I'm migrating some pre Java 10 code and I'm wondering if IntelliJ offers a way to automatically refactor the code to replace the variable declarations that uses the actual type with var wherever it's possible.
The code is full of stuff like:
String status = "empty";
BigDecimal interest = BigDecimal.ZERO;
List<Future<Boolean>> results = es.invokeAll(tasks);
LocalDate start = LocalDate.of(2020, 1, 1);
And I would prefer:
var status = "empty";
var interest = BigDecimal.ZERO;
var results = es.invokeAll(tasks);
var start = LocalDate.of(2020, 1, 1);
I already looked in IntelliJ's settings (Code Style/Inspections) and couldn't find anything.
Go to File | Settings, there select Editor | Inspections, then under Java | Java language level migration aids | Java 10.
Right click on Local variable type can be omitted and select Weak Warning or similar.
Move Your cursor onto any of those warnings in Your code (highlighted grey), open quick fix context help (alt+enter), at Replace explicit type with 'var' move to the right and select Fix all 'Local variable type can be omitted' problems in file
Thanks for #olga-klisho for the idea (in comments)
I'm using IntelliJ IDEA 2021.3.2, but don't think the setting is new.
I've been struggling with this one myself.
It seems that the first time to install IntelliJ locally, by default, it will fall back to using traditional defining of variables (i.e. String s = new String();)
How I managed to change it into using var is after I declared something, for example new String(), either I pressed ⌥ Alt/Option+Enter to declare a variable for that declaration or by using ⌘ Command+⇧ Shift+V shortcut (I'm using Mac and classic Intellij key mapping, so YMMV) which activates declaration of a variable, this would show as follows:
As you see, it suggest to hit that key combination shortcut or clicking on the settings button that would open a pop up like this one:
Make sure you have Declare var type selected and you should be good to go.
Use the IntelliJ Edit -> Find -> Replace... option.
Or Ctrl + R
I have configured vim + eclim OK. Now I can use Ctrl+X and Ctrl+U complete functions. But there is no arguments hint. For example,
FileInputStream fins = new FileInputStream(/* what arguments can be used here? eclipse will show those but eclim not */);
how to show arguments hint in vim + eclim?
Resurrecting this old question, since I stumbled on this.
You can use eclim to lookup the java docs of the class and look through the list of constructors that way using the :JavaDocSearch command.
Because the command uses a browser to render the javadocs, you'll need to add to your .vimrc:
let g:EclimBrowser = 'browser-executable-name'
Replacing browser-executable-name with your console-based browser of choice. Example: lynx, links, w3m
Then navigate over FileInputStream with your cursor and run the command :JavaDocSearch and it will pop up the java doc for the class.
Or enter the class name manually: :JavaDocSearch java.io.FileInputStream
You can use the YouCompleteMe (YCM) plugin with options
let g:ycm_add_preview_to_completeopt = 1
let g:ycm_autoclose_preview_window_after_insertion = 1
Note that this does not work for your Constructor invocations. But at least prototypes for method calls will be shown.
Also, if you don't like the auto-popup of YCM, it can be switched off.
A)
public class SomeClass
{
private SomeClass()
{
}
public String someMethod()
{
return "";
}
}
B)
public class SomeOtherClass{
private SomeOtherClass(){
}
public String someOtherMethod(){
return "";
}
}
I have joined a new team and will be working on a project which follows the A) convention. However, I have always been the B) java style person and am way more comfortable with B).
1)On the checked out code, is there a way I could convert the java code style in my eclipse to B)
2)And also ensure the project->Team->Synch with Repo ignores this style change when checking for updates ?
3)Before comitting, I want to switch the code back to the commonly followed style and check it in. I synch for changes every morning and commit changes throughout the day.
Is creating a new profile in the preferences->code style->Formatter the only way ? I also looked at http://astyle.sourceforge.net/ but I am somehow confident there is a simpler eclipse solution to this. How could I achieve this in the simplest possible way ?
I am using eclipse kepler
Work flow:
In Windows > Preferences > Java > Editors Save Actions deselect formatting on save.
Check out code.
Clean up your code(Right click on project go to Source > Clean up. Note this works on project level but not on working set, so you have to do it on each and every project) with your Formatter(B) profile enabled.
In Windows > Preferences > Java > Editors Save Actions select formatting on save and start working.
Same as step 1.
Same as 3 but with formatter profile A.
Commit the code.
These steps can be automated with Ant/Maven script(?) or by developing your own eclipse plug-in.
On sync comparator will NOT ignore style change. IMHO there is no escape. Clean up before sync is only the go.
In Git SCM there are some commit and checkout hooks but I haven't explored on this.
I want to use regions for code folding in Eclipse; how can that be done in Java?
An example usage in C#:
#region name
//code
#endregion
Jet Brains IDEA has this feature. You can use hotkey surround with for that (ctrl + alt + T). It's just IDEA feature.
Regions there look like this:
//region Description
Some code
//endregion
There's no such standard equivalent. Some IDEs - Intellij, for instance, or Eclipse - can fold depending on the code types involved (constructors, imports etc.), but there's nothing quite like #region.
