Develop Reference

Box Java sdk - The API returned an error code 404 - Not Found

I need to create a utility, which downloads the files from the box folder. But I am unable to get it working though:
package com.box.sdk.example;
import com.box.sdk.BoxConfig;
import com.box.sdk.BoxDeveloperEditionAPIConnection;
import com.box.sdk.BoxFile;
import com.box.sdk.BoxFolder;
import com.box.sdk.BoxItem;
import java.io.BufferedReader;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
public class PlayGround {
public static void main(String[] args) {
Path configPath = Paths.get("config.json");
Path currentDir = Paths.get("").toAbsolutePath();
try (BufferedReader reader = Files.newBufferedReader(configPath, Charset.forName("UTF-8"))) {
BoxConfig boxConfig = BoxConfig.readFrom(reader);
BoxDeveloperEditionAPIConnection client = BoxDeveloperEditionAPIConnection.getAppEnterpriseConnection(boxConfig);
String folderId = "125601757844";
BoxFolder folder = new BoxFolder(client, folderId);
String folderName = folder.getInfo().getName();
Path localFolderPath = currentDir.resolve(Paths.get(folderName));
if (!Files.exists(localFolderPath)) {
localFolderPath = Files.createDirectory(localFolderPath);
} else {
localFolderPath = resetLocalFolder(localFolderPath);
}
for (BoxItem.Info itemInfo : folder) {
if (itemInfo instanceof BoxFile.Info) {
BoxFile.Info fileInfo = (BoxFile.Info) itemInfo;
BoxFile file = new BoxFile(client, fileInfo.getID());
String localFilePath = localFolderPath.resolve(Paths.get(fileInfo.getName())).toAbsolutePath()
.toString();
FileOutputStream stream = new FileOutputStream(localFilePath);
file.download(stream);
stream.close();
}
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
static Path resetLocalFolder(Path localFolderPath) throws IOException {
Files.list(localFolderPath).forEach(file -> {
System.out.println(file.getFileName());
try {
Files.delete(file.toAbsolutePath());
} catch (IOException e) {
}
});
Files.delete(localFolderPath);
localFolderPath = Files.createDirectory(localFolderPath);
return localFolderPath;
}
}
When I run this code, I get the following exception:
Exception in thread "main" com.box.sdk.BoxAPIResponseException: The API returned an error code [404 | lsgp4zgkfg6qipxg.0d094ed7daa5f78921603840e0fa470e1] not_found - Not Found
at com.box.sdk.BoxAPIResponse.<init>(BoxAPIResponse.java:92)
at com.box.sdk.BoxJSONResponse.<init>(BoxJSONResponse.java:32)
at com.box.sdk.BoxAPIRequest.trySend(BoxAPIRequest.java:680)
at com.box.sdk.BoxAPIRequest.send(BoxAPIRequest.java:382)
at com.box.sdk.BoxAPIRequest.send(BoxAPIRequest.java:349)
at com.box.sdk.BoxFolder.getInfo(BoxFolder.java:289)
at com.box.sdk.example.PlayGround.main(PlayGround.java:26)
Note: I am able to run the above code, by using developer token, which lasts for 1 hour, but I can't build my production application on such volatile code.
BoxAPIConnection client = new BoxAPIConnection("3i8b5sPnxUotd5etDuUkzGjXXzBphty9");

Convert avro file into csv in java web application

We have a requirement where we would like to convert an avro file which we download from our third party vendor API in our java web application. I tried going through some of the resources where all i could find was command s to execute with help of avro-tools.jar But i am looking for a way to achieve this within Java web application. Any help greatly appreciated.

You can use avro-tools to read the avro records , get Schema and records from the file
Attaching a rough draft :
I'm using JSON as intermediary ,You can modify it to any format of your choice
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.json.CDL;
import org.json.JSONArray;
import org.json.JSONException;
import org.apache.avro.Schema;
import org.apache.avro.Schema.Field;
import org.apache.avro.file.DataFileReader;
import org.apache.avro.generic.GenericData;
import org.apache.avro.generic.GenericDatumReader;
import org.apache.commons.io.FileUtils;
public class AvroToCSV {
public static void readAvro(File file) {
// Read Avro ,parse Schema to get field names and parse it to json
try {
GenericDatumReader<GenericData.Record> datum = new GenericDatumReader<GenericData.Record>();
DataFileReader<GenericData.Record> reader = new DataFileReader<GenericData.Record>(file, datum);
GenericData.Record record = new GenericData.Record(reader.getSchema());
Schema schema = reader.getSchema();
List<String> fieldValues = new ArrayList<>();
JSONArray jsonArray = new JSONArray();
for (Field field : schema.getFields()) {
fieldValues.add(field.name());
}
while (reader.hasNext()) {
reader.next(record);
Map<String, String> jsonFileds = new HashMap<String, String>();
for (String item : fieldValues) {
System.out.println(item);
jsonFileds.put(item, record.get(item).toString());
}
jsonArray.put(jsonFileds);
}
System.out.println(jsonArray.toString());
reader.close();
jsonToCSV(jsonArray);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void jsonToCSV(JSONArray json) {
File file = new File("avroToJson.csv");
String csv;
try {
csv = CDL.toString(json);
FileUtils.writeStringToFile(file, csv);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void main(String[] args) {
File f = new File("test.avro");
readAvro(f);
}
}

