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Java : 64 based string decode / parse failed

I am trying to convert this 64 based encoded JSON string and convert received JSON into POJO using flexjson API.
First try block, converts direct JSON as string into object which is success. This string is decoded using online tool.
Now second try block, try to convert 64 based string into an object in a similar way but converting the 64based string on the run which is throwing exception flexjson.JSONException: Expected a ',' or ']' at character 10
try {
AsyncResponseDO asyncResponseDO = new JSONDeserializer<AsyncResponseDO>().deserialize("{\"relatesTo\":\"7_Sept2017_IF01\"}", AsyncResponseDO.class);
System.out.println(asyncResponseDO.getRelatesTo());
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
AsyncResponseDO asyncResponseDO = new JSONDeserializer<AsyncResponseDO>().deserialize(Base64.decodeBase64("eyJyZWxhdGVzVG8iOiI3X1NlcHQyMDE3X0lGMDEifQ==".getBytes()).toString(), AsyncResponseDO.class);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
POJO class :
public class AsyncResponseDO {
private String relatesTo;
public String getRelatesTo() {
return relatesTo;
}
public void setRelatesTo(String relatesTo) {
this.relatesTo = relatesTo;
}
}

new String(Base64.decodeBase64("eyJyZWxhdGVzVG8iOiI3X1NlcHQyMDE3‌X0lGMDEifQ==".getByt‌es()));
This will convert into a proper string.
I referred to https://www.mkyong.com/java/how-do-convert-byte-array-to-string-in-java/

Performance tune code in O (n^2) to be more performant

I have this spring boot java controller having code that utilizes the OpenKM document management API to search the document management system for documents and display results using Ajax, HTML, CSS and Jquery datatables on the front-end.
Due to the way the API was written, I cannot get a document object with its metadata in one call but will need to use an output of the first API operation's call as a filter for another API operation method in two nested for loops.
Additionally, I had to iterate the toString method of an API return object to retrieve the metadata information, as they were not accessible through the return object's properties.
The problem is the performance of this code. I would like to see if there is a way to optimize this code.
// Read the property or metadata to use in constituting the StoredDocument object
for (QueryResult queryResult : resultSet.getResults()) {
// Create a locally-scoped List<String>
List<String> listOfStoredDocumentProperties = new ArrayList<String>();
Document document = queryResult.getDocument();
String nodeId = document.getPath();
// Populate storedDocument object
storedDocument = new StoredDocument();
storedDocument.setAuthor(document.getAuthor());
storedDocument.setCreated(document.getCreated());
storedDocument.setLastModified(document.getLastModified());
storedDocument.setPath(document.getPath());
storedDocument.setPermissions(document.getPermissions());
storedDocument.setSize(document.getActualVersion().getSize());
storedDocument.setUuid(document.getUuid());
storedDocument.setVersionNumber(document.getActualVersion().getName());
// System.out.println(nodeId);
try {
listOfFormElement = okm.getPropertyGroupProperties(nodeId, documentVo.getGroupId());
int counterForTrackingDocDirectionPos = 0;
for (FormElement formElement : listOfFormElement) {
++counterForTrackingDocDirectionPos;
if (counterForTrackingDocDirectionPos == 4) {
String formElementString = formElement.toString();
// System.out.println("formElementString: " + formElementString);
System.out.println("name: " + formElement.getName());
System.out.println("formElement: " + formElement);
String transformedFormElementString = StringUtils.EMPTY;
try {
transformedFormElementString = formElementString.substring(0, formElementString.indexOf(", selected=true"));
// Read the string from a position that is 3 steps before the last position in the string.
transformedFormElementString = transformedFormElementString
.substring(transformedFormElementString.length() - 3, transformedFormElementString.length()).trim();
transformedFormElementString = transformedFormElementString.startsWith("=")
? transformedFormElementString.substring(1, transformedFormElementString.length()) : transformedFormElementString;
} catch (Exception ex) {
// To catch scenario where formElementString.indexOf(", selected=true") does not find the
// specified string. This happens when document direction is not set and therefore is
// selected=false for both the options IN and OUT.
transformedFormElementString = "NOT SET";
}
listOfStoredDocumentProperties.add(transformedFormElementString);
System.out.println("transformedFormElementString: " + transformedFormElementString);
} else {
String formElementString = formElement.toString();
String transformedFormElementString = formElementString.substring(formElementString.indexOf("value="),
formElementString.indexOf("data="));
// Remove the preceding 'value=' and the last 2 character-constituted string ", "
transformedFormElementString = transformedFormElementString.substring(6, transformedFormElementString.length() - 2).trim();
listOfStoredDocumentProperties.add(transformedFormElementString);
}
}
storedDocument.setCompanyName(listOfStoredDocumentProperties.get(0));
storedDocument.setProductLine(listOfStoredDocumentProperties.get(1));
storedDocument.setSubjectHeading(listOfStoredDocumentProperties.get(2));
storedDocument.setDocumentDirection(listOfStoredDocumentProperties.get(3));
storedDocument.setDocumentType(listOfStoredDocumentProperties.get(4));
storedDocument.setReferenceNumber(listOfStoredDocumentProperties.get(5));
storedDocument.setDate(ISO8601.parseBasic(listOfStoredDocumentProperties.get(6)).getTime().toString());
// Add the storedDocument object to the return list
listOfstoredDocuments.add(storedDocument);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchGroupException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (PathNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (RepositoryException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (DatabaseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (UnknowException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (WebserviceException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

