Custom AbstractEndpoint listening to "/" (root) - spring-boot

I've implemented a starter that configures Swagger the way I like. In addition, I'd like to redirect every call to the app's root URL (e.g. localhost:8080) to /swagger-ui.html.
Therefore, I added an own AbstractEndpoint which is instantiated in the #Configuration class as follows:
#Configuration
#Profile("swagger")
#EnableSwagger2
public class SwaggerConfig {
...
#Bean
public RootEndpoint rootEndpoint() {
return new RootEndpoint();
}
#Bean
#ConditionalOnBean(RootEndpoint.class)
#ConditionalOnEnabledEndpoint("root")
public RootMvcEndpoint rootMvcEndpoint(RootEndpoint rootEndpoint) {
return new RootMvcEndpoint(rootEndpoint);
}
}
The respective classes look like this:
public class RootEndpoint extends AbstractEndpoint<String> {
public RootEndpoint() {
super("root");
}
#Override
public String invoke() {
return ""; // real calls shall be handled by RootMvcEndpoint
}
}
and
public class RootMvcEndpoint extends EndpointMvcAdapter {
public RootMvcEndpoint(RootEndpoint delegate) {
super(delegate);
}
#RequestMapping(method = {RequestMethod.GET}, produces = { "*/*" })
public void redirect(HttpServletResponse httpServletResponse) throws IOException {
httpServletResponse.sendRedirect("/swagger-ui.html");
}
}
As stated in public RootEndpoint(), the custom Endpoint is bound to /root. Unfortunately, I can't specify super(""); or super("/"); as those values throw an exception (Id must only contains letters, numbers and '_').
How can I achieve having a custom Endpoint listening to the root URL in a starter using #Configuration files to instantiate beans?

I solved it with an easier approach by adding a WebMvcConfigurerAdapter bean in the #Configuration:
#Bean
public WebMvcConfigurerAdapter redirectToSwagger() {
return new WebMvcConfigurerAdapter() {
#Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("").setViewName("redirect:/swagger-ui.html");
}
};
}

Related

how can application yaml value inject at runtime in spring boot?

I want to change the value of application.yaml at loading time.
ex) application.yaml
user.name: ${name}
Here, I want to put this value by calling an external API such as a vault, rather than a program argument when the jar is executed with the name value.
First of all, I think I need to write code that implements EnvironmentPostProcessor and calls external API, but I don't know how to inject that value. can I get help?
public class EnvironmentConfig implements EnvironmentPostProcessor {
#Override
public void postProcessEnvironment(ConfigurableEnvironment environment,
SpringApplication application) {
// API CAll
// how can inject yaml value??
}
}
I don't know which way to orient myself.
OPTION 1: doing it via EnvironmentPostProcessor:
assuming you have registered you EnvironmentPostProcessor in /resources/META-INF/spring.factories file:
org.springframework.boot.env.EnvironmentPostProcessor=package.to.environment.config.EnvironmentConfig
all you need is to add your custom PropertySource:
public class EnvironmentConfig implements EnvironmentPostProcessor {
#Override
public void postProcessEnvironment(ConfigurableEnvironment environment,
SpringApplication application) {
environment.getPropertySources()
.addFirst(new CustomPropertySource("customPropertySource"));
}
}
public class CustomPropertySource extends PropertySource<String> {
public CustomPropertySource(String name) {
super(name);
}
#Override
public Object getProperty(String name) {
if (name.equals("name")) {
return "MY CUSTOM RUNTIME VALUE";
}
return null;
}
}
OPTION 2: doing it via PropertySourcesPlaceholderConfigurer:
A class that is responsible for resolving these palceholders is a BeanPostProcessor called PropertySourcesPlaceholderConfigurer (see here).
So you could override it and provide you custom PropertySource that would resolve your needed property like so:
#Component
public class CustomConfigurer extends PropertySourcesPlaceholderConfigurer {
#Override
protected void processProperties(ConfigurableListableBeanFactory beanFactoryToProcess, ConfigurablePropertyResolver propertyResolver) throws BeansException {
((ConfigurableEnvironment) beanFactoryToProcess.getBean("environment"))
.getPropertySources()
.addFirst(new CustomPropertySource("customPropertySource"));
super.processProperties(beanFactoryToProcess, propertyResolver);
}
}
use ConfigurationProperties for your properties and change it via an api like this:
#Component
#ConfigurationProperties(prefix = "user")
public class AppProperties {
private String name;
//getter and setter
}
#RestController
public class AppPropertiesController {
#Autowire
AppProperties prop;
#PostMapping("/changeProp/{name}")
public void change(#PathVariable String name){
prop.setName(name);
}
}