Write a json file in java

I want to write a json file in java, but it doesn't work, I get this warning:
I want to know how to do this, because I am going to convert a cfg file that is tabbed to json.
Type safety: The method add(Object) belongs to the raw type ArrayList. References to generic type ArrayList<E> should be parameterized
and I have this code:
package json;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
public class JsonWriter {
public static void main(String[] args) {
JSONObject countryObj = new JSONObject();
countryObj.put("Name", "India");
countryObj.put("Population", new Integer(1000000));
JSONArray listOfStates = new JSONArray();
listOfStates.add("Madhya Pradesh");
listOfStates.add("Maharastra");
listOfStates.add("Rajasthan");
countryObj.put("States", listOfStates);
try {
// Writing to a file
File file=new File("JsonFile.json");
file.createNewFile();
FileWriter fileWriter = new FileWriter(file);
System.out.println("Writing JSON object to file");
System.out.println("-----------------------");
System.out.print(countryObj);
fileWriter.write(countryObj.toJSONString());
fileWriter.flush();
fileWriter.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}

I would suggest that you just make a simple ArrayList with your objects, and then serialize them into JSON with a serializer (Using the Jacksoin library in the example below). It would look something like this:
First, define your model in a class (Made without incapsulations for readability):
public class Country{
public String name;
public Integer population;
public List<String> states;
}
Then you can go ahead and create it, and populate the list:
import java.io.File;
import java.io.IOException;
import org.codehaus.jackson.JsonGenerationException;
import org.codehaus.jackson.map.JsonMappingException;
import org.codehaus.jackson.map.ObjectMapper;
public class JsonWriter {
public static void main(String[] args) {
Country countryObj = new Country();
countryObj.name = "India";
countryObj.population = 1000000;
List<String> listOfStates = new ArrayList<String>();
listOfStates.add("Madhya Pradesh");
listOfStates.add("Maharastra");
listOfStates.add("Rajasthan");
countryObj.states = listOfStates ;
ObjectMapper mapper = new ObjectMapper();
try {
// Writing to a file
mapper.writeValue(new File("c:\\country.json"), countryObj );
} catch (IOException e) {
e.printStackTrace();
}
}
}

kryo serializing of class (task object) in apache spark returns null while de-serialization

