Questions tagged as 'java'

Tagged questions
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Problems with Traffic Lights (Producer / Consumer)

Hello! I am trying to solve the Problem of the Producer / Consumer using traffic lights, but I am having difficulties. I'm using one producer thread and one consumer thread, but I think the program is initializing the producer and not doing the...
asked by 11.10.2017 / 13:45
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JFXTextField is not a valid type. Error starting JavaFX application

I'm using a lib in JavaFX for styling, and one of the stylings I'm using is the JFXTextField, however, while compiling the application, I run into this error:    JFXTextField is not a valid type What is the solution? Thankful.     
asked by 14.10.2017 / 00:16
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The difference between the ClassPath environment variable and the project .classpath files in JAR

When we install the JDK, we create an environment variable called CLASSPATH, which has the value JAVA_HOME, which in turn has the jdk address, which contains all Java development libraries, correct? > This is for the Java compiler to find the...
asked by 10.10.2017 / 03:07
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Why inflate a Layout in Fragments instead of setting one already ready? Ex: setContentView (R.layout.activity_example)

I'm learning about Android and would like to better understand how this part of the system works. Instead of inflating a layout, would not it be simpler to do as when creating an Activity, such as overwriting the onCreate method and setting u...
asked by 25.01.2018 / 01:04
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Error executing function in PL / SQL

Code CREATE OR REPLACE FUNCTION BuscaNome RETURN t_name IS t_name VARCHAR(20); BEGIN SELECT T.DS_TURMA INTO t_name FROM TURMA T WHERE T.CD_TURMA = 13; RETURN t_name; END; Error:    Error: PL / SQL: Compilation unit an...
asked by 22.01.2018 / 19:18
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Access the SQLite database (and other storage types) of the emulator

I'm developing an app that uses SQLite, SharedPreferences, etc . On my device with access root I can access all this information with some specific app's for that (which require root access), mainly the bank to see if the table a...
asked by 30.01.2018 / 19:48
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Uploading files with Java

Good morning! I was trying to upload files, where I have a webpage that makes a request for my servlet. In the form of the page I have an input of type file and another one of type text. The coding mode of this form is as "multipart / form-data"...
asked by 31.01.2018 / 11:10
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Delayed inter-screen application

When I change the screen, there is always a delay from one screen to another and this is annoying. You see clearly that one screen closes to open another. do you know that java symbol that stays when you open an application? Then when I open...
asked by 30.01.2018 / 21:17
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How to format the output of resultSet via System.out.println in Java?

Hello, I am printing on the screen the result of a SELECT that I have stored in an object type resultSet (sql.ResultSet). But it comes out "all crooked". I tried to use the "\ t" between each printed column, but it did not help. Here is the part...
asked by 30.01.2018 / 19:56
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Call more than one callback at a time

I need a WorkerClass that generates sequential numbers to print through a Callback Interface these numbers in the MainActivity and in a SegundaActivity when opened. My problem is that when SegundaActivity is open the MainActivity no longer recei...
asked by 31.01.2018 / 00:00