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• Oracle
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do you have exception: AbstractMethodError: javax.xml.parsers.DocumentBuilderFactory.setFeature(L/java.lang.String;Z)V

SOLVE:

private static void OutputJaxpImplementationInfo() {
   System.out.println(getJaxpImplementationInfo("DocumentBuilderFactory", DocumentBuilderFactory.newInstance().getClass()));
   System.out.println(getJaxpImplementationInfo("XPathFactory", XPathFactory.newInstance().getClass()));
   System.out.println(getJaxpImplementationInfo("TransformerFactory", TransformerFactory.newInstance().getClass()));
   System.out.println(getJaxpImplementationInfo("SAXParserFactory", SAXParserFactory.newInstance().getClass()));
   System.out.println(getJaxpImplementationInfo("SchemaFactory", SchemaFactory.newInstance().getClass())); // TODO: don't correct for Java 8+
}

private static String getJaxpImplementationInfo(String componentName, Class componentClass) {
   CodeSource source = componentClass.getProtectionDomain().getCodeSource();
   return MessageFormat.format(
      "{0} implementation: {1} loaded from: {2}",
      componentName,
      componentClass.getName(),
      source == null ? "Java Runtime" : source.getLocation());
}

1. Font static class:

public static final String SOME_FONT = pathToFont("SomeFont");

private static String pathToFont(String fontName) {
  try {
    return FontUtils.class.getClassLoader().getResource("").toURI().toString() + _path to font with fontName_ + ".ttf";
  } catch (URISyntaxException e) {
    e.printStackTrace();
    return null;
  }
}

2. (a) if using flying saucer:

ITextRenderer renderer = new ITextRenderer();
if (FontsUtils.SEGOE_UI_FONT_PATH != null)
  renderer.getFontResolver().addFont(FontsUtils.SOME_FONT, BaseFont.IDENTITY_H, BaseFont.EMBEDDED);

2. (b) if pure:

CSSResolver cssResolver = new StyleAttrCSSResolver();

// FOR FONT(s)
XMLWorkerFontProvider fontProvider = new XMLWorkerFontProvider(XMLWorkerFontProvider.DONTLOOKFORFONTS);
fontProvider.register(FontUtils.SOME_FONT);
CssAppliersImpl cssAppliers = new CssAppliersImpl(fontProvider);

// HTML
HtmlPipelineContext htmlContext = new HtmlPipelineContext(cssAppliers);
htmlContext.setTagFactory(Tags.getHtmlTagProcessorFactory());

// Pipelines
ElementList elements = new ElementList();
ElementHandlerPipeline pdf = new ElementHandlerPipeline(elements, null);
HtmlPipeline html = new HtmlPipeline(htmlContext, pdf);
CssResolverPipeline css = new CssResolverPipeline(cssResolver, html);

// XML Worker
XMLWorker worker = new XMLWorker(css, true);
XMLParser p = new XMLParser(worker);

• Jasper Reports
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    • Jasper Studio
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  • Reporting docs
  • Output matrix
  • embeding examples

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  • Compare Metabase

• 1st - 2015 year
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• 4th - 2021 year

• Spring Boot Rest Project Structure
• Микросервисная архитектура на современном стеке Java-технологий
• Переписываем домашний проект на микросервисы (Java, Spring Boot, Gradle)
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• REST API Design Best Practices
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• Spring Boot REST + Vue есть много разных нюансов,один из них,как один DTO выгружать через разные View - разные поля скрывать/показывать

• CUSTOM Spring Boot error handling LIB
• Guide to Spring Boot REST API Error Handling
• Strictly REST — API Exception and Error Handling — A Spring @RestControllerAdvice Approach (NEED ACCOUNT) source
• @RestControllerAdvice example in Spring Boot
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• Get Started with Custom Error Handling in Spring Boot
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• Основы работы с Spring Security
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• Пять простых шагов для понимания JSON Web Tokens (JWT)
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• Keycloak + Spring Boot полное копирование статьи на версиях спирга 5.4.5+/бута 2.4.4+ не работает
• OAuth2 Redirect (medium)
• ResourceService (medium)
• OAuth2 (baeldung)
• Spring Boot Keycloak (baeldung)