I am using java spark API to write some test application . I am using a class which doesn't extends serializable interface . So to make the application work I am using kryo serializer to serialize the class . But the problem which I observed while debugging was that during the de-serialization the returned class object becomes null and in turn throws a null pointer exception . It seems to be closure problem where things are going wrong but not sure.Since I am new to this kind of serialization I don't know where to start digging.
Here is the code I am testing :
package org.apache.spark.examples;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.UnknownHostException;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.api.java.function.Function;
/**
* Spark application to test the Serialization issue in spark
*/
public class Test {
static PrintWriter outputFileWriter;
static FileWriter file;
static JavaSparkContext ssc;
public static void main(String[] args) {
String inputFile = "/home/incubator-spark/examples/src/main/scala/org/apache/spark/examples/InputFile.txt";
String master = "local";
String jobName = "TestSerialization";
String sparkHome = "/home/test/Spark_Installation/spark-0.7.0";
String sparkJar = "/home/test/TestSerializationIssesInSpark/TestSparkSerIssueApp/target/TestSparkSerIssueApp-0.0.1-SNAPSHOT.jar";
SparkConf conf = new SparkConf();
conf.set("spark.closure.serializer","org.apache.spark.serializer.KryoSerializer");
conf.set("spark.kryo.registrator", "org.apache.spark.examples.MyRegistrator");
// create the Spark context
if(master.equals("local")){
ssc = new JavaSparkContext("local", jobName,conf);
//ssc = new JavaSparkContext("local", jobName);
} else {
ssc = new JavaSparkContext(master, jobName, sparkHome, sparkJar);
}
JavaRDD<String> testData = ssc.textFile(inputFile).cache();
final NotSerializableJavaClass notSerializableTestObject= new NotSerializableJavaClass("Hi ");
#SuppressWarnings({ "serial", "unchecked"})
JavaRDD<String> classificationResults = testData.map(
new Function<String, String>() {
#Override
public String call(String inputRecord) throws Exception {
if(!inputRecord.isEmpty()) {
//String[] pointDimensions = inputRecord.split(",");
String result = "";
try {
FileWriter file = new FileWriter("/home/test/TestSerializationIssesInSpark/results/test_result_" + (int) (Math.random() * 100));
PrintWriter outputFile = new PrintWriter(file);
InetAddress ip;
ip = InetAddress.getLocalHost();
outputFile.println("IP of the server: " + ip);
result = notSerializableTestObject.testMethod(inputRecord);
outputFile.println("Result: " + result);
outputFile.flush();
outputFile.close();
file.close();
} catch (UnknownHostException e) {
e.printStackTrace();
}
catch (IOException e1) {
e1.printStackTrace();
}
return result;
} else {
System.out.println("End of elements in the stream.");
String result = "End of elements in the input data";
return result;
}
}
}).cache();
long processedRecords = classificationResults.count();
ssc.stop();
System.out.println("sssssssssss"+processedRecords);
}
}
Here is the KryoRegistrator class
package org.apache.spark.examples;
import org.apache.spark.serializer.KryoRegistrator;
import com.esotericsoftware.kryo.Kryo;
public class MyRegistrator implements KryoRegistrator {
public void registerClasses(Kryo kryo) {
kryo.register(NotSerializableJavaClass.class);
}
}
Here is the class I am serializing :
package org.apache.spark.examples;
public class NotSerializableJavaClass {
public String testVariable;
public NotSerializableJavaClass(String testVariable) {
super();
this.testVariable = testVariable;
}
public String testMethod(String vartoAppend){
return this.testVariable + vartoAppend;
}
}

This is because spark.closure.serializer only supports the Java serializer. See http://spark.apache.org/docs/latest/configuration.html about spark.closure.serializer

ArrayList to XML

I am trying to take the contents of an ArrayList and put them into an XML file. Does anyone have a quick,clean and easy solution to this rather that having to use streams and handle exceptions?
For more information, Here is the code I have currently I am getting problem with it, one of which its not creating the file.
package ie.wit.io;
import ie.wit.abs.Device;
import ie.wit.abs.Device;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JOptionPane;
public class FileHandler
{
private FileOutputStream outByteStream;
private ObjectOutputStream OOStream;
private FileInputStream inByteStream;
private ObjectInputStream OIStream;
private File aFile;
public void setUpFile()
{
aFile = new File("data.xml");
}
public boolean isFileEmpty()
{
return (aFile.length() <= 0);
}
public void writeToFile(ArrayList<Device> team)
{
try
{
outByteStream = new FileOutputStream(aFile);
OOStream = new ObjectOutputStream(outByteStream);
OOStream.writeObject(team);
outByteStream.close();
OOStream.close();
}
catch(IOException e)
{
JOptionPane.showMessageDialog(null,"I/O Error" + e + "\nPlease Contact your Administrator :-)");
}
}
currentClass)
public ArrayList<Device> readFromFile()
{
ArrayList<Device> temp = null;
try
{
inByteStream = new FileInputStream(aFile);
OIStream = new ObjectInputStream(inByteStream);
if(!this.isFileEmpty())
temp = (ArrayList<Device>)OIStream.readObject();
inByteStream.close();
OIStream.close();
}
catch(IOException e)
{
JOptionPane.showMessageDialog(null,"I/O Error" + e + "\nPlease Contact your Administrator :-)");
}
catch(Exception e)
{
JOptionPane.showMessageDialog(null,"General Error" + e + "\nPlease Contact your Administrator :-)");
}
return temp;
}
}

There are many libraries to do that task.
Here is what I'm doing so far. Edit as per your requirement.
protected String getDocmentsAsString(List<News> documentsListByIndex) {
if(documentsListByIndex.size()>0){
try {
XStream xstream = new XStream(new JsonHierarchicalStreamDriver());
xstream.setMode(XStream.NO_REFERENCES);
xstream.alias("news", News.class);
return xstream.toXML(documentsListByIndex);
} catch (Exception e) {
e.printStackTrace();
}
}
return null;
}
Im using http://x-stream.github.io/json-tutorial.html

You can use a StringBuilder and generate the XML yourself.. It depends on how many items you want to convert. The fastest way is just pushing out the XML data using a StringBuilder.

I recommend to:
create a XSD
generate JAXB Java classes (e.g. using a Maven Plugin)
create instances of the JAXB Java classes and fill up the data
marshal the JAXB Java classes to XML