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Append every class field with a constant string in Java

I have lots of classes representing user screens in the application that I am testing (page objects). Each of the page objects contains various number of elements with wach of the having an ID. I need to declare those IDs. It looks something like this:
public class MessagesScreen extends BasePage {
private static final String backArrowButtonID = PACKAGE_NAME_ID + "backArrow";
private static final String noMessagesImageID = PACKAGE_NAME_ID + "empty_messages_icon";
private static final String noMessagesTextViewI = PACKAGE_NAME_ID + "label_no_documents";
private static final String errorTextViewID = PACKAGE_NAME_ID + "text_error_response";
private static final String progressBarID = PACKAGE_NAME_ID + "message_list_progress_bar";
private static final String messagesRecyclerViewID = PACKAGE_NAME_ID + "messageList";
private static final String swipeRefreshLayoutID = PACKAGE_NAME_ID + "swipeRefreshLayout";
private static final String instantMessageLayoutID = PACKAGE_NAME_ID + "item_instant_message_layout";
}
Each of the IDs needs to have the an environmental variable added as above.
My question is: is there any nifty way of not having to repeat this PACKAGE_NAME_ID all the time? Is there a way of automatic assigning the constant string to every new class field?

Using an enum here will improve your code in many ways. In addition to solving your current problem, you'd be using the right tool for constants.
enum IdKey {
BACK_ARROW_BUTTON_ID("backArrow"),
NO_MESSAGES_IMAGE_ID("empty_messages_icon"),
NO_MESSAGES_TEXT_VIEW_ID("label_no_documents"),
ERROR_TEXT_VIEW_ID("text_error_response"),
PROGRESS_BAR_ID("message_list_progress_bar"),
MESSAGES_RECYCLER_VIEW_ID("messageList"),
SWIPE_REFRESH_LAYOUT_ID("swipeRefreshLayout"),
INSTANT_MESSAGE_LAYOUT_ID("item_instant_message_layout");
private final String suffix;
private IdKey(String suffix) {
this.suffix = suffix;
}
public String getSuffix() {
return BasePage.PACKAGE_NAME_ID + this.suffix;
}
}
And all you'd have to do wherever you were using your fields is just call:
IdKey.BACK_ARROW_BUTTON_ID.getSuffix();
And the code is both more reliable and cleaner. You can even nest the enum as a private member of MessagesScreen.

I might consider an enum in this case, you can still reference a specific value in the code and override the toString to return your message in the format you want
I have lots of classes representing user screens in the application that I am testing (page objects). Each of the page objects contains various number of elements with wach of the having an ID. I need to declare those IDs. It looks something like this:
public enum MessagesScreen {
BACK_ARROW("backArrow"),
NO_MESSAGES_IMAGE("empty_messages");
private String value;
private Messages(String value) {
this.value = value;
}
#Override public String toString() {
return PACKAGE_NAME_ID + this.value;
}
}

As you cannot enrich the state of final variables after their valuing, I would do things in the other way : providing a getter that adds the desired prefix.
public class MessagesScreen extends BasePage {
private static final String backArrowButtonID = "backArrow";
private static final String noMessagesImageID = "empty_messages_icon";
///...
public String getIdWithPrefix(String constantValue){
return PACKAGE_NAME_ID + constantValue;
}
}
Note that with an enum it would be more robust as Strings accept a very large range of possible values whereas enums don't.
It will require you to change many classes but it is worthful.
The ernest_k answer shows that very well.

Autocomplete for upper-case constants with underscores in Eclipse?

is there a possibility to activate autocomplete for constants with underscores _?
I have a class with many constants, where many of them begin same. Example:
// Component details
public static final String PROPERTY_NAME_COMPONENT_MATERIAL_NUMBER = "name";
public static final String PROPERTY_NAME_COMPONENT_OVERALL_WORK_STATUS = "componentOverallWorkStatus";
public static final String PROPERTY_NAME_COMPONENT_RELEASE_STATUS = "freigabestatus";
public static final String PROPERTY_NAME_COMPONENT_DESCRIPTION = "label";
public static final String PROPERTY_NAME_COMPONENT_AMOUNT = "newAmount";
public static final String PROPERTY_NAME_COMPONENT_BASE_QUANTITY_UNIT = "basismengeneinheit";
public static final String PROPERTY_NAME_COMPONENT_PRODUCER = "hersteller";
public static final String PROPERTY_NAME_COMPONENT_PRODUCER_FRAGMENT_NUMBER = "herstellerteilenummer";
public static final String PROPERTY_NAME_COMPONENT_EXCLUDE_ALTERNATIVE_ARTICLE = "componentExcludeAlternativeArticle";
public static final String PROPERTY_NAME_COMPONENT_GENERAL_INFO = "componentGeneralInfo";
They all start with PROPERTY_NAME_COMPONENT and if I now begin to type this
System.out.println(ClassWithThoseConstants.P
and press Ctrl + Space. Now I got all constansts starting with P, which is fine. But now I'd like to go further with camelcase style, i.e. PNCP which shall lead to the options:
PROPERTY_NAME_COMPONENT_PRODUCER and PROPERTY_NAME_COMPONENT_PRODUCER_FRAGMENT_NUMBER.
Typing P_N_C_P doesn't help either. Is there a possibility? I couldn't find any.