The solution for it is extending the REST API. In the professional edition, the REST API is extensible with plugins architecture https://docs.openkm.com/kcenter/view/okm-6.4/creating-your-own-rest-plugin-(-extending-rest-api-).html, in the community this option still is not present. The idea is to build a method from server side what provide the exact data what really you need, creating high-level methods.

How to not use nested try catch blocks when parsing JSON?

Is there a more elegant solution to my code below than to have multiple nested try-catch blocks for JSONException?
The reason I nest them is because I don't want to rest of the parsing to stop if there is one error in parsing. I want each to be independent of each other.
if (obj.has(GlobalVars.KEY_DESC)) {
try {
JSONObject descObj = obj.getJSONObject(GlobalVars.KEY_DESC);
if (descObj.has(GlobalVars.KEY_COUNTRY)) {
try {
description.put(GlobalVars.KEY_COUNTRY, descObj.getString(GlobalVars.KEY_COUNTRY));
}
catch (JSONException e) { e.printStackTrace(); }
}
if (descObj.has(GlobalVars.KEY_CITY)) {
try {
description.put(GlobalVars.KEY_COUNTRY, descObj.getString(GlobalVars.KEY_CITY));
}
catch (JSONException e) { e.printStackTrace(); }
}
if (descObj.has(GlobalVars.KEY_POSTAL)) {
try {
description.put(GlobalVars.KEY_COUNTRY, descObj.getString(GlobalVars.KEY_POSTAL));
}
catch (JSONException e) { e.printStackTrace(); }
}
if (descObj.has(GlobalVars.KEY_STREET)) {
try {
description.put(GlobalVars.KEY_COUNTRY, descObj.getString(GlobalVars.KEY_STREET));
}
catch (JSONException e) { e.printStackTrace(); }
}
if (descObj.has(GlobalVars.KEY_SUBSTREET)) {
try {
description.put(GlobalVars.KEY_COUNTRY, descObj.getString(GlobalVars.KEY_SUBSTREET));
}
catch (JSONException e) { e.printStackTrace(); }
}
if (descObj.has(GlobalVars.KEY_YEAR)) {
try {
description.put(GlobalVars.KEY_COUNTRY, descObj.getInt(GlobalVars.KEY_YEAR));
}
catch (JSONException e) { e.printStackTrace(); }
}
if (descObj.has(GlobalVars.KEY_SQUARE_METERS)) {
try {
description.put(GlobalVars.KEY_COUNTRY, descObj.getInt(GlobalVars.KEY_SQUARE_METERS));
}
catch (JSONException e) { e.printStackTrace(); }
}
}
catch (JSONException e) { e.printStackTrace(); }
}

You seems to be doing similar stuff in all of your if statements:
try {
description.put(GlobalVars.KEY_COUNTRY, descObj.getString(GlobalVars.KEY_COUNTRY));
}
catch (JSONException e) { e.printStackTrace(); }
So you can move this code to a method and can call that method from each if statement. It will make your code cleaner

