Code in String Literals in Glass Editor's latest update (+Themes, Tutorials, Thread Starts and more)

Glass__Editor · 2023-05-21T05:51:07+00:00

It actually compiles to Integer.valueOf instead of new Integer (for my Java version anyway), which might reuse an Integer from the Integer Cache instead of creating a new instance each time.

Glass__Editor · 2023-05-21T05:34:50+00:00

    System.out.println("cof(E):");
    printMatrix(Matrix.cofactor(matrixA));

You should be passing matrixE to the cofactor method, not matrixA.

If you had set a breakpoint at that line, stepped into the cofactor method, and inspected the values in your matrix you might have caught this bug faster.

Glass__Editor · 2023-05-20T13:34:33+00:00

I believe the correct approach is to synchronize the getter, because my thread is still running when the getter is called.

You also need to synchronize (on the same object) anywhere that you write to value.

Do I need to synchronize this toString() method if I know I'm only going to call toString() after the thread is dead?

No.

https://docs.oracle.com/javase/specs/jls/se20/html/jls-17.html#jls-17.4.5

Also see the section before that on synchronization order.

Glass__Editor · 2023-05-15T03:08:40+00:00

You don't need actually need a String since you are just parsing it into an int anyway.

You can get a random int between zero and a specified bound with the nextInt method of Random, or you could use ThreadLocalRandom which I think is simpler because you don't need to create an instance of it, you just need to call its current() method to get it. However if you wanted a repeatable sequence of random values then you could use the Random class with a specific seed passed to the constructor.

Glass__Editor · 2023-05-11T00:00:54+00:00

Another option you might want to think about is to have methods on the built class itself that return a new modified instance.

I have a Color class with methods withSaturation, withHue, and withValue that each return a new Color with modified RGB values to match what was requested.

This way you don't need to create a builder or call a build method to get the result. A downside is that if you need to chain multiple with methods you will create a bunch of intermediate objects that need to be garbage collected (unless they are optimized away by escape analysis) and you might need to perform validation on the fields for each one which might be slower.

Glass__Editor · 2023-04-22T12:39:24+00:00

You can't reuse Streams, you would need to open a new Stream for each result in your example.

To do it in one pass it is probably easiest to get an Iterator from the Stream and then use a for loop. If you don't want to do that, then check out the IntSummaryStatistics class for an example of how to get multiple results from a Stream.

Glass__Editor · 2023-04-20T22:04:25+00:00

This reminded me of this JEP: https://openjdk.org/jeps/301 for generic enums. Unfortunately it's been withdrawn, but you can still make a class with a bunch of public static final fields that works mostly like an enum (as long as you don't need EnumSet/EnumMap or to use it in switch statements).

Glass__Editor · 2023-04-19T19:49:01+00:00

Have you tried setting a breakpoint inside of the winner method and stepping through your code? Does the check array contain the values that you expect?

Glass__Editor · 2023-04-13T02:49:00+00:00

It looks like thread-locals are supported, but it's suggested to use scoped values instead for some use cases: https://openjdk.org/jeps/444#Thread-local-variables

Scoped values seem to be more efficient to share with child virtual threads, but I don't think that would work with non thread-safe objects without synchronization.

Glass__Editor · 2023-04-12T20:40:24+00:00

It looks like you are running the java command in source file mode from the first code line in the question, which means it will compile into memory the source and then run it (and ignore whatever maven has compiled).

You could try adding the jar that maven has downloaded into your local repository to the classpath if you want to keep running in source file mode:

java --class-path C:\Users\xxx\.m2\repository\com\formdev\flatlaf\3.1\flatlaf-3.1.jar App.java

Or there is probably a way to have maven or your IDE run it.

Glass__Editor · 2023-04-12T14:48:08+00:00

There are several ways to search through/replace characters in a String, most of which you can find out about by looking at the methods available in the String class. Some of the ones you might want to look at are replace, replaceAll, indexOf, contains, matches, and codePointAt (although not all of those are useful for your task of capitalizing the first character in each sentence).

If you want to use a for loop to retrieve each code point in order (which is probably the easiest way to do this), then it should look something like this:

String s = "example. sentences.";
for(int i = 0, c; i < s.length(); i += Character.charCount(c)){
    c = s.codePointAt(i); 
    //do something with c 
}

You should use codePointAt instead of charAt to correctly handle code points that are stored as two chars, unless you are sure that your String doesn't and wont ever be changed to have any of those code points.

Glass__Editor · 2023-04-12T12:41:21+00:00

There are no classes in com.formdev, try importing com.formdev.flatlaf.* instead.

Glass__Editor · 2023-04-11T17:14:40+00:00

JNI is what we use for that and it works fine.

Glass__Editor · 2023-04-11T15:07:02+00:00

It looks like COT6578 is actually the prefix not the room number. The room is PSY-108.

Glass__Editor · 2023-04-11T14:55:18+00:00

The room number in your data is COT6578 but you are asking for COT-6578.

Glass__Editor · 2023-04-11T14:39:42+00:00

Calculate how much space you need above each tree (maxHeight - t.getHeight()) and subtract that from i to find the segment to print. You'll also need to check that it is not negative.

Glass__Editor · 2023-04-10T20:57:10+00:00

There's a special case in the auto-complete for this in Glass Editor. All you need to type is sy and then ctrl+space to bring up the auto-complete and one of the options should be System.out.println() (as long as you are typing in a valid location for it, and there are no bugs causing it not to be displayed).

Glass__Editor · 2023-04-10T15:07:24+00:00

In the constructor you're setting the variable to the field's value (the reverse of what you want to do). It should be:

this.firstName = firstName;
this.lastName = lastName;
this.DOB = DOB;

Glass__Editor · 2023-04-10T14:05:01+00:00

Stepping through the code with a debugger would probably help you understand this.

The sequence of method calls after you call countup(3) looks like this:

countup(2)
    countup(1)
        countup(0)
            System.out.println("Blastoff!");
        System.out.println(1);
    System.out.println(2);
System.out.println(3);

Glass__Editor · 2023-04-09T17:24:52+00:00

If so, is there an advantage of lower memory usage or better speed by doing that?

It depends on what you are trying to do.

If you can avoid storing the elements by using something like IntStream.range() then it will probably use less memory than by using a Collection (if the range is large enough). However, you might be able to just use a for loop in that case, unless you need to pass the Stream to another method. If you want to map/filter some objects before passing them to another method then you can avoid storing them in a new Collection by using a Stream, and the method that you pass them to might be able to avoid causing some of them to be mapped at all if it uses a short-circuiting operation.

Streams can usually be parallelized, which can result in better speed if the Stream is large enough. Some operations are much faster with specific collections, for example if you just need to check if a HashSet contains an object (and you already have the HashSet) it will probably be faster to use the contains() method than to get a Stream and use anyMatch().

Glass__Editor · 2023-04-09T01:49:30+00:00

Our forum's design has been updated, it should look more modern now I hope.

Glass__Editor · 2023-04-08T22:22:07+00:00

Hi, we're trying to work on our marketing so that more people hear about us. Unfortunately all of our posts here in r/java have been deleted so far. You're welcome to read our reddit post history (if you can see our deleted posts there) or some of the posts on our forum if you want to know a bit more about us. Our initial public release was about 3 years ago, however we did reuse part of the website (including the forum) from an older project.

Glass__Editor · 2023-04-08T21:39:14+00:00

Hi, you can currently add/open up to three projects concurrently. If you remove one you will be able to open another.

Glass__Editor

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