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For defining a SynchronousQueue in Java, we need the BlockingQueue interface as follows: BlockingQueue queue = new SynchronousQueue();
Working with and comparing multiple queries at the same time can be a pain, at least for me. Two independent query windows take up more space on screen, or having
Use getsizeof method to retrieve the size of an object in bytes. See below for an example: str = “devx” print(sys.getsizeof(str))
MySQL provides numerous mathematical calculations that can be computed with inbuilt functions. In order to find the TAN of a number, we can use the following: Query: SELECT TAN(400); Sample
Converting List to Set: List list = Arrays.asList(1, 2, 3);Set set = new HashSet(list); Converting Set to List: Set set = Sets.newHashSet(1, 2, 3);List list = new ArrayList(set);
The quickest solution for sorting an array in Java relies on Arrays.sort() method as below: int[] arr = {5, 12, 3, 44, 55}; Arrays.sort(arr);
There are numerous times when we get confused with the paths of our imported modules. A quick way to see their path in code is by performing a print. For
Consider a Review object with three properties: article, book and magazine. Let’s assume that only one of these three properties should be set as non-null. For checking this constraint we
The SUBSTRING_INDEX helps in extracting a part of the given string from the beginning to the match in the index. Query: SELECT SUBSTRING_INDEX(‘MySQL Database’, ‘a’, 2) AS SUBSTRING_INDEX; Here, the
The best way to declare a Pattern in Java is as a constant, since Pattern is immutable. Use the following code: private static final Pattern PATTERN = Pattern.compile(” +”); Further,
Sometimes you want to select all the columns, without using the *. Specifying column names speeds up your query. The problem comes in with large tables or tables with difficult
Use the dir() function to return the list of the attributes and methods of the object. Syntax :dir({object})
If we have a code-point, we can check if it is a Unicode surrogate pair as follows: int cp = some_code_point;if(Character.charCount(cp) == 2) { // 2 means a surrogate pair
Port BindExceptions can occur if a port is already occupied by some other process and you try to use it again. Below is a simple example that demonstrates this and
To convert, e.g., the number 144 to the string ???144???, use the built-in type constructor??str()
Passing parameters to an SQL query written via @Query can be done via @Param or via positional parameters: // via @Param@Query(value = “SELECT p FROM Product p WHERE p.department=:department”)List fetchByDepartment(@Param(“department”)
I hate repetitive tasks. I am not a robot. However, the problem is that there are some tasks that can be quite repetitive or just take too many steps to
Use the int() type constructor to convert a string to number. Sample code: int(‘208’) == 208
Class annotations can be inspected via reflection as follows: Class clazz = Foo.class;Annotation[] clazzAnnotations = clazz.getAnnotations();
After a user has been created and is currently in use, a need might arise for the user account to be locked. MySQL provides a mechanism to alter the user
Calling a private constructor from outside its class can be done via Reflection as follows: public final class Users { private Users() {} // static members}Class usersClass = Users.class;Constructor emptyUsersCnstr
This is a neat trick I have learnt recently. When dealing with large lists of information, we, as developers, sometimes need to copy them, then add commas manually. Say, for
Using ThreadPoolExecutor from the concurrent.futures library, we can spin threads quickly and execute tasks in parallel. Wrap your time consuming method with the thread pool executor.. Without threading: for task
One of the widely wasted resources in the world today is: Memory. Due to inefficient programming, surprising (sometimes ???shocking???) amount of memory is wasted. We see this pattern repeated in several enterprise applications. To prove this case, we conducted a small study. We analyzed the famous spring boot pet clinic application to see how much memory it is wasting. This application has been designed by the community to show how the spring application framework can be used to build simple but powerful database-oriented applications.
Returning a stream of int zero-extending the char values from a String can be done via chars(): String str = “hello world”;IntStream chars = str.chars();
Often, file sizes are too big to back them up or share them with someone. You can create a compressed version that will save you disk space, transfer time, etc.
We can get all columns in all tables of a specific data type. The example below gets all INT columns in the entire database SELECT OBJECT_NAME(sys.columns.OBJECT_ID) as TableName, sys.columns.name as
You can run a Registry Query from the command prompt to ascertain if TLS 1.2 is enabled on a server or not. reg query “HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlSecurityProvidersSCHANNELProtocolsTLS 1.2Client” reg query “HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlSecurityProvidersSCHANNELProtocolsTLS 1.2Server”
Most of us are familiar with AUTO_INCREMENT, and have used it in at least one context. However, the following behavior is a little tricky, especially when we fail to observe — and
For setting database dialect in Spring Boot, rely on spring.jpa.properties.hibernate.dialect?property in application.properties. For example, setting the MySQL5Dialect dialect can be done as below: spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5Dialect
