -1,53 +1,30 @@
 package example;
 
 import com.amazonaws.services.lambda.runtime.Context;
-import com.amazonaws.services.lambda.runtime.LambdaLogger;
 import com.amazonaws.services.lambda.runtime.RequestStreamHandler;
 
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-import com.google.gson.JsonSyntaxException;
-
-import java.util.HashMap;
 import java.io.InputStream;
 import java.io.IOException;
 import java.io.OutputStream;
-import java.io.InputStreamReader;
-import java.io.BufferedReader;
-import java.io.OutputStreamWriter;
-import java.io.PrintWriter;
-import java.io.BufferedWriter;
-import java.nio.charset.Charset;
-import java.lang.IllegalStateException;
 
 // Handler value: example.HandlerStream
 public class HandlerStream implements RequestStreamHandler {
-  Gson gson = new GsonBuilder().setPrettyPrinting().create();
+
   @Override
   public void handleRequest(InputStream inputStream, OutputStream outputStream, Context context) throws IOException
   {
-    LambdaLogger logger = context.getLogger();
-    BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, Charset.forName("US-ASCII")));
-    PrintWriter writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream, Charset.forName("US-ASCII"))));
-    try
-    {
-      HashMap event = gson.fromJson(reader, HashMap.class);
-      logger.log("STREAM TYPE: " + inputStream.getClass().toString());
-      logger.log("EVENT TYPE: " + event.getClass().toString());
-      writer.write(gson.toJson(event));
-      if (writer.checkError())
-      {
-        logger.log("WARNING: Writer encountered an error.");
+    int nextChar;
+    try {
+      while ((nextChar = inputStream.read()) != -1) {
+        outputStream.write(nextChar);
       }
-    }
-    catch (IllegalStateException | JsonSyntaxException exception)
-    {
-      logger.log(exception.toString());
-    }
-    finally
-    {
-      reader.close();
-      writer.close();
+    } catch (IOException e) {
+      e.printStackTrace();
+    } finally {
+      inputStream.close();
+      String finalString = outputStream.toString();
+      System.out.println(finalString);
+      outputStream.close();
     }
   }
 }

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

@@ -4,19 +4,16 @@
 import com.amazonaws.services.lambda.runtime.RequestHandler;
 import com.amazonaws.services.lambda.runtime.LambdaLogger;
 
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-
 // Handler value: example.HandlerString
 public class HandlerString implements RequestHandler<String, Integer>{
-  Gson gson = new GsonBuilder().setPrettyPrinting().create();
+
   @Override
   public Integer handleRequest(String event, Context context)
   {
     LambdaLogger logger = context.getLogger();
     // process event
-    logger.log("EVENT: " + gson.toJson(event));
+    logger.log("EVENT: " + event);
     logger.log("EVENT TYPE: " + event.getClass().toString());
-    return context.getRemainingTimeInMillis() ;
+    return context.getRemainingTimeInMillis();
   }
 }

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

@@ -4,21 +4,18 @@
 import com.amazonaws.services.lambda.runtime.RequestHandler;
 import com.amazonaws.services.lambda.runtime.LambdaLogger;
 
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-
-import java.util.Map;
-
 // Handler value: example.HandlerWeatherData
 public class HandlerWeatherData implements RequestHandler<WeatherData, WeatherData>{
-  Gson gson = new GsonBuilder().setPrettyPrinting().create();
+
   @Override
   public WeatherData handleRequest(WeatherData event, Context context)
   {
     LambdaLogger logger = context.getLogger();
-    // process event
-    logger.log("EVENT: " + gson.toJson(event));
+    // log execution details
+    logger.log("EVENT: " + event);
     logger.log("EVENT TYPE: " + event.getClass().toString());
+
+    // // process event
     return event;
   }
 }

sample-apps/java-basic/src/test/java/example/InvokeTest.java

@@ -1,17 +1,13 @@
 package example;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import org.junit.jupiter.api.Test;
 
 import com.amazonaws.services.lambda.runtime.Context;
-import com.amazonaws.services.lambda.runtime.RequestHandler;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.List;
-import java.util.ArrayList;
 import java.util.HashMap;
 
 class InvokeTest {