With Android Studio, try this:
//region VARIABLES
private String _sMyVar1;
private String _sMyVar2;
//endregion
Careful : no blank line after //region ...
And you will get:
No equivalent in the language... Based on IDEs...
For example in netbeans:
NetBeans/Creator supports this syntax:
// <editor-fold defaultstate="collapsed" desc="Your Fold Comment">
...
// </editor-fold>
http://forums.java.net/jive/thread.jspa?threadID=1311
Custom code folding feature can be added to eclipse using CoffeeScript code folding plugin.
This is tested to work with eclipse Luna and Juno. Here are the steps
Download the plugin from here
Extract the contents of archive
Copy paste the contents of plugin and features folder to the same named folder inside eclipse installation directory
Restart the eclipse
Navigate Window >Preferences >Java >Editor >Folding >Select folding to use: Coffee Bytes Java >General tab >Tick checkboxes in front of User Defined Fold
Create new region as shown:
Restart the Eclipse.
Try out if folding works with comments prefixed with specified starting and ending identifiers
You can download archive and find steps at this Blog also.
For Eclipse IDE the Coffee-Bytes plugin can do it, download link is here.
EDIT:
Latest information about Coffee-Bytes is here.
This is more of an IDE feature than a language feature. Netbeans allows you to define your own folding definitions using the following definition:
// <editor-fold defaultstate="collapsed" desc="user-description">
...any code...
// </editor-fold>
As noted in the article, this may be supported by other editors too, but there are no guarantees.
the fastest way in Android Studio (or IntelliJ IDEA)
highlight the code you want to surround it
press ctrl + alt + t
press c ==> then enter the description
enjoy
AndroidStudio region
Create region
First, find (and define short cut if need) for Surround With menu
Then, select the code, press Ctrl+Alt+Semicolon -> choose region..endregion...
Go to region
First, find Custom Folding short cut
Second, from anywhere in your code, press Ctrl+Alt+Period('>' on keyboard)
Contrary to what most are posting, this is NOT an IDE thing. It is a language thing. The #region is a C# statement.
I were coming from C# to java and had the same problem and the best and exact alternative for region is something like below (working in Android Studio, dont know about intelliJ):
//region [Description]
int a;
int b;
int c;
//endregion
the shortcut is like below:
1- select the code
2- press ctrl + alt + t
3- press c and write your description
The best way
//region DESCRIPTION_REGION
int x = 22;
// Comments
String s = "SomeString";
//endregion;
Tip: Put ";" at the end of the "endregion"
If anyone is interested, in Eclipse you can collapse all your methods etc in one go, just right click when you'd normally insert a break point, click 'Folding' > 'Collapse all'. It know it's not an answer to the question, but just providing an alternative to quick code folding.
here is an example:
//region regionName
//code
//endregion
100% works in Android studio
#region
// code
#endregion
Really only gets you any benefit in the IDE. With Java, there's no set standard in IDE, so there's really no standard parallel to #region.
I usually need this for commented code so I use curly brackets at start and end of that.
{
// Code
// Code
// Code
// Code
}
It could be used for code snippets but can create problems in some code because it changes the scope of variable.
vscode
I use vscode for java and it works pretty much the same as visual studio except you use comments:
//#region name
//code
//#endregion
Meet custom folding regions ⌥⌘T
Actually johann, the # indicates that it's a preprocessor directive, which basically means it tells the IDE what to do.
In the case of using #region and #endregion in your code, it makes NO difference in the final code whether it's there or not. Can you really call it a language element if using it changes nothing?
Apart from that, java doesn't have preprocessor directives, which means the option of code folding is defined on a per-ide basis, in netbeans for example with a //< code-fold> statement
On Mac and Android Studio follow this sequence:
Highlight the source code to fold
Press Alt+Command+t
Select <editor-fold>
Also you can select other options:
In Visual Studio Code, try this:
//region Variables
// Code you need
//endregion
In Eclipse you can collapse the brackets wrapping variable region block. The closest is to do something like this:
public class counter_class
{
{ // Region
int variable = 0;
}
}
Just intall and enable Coffee-Bytes plugin (Eclipse)
There is some option to achieve the same, Follow the below points.
1) Open Macro explorer:
2) Create new macro:
3) Name it "OutlineRegions" (Or whatever you want)
4) Right Click on the "OutlineRegions" (Showing on Macro Explorer) select the "Edit" option and paste the following VB code into it:
Imports System
Imports EnvDTE
Imports EnvDTE80
Imports EnvDTE90
Imports EnvDTE90a
Imports EnvDTE100
Imports System.Diagnostics
Imports System.Collections
Public Module OutlineRegions
Sub OutlineRegions()
Dim selection As EnvDTE.TextSelection = DTE.ActiveDocument.Selection
Const REGION_START As String = "//#region"
Const REGION_END As String = "//#endregion"
selection.SelectAll()
Dim text As String = selection.Text
selection.StartOfDocument(True)
Dim startIndex As Integer
Dim endIndex As Integer
Dim lastIndex As Integer = 0
Dim startRegions As Stack = New Stack()
Do
startIndex = text.IndexOf(REGION_START, lastIndex)
endIndex = text.IndexOf(REGION_END, lastIndex)
If startIndex = -1 AndAlso endIndex = -1 Then
Exit Do
End If
If startIndex <> -1 AndAlso startIndex < endIndex Then
startRegions.Push(startIndex)
lastIndex = startIndex + 1
Else
' Outline region ...
