Develop Reference

Is it possible to transfer a folder from GCS to Bigquery using Java API

When I tried to give the source URI of a folder inside my bucket (which has around 400 CSV files) in the Java program, it has not moved any files to BQ table. If I try with a single csv file , it moves.
package com.example.bigquerydatatransfer;
import com.google.api.gax.rpc.ApiException;
import com.google.cloud.bigquery.datatransfer.v1.CreateTransferConfigRequest;
import com.google.cloud.bigquery.datatransfer.v1.DataTransferServiceClient;
import com.google.cloud.bigquery.datatransfer.v1.ProjectName;
import com.google.cloud.bigquery.datatransfer.v1.TransferConfig;
import com.google.protobuf.Struct;
import com.google.protobuf.Value;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
// Sample to create google cloud storage transfer config
public class Cloud_to_BQ {
public static void main(String[] args) throws IOException {
final String projectId = "dfp-bq";
String datasetId = "mytest1";
String tableId = "PROG_DATA";
String sourceUri = "gs://dfp-bq/C:\\PROG_Reports";
String fileFormat = "CSV";
String fieldDelimiter = ",";
String skipLeadingRows = "1";
Map<String, Value> params = new HashMap<>();
params.put(
"destination_table_name_template", Value.newBuilder().setStringValue(tableId).build());
params.put("data_path_template", Value.newBuilder().setStringValue(sourceUri).build());
params.put("write_disposition", Value.newBuilder().setStringValue("APPEND").build());
params.put("file_format", Value.newBuilder().setStringValue(fileFormat).build());
params.put("field_delimiter", Value.newBuilder().setStringValue(fieldDelimiter).build());
params.put("skip_leading_rows", Value.newBuilder().setStringValue(skipLeadingRows).build());
TransferConfig transferConfig =
TransferConfig.newBuilder()
.setDestinationDatasetId(datasetId)
.setDisplayName("Trial_Run_PROG_DataTransfer")
.setDataSourceId("google_cloud_storage")
.setParams(Struct.newBuilder().putAllFields(params).build())
.setSchedule("every 24 hours")
.build();
createCloudStorageTransfer(projectId, transferConfig);
}
public static void createCloudStorageTransfer(String projectId, TransferConfig transferConfig)
throws IOException {
try (DataTransferServiceClient client = DataTransferServiceClient.create()) {
ProjectName parent = ProjectName.of(projectId);
CreateTransferConfigRequest request =
CreateTransferConfigRequest.newBuilder()
.setParent(parent.toString())
.setTransferConfig(transferConfig)
.build();
TransferConfig config = client.createTransferConfig(request);
System.out.println("Cloud storage transfer created successfully :" + config.getName());
} catch (ApiException ex) {
System.out.print("Cloud storage transfer was not created." + ex.toString());
}
}
}
Is there any way I can move all the files to the BQ table at a stretch?
2022-08-04T07:27:50.185847509ZNo files found matching: "gs://dfp-bq/C:\PROG_Reports" - This is the BQ logs for the Run.

example OAuth 1.0 implementation in java

I need an example in java to be able to consume an API using OAuth 1.0 to generate the token :
NB: i have only those informations (the consumerKey, ConsumerSecret, AccesToken and the acessTokenSecret).
I have searched int the internet but I have not found a result that can help me.

