Using Spring with java configuration only, is possible define something similar to
<error-page>
<error-code>404</error-code>
<location>/notfound</location>
</error-page>
fragment of web.xml ?
You'll need to define an error page at servlet container level, which forwards to your custom controller.
#Component
public class CustomizationBean implements EmbeddedServletContainerCustomizer {
#Override
public void customize(ConfigurableEmbeddedServletContainer container) {
container.addErrorPages(new ErrorPage(HttpStatus.NOT_FOUND, "/error"));
}
}
Related
I have a strange behaviour with a Spring Data Rest implementation (version 2.5.2.RELEASE).
I'm trying to register a #Bean of ResourceProcessor<Resource<Entity>>, but there is something strange.
I'm trying with two kinds of solutions:
1) Declaring the #Bean in a class:
#Bean
public ResourceProcessor<Resource<Author>> authorProcessor() {
return new ResourceProcessor<Resource<Author>>() {
#Override
public Resource<Author> process(Resource<Author> resource) {
System.out.println("method process of bean ResourceProcessor of class RepositoryBaseConfiguration");
return resource;
}
};
}
2) Implementing the interface ResourceProcessor:
#Component
public class AuthorResourceProcessor implements ResourceProcessor<Resource<Author>> {
#Override
public Resource<Author> process(Resource<Author> resource) {
System.out.println("method process of class AuthorResourceProcessor");
return resource;
}
}
The processors are completely ignored: the message is never printed.
I noticed that the class org.springframework.data.rest.webmvc.ResourceProcessorInvoker has a constructor:
public ResourceProcessorInvoker(Collection<ResourceProcessor<?>> processors) {
//...
}
This constructor is invoked 2 times at the start of the application instead of only one time (as I will expect), and I don't understand why.
The first time, the "processors" variable is solved with the two beans (as expected) and with the bean org.springframework.data.rest.webmvc.ProfileResourceProcessor.
But the second time, the "processors" variable is solved with only the bean org.springframework.data.rest.webmvc.ProfileResourceProcessor.
The second configuration #Override the first one.
Any idea?
The problem depends on the configurations loaded at the startup of the application.
I had this configuration on the web.xml:
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/spring/spring-web-config.xml</param-value>
</context-param>
<servlet>
<servlet-name>rest</servlet-name>
<servlet-class>org.springframework.data.rest.webmvc.RepositoryRestDispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
So, the ContextLoaderListener loaded the correct configuration in the first time; the "load-on-startup" property of the servlet "RepositoryRestDispatcherServlet" launch a second context configuration load.
I also had a custom class that extended org.springframework.data.rest.webmvc.config.RepositoryRestMvcConfiguration, but this custom class was ignored by the moment that the constructor of RepositoryRestDispatcherServlet load the default RepositoryRestMvcConfiguration, causing the lost of the configurations.
To solve that issue I have created a custom RepositoryRestDispatcherServlet in this way:
public class AppRepositoryRestDispatcherServlet extends DispatcherServlet {
/**
*
*/
private static final long serialVersionUID = 1L;
public AppRepositoryRestDispatcherServlet() {
configure();
}
public AppRepositoryRestDispatcherServlet(WebApplicationContext webApplicationContext) {
super(webApplicationContext);
configure();
}
private void configure() {
setContextClass(AnnotationConfigWebApplicationContext.class);
setContextConfigLocation(RepositoryBaseConfiguration.class.getName());
}
}
The class is the same as RepositoryRestDispatcherServlet, with the only difference that in the setContextConfigLocation is passed the custom class that extends RepositoryRestMvcConfiguration (RepositoryBaseConfiguration in this example).
Obviously I had to update the web.xml as follows:
<servlet>
<servlet-name>rest</servlet-name>
<servlet-class>my.package.AppRepositoryRestDispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
In this way, the configuration is correctly loaded and mantained.
In my Spring Boot application with packaging type as war, i am configuring Spring MVC. As i understand we dont have to configure Dispatcher Servlet Manually. However, i old style of web.xml i used to configure Dispatcher Servlet and then i used to pass contextClass and contextConfigLocation as follows
<servlet>
<description>
</description>
<display-name>DispatcherServlet</display-name>
<servlet-name>DispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<description>contextClass</description>
<param-name>contextClass</param-name>
<param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContext</param-value>
</init-param>
<init-param>
<description>contextConfigLocation</description>
<param-name>contextConfigLocation</param-name>
<param-value>com.xxx.yyy.jdorderspringmvcweb.config.SpringMvcConfig</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
I belive this was to indicate that SpringMvcConfig (my custom class with spring mvc configuration) is the configuration class for Spring MVC..
