List S3 lambda

build.gradle

@@ -1,7 +1,7 @@
 group 'pl.grondek'
-version '1.0-SNAPSHOT'
 
 subprojects {
+    version '1.0-SNAPSHOT'
     apply plugin: 'java'
 
     sourceCompatibility = 1.8

s3-lambda/build.gradle

@@ -0,0 +1,13 @@
+dependencies {
+    compile 'com.amazonaws:aws-lambda-java-core:1.2.0'
+    compile 'com.amazonaws:aws-java-sdk-s3:1.11.283'
+}
+
+task fatJar(type: Jar) {
+    manifest {
+        attributes 'Implementation-Title': 'Gradle Jar File Example',
+                'Implementation-Version': version
+    }
+    from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
+    with jar
+}

s3-lambda/src/main/java/pl/grondek/aws/lambda/s3/ListS3Lambda.java

@@ -0,0 +1,26 @@
+package pl.grondek.aws.lambda.s3;
+
+import com.amazonaws.services.lambda.runtime.Context;
+import com.amazonaws.services.lambda.runtime.RequestHandler;
+import com.amazonaws.services.s3.AmazonS3ClientBuilder;
+import com.amazonaws.services.s3.model.S3ObjectSummary;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class ListS3Lambda implements RequestHandler<Void, List<String>> {
+    @Override
+    public List<String> handleRequest(Void input, Context context) {
+        final String bucketName = System.getenv("BUCKET_NAME");
+        final String bucketRegion = System.getenv("REGION");
+
+        return AmazonS3ClientBuilder.standard()
+                .withRegion(bucketRegion)
+                .build()
+                .listObjects(bucketName)
+                .getObjectSummaries()
+                .stream()
+                .map(S3ObjectSummary::getKey)
+                .collect(Collectors.toList());
+    }
+}

settings.gradle

@@ -1,3 +1,4 @@
 rootProject.name = 'aws'
 
 include "left-pad-lambda"
+include "s3-lambda"