Configuration for RestController Deserializing YAML into pojo Uploaded as raw body?

What will be the equivalent configuration of below spring mvc code in spring 5 webflux? how can i add multiple converters in webflux?
#Configuration
public class YamlConfiguration extends WebMvcConfigurerAdapter {
#Override
public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
converters.add(new YamlJackson2HttpMessageConverter());
}
}
final class YamlJackson2HttpMessageConverter extends AbstractJackson2HttpMessageConverter {
YamlJackson2HttpMessageConverter() {
super(new YAMLMapper(), MediaType.parseMediaType("application/x-yaml"));
}
}
I know this is old, but after digging and finding no answers, I was finally able to piece this together using a bunch of different posts, posting here in hopes of helping future people.
/**
* Modelled off of Jackson2JsonDecoder
*/
public class Jackson2YamlDecoder extends AbstractJackson2Decoder {
public Jackson2YamlDecoder() {
super(YAMLMapper.builder().build(), new MimeType("application","x-yaml"));
}
}
/**
* Modelled off of Jackson2JsonEncoder
*/
public class Jackson2YamlEncoder extends AbstractJackson2Encoder {
#Nullable
private final PrettyPrinter ssePrettyPrinter;
public Jackson2YamlEncoder() {
super(YAMLMapper.builder().build(), new MimeType("application","x-yaml"));
this.ssePrettyPrinter = initSsePrettyPrinter();
}
private static PrettyPrinter initSsePrettyPrinter() {
DefaultPrettyPrinter printer = new DefaultPrettyPrinter();
printer.indentObjectsWith(new DefaultIndenter(" ", "\ndata:"));
return printer;
}
#Override
protected ObjectWriter customizeWriter(ObjectWriter writer, MimeType mimeType, ResolvableType elementType, Map<String, Object> hints) {
return this.ssePrettyPrinter != null && MediaType.TEXT_EVENT_STREAM.isCompatibleWith(mimeType) && writer.getConfig().isEnabled(SerializationFeature.INDENT_OUTPUT) ? writer.with(this.ssePrettyPrinter) : writer;
}
}
#Configuration
public class WebFluxConfig implements WebFluxConfigurer {
#Override
public void configureHttpMessageCodecs(ServerCodecConfigurer configurer) {
CodecConfigurer.CustomCodecs customCodecs = configurer.customCodecs();
customCodecs.registerWithDefaultConfig(new Jackson2YamlDecoder());
customCodecs.registerWithDefaultConfig(new Jackson2YamlEncoder());
}
}
I found that if you just register the YAML HttpMessageConverter as a bean webflux will automatically use it.