I think you don't need to use all these try catch if you use Gson lib, it ignored missing fields and continue the parsing, but you can register the missing fields by using the below code:
package json;
import java.lang.reflect.Field;
import java.lang.reflect.Type;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonParseException;
public class App {
public static void main(String[] args) {
Gson gson = new GsonBuilder().registerTypeAdapter(
MyAnnotationBean.class,
new AnnotatedDeserializer<MyAnnotationBean>()).create();
String json = "{\"desc\":\"This is desc\",\"country\":\"this is country\"}";
MyAnnotationBean tab = gson.fromJson(json, MyAnnotationBean.class);
System.out.println(tab.desc);
System.out.println(tab.country);
json = "{\"desc\":\"This is desc\"}";
tab = gson.fromJson(json, MyAnnotationBean.class);
System.out.println(tab.desc);
System.out.println(tab.country);
json = "{\"country\":\"This is country\"}";
tab = gson.fromJson(json, MyAnnotationBean.class);
System.out.println(tab.desc);
System.out.println(tab.country);
}
}
class MyAnnotationBean {
public String desc;
public String country;
}
class AnnotatedDeserializer<T> implements JsonDeserializer<T> {
public T deserialize(JsonElement je, Type type,
JsonDeserializationContext jdc) throws JsonParseException {
T obj = new Gson().fromJson(je, type);
Field[] fields = obj.getClass().getDeclaredFields();
for (Field f : fields) {
try {
f.setAccessible(true);
if (f.get(obj) == null) {
// throw new JsonParseException("required json " +
// f.getName());
// add your code to know missing fields
}
} catch (IllegalArgumentException ex) {
ex.printStackTrace();
} catch (IllegalAccessException ex) {
ex.printStackTrace();
}
}
return obj;
}
}

IF and ELSE in TRY CATCH?

I have this code
root = new Root();
root.checkRootMethod2();
TextView=(TextView)view.findViewById(R.id.textView4);
if(root.checkRootMethod2()) {
TextView.setText(Html.fromHtml("<b>TEXT 01</b><br>"));
} else {
TextView.setText(Html.fromHtml("<b>TEXT 02</b><br>"));
}
try {
if (root.RootAvailibility() && (root.checkRootMethod3())) {
try {
Process process = Runtime.getRuntime().exec("su");
OutputStream stdin = process.getOutputStream();
stdin.flush();
stdin.close();
} catch(Exception e) {
}
TextView.append(Html.fromHtml(
"<b><font color=\"green\">TEXT 03</b></font>"));
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
root.busybox();
TextView.append(Html.fromHtml(
"<br><b><font color=\"green\">TEXT 04</b></font>"));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch(Exception e) {
TextView.append(Html.fromHtml(
"<br><b><font color=\"red\">TEXT05</b></font>"));
}
I wish that if if (root.RootAvailibility() && (root.checkRootMethod3())) return true Viewing a TextView that says something.If return false, another TextView that displays something else. As happens for root.checkRootMethod2 (); Same goes for root.busybox (); Do you have any idea on how I can do? Now visualize always Text04

try {
if (root.RootAvailibility() && (root.checkRootMethod3()))
{
try
{
/// your code ...
}
catch(Exception e){ }
TextView.append(Html.fromHtml("<b><font color=\"green\">TEXT 03</b></font>"));
}
}catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// Codes here runs always regardless of if clause.
the code (try block in your case) runs regardless of the if condition as the try block clears the scope of if block.
Either put try completely inside if block or surround both if,else statement by a single try block.

I don't know what is the need of multiple try/catch here :
try {
if (root.RootAvailibility() && (root.checkRootMethod3()))
{
try
{
You can add one more catch(Exception e) to the upper try/catch block and that will serve the same purpose.
Secondly there is no else part to this if (root.RootAvailibility() && (root.checkRootMethod3())). So, if it is false the program will simply move forward.

Well you're always going to see Text04 because there's no conditional that excludes it. The try catch block it's in is at the top level.
It would help if you could provide a short, self-contained, compilable example of your code. There's clearly other potentially relevant code missing. For example, the try that goes with that last catch block. Also, it might help you to comment the beginning and end of your code blocks so that you can tell what's included in the if else statements.

Program won't run because variables "may be uninitialized"?