However, In spring boot if Dispatcher Servlet is configured Automatically, how can i pass my custom class to dispatcher Servlet ?
In my Spring Boot application, my SpringMvcConfig class extends from WebMvcConfigurerAdapter and is annotated with #Configuration class
Help Needed...
Right in the configuration class which is annotated by #Configuration you could define your dispatcherServlet and pass init-parameter to it.
#Bean
public ServletRegistrationBean dispatcherServletRegistration() {
ServletRegistrationBean registrationBean = new ServletRegistrationBean(dispatcherServlet());
registrationBean.addInitParameter("contextClass","org.springframework.web.context.support.AnnotationConfigWebApplicationContext");
registrationBean.addInitParameter("contextConfigLocation","com.xxx.yyy.jdorderspringmvcweb.config.SpringMvcConfig");
return registrationBean;
}
Another way would be to create a paramter map and then set parameter for registration bean. This stream shows how to do it.
I think you have to create a config class as follow:
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
public class MySpringMvcDispatcherServletInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
#Override
protected Class<?>[] getRootConfigClasses() {
// TODO Auto-generated method stub
return null;
}
#Override
protected Class<?>[] getServletConfigClasses() {
return new Class[] { DemoAppConfig.class };
}
#Override
protected String[] getServletMappings() {
return new String[] { "/" };
}
}
Currently I have a web application where we are using web.xml to configure the application. The web.xml has welcome-file-list.
<web-app>
...
<welcome-file-list>
<welcome-file>home.html</welcome-file>
</welcome-file-list>
</web-app>
We are planning to use spring framework and use java class for application configuration.
class MyApplication extends WebApplicationInitializer {
public void onStartUp(ServletContext context){
...
}
}
How do I specify welcome-file-list in this java class?
While developing Spring MVC application with pure Java Based Configuration, we can set the home page by making our application configuration class extending the WebMvcConfigurerAdapter class and override the addViewControllers method where we can set the default home page as described below.
#Configuration
#EnableWebMvc
#ComponentScan(basePackages = { "com.myapp.controllers" })
public class ApplicationConfig extends WebMvcConfigurerAdapter {
#Bean
public InternalResourceViewResolver getViewResolver() {
InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
viewResolver.setPrefix("/WEB-INF/view/");
viewResolver.setSuffix(".jsp");
return viewResolver;
}
#Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/").setViewName("home");
}
}
It returns home.jsp view which can be served as home page. No need to create a custom controller logic to return the home page view.
The JavaDoc for addViewControllers method says -
Configure simple automated controllers pre-configured with the
response status code and/or a view to render the response body. This
is useful in cases where there is no need for custom controller logic
-- e.g. render a home page, perform simple site URL redirects, return a 404 status with HTML content, a 204 with no content, and more.
2nd way - For static HTML file home page we can use the code below in our configuration class. It will return index.html as a home page -
#Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/").setViewName("forward:/index.html");
}
3rd way - The request mapping "/" below will also return home view which can be served as a home page for an app. But the above ways are recommended.
#Controller
public class UserController {
#RequestMapping(value = { "/" })
public String homePage() {
return "home";
}
}
You can't
As specified in Java Doc
public interface WebApplicationInitializer
Interface to be implemented
in Servlet 3.0+ environments in order to configure the ServletContext
programmatically -- as opposed to (or possibly in conjunction with)
the traditional web.xml-based approach.
but you still need minimal configuration in web.xml , such as for
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
#EnableWebMvc
#Configuration
#ComponentScan("com.springapp.mvc")
public class MvcConfig extends WebMvcConfigurerAdapter {
...
#Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
registry.addResourceHandler("/*.html").addResourceLocations("/WEB-INF/pages/");
}
#Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/").setViewName("forward:/index.html");
}
...
}
This might help.
this works for me...
#Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/").setViewName("forward:/index.html");
}
We have an existing spring web app deployed as a WAR file into Amazon Elastic Beanstalk. Currently we load properties files as http resources to give us a single source of property placeholder config resolution. Im investigating replacing this with the new spring cloud configuration server to give us the benefits of git versioning etc.
However the documentation (http://cloud.spring.io/spring-cloud-config/spring-cloud-config.html) only seems to describe a Spring Boot client application. Is it possible to set up the Spring Cloud Config Client in an existing web app? Do I need to manually set up the Bootstrap parent application context etc - are there any examples of this? Our current spring configuration is XML based.