#Specializes in Spring

CDI has the feature of Specialization, and I'm looking for that in the Spring world.
Details.
In CDI, the #Specializes annotation allows one to change the behaviour of a bean just by overriding it. This is completely transparent to users of that bean, e.g. if we'd have
public class OneBean {
public String whoAmI() { return "OneBean"; }
}
#Specializes
public class AnotherBean extends OneBean {
#Override
public String whoAmI() { return "AnotherBean"; }
}
we could
public class SomewhereElse {
#Inject
OneBean oneBean; // we know nothing of AnotherBean here!
public void guessWhosThere() {
return oneBean.whoAmI(); // yet it returns "AnotherBean"
}
}
This gets really useful as soon as OneBean is actually used with and without AnotherBean. For example, if OneBean is in one.jar and AnotherBean is in another.jar, we can change the bean's behaviour just by reconfiguring the classpath.
Question. Does something like Specialization also exist in Spring?
I could only find the #Primary annotation, which however has a different semantics: #Primary does not replace one bean, but only marks one of multiple alternatives as the primary one. Especially, as I understood, I could not build a deep inheritance hierarchy as it's possible with #Specializes.
Short answer
In Spring 4, this is not possible. Period. Still, in 2016, nothing like this is possible with Spring's obsolete dependency injection model.
Seems like there is no similar annotation in spring, but you can achive it via #Qualifier.
Beans:
#Resource("oneBean")
public class OneBean {
public String whoAmI() { return "OneBean"; }
}
#Resource("anotherBean")
public class AnotherBean extends OneBean {
#Override
public String whoAmI() { return "AnotherBean"; }
}
SomewhereElse:
public class SomewhereElse {
#Autowired
#Qualifier("anotherBean")
OneBean oneBean;
public void guessWhosThere() {
return oneBean.whoAmI(); // returns "AnotherBean"
}
}
Edited.
Also you can develop your own annotation and use it in BeanPostProcessor, look at spring docs here
OR even better to use CustomAutowireConfigurer, see here
With Spring boot, you could probably get a similar result by leveraging its auto-configure mechanism, e.g. with a bean condition such as #ConditionalOnMissingBean:
public class OneBean {
public String whoAmI() { return "OneBean"; }
}
#Configuration
public class OneConfiguration {
#Bean
#ConditionalOnMissingBean
public OneBean getBean() { return new OneBean(); }
}
#Component
public class AnotherBean extends OneBean {
#Override
public String whoAmI() { return "AnotherBean"; }
}
However, you would have to make sure that all configurations are built accordingly if you don't know for sure which ones will be specialized:
public class OneBean {
public String whoAmI() { return "OneBean"; }
}
public class AnotherBean extends OneBean {
#Override
public String whoAmI() { return "AnotherBean"; }
}
public class YetAnotherBean extends AnotherBean {
#Override
public String whoAmI() { return "YetAnotherBean"; }
}
#Configuration
public class OneConfiguration {
#Bean
#ConditionalOnMissingBean
public OneBean getBean() { return new OneBean(); }
}
#Configuration
public class AnotherConfiguration {
#Bean
#ConditionalOnMissingBean
public AnotherBean getBean() { return new AnotherBean(); }
}
#Configuration
public class YetAnotherConfiguration {
#Bean
#ConditionalOnMissingBean
public YetAnotherBean getBean() { return new YetAnotherBean(); }
}
// and so on...

Change main endpoint in Spring Data Rest (usind Spring Boot)

Im building a small application using Spring (Boot, Data, Data Rest).
I have some JpaRepositories that aumotatically are exported as Rest endpoints.
What i want to do is to change the base path from / to /api.
Now to list all people for example i do a GET to http://localhost:8080/people and i want the url to be http://localhost:8080/api/people.
I tried adding this config class but nothing happened (it seems that Spring Boot overrides this config):
public class SpringWebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer{
#Override
protected Class<?>[] getRootConfigClasses()
{
return new Class<?>[] { Application.class};
}
#Override
protected Class<?>[] getServletConfigClasses()
{
return new Class<?>[] { RestExporterRestConfig.class, RepositoryRestMvcConfiguration.class };
}
#Override
protected String[] getServletMappings()
{
return new String[] { "/api/*" };
}
}
My Application.java:
#Configuration
#ComponentScan
#Import(RestExporterRestConfig.class)
#EnableJpaRepositories
#EnableAutoConfiguration
public class Application extends SpringBootServletInitializer {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
and RestExporterRestConfig:
#Configuration
public class RestExporterRestConfig extends RepositoryRestMvcConfiguration {
#Bean
public Validator validator() {
return new LocalValidatorFactoryBean();
}
#Override
protected void configureValidatingRepositoryEventListener(ValidatingRepositoryEventListener v) {
v.addValidator("beforeCreate", validator());
}
#Bean
#Qualifier
public DefaultFormattingConversionService defaultConversionService() {
DefaultFormattingConversionService conversionService = new DefaultFormattingConversionService();
conversionService.addConverter(StringToDate.INSTANCE);
return conversionService;
}
#Bean
public DomainClassConverter<?> domainClassConverter() {
return new DomainClassConverter<DefaultFormattingConversionService>(defaultConversionService());
}
}
Well i figured it out. SpringWebAppInitializer is not necesary in this case. I just added this code to Application.java:
#Bean
public ServletRegistrationBean dispatcherRegistration(DispatcherServlet dispatcherServlet) {
ServletRegistrationBean reg = new ServletRegistrationBean(dispatcherServlet);
reg.addUrlMappings("/api/*");
return reg;
}
I think this is the correct way to modify (add, change mappings, etc) servlets using Spring Boot.