selection.MoveToLineAndOffset(CalcLineNumber(text, CInt(startRegions.Pop())), 1)
selection.MoveToLineAndOffset(CalcLineNumber(text, endIndex) + 1, 1, True)
selection.OutlineSection()
lastIndex = endIndex + 1
End If
Loop
selection.StartOfDocument()
End Sub
Private Function CalcLineNumber(ByVal text As String, ByVal index As Integer)
Dim lineNumber As Integer = 1
Dim i As Integer = 0
While i < index
If text.Chars(i) = vbCr Then
lineNumber += 1
i += 1
End If
i += 1
End While
Return lineNumber
End Function
End Module
5) Save the macro and close the editor.
6) Now let's assign shortcut to the macro. Go to Tools->Options->Environment->Keyboard and search for your macro in "show commands containing" textbox (Type: Macro into the text box, it will suggest the macros name, choose yours one.)
7) now in textbox under the "Press shortcut keys" you can enter the desired shortcut. I use Ctrl+M+N.
Use:
return
{
//Properties
//#region
Name:null,
Address:null
//#endregion
}
8) Press the saved shortcut key
See below result:
I'm extremely frustrated with the Eclipse formatting rules for a series of qualified invocations (i.e., the Builder pattern style). For example, here is my preferred formatting for some code that creates a new Apache Commons CLI Options object:
Options options = new Options()
.addOption(OPTION_HELP_SHORT, OPTION_HELP, false, "print usage information")
.addOption(OPTION_VERSION_SHORT, OPTION_VERSION, false,
"print version and exit")
.addOption(OptionBuilder.withLongOpt(OPTION_PROPERTIES)
.hasArg()
.withArgName("FILE")
.withType(File.class)
.withDescription("specify a user properties file")
.create());
I.e., parameters are wrapped and indented if necessary and all qualified invocations except the first, unless necessary, are wrapped and indented if there is more than one. If a parameter list wraps inside a qualified invocation, the invocation should wrap first.
The default formatting in Eclipse ("Wrap only when necessary" for arguments and invocations) yields the following mess:
Options options = new Options().addOption(
OPTION_HELP_SHORT, OPTION_HELP, false, "print usage information")
.addOption(OPTION_VERSION_SHORT, OPTION_VERSION, false,
"print version and exit").addOption(
OptionBuilder.withLongOpt(OPTION_PROPERTIES).hasArg().withArgName(
"FILE").withType(File.class).withDescription(
"specify a user properties file").create());
Going into "Java Code Style -> Formatter -> Line Wrapping" and the line wrapping setting to "Wrap all elements, except first element if not necessary" for invocations yields:
Options options = new Options().addOption(
OPTION_HELP_SHORT, OPTION_HELP, false, "print usage information")
.addOption(OPTION_VERSION_SHORT, OPTION_VERSION, false,
"print version and exit")
.addOption(
OptionBuilder.withLongOpt(OPTION_PROPERTIES).hasArg().withArgName(
"FILE").withType(File.class).withDescription(
"specify a user properties file").create());
I don't like that the OptionBuilder expression isn't being wrapped, or that "FILE" gets wrapped without also wrapping withArgName.
Changing the indentation to "Indent on column" yields:
Options options = new Options().addOption(OPTION_HELP_SHORT, OPTION_HELP,
false, "print usage information")
.addOption(OPTION_VERSION_SHORT,
OPTION_VERSION, false,
"print version and exit")
.addOption(
OptionBuilder.withLongOpt(
OPTION_PROPERTIES)
.hasArg()
.withArgName("FILE")
.withType(File.class)
.withDescription(
"specify a user properties file")
.create());
The is breaking the lines where I'd prefer, but pushing things over much too far to the right.
Is there any way to convince Eclipse to apply my preferred formatting style or something closer to it than any of the above?
Turning off formatting with comments, or inserting line comments is too tedious.
The best way is described here:
... or you can select "Line Wrapping > Never join already wrapped
lines" globally. Then, you can break it manually and the formatter
will only format inside lines (or add additional line breaks if
necessary).
With this setting Eclipse formatter will stop ruining your builder statements.
Use comments:
Object o = foo() //
.bar() //
.toString();
Update for 2021. It is possible to change, navigate to: Code Style -> Formatter -> Line Wrapping -> Wrapping settings -> Function Calls -> Qualified invocations and change value to "Wrap all elements, except first element if not necessary"
In Eclipse 3.6 It's possible to turn off formatting for a region of code. See my answer to
How to turn off the Eclipse code formatter for certain sections of Java code?
AFAIK, this is known problem with Eclipse Formatter:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=59891
On the menu select Window -> Preferences when the window opens select Java -> Code Style -> Formatter and from there you can create your own format style to use by selecting the new or edit option. When editing a formatting profile a new window opens that gives you a lot of different options to use.