I'm trying to make a new thread for parsing xml from an rss feed. When I click run it says there are errors please correct them etc. I have 2 classes in my project. The other class has no errors and this class below has only warnings that a lot of the things in the try/catch statements may be uninitialized. I understand that and figured I should still be able to run the program anyways, I expect them to be initialized and if they're not that's fine I want to know about it. Is this really what's going on or am I missing something? I thought it would compile if something may be uninitialized but its not certainly uninitialized.
public class RssParse extends Thread {
Thread th=new Thread() {
public void run(){
System.out.println("1");
URL iotd;
try {
iotd = new URL("http://www.nasa.gov/rss/image_of_the_day.rss");
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("2");
BufferedReader in;
try {
in = new BufferedReader(new InputStreamReader(iotd.openStream()));
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
System.out.println("3");
XmlPullParserFactory factory;
try {
factory = XmlPullParserFactory.newInstance();
} catch (XmlPullParserException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
factory.setNamespaceAware(true);
System.out.println("4");
XmlPullParser xpp;
try {
xpp = factory.newPullParser();
} catch (XmlPullParserException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("5");
try {
xpp.setInput(in);
} catch (XmlPullParserException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("6");
int eventType;
try {
eventType = xpp.getEventType();
} catch (XmlPullParserException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(eventType+"!!!!!!!!!!!!!!!!");
while(eventType!=XmlPullParser.END_DOCUMENT){
if(eventType==XmlPullParser.START_DOCUMENT){
System.out.println("start");
}
}
try {
in.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}//method
};//thread
}//class

Look at this try/catch block for example :
URL iotd;
try {
iotd = new URL("http://www.nasa.gov/rss/image_of_the_day.rss");
} catch (MalformedURLException e) {
e.printStackTrace();
}
If iotd = new URL("...") fails, iotd will remain uninitialized.
There are two ways to deal with this :
Assign a default value to iotd, like : URL iotd = null; However, it's bad here because if you use iotd later its value may be null and can throw a NullPointerException.
Stop the execution of your function if something failed instead of just printing the stack trace. For example you can add a return statement in the catch block :
URL iotd;
try {
iotd = new URL("http://www.nasa.gov/rss/image_of_the_day.rss");
} catch (MalformedURLException e) {
e.printStackTrace();
return;
}

All the warnings you are getting are because all your catch blocks are not dealing with the exception at all (just printing the stacktrace to standard out).
Let's see it through an example:
URL iotd;
try {
iotd = new URL("http://www.nasa.gov/rss/image_of_the_day.rss");
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
at that snipped you are declaring a iotd variable as a URL but without initializing it (not assigning any value), you do it inside the try block - which isn't wrong by the way. However if for any reason the statement inside the try block throws an exception program flow will go to the catch block leaving the iotd variable with its initial value (unassigned).
So, in that case, execution of the program will continue and when reaching this statement:
in = new BufferedReader(new InputStreamReader(iotd.openStream()));
it will find no value assigned to the iotd variable.
To remove the warning regarding the uninitialized value you can either assign a null value to the variable when declaring it or rethrow another exception inside the catch block, stopping the program flow.
In the other hand, the snippet you posted here is not just one class, it's actually two as you are extending the Thread class and then creating an anonymous one inside its body. Using threads is easier than that in Java, just implement the Runnable interface and then instantiate a new thread from that interface:
public class MyRunnable implements Runnable {
public void run() {
// do stuff
}
}
and then:
new Thread(new MyRunnable()).start();
cheers

you need to initialize the variables above the try catch block, or give them a value in catch or finally block
find updated code here
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlPullParserFactory;
public class RssParse extends Thread {
Thread th=new Thread() {
public void run(){
System.out.println("1");
URL iotd=null;
try {
iotd = new URL("http://www.nasa.gov/rss/image_of_the_day.rss");
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("2");
BufferedReader in=null;
try {
in = new BufferedReader(new InputStreamReader(iotd.openStream()));
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
System.out.println("3");
XmlPullParserFactory factory=null;
try {
factory = XmlPullParserFactory.newInstance();
} catch (XmlPullParserException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
factory.setNamespaceAware(true);
System.out.println("4");
XmlPullParser xpp=null;
try {
xpp = factory.newPullParser();
} catch (XmlPullParserException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("5");
try {
xpp.setInput(in);
} catch (XmlPullParserException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("6");
int eventType=-1; // set to a default value of your choice
try {
eventType = xpp.getEventType();
} catch (XmlPullParserException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(eventType+"!!!!!!!!!!!!!!!!");
while(eventType!=XmlPullParser.END_DOCUMENT){
if(eventType==XmlPullParser.START_DOCUMENT){
System.out.println("start");
}
}
try {
in.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}//method
};//thread
}//class