I'm looking for the same but, actually, I have an example provided by the admins of the API that I'm trying to consume.
Since no one replied to this thread, I'll paste the mentioned example here, hoping it could help in some way.
Also, if someone can give me a hand, understand the code and explain how to implement it, it would be great.
package com.example.entities;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.WebResource;
import com.sun.jersey.api.client.filter.LoggingFilter;
import com.sun.jersey.oauth.client.OAuthClientFilter;
import com.sun.jersey.oauth.signature.HMAC_SHA1;
import com.sun.jersey.oauth.signature.OAuthParameters;
import com.sun.jersey.oauth.signature.OAuthSecrets;
public class SSRestServiceClient {
/*
* private constructor to avoid construction of object.
*/
private SSRestServiceClient(String url, String consumerKey, String consumerSecret, int timeoutSeconds) {
OAuthParameters params = new OAuthParameters().signatureMethod(HMAC_SHA1.NAME).consumerKey(consumerKey).version(OAUTH_VERSION);
OAuthSecrets secrets = new OAuthSecrets().consumerSecret(consumerSecret);
Client httpClient = Client.create();
httpClient.setConnectTimeout(timeoutSeconds * 1000);
httpClient.setReadTimeout(timeoutSeconds * 1000);
OAuthClientFilter filter = new OAuthClientFilter(httpClient.getProviders(), params, secrets);
httpClient.addFilter(filter);
httpClient.addFilter(new LoggingFilter());
this.consumerKey = consumerKey;
this.webResource = httpClient.resource(url);
}
/*
* Creates instance of the Client class, returns existing instance if it's already created.
*/
public static synchronized SSRestServiceClient getInstance(String url, String consumerKey, String consumerSecret) {
return getInstance(url, consumerKey, consumerSecret, 0);
}
/*
* Creates instance of the Client class, returns existing instance if it's already created.
*/
public static synchronized SSRestServiceClient getInstance(String url, String consumerKey,String consumerSecret, int timeoutSeconds) {
if (client == null || client.getConsumerKey() == null || !client.getConsumerKey().equals(consumerKey)) {
if (timeoutSeconds != 0 && timeoutSeconds < ONE_MINUTE) {
timeoutSeconds = ONE_MINUTE;
}
client = new SSRestServiceClient(url, consumerKey, consumerSecret, timeoutSeconds);
}
return client;
}
/*
* Return a list of all active source cities.
*/
#Override
public CityList getAllSources() {
return webResource.path(GET_ALL_SOURCES).get(CityList.class);
}
}

AWS Email Template usage using java (bulk email)

Can some one give me a direction how can I implement this aws email template tutorial by a java code? Through java code I want to set this AWS Email Template and through java only I want to set the parameter values to the template and through java only I want to send the email.
I cant find any tutorial or direction from which I can translate above requests in java code.

The "code" in your link is actually just some JSON templates for sending and formatting email, and a few calls to an AWS command line tool. If you need to make AWS send email calls from a Java process then you need to take a look at:
The SES API
The Javadoc for the Java client lib

I am able to code it successfully. Pasting the example code here.
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Calendar;
import java.util.List;
import com.amazonaws.auth.AWSStaticCredentialsProvider;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.services.simpleemail.AmazonSimpleEmailService;
import com.amazonaws.services.simpleemail.AmazonSimpleEmailServiceClientBuilder;
import com.amazonaws.services.simpleemail.model.BulkEmailDestination;
import com.amazonaws.services.simpleemail.model.BulkEmailDestinationStatus;
import com.amazonaws.services.simpleemail.model.Destination;
import com.amazonaws.services.simpleemail.model.SendBulkTemplatedEmailRequest;
import com.amazonaws.services.simpleemail.model.SendBulkTemplatedEmailResult;
public class AmazonSESSample2 {
public static void main(String[] args) throws IOException {
String accessKeyId = "accessKeyId";
String secretKeyId = "secretKeyId";
String region = "us-east-1";
List<BulkEmailDestination> listBulkEmailDestination = null;
SendBulkTemplatedEmailRequest sendBulkTemplatedEmailRequest = null;
try {
AmazonSimpleEmailService client = getAmazonSESClient(accessKeyId, secretKeyId, region);
listBulkEmailDestination = new ArrayList<>();
for(String email : getRecievers()) {
String replacementData="{"
+ "\"FULL_NAME\":\"AAA BBB\","
+ "\"USERNAME\":\""+email+"\","
+ "}";
BulkEmailDestination bulkEmailDestination = new BulkEmailDestination();
bulkEmailDestination.setDestination(new Destination(Arrays.asList(email)));
bulkEmailDestination.setReplacementTemplateData(replacementData);
listBulkEmailDestination.add(bulkEmailDestination);
}
sendBulkTemplatedEmailRequest = new SendBulkTemplatedEmailRequest();
sendBulkTemplatedEmailRequest.setSource("noreply#mydomain.com");
sendBulkTemplatedEmailRequest.setTemplate("welcome-email-en_GB-v1");
sendBulkTemplatedEmailRequest.setDefaultTemplateData("{\"FULL_NAME\":\"friend\", \"USERNAME\":\"unknown\"}");
sendBulkTemplatedEmailRequest.setDestinations(listBulkEmailDestination);
SendBulkTemplatedEmailResult res = client.sendBulkTemplatedEmail(sendBulkTemplatedEmailRequest);
System.out.println("======================================");
System.out.println(res.getSdkResponseMetadata());
System.out.println("======================================");
for(BulkEmailDestinationStatus status : res.getStatus()) {
System.out.println(status.getStatus());
System.out.println(status.getError());
System.out.println(status.getMessageId());
}
} catch (Exception ex) {
System.out.println("The email was not sent. Error message: " + ex.getMessage());
ex.printStackTrace();
}
}
public static List<String> getRecievers() {
ArrayList<String> list = new ArrayList<>();
list.add("aaa+1#gmail.com");
list.add("aaa+2#gmail.com");
list.add("aaa+3#gmail.com");
list.add("aaa+4#gmail.com");
return list;
}
public static AmazonSimpleEmailService getAmazonSESClient(String accessKeyId, String secretKeyId, String region) {
BasicAWSCredentials awsCreds = new BasicAWSCredentials(accessKeyId, secretKeyId);
AmazonSimpleEmailService client = AmazonSimpleEmailServiceClientBuilder.standard()
.withCredentials(new AWSStaticCredentialsProvider(awsCreds))
.withRegion(region)
.build();
return client;
}
}

