Java
-
Using java to read data from MySQL database
First, I'm using jtextfields to read the user's product name and product quantity For this product, I use SQL query to…… -
Create an empty object in Java?
How did you do it? It's so simple: Name myName = new Name(); I'm a little confused It should be a class without instan…… -
java. Lang. stackoverflowerror Why do I get stackoverflow exception here
I have a list of parent and child items displayed in a hierarchy I want to switch their extended property Therefore, i…… -
Java – which one to choose between calling the function twice and storing the return value in a variable?
I have the following situation I occasionally encounter similar situations Which is more suitable for the following tw…… -
Partitioning and analyzing Java arrays using multithreading
I have to initialize a floating point [12000] 12000 times through the for loop Then I scan the array for values that e…… -
Using other modes except ECB and decrypting with DES will throw “invalidkeyexception: missing parameter”
I basically use http://www.avajava.com/tutorials/lessons/how-do-i-encrypt-and-decrypt-files-using-des.html The code en…… -
Java – StringBuilder using string instead of StringBuilder
I use StringBuilder instead of string in my code But when I look at its source code, the substring () method abstracts…… -
What caused my program to hang without quitting normally? (pipeline, read system call, while loop)
I have a program. I write to the pipeline from several sub processes, and then try to read all messages written to eac…… -
Java – is there any reason to use constants instead of messages?
I want to internationalize my GWT application After reading the documentation, I can't see why constants are used inst…… -
Java – get null when retrieving int from another class
Basically, I did this program, and the computer generated a random card I created a class called 'rndnumber', which ge…… -
Java – convert sentences to arrays and delete characters and print new sentences
Disclaimer: This is a homework assignment The goal of the program is to propose a sentence and then: – convert upperca…… -
Can I use JavaCard framework 2.2 In version 1, the ‘alg’ in the ‘signature’ class is used_ HMAC_ SHA1 ‘method?
I want to use JavaCard security. ALG in signature class_ HMAC_ SHA1 method But my JavaCard Framework version is 2.2 1.…… -
Java – how do I get the absolute path of a file in a directory?
I have a directory containing files, directories, subdirectories, etc How do I use the Apache Hadoop API to get an abs…… -
Java：String. How does the contains (string) function work in Java?
I know that the time complexity of brute force method is n * m (M is the length of the first string and N is the lengt…… -
What is the difference between stackpane and root in JavaFX?
I'm doing pie charts for JavaFX practice The following is the code for developing pie chart If I use group and stackpa…… -
Java – data is not written to the printwriter
I'm actually trying to create a program: public void setUpNetwork(){ try { Socket sock = new Socket("l…… -
Neo4j Connector for java
Does the neo4j server running on localhost: 7474 have a connector that can be used in Java? I'm looking for 'JDBC' sim…… -
Java – write lock to HashMap
I have an asynchronously updated HashMap I need to perform operations involving the map, which requires that the map d…… -
Java – NullPointerException when accessing array in class
I am new to this forum and Java The following code compiles, but when I try to enter a value for a variable, I get Nul…… -
Java – how many string objects are created for the following?
String summer = new String("Summer"); String summer = new String("Summer"); String summer2 = "Summer"; System.out.prin…… -
Java – spring MVC class suddenly cannot find dispatcherservlet
My webapp is running and everything is fine until I try to implement some fileUpload Feb 11,2014 4:11:35 PM org.apache…… -
Java – the best layout / nested layout for this structure
I'm new to swing. I'm trying to create an interface, such as: ——————————The text text of the information text 124124 1…… -
Java general Observer mode to achieve the original type is not selected.
I'm currently trying to take advantage of the general implementation of observer mode in Java. I find it seems to work…… -
Is it normal to put all Java Swing GUIs in one class?
I just started swing development and had problems Is it normal to put the whole GUI into a single class? The applicati…… -
Java – how to use selenium to record test cases in IE
I'm a beginner in selenium My application is only ie compatible I know that we can run test cases in any browser using…… -
Java – how to reverse a map
Let's look at a map: > A – > {1,2,3} > B – > {3,4,5} > C – > {2,3,5} I need to reverse this map and …… -
Java – jsonpath finds all objects (restassured)
This is my JSON: [ { "id": 9741962,"name": "getName","isActive": true },{ "id": 1,"name": "New","isActive": tr…… -
java. lang.NoSuchMethodError：org. apache. log4j. Logger
We use ivy to manage multi - Project Java applications, and recently this error began to appear when we built What cau…… -
An object can create multiple threads in Java
I am a novice in multithreading. I wrote the following code during practice I want to call the createthreaded method t…… -
Java – recursively sort ArrayLists into a tree
I have an ArrayList of objects But I need a tree with the following parameters: >Some objects should not have child…… -
Java – a data structure for saving the contents of the parsed CSV file
I'm trying to find the best way to parse CSV files in Java Now each line has x messages For example, the first line ca…… -
Java – add() in fragmenttransaction cannot be applied?
Could not be added to the fragment transaction due to the following error. How would you do this? add() in FragmentTra……