宝贝腿开大点我添添公视频免费 ,国产成人综合亚洲网站

Article Tags

Home

Technical Articles

Java

javaTutorial

Extract LinearSVC model coefficients and intercepts from Apache Flink ML

This article describes how to extract hyperplanar parameters, including coefficients and intercepts, from Apache Flink ML-trained LinearSVC model. By extracting these parameters, users can integrate model rules into Flink CEP's pattern matching API to implement more complex stream processing logic. This article provides Python and Java sample code to help users get started quickly.

Aug 22, 2025 am 08:33 AM

Modify final fields using reflection in Java 17

This article describes how to modify non-static final fields using reflection in Java 17. Due to Java version updates, the old reflection techniques no longer work. This article provides a new solution to bypass Java's modular limitations through VarHandle and JVM startup parameters, thereby achieving the purpose of modifying final fields. This method is more secure and reliable, avoiding the risks that may pose by directly operating the modifiers field.

Aug 22, 2025 am 08:12 AM

How to get the selected value of JRadioButton in Java Swing

In Java Swing applications, calling toString() method directly on the ButtonModel object returned by ButtonGroup.getSelection() is usually unable to obtain the JRadioButton's display text or the logical value it represents, but instead obtains a useless memory address string. The correct way to solve this problem is to set a meaningful actionCommand for each JRadioButton and then get the selected string value via ButtonGroup.getSelection().getActionCommand(), make sure to check the ButtonMod before getting

Aug 22, 2025 am 08:09 AM

How to override the equals and hashCode methods in Java?

The equals and hashCode methods must be rewritten at the same time to ensure that the object works correctly in collections such as HashMap, HashSet, etc. 1. The equals method needs to satisfy reflexivity, symmetry, recursion, consistency and is not equal to null. Objects.equals is used to process field comparisons; 2. The hashCode method requires that equal objects must return the same hash value, and it is recommended to use Objects.hash to generate; 3. When paying attention to logic equality or using objects as collection elements or mapping keys, it must be rewritten; 4. The code can be automatically generated with the help of IDE or Lombok's @EqualsAndHashCode, but it must include all related fields, otherwise it will cause a hash set.

Aug 22, 2025 am 08:05 AM

Java Persistence with Spring Data JPA and Hibernate

The core of SpringDataJPA and Hibernate working together is: 1. JPA is the specification and Hibernate is the implementation, SpringDataJPA encapsulation simplifies DAO development; 2. Entity classes map database structures through @Entity, @Id, @Column, etc.; 3. Repository interface inherits JpaRepository to automatically implement CRUD and named query methods; 4. Complex queries use @Query annotation to support JPQL or native SQL; 5. In SpringBoot, integration is completed by adding starter dependencies and configuring data sources and JPA attributes; 6. Transactions are made by @Transactiona

Aug 22, 2025 am 07:52 AM

java jpa

Calculate the time difference of LocalDateTime in Java

This article describes how to use the LocalDateTime class in Java to calculate the difference between two dates and times and display it in minutes. By using DateTimeFormatter to parse the date string, then use the Duration class to calculate the time difference, and finally convert the result into minutes, making it easier to judge and process the time interval.

Aug 22, 2025 am 07:42 AM

How to create a REST API with Spring Boot in Java?

Yes, it is very simple to create a RESTAPI in Java using SpringBoot. You only need to generate a project through SpringInitializr, add SpringWeb dependencies, create a Book model class and define a BookController with annotations such as @GetMapping, @PostMapping, @PutMapping and @DeleteMapping to implement the function of adding, deleting, modifying and checking. After running the application, you can access the API interface through the default port 8080. The framework automatically handles JSON serialization and HTTP routing. Developers can focus on business logic implementation.

Aug 22, 2025 am 06:09 AM

How to decode a Base64 string in Java?

To decode Base64 string, use java.util.Base64 class: 1. Call Base64.getDecoder().decode(String) to decode Base64 string to byte[]; 2. Use newString(decodedBytes, StandardCharsets.UTF_8) to convert it to a string; 3. For URL security or MIME formats, use Base64.getUrlDecoder() or Base64.getMimeDecoder() respectively; 4. Use try-catch to process IllegalArgumentExc with try-catch;

Aug 22, 2025 am 06:06 AM

java base64

The correct way to generate a title that accurately expresses the article's topic's correct way to find the first non-repeat character in a string

This article aims to solve the problem of function returning the entire input string when searching for the first non-repeat character in a string in Java. By modifying the return value, it returns only the target character, avoiding outputting redundant information. This article provides a modified code example and explains how to convert characters into strings using the String.valueOf() method to achieve the expected functionality.

Aug 22, 2025 am 05:24 AM

What is Mockito in Java?

MockitoisusedtocreatemockobjectsinJavaunittests,allowingdeveloperstoisolatethecodeundertestbyreplacingdependencieswithcontrollabletestdoubles;itenablesstubbingmethodcalls,verifyinginteractions,andsimulatingexceptions,ensuringtestsarefast,reliable,and

Aug 22, 2025 am 05:05 AM

java mockito

How to use sockets in Java

TCP-based network communication can be implemented using the Socket class and ServerSocket class in Java, where ServerSocket is used for server listening connections, and Socket is used for client connections and data transmission. 2. The server waits for the client to connect through the accept() method, and uses the input and output stream to send and receive data. The client connects to the server through the specified IP and port and exchanges information. 3. In actual programming, you need to pay attention to: select ports above 1024 to avoid conflicts, use try-with-resources to ensure resource release, handle IOException exceptions, and understand the blocking characteristics of methods such as readLine() and accept(). 4. For

Aug 22, 2025 am 04:58 AM

how to implement a singleton pattern in java

The best way to implement singleton pattern using Java is BillPugh's static inner class or enumeration method. The former implements lazy loading and thread safety through static inner class, and the latter ensures uniqueness under serialization and reflection by the JVM. It is recommended to choose according to requirements: enumeration is suitable for high security scenarios, and static inner classes are suitable for scenarios that require flexibility and performance.

Aug 22, 2025 am 04:14 AM

Implementation and optimization of string pooling in Couchbase

This article discusses how to optimize memory usage by using string pooling technology when storing large amounts of string data in Couchbase cache. In view of the case where Jackson is used to deserialize by default in Couchbase Java SDK, this article introduces how to implement string pooling by customizing Jackson deserializer, thereby effectively reducing the size of cached documents and improving performance.

Aug 22, 2025 am 04:09 AM

How to clone an object in Java

Cloning objects in Java requires selecting shallow cloning or deep cloning according to your needs. 1. Use the clone() method to implement shallow cloning: you need to implement the Cloneable interface and override the clone() method, but only copy the basic type field, and the reference type field shares the same object. Modification will affect the original object. 2. Manually implement deep cloning: When rewriting the clone() method, clone() is also called on referenced objects such as Address to ensure that all hierarchical objects are independent, but all related classes are required to support cloning. 3. Use copy constructor or factory method: manually copy each field through constructor such as Person (Personother) and create a new instance of the reference object. The advantage is that there is no need to implement Clone

Aug 22, 2025 am 03:09 AM