Java: Simple HTTP Server application that responds in JSON

I want to create a very simple HTTP server application in Java.
For example, if I run the server on localhost in port 8080, and I make to following call from my browser, I want to get a Json array with the string 'hello world!':
http://localhost:8080/func1?param1=123&param2=456
I would like to have in the server something that looks like this (very abstract code):
// Retunrs JSON String
String func1(String param1, String param2) {
// Do Something with the params
String jsonFormattedResponse = "['hello world!']";
return jsonFormattedResponse;
}
I guess that this function should not actually "return" the json, but to send it using some HTTP response handler or something similar...
What it the simplest way to do it, without a need to get familiar with many kinds of 3rd party libraries that have special features and methodology?

You could use classes from the package com.sun.net.httpserver:
import com.sun.net.httpserver.Headers;
import com.sun.net.httpserver.HttpServer;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.InetSocketAddress;
import java.net.URI;
import java.net.URLDecoder;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
public class JsonServer {
private static final String HOSTNAME = "localhost";
private static final int PORT = 8080;
private static final int BACKLOG = 1;
private static final String HEADER_ALLOW = "Allow";
private static final String HEADER_CONTENT_TYPE = "Content-Type";
private static final Charset CHARSET = StandardCharsets.UTF_8;
private static final int STATUS_OK = 200;
private static final int STATUS_METHOD_NOT_ALLOWED = 405;
private static final int NO_RESPONSE_LENGTH = -1;
private static final String METHOD_GET = "GET";
private static final String METHOD_OPTIONS = "OPTIONS";
private static final String ALLOWED_METHODS = METHOD_GET + "," + METHOD_OPTIONS;
public static void main(final String... args) throws IOException {
final HttpServer server = HttpServer.create(new InetSocketAddress(HOSTNAME, PORT), BACKLOG);
server.createContext("/func1", he -> {
try {
final Headers headers = he.getResponseHeaders();
final String requestMethod = he.getRequestMethod().toUpperCase();
switch (requestMethod) {
case METHOD_GET:
final Map<String, List<String>> requestParameters = getRequestParameters(he.getRequestURI());
// do something with the request parameters
final String responseBody = "['hello world!']";
headers.set(HEADER_CONTENT_TYPE, String.format("application/json; charset=%s", CHARSET));
final byte[] rawResponseBody = responseBody.getBytes(CHARSET);
he.sendResponseHeaders(STATUS_OK, rawResponseBody.length);
he.getResponseBody().write(rawResponseBody);
break;
case METHOD_OPTIONS:
headers.set(HEADER_ALLOW, ALLOWED_METHODS);
he.sendResponseHeaders(STATUS_OK, NO_RESPONSE_LENGTH);
break;
default:
headers.set(HEADER_ALLOW, ALLOWED_METHODS);
he.sendResponseHeaders(STATUS_METHOD_NOT_ALLOWED, NO_RESPONSE_LENGTH);
break;
}
} finally {
he.close();
}
});
server.start();
}
private static Map<String, List<String>> getRequestParameters(final URI requestUri) {
final Map<String, List<String>> requestParameters = new LinkedHashMap<>();
final String requestQuery = requestUri.getRawQuery();
if (requestQuery != null) {
final String[] rawRequestParameters = requestQuery.split("[&;]", -1);
for (final String rawRequestParameter : rawRequestParameters) {
final String[] requestParameter = rawRequestParameter.split("=", 2);
final String requestParameterName = decodeUrlComponent(requestParameter[0]);
requestParameters.putIfAbsent(requestParameterName, new ArrayList<>());
final String requestParameterValue = requestParameter.length > 1 ? decodeUrlComponent(requestParameter[1]) : null;
requestParameters.get(requestParameterName).add(requestParameterValue);
}
}
return requestParameters;
}
private static String decodeUrlComponent(final String urlComponent) {
try {
return URLDecoder.decode(urlComponent, CHARSET.name());
} catch (final UnsupportedEncodingException ex) {
throw new InternalError(ex);
}
}
}
On a side note, ['hello world!'] is invalid JSON. Strings must be enclosed in double quotes.