1. w/o Exception Handler (with ErrorController) > response.sendError in some filter/handler then you need implements ErrorController in @Advice handler
2. with Exception Handler > response.setStatus and HandlerExceptionResolver with resolveException(request, response, null, exception)
3. or send response as is through writer or stream

source

• Spring Cloud API Gateway
• Spring Cloud Netflix Microservices

• Spring Cloud OpenFeign и авторизация (OAuth2). Ещё проще (моя статья)
• Spring Cloud OpenFeign и авторизация
• Provide an OAuth2 Token to a Feign Client tutorial's src was very helpfully
• spring-security-openfeign source (custom)
• Spring Cloud: Feign OAuth2 authentication
• Microservices with Spring Boot and Spring Cloud. From config server to OAuth2 server (without inMemory things) — Part 3

Very help:

• source code
  • FeignAutoConfiguration from org.springframework.cloud.openfeign
  • OAuth2AccessTokenInterceptor from org.springframework.cloud.openfeign.security
• docs
  • Actual spring-cloud-openfeign DOCS
  • OLD spring-cloud-openfeign DOCS

import lombok.RequiredArgsConstructor;
import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.autoconfigure.security.oauth2.client.OAuth2ClientProperties;
import org.springframework.cloud.openfeign.security.OAuth2AccessTokenInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.security.oauth2.client.AuthorizedClientServiceOAuth2AuthorizedClientManager;
import org.springframework.security.oauth2.client.OAuth2AuthorizedClientManager;
import org.springframework.security.oauth2.client.OAuth2AuthorizedClientService;
import org.springframework.security.oauth2.client.registration.ClientRegistrationRepository;

/**
 *  Config for optional OAuth2 token header in some feign clients.<br/>
 *  Get <b><u>first</u></b> registration from properties by default for configuration.
 */
@RequiredArgsConstructor
public class OAuthFeignConfig {
    private final OAuth2ClientProperties oAuth2ClientProperties;

    @Bean
    @ConditionalOnBean({OAuth2AuthorizedClientService.class, ClientRegistrationRepository.class})
    @ConditionalOnMissingBean
    public OAuth2AuthorizedClientManager feignOAuth2AuthorizedClientManager(ClientRegistrationRepository clientRegistrationRepository,
            OAuth2AuthorizedClientService oAuth2AuthorizedClientService) {
        return new AuthorizedClientServiceOAuth2AuthorizedClientManager(clientRegistrationRepository, oAuth2AuthorizedClientService);
    }

    @Bean
    @ConditionalOnBean(OAuth2AuthorizedClientManager.class)
    public OAuth2AccessTokenInterceptor defaultOAuth2AccessTokenInterceptor(OAuth2AuthorizedClientManager oAuth2AuthorizedClientManager) {
        return new OAuth2AccessTokenInterceptor(oAuth2ClientProperties.getRegistration().keySet().iterator().next(), oAuth2AuthorizedClientManager);
    }
}

if you are using @Query annotation in repository and using hikari, add

spring.datasource.hikari.schema: other_services

additional to

spring.jpa.properties.hibernate.default_schema: other_services

1. client send only @RequestPart
2. server receive only @RequestPart then change on server @RequestPart to @RequestParam

if on server used @PathVariable with @RequestPart - all will work as you expect

• @ConfigurationProperties vs. @Value
• Валидация данных при помощи Bean Validation API
• Injecting HTTP Headers in Spring Rest Controller
• Spring @Transactional — ошибки, которые совершали все

Утилита для проверки сертификата - keytool.

Обратите внимание что openssl может показывать поле street, вместо STREET. Также openssl "переворачивает" поля сертификата, отображая их в зеркальном порядке. При проверке штатными средствами Windows также могут быть недостатки: поле ST=Moscow отображается как S=Moscow. Выполните проверку своего DN сертификата несколькими инструментами, кафка требует полного соответствия полей, их порядка и регистра всех букв

• add without explicit indication of trust
• add with explicit indication of trust

#It will check the chain and if it doesn't like it, java will throw an error

keytool -import -alias CHOOSE-AN-ALIAS -file certificate.pem -keystore /path/to/your/truststore

#In the second case, you say to explicitly trust this certificate, even if there is something wrong with the chain

keytool -trustcacerts -keystore /path/to/your/truststore -storepass changeit -importcert -alias <your_alias> -file <path_to_file>

† On RHEL, update your truststore using the update-ca-trust command.

‡ On Ubuntu, update your truststore using the update-ca-certificates command.