Javaconfig bean overiding does not take in account added #DependsOn

While overrding a Javaconfig Bean by extending the original #Configuration class, I would like to add a #DependsOn for the new Bean definition.
However, this depends-on seems not to be taken in account. here is a TestCase reproducing my issues:
public class SpringTest {
#Test
public void testDependsOnTakenInAccount() {
AnnotationConfigApplicationContext ctx2 = new AnnotationConfigApplicationContext(AConfig.class, CConfig.class);
Assert.assertEquals("overriden", ctx2.getBean("bean"));
}
#Configuration
public static class AConfig {
#Bean
public Object bean() {
return "not overriden";
}
}
#Configuration
public static class CConfig extends AConfig {
protected boolean isInitialized = false;
#Bean
public Void doInit() {
isInitialized = true;
return null;
}
#Bean
#DependsOn("doInit")
public Object bean() {
if (!isInitialized) {
throw new RuntimeException("Not initialized");
}
return "overriden";
}
}
}
Is this an expected behavior? If yes, how can I add dependency while overriding a bean?
For me seems like a bug.
When overriding a #Bean factory method in a Configuration class, the parent BeanDefinition wins and get registered on the BeanFactory overriding the child one.
So you cannot configure the bean with annotaions (because it will be overriden).
The following Test result on
expected:<[doInit]> but was:<[otherBean]>
#RunWith(JUnit4ClassRunner.class)
public class DependOnTest {
#Test
public void testBeanDefinitionOverriding() {
AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(Config.class);
BeanDefinition bd = ctx.getBeanDefinition("bean");
Assert.assertEquals("doInit", bd.getDependsOn()[0]);
}
#Configuration
public static class ParentConfig {
#Bean
#DependsOn("otherBean")
public String bean() {
return "not overriden";
}
#Bean
public String otherBean() {
return "otherBean";
}
}
#Configuration
public static class Config extends ParentConfig {
#Bean
public String doInit() {
return "doInit";
}
#Bean
#DependsOn("doInit")
public String bean() {
return "overriding";
}
}
}
I think that problem start on ConfigurationClassParser:
// recursively process the configuration class and its superclass hierarchy
do {
metadata = doProcessConfigurationClass(configClass, metadata);
}
while (metadata != null);
That result on overriden method added to CongurationClass.beanMethods
It could be fixed checking if the beanMethod was already added from a superclass in ConfigurationClass.addBeanMethod()
public void addBeanMethod(BeanMethod method) {
// Check if already added a bean method from superclass
for (BeanMethod beanMethod : beanMethods) {
if (beanMethod.getMetadata().getMethodName().equals(method.getMetadata().getMethodName()) &&
!(beanMethod.getMetadata().getDeclaringClassName()).equals(method.getMetadata().getDeclaringClassName()))
// log and return.
return;
}
this.beanMethods.add(method);
}
As pointed out by Jose Luis Martin, this has been confirmed as a bug by Spring team.
I've workarounded it with:
#DependsOn("doInit")
#Bean
public Void notOverridingBean() {
return null;
}
#Bean
public Object bean(Object notOverridingBean) {
return "overriden";
}
an alternative is to override the bean in another #Configuration class.

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