You could :
Install Apache Tomcat, and just drop a JSP into the ROOT project that implements this.
I second #xehpuk. It's not actually that hard to write your own single class HTTP server using just standard Java. If you want to do it in earlier versions you can use NanoHTTPD, which is a pretty well known single class HTTP server implementation.
I would personally recommend that you look into Apache Sling (pretty much THE Reference implementation of a Java REST api). You could probably implement your requirements here using Sling without ANY programming at all.
But as others have suggested, the standard way to do this is to create a java WAR and deploy it into a 'servlet container' such as Tomcat or Jetty etc.

If you are already familiar with servlet you do not need much to create a simple server to achieve what you want. But I would like to emphasize that your needs will likely to increase rapidly and therefore you may need to move to a RESTful framework (e.g.: Spring WS, Apache CXF) down the road.
You need to register URIs and get parameters using the standard servlet technology. Maybe you can start here: http://docs.oracle.com/cd/E13222_01/wls/docs92/webapp/configureservlet.html
Next, you need a JSON provider and serialize (aka marshall) it in JSON format. I recommend JACKSON. Take a look at this tutorial:
http://www.sivalabs.in/2011/03/json-processing-using-jackson-java-json.html
Finally, your code will look similar to this:
public class Func1Servlet extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
String p1 = req.getParameter("param1");
String p2 = req.getParameter("param2");
// Do Something with the params
ResponseJSON resultJSON = new ResponseJSON();
resultJSON.setProperty1(yourPropert1);
resultJSON.setProperty2(yourPropert2);
// Convert your JSON object into JSON string
Writer strWriter = new StringWriter();
mapper.writeValue(strWriter, resultJSON);
String resultString = strWriter.toString();
resp.setContentType("application/json");
out.println(resultString );
}
}
Map URLs in your web.xml:
<servlet>
<servlet-name>func1Servlet</servlet-name>
<servlet-class>myservlets.func1servlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>func1Servlet</servlet-name>
<url-pattern>/func1/*</url-pattern>
</servlet-mapping>
Keep in mind this is a pseudo-code. There are lots you can do to enhance it, adding some utility classes, etc...
Nevertheless, as your project grows your need for a more comprehensive framework becomes more evident.