Best way to write Custom Exception

I am trying to write a custom exception with 3 constroctors. Can I initize final variables in 3 different constroctors? I am getting compilation errors. How to make this error free?
public class CrifServiceFaultException extends RuntimeException {
/**
*
*/
private static final long serialVersionUID = 1L;
public CrifServiceFaultException(String message) {
// // - The blank final field errorDescription may not have been
super(message);
}
public CrifServiceFaultException(String processCode,
String processDescription, String transformCode,
String transformDescription) {
// - The blank final field errorDescription may not have been
initialized
super(processDescription + " " + transformDescription);
this.processCode = processCode;
this.processDescription = processDescription;
this.transformCode = transformCode;
this.transformDescription = transformDescription;
}
public CrifServiceFaultException(String errorCode, String errorDescription) { // The blank final field transformDescription may not have been initialized
super(errorDescription);
setErrorCode(errorCode);
setErrorDescription(errorDescription);
}
final private String processCode;
final private String processDescription;
final private String transformCode;
final private String transformDescription;
final private String errorCode;
final private String errorDescription;
// getters are here
}

Because, according to Java specifications, every final variable must be initialized before the end of the constructor.
In your case in each constructor you leave some of them uninitialized (formally they're blank). In short you have to set a value for them (even when unused in a specific constructor):
public CrifServiceFaultException(String message)
{
super(message);
processCode = "";
processDescription = "";
transformCode= "";
transformDescription= "";
errorCode= "";
errorDescription= "";
}
public CrifServiceFaultException(String processCode,
String processDescription, String transformCode,
String transformDescription)
{
super(processDescription + " " + transformDescription);
this.processCode = processCode;
this.processDescription = processDescription;
this.transformCode = transformCode;
this.transformDescription = transformDescription;
errorCode= "";
errorDescription= "";
}
public CrifServiceFaultException(String errorCode, String errorDescription)
{
super(errorDescription);
setErrorCode(errorCode);
setErrorDescription(errorDescription);
processCode = "";
processDescription = "";
transformCode= "";
transformDescription= "";
}
Note that even documentation says that:
...Declaring a variable final can serve as useful documentation...
From such sentence what we can guess is that final is only a decoration useful to avoid trivial mistakes at compile time (practically pretty similar to what const is in C++). Anyway IMO we shouldn't ever assume final variables are mutable (even through JNI) because they may enable strong optimizations at run-time (I'm thinking specifically about HotSpot): think about concurrent access and cache coherency (especially for primitive types).

How to prevent the removal of leading whitespace from declarations in IntelliJ Jetbrains editor?

So when I have a lot of constants in Java I like to line up the initializers like this:
public static final String XML_QUESTION_ID_ELEMENT_NAME = "questionID";
public static final String XML_QUESTION_NAME_ELEMENT_NAME = "questionName";
public static final String XML_QUESTION_TEST_ELEMENT_NAME = "question";
public static final String XML_QUESTION_SCRAMBLE_ANSWERS_ELEMENT_NAME = "scramAns";
public static final String XML_QUESTION_REATIAN_ANSWER_ORDER_ELEMENT_NAME = "retOrder";
public static final String XML_QUESTION_ENCRYPTED_ANSWER_HASH = "encAnsHash";
public static final String XML_ANSWER_CHOICE_ELEMENT_NAME = "answerChoice";
I think it is easier to read. However, when I reload the project or reopen intellij it strips the leading white space so it goes back to looking like this:
public static final String XML_TEST_NAME_ELEMENT_NAME = "testName";
public static final String XML_AUTHOR_NAME_ELEMENT_NAME = "author";
public static final String XML_SCHOOL_NAME_ELEMENT_NAME = "school";
public static final String XML_PERIOD_NAME_ELEMENT_NAME = "class";
public static final String XML_DATE_ELEMENT_NAME = "date";
I already looked through indentation and editor settings but did not see anything that corresponded to this problem. Any help is appreciated! and as always, a big thanks to the community.