REMOTE_HOST=untrusted-root.badssl.com

echo | openssl s_client -showcerts -partial_chain \
    -servername ${REMOTE_HOST} -connect ${REMOTE_HOST}:443 \
    | awk '/BEGIN/,/END/{ if(/BEGIN/){a++}; out="cert"a".pem"; print >out}'

REMOTE_HOST=$1

echo \
    | openssl s_client -showcerts -partial_chain \
    -servername ${REMOTE_HOST} -connect ${REMOTE_HOST}:443 \
    | awk '/BEGIN/,/END/{ if(/BEGIN/){a++}; out="'"${remote_host}"'"a".pem"; print >out}'

Samples

• logging (pure Java)
• log4j > log4j2
• Logback (used with SLF4J)
• SLF4J (simple logging facade for java)

• SLF4J → Logback
• SLF4J → slf4j-log4j12 → Log4j
• SLF4J → log4j-slf4j-impl → Log4j 2
• SLF4J → slf4j-jdk14 → JUL
• SLF4J → slf4j-jcl → JCL
• JCL → JUL
• JCL → Log4j
• log4j2-api → log4j2-cor
• log4j2-api → log4j-to-slf4j → SLF4J

• ALL – The ALL has the lowest possible rank and is intended to turn on all logging. => All logging.
• TRACE – The TRACE Level designates finer-grained informational events than the DEBUG => Fine.
• DEBUG – The DEBUG Level designates fine-grained informational events that are most useful to debug an application. => Debugging.
• INFO – The INFO level designates informational messages that highlight the progress of the application at coarse-grained level. => Highlight information.
• WARN – The WARN level designates potentially harmful situations. => Warning.
• ERROR – The ERROR level designates error events that might still allow the application to continue running. => Error.
• FATAL – The FATAL level designates very severe error events that will presumably lead the application to abort. => Critical error.
• OFF – The OFF has the highest possible rank and is intended to turn off logging. => Disable logging.

%m: Outputs log contents
%p: Outputs priority such as debug, info, warn, error, fatal, etc.
%r: Outputs elapsed time in milliseconds from application start to event occurrence
%c: Outputs package
%c{ n}: Reversely output as many packages as n (number) from the bottom.
Example) When %c{2}, abc is output as bc.
%n: Output newline character. Output \r\n or \n depending on platform.
%d: Event occurrence date output (It slows down the execution speed of the program.)
Ex) %d{HH:mm:ss} or %d{dd MMMM yyyy HH:mm:ss}
%C: Caller's class name output
example ) When %C{2}, abcTestClass is output as c.TestClass.
%M: method name.
%F: Program file name.
%l: information of caller
%L: number of lines of caller
%x: Nested diagnostic context (NDC)
associated with the thread %X: Mapped diagnostic context (MDC) associated with the thread
%%: Display
%t: Thread name

• vladmihalcea
• Николай Алименков repo

• JEE Conf

• Datasource Proxy
  • Datasource Proxy
  • p6spy
• Queries counting interceptor
  • db-util

jpa.show-sql: true
hibernate:
  generate_statistics: true # enable statistics
  format_sql: true
  use_sql_comments: true

# more info
logging.level:
  org.hibernate: INFO
  org.hibernate.SQL: DEBUG
  org.hibernate.type: TRACE
  org.hibernate.hql.ast.AST: INFO
  org.hibernate.tool.hbm2ddl: WARN
  org.hibernate.hql: DEBUG
  org.hibernate.cache: INFO
  org.hibernate.jdbc: DEBUG
  org.hibernate.stat: DEBUG

• hibernate.jdbc.fetch_size - how much batch rows need read from DB. Only for Oracle, you might want to set it since the default fetchSize is just 10.

• hibernate.jdbc.batch_size - how much operation in batch multiple INSERT, UPDATE, and DELETE statements can be set in a single database call.

  • hibernate.order_inserts -
  • hibernate.order_updates -

• Hibernate pooled and pooled-lo identifier generators
• Hibernate's table generator optimizers
• spring.jpa.properties.hibernate.id.optimizer.pooled.preferred: pooled-lo or hibernate.id.optimizer.pooled.preferred: pooled-lo

• Ultimate Guide for Reading Files in Java (Benchmarks)
• Java Files Tutorial
  • How to Read Files Easily and Fast [Part 1]
  • How to Write Files Quickly and Easily [Part 2]
• Full Stack "course"