Run main to start the server on port 8080
public class Main {
public static void main(String[] args) throws LifecycleException {
Tomcat tomcat = new Tomcat();
Context context = tomcat.addContext("", null);
Tomcat.addServlet(context, "func1", new HttpServlet() {
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
Object response = func1(req.getParameter("param1"), req.getParameter("param2"));
ObjectMapper mapper = new ObjectMapper();
mapper.writeValue(resp.getWriter(), response);
}
});
context.addServletMappingDecoded("/func1", "func1");
tomcat.start();
tomcat.getServer().await();
}
private static String[] func1(String p1, String p2) {
return new String[] { "hello world", p1, p2 };
}
}
Gradle dependencies:
dependencies {
compile group: 'org.apache.tomcat.embed', name: 'tomcat-embed-core', version: '8.5.28' // doesn't work with tomcat 9
compile group: 'com.fasterxml.jackson.core', name: 'jackson-databind', version: '2.9.4'
}

Amazon Product Advertising API through Java/SOAP

I have been playing with Amazon's Product Advertising API, and I cannot get a request to go through and give me data. I have been working off of this: http://docs.amazonwebservices.com/AWSECommerceService/2011-08-01/GSG/ and this: Amazon Product Advertising API signed request with Java
Here is my code. I generated the SOAP bindings using this: http://docs.amazonwebservices.com/AWSECommerceService/2011-08-01/GSG/YourDevelopmentEnvironment.html#Java
On the Classpath, I only have: commons-codec.1.5.jar
import com.ECS.client.jax.AWSECommerceService;
import com.ECS.client.jax.AWSECommerceServicePortType;
import com.ECS.client.jax.Item;
import com.ECS.client.jax.ItemLookup;
import com.ECS.client.jax.ItemLookupRequest;
import com.ECS.client.jax.ItemLookupResponse;
import com.ECS.client.jax.ItemSearchResponse;
import com.ECS.client.jax.Items;
public class Client {
public static void main(String[] args) {
String secretKey = <my-secret-key>;
String awsKey = <my-aws-key>;
System.out.println("API Test started");
AWSECommerceService service = new AWSECommerceService();
service.setHandlerResolver(new AwsHandlerResolver(
secretKey)); // important
AWSECommerceServicePortType port = service.getAWSECommerceServicePort();
// Get the operation object:
com.ECS.client.jax.ItemSearchRequest itemRequest = new com.ECS.client.jax.ItemSearchRequest();
// Fill in the request object:
itemRequest.setSearchIndex("Books");
itemRequest.setKeywords("Star Wars");
// itemRequest.setVersion("2011-08-01");
com.ECS.client.jax.ItemSearch ItemElement = new com.ECS.client.jax.ItemSearch();
ItemElement.setAWSAccessKeyId(awsKey);
ItemElement.getRequest().add(itemRequest);
// Call the Web service operation and store the response
// in the response object:
com.ECS.client.jax.ItemSearchResponse response = port
.itemSearch(ItemElement);
String r = response.toString();
System.out.println("response: " + r);
for (Items itemList : response.getItems()) {
System.out.println(itemList);
for (Item item : itemList.getItem()) {
System.out.println(item);
}
}
System.out.println("API Test stopped");
}
}
Here is what I get back.. I was hoping to see some Star Wars books available on Amazon dumped out to my console :-/:
API Test started
response: com.ECS.client.jax.ItemSearchResponse#7a6769ea
com.ECS.client.jax.Items#1b5ac06e
API Test stopped
What am I doing wrong (Note that no "item" in the second for loop is being printed out, because its empty)? How can I troubleshoot this or get relevant error information?

