Switch on Enum in Java
Why can’t you switch on an enum in Java? It seems simple enough to do and would make for some convenient code. Also this question could apply to String‘s. You can switch on a char, but not a String …?
Java
Calculating the angle between the line defined by two points
Assumptions: x is the horizontal axis, and increases when moving from left to right. y is the vertical axis, and increases from bottom to top. (touch_x, touch_y) is the point selected by the user. (center_x, center_y) is the point at the center of the screen. theta is measured counter-clockwise from the +x axis. Then: Edit: you mentioned in a comment that y increases from top to bottom. … Read more
in java what does the @ symbol mean?
The @ symbol denotes a Java Annotation. What a Java annotation does, is that it adds a special attribute to the variable, method, class, interface, or other language elements. (This can be configured when you declare the annotation) When you add an annotation to something, other parts of the program can check whether something has an annotation … Read more
Usage of @see in JavaDoc?
Yeah, it is quite vague. You should use it whenever for readers of the documentation of your method it may be useful to also look at some other method. If the documentation of your methodA says “Works like methodB but …”, then you surely should put a link. An alternative to @see would be the inline {@link …} tag: … Read more
Can I multiply strings in Java to repeat sequences?
I have something like the following: I’d like to append i “0”s to the someNum string. Does it have some way I can multiply a string to repeat it like Python does? So I could just go: or something similar? Where, in this case, my final result would be: “123000”.
Error – trustAnchors parameter must be non-empty
This bizarre message means that the trustStore you specified was: empty, not found, or couldn’t be opened (due to wrong/missing trustStorePassword, or file access permissions, for example). See also @AdamPlumb’s answer below.
Copying and modifying array elements
The for loop in which you copy the values from oldscores to newscores is never run in the case of SCORES_SIZE == 1, since SCORES_SIZE – 1 == 0, and 0 < 0 is false immediately. Move the newScores[SCORES_SIZE – 1] = oldScores[0]; line outside the for loop:
org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘MyController’:
Copied from the stacktrace: BeanInstantiationException: Could not instantiate bean class [com.gestEtu.project.model.dao.CompteDAOHib]: No default constructor found; nested exception is java.lang.NoSuchMethodException: com.gestEtu.project.model.dao.CompteDAOHib.<init>() By default, Spring will try to instantiate beans by calling a default (no-arg) constructor. The problem in your case is that the implementation of the CompteDAOHib has a constructor with a SessionFactory argument. By adding the @Autowired annotation to a constructor, … Read more
Illegal Escape Character “\”
The character ‘\’ is a special character and needs to be escaped when used as part of a String, e.g., “\”. Here is an example of a string comparison using the ‘\’ character: You can also perform direct character comparisons using logic similar to the following:
“Content is not allowed in prolog” when parsing perfectly valid XML on GAE
The encoding in your XML and XSD (or DTD) are different.XML file header: <?xml version=’1.0′ encoding=’utf-8′?>XSD file header: <?xml version=’1.0′ encoding=’utf-16′?> Another possible scenario that causes this is when anything comes before the XML document type declaration. i.e you might have something like this in the buffer: or even a space or special character. There are some … Read more