Go to settings->Code Style->Java->Wrapping And Braces->Field Groups-> select the check box for Align in Columns.
This should give you the desired indentation.

Generate custom Java Getters and Setters

I want to generate custom getters and setter, so I can handle variables better when I will be saving these instances into SQL database. I want to generate something like:
public class Test extends SQLEntry {
private static final String NAME = "Name";
public String getName() {
return get(NAME);
}
public void setName(String name) {
set(NAME, name);
}
}
But as I can see in Eclipse it generates only the following code:
public class Test {
private String name;
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
}
Is there some plugin, that can do it? Or am I missing something?
I have like 20 classes and I will not write this manually.

I dont know why you need this, but here is the approach to custom Getters and Setters.
You can update all generated setters and getters by going to preferences > java > Code Style > code Templates and selecting code then edit Getter body and Setter body and put this:
Getter body: return get(${field});
Setter body: set(${field}, ${param});
Let me know if that works

I recommend that instead of doing what you describe, you should use Spring Data. Specifically the BeanPropertyRowMapper class in the org.springframework.jdbc.core package will do what you want.
Read more in the Spring API documentation.

there is no other plugin available!
how can some plugin write code that is specific to your business logic!
you have to write the code manually for setters and getters in all the classes!

Try write-it-once. Template based code generator. You write custom template using Groovy, and generate file depending on java reflections. It's the simplest way to generate any file. You can make getters/settest/toString by generating AspectJ or java files, SQL based on JPA annotations, inserts / updates based on enums and so on.

On the end I found it that it is the best to do it your self...
If you like writing a code than you will enjoy this solution the most.
public class CodeGenerator {
private final static String ENCODING = "UTF-8";
private final static String FILE_NAME = "File.txt";
public static void main(String[] args) {
try {
ArrayList<Carriage> names = getNames();
for (Carriage c : names) {
createSetter(c.name, c.capitalName);
createGetter(c.name, c.capitalName);
}
} catch (FileNotFoundException ex) {
ex.printStackTrace();
}
}
private static ArrayList<Carriage> getNames() throws FileNotFoundException {
File file = new File("/");
InputStream is = CodeGenerator.class.getResourceAsStream(FILE_NAME);
Scanner s = new java.util.Scanner(is, ENCODING).useDelimiter("\\A");
String content = s.next();
String[] lines = content.split(System.getProperty("line.separator"));
ArrayList<Carriage> ret = new ArrayList<Carriage>();
for (String line : lines) {
line = line.replaceAll("\\r", "");
int firstCapitalIndex = line.indexOf("String") + 7;
int secondCapitalIndex = line.indexOf(" ", firstCapitalIndex);
int firstIndex = line.indexOf("\"") + 1;
int secondIndex = line.indexOf("\"", firstIndex + 1);
Carriage c = new Carriage();
c.name = line.substring(firstIndex, secondIndex);
c.capitalName = line.substring(firstCapitalIndex, secondCapitalIndex);
ret.add(c);
}
return ret;
}
public static void createSetter(String name, String capitalName) {
String str = "public void set" + name + "(String val) {\n"
+ "\tset(" + capitalName + ", val);\n"
+ "}\n";
System.out.println(str);
}
public static void createGetter(String name, String capitalName) {
String str = "public String get" + name + "() {\n"
+ "\treturn (String) get(" + capitalName + ");\n"
+ "}\n";
System.out.println(str);
}
carriage:
package codegenerator;
public class Carriage {
public String name;
public String capitalName;
}
And to File.txt I just coppy all defined constants and run the generator...
public static final String NAME = "Name";
public static final String PHONE = "Phone";
public static final String EMAIL = "Email";
public static final String ADDRESS_1 = "Address1";
public static final String ADDRESS_2 = "Address2";
public static final String ADDRESS_3 = "Address3";
public static final String ICO = "Ico";
public static final String DIC = "Dic";
public static final String ADMIN_LOGIN = "AdminLogin";
public static final String ADMIN_PASSWORD = "AdminPassword";
public static final String LANGUAGE = "Language";
public static final String CODE = "CODE";
public static final String MONTHLY_PAYMENT = "MonthlyPayment";