I don't use the SOAP API but your Bounty requirements didn't state that it had to use SOAP only that you wanted to call Amazon and get results. So, I'll post this working example using the REST API which will at least fulfill your stated requirements:
I would like some working example code that hits the amazon server and returns results
You'll need to download the following to fulfill the signature requirements:
http://associates-amazon.s3.amazonaws.com/signed-requests/samples/amazon-product-advt-api-sample-java-query.zip
Unzip it and grab the com.amazon.advertising.api.sample.SignedRequestsHelper.java file and put it directly into your project. This code is used to sign the request.
You'll also need to download Apache Commons Codec 1.3 from the following and add it to your classpath i.e. add it to your project's library. Note that this is the only version of Codec that will work with the above class (SignedRequestsHelper)
http://archive.apache.org/dist/commons/codec/binaries/commons-codec-1.3.zip
Now you can copy and paste the following making sure to replace your.pkg.here with the proper package name and replace the SECRET and the KEY properties:
package your.pkg.here;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.StringWriter;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.Document;
import org.xml.sax.SAXException;
public class Main {
private static final String SECRET_KEY = "<YOUR_SECRET_KEY>";
private static final String AWS_KEY = "<YOUR_KEY>";
public static void main(String[] args) {
SignedRequestsHelper helper = SignedRequestsHelper.getInstance("ecs.amazonaws.com", AWS_KEY, SECRET_KEY);
Map<String, String> params = new HashMap<String, String>();
params.put("Service", "AWSECommerceService");
params.put("Version", "2009-03-31");
params.put("Operation", "ItemLookup");
params.put("ItemId", "1451648537");
params.put("ResponseGroup", "Large");
String url = helper.sign(params);
try {
Document response = getResponse(url);
printResponse(response);
} catch (Exception ex) {
Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
}
}
private static Document getResponse(String url) throws ParserConfigurationException, IOException, SAXException {
DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
Document doc = builder.parse(url);
return doc;
}
private static void printResponse(Document doc) throws TransformerException, FileNotFoundException {
Transformer trans = TransformerFactory.newInstance().newTransformer();
Properties props = new Properties();
props.put(OutputKeys.INDENT, "yes");
trans.setOutputProperties(props);
StreamResult res = new StreamResult(new StringWriter());
DOMSource src = new DOMSource(doc);
trans.transform(src, res);
String toString = res.getWriter().toString();
System.out.println(toString);
}
}
As you can see this is much simpler to setup and use than the SOAP API. If you don't have a specific requirement for using the SOAP API then I would highly recommend that you use the REST API instead.
One of the drawbacks of using the REST API is that the results aren't unmarshaled into objects for you. This could be remedied by creating the required classes based on the wsdl.

This ended up working (I had to add my associateTag to the request):
public class Client {
public static void main(String[] args) {
String secretKey = "<MY_SECRET_KEY>";
String awsKey = "<MY AWS KEY>";
System.out.println("API Test started");
AWSECommerceService service = new AWSECommerceService();
service.setHandlerResolver(new AwsHandlerResolver(secretKey)); // important
AWSECommerceServicePortType port = service.getAWSECommerceServicePort();
// Get the operation object:
com.ECS.client.jax.ItemSearchRequest itemRequest = new com.ECS.client.jax.ItemSearchRequest();
// Fill in the request object:
itemRequest.setSearchIndex("Books");
itemRequest.setKeywords("Star Wars");
itemRequest.getResponseGroup().add("Large");
// itemRequest.getResponseGroup().add("Images");
// itemRequest.setVersion("2011-08-01");
com.ECS.client.jax.ItemSearch ItemElement = new com.ECS.client.jax.ItemSearch();
ItemElement.setAWSAccessKeyId(awsKey);
ItemElement.setAssociateTag("th0426-20");
ItemElement.getRequest().add(itemRequest);
// Call the Web service operation and store the response
// in the response object:
com.ECS.client.jax.ItemSearchResponse response = port
.itemSearch(ItemElement);
String r = response.toString();
System.out.println("response: " + r);
for (Items itemList : response.getItems()) {
System.out.println(itemList);
for (Item itemObj : itemList.getItem()) {
System.out.println(itemObj.getItemAttributes().getTitle()); // Title
System.out.println(itemObj.getDetailPageURL()); // Amazon URL
}
}
System.out.println("API Test stopped");
}
}

It looks like the response object does not override toString(), so if it contains some sort of error response, simply printing it will not tell you what the error response is. You'll need to look at the api for what fields are returned in the response object and individually print those. Either you'll get an obvious error message or you'll have to go back to their documentation to try to figure out what is wrong.

You need to call the get methods on the Item object to retrieve its details, e.g.:
for (Item item : itemList.getItem()) {
System.out.println(item.getItemAttributes().getTitle()); //Title of item
System.out.println(item.getDetailPageURL()); // Amazon URL
//etc
}
If there are any errors you can get them by calling getErrors()
if (response.getOperationRequest().getErrors() != null) {
System.out.println(response.getOperationRequest().getErrors().getError().get(0).getMessage());
}