Refrenced: https://wenku.baidu.com/view/493cf9eba300a6c30d229f49.html
Root WebApplicationContext and the Servlet WebApplicationContext uses Environment and initializes PropertySources based on the spring profile. For non-spring boot apps, we need to customize these to get the properties from Config Server and to refresh the beans whenever there is a property change. Below are the changes that needs to happen to get the config working in SpringMVC. You will also need a system property for spring.profile.active
Create a CustomBeanFactoryPostProcessor and set lazyInit on all bean definitions to true to initialize all bean lazily i.e. beans are initialized only upon a request.
#Component
public class AddRefreshScopeProcessor implements BeanFactoryPostProcessor, ApplicationContextAware {
private static ApplicationContext applicationContext;
#SuppressWarnings("unchecked")
#Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
String[] beanNames = applicationContext.getBeanDefinitionNames();
for(int i=0; i<beanNames.length; i++){
BeanDefinition beanDef = beanFactory.getBeanDefinition(beanNames[i]);
beanDef.setLazyInit(true);
beanDef.setScope("refresh");
}
}
#Override
public void setApplicationContext(ApplicationContext context)
throws BeansException {
applicationContext = context;
}
/**
* Get a Spring bean by type.
*
* #param beanClass
* #return
*/
public static <T> T getBean(Class<T> beanClass) {
return applicationContext.getBean(beanClass);
}
/**
* Get a Spring bean by name.
*
* #param beanName
* #return
*/
public static Object getBean(String beanName) {
return applicationContext.getBean(beanName);
}
}
Create a custom class extending StandardServletEnvironment and overriding the initPropertySources method to load additional PropertySources (from config server).
public class CloudEnvironment extends StandardServletEnvironment {
#Override
public void initPropertySources(ServletContext servletContext, ServletConfig servletConfig) {
super.initPropertySources(servletContext,servletConfig);
customizePropertySources(this.getPropertySources());
}
#Override
protected void customizePropertySources(MutablePropertySources propertySources) {
super.customizePropertySources(propertySources);
try {
PropertySource<?> source = initConfigServicePropertySourceLocator(this);
propertySources.addLast(source);
} catch (
Exception ex) {
ex.printStackTrace();
}
}
private PropertySource<?> initConfigServicePropertySourceLocator(Environment environment) {
ConfigClientProperties configClientProperties = new ConfigClientProperties(environment);
configClientProperties.setUri("http://localhost:8888");
configClientProperties.setProfile("dev");
configClientProperties.setLabel("master");
configClientProperties.setName("YourApplicationName");
System.out.println("##################### will load the client configuration");
System.out.println(configClientProperties);
ConfigServicePropertySourceLocator configServicePropertySourceLocator =
new ConfigServicePropertySourceLocator(configClientProperties);
return configServicePropertySourceLocator.locate(environment);
}
}
Create a custom ApplicatonContextInitializer and override the initialize method to set the custom Enviroment instead of the StandardServletEnvironment.
public class ConfigAppContextInitializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {
#Override
public void initialize(ConfigurableApplicationContext applicationContext) {
applicationContext.setEnvironment(new CloudEnvironment());
}
}
Modify web.xml to use this custom context initializer for both application context and servlet context.
<servlet>
<servlet-name>dispatcher</servlet-name>
<servlet-class>
org.springframework.web.servlet.DispatcherServlet
</servlet-class>
<init-param>
<param-name>contextInitializerClasses</param-name>
<param-value>com.my.context.ConfigAppContextInitializer</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dispatcher</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<context-param>
<param-name>contextInitializerClasses</param-name>
<param-value>com.my.context.ConfigAppContextInitializer</param-value>
</context-param>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/dispatcher-servlet.xml</param-value>
</context-param>
To refresh the beans created a refresh endpoint you will also need to refresh the application Context.
#Controller
public class RefreshController {
#Autowired
private RefreshAppplicationContext refreshAppplicationContext;
#Autowired
private RefreshScope refreshScope;
#RequestMapping(path = "/refreshall", method = RequestMethod.GET)
public String refresh() {
refreshScope.refreshAll();
refreshAppplicationContext.refreshctx();
return "Refreshed";
}
}
RefreshAppplicationContext.java
#Component
public class RefreshAppplicationContext implements ApplicationContextAware {
private ApplicationContext applicationContext;
public void setApplicationContext(ApplicationContext applicationContext) {
this.applicationContext = applicationContext;
}
public void refreshctx(){
((XmlWebApplicationContext)(applicationContext)).refresh();
}
}
I have similar requirement; I have a Web Application that uses Spring XML configuration to define some beans, the value of the properties are stored in .property files. The requirement is that the configuration should be loaded from the hard disk during the development, and from a Spring Cloud Config server in the production environment.
My idea is to have two definition for the PropertyPlaceholderConfigurer; the first one will be used to load the configuration from the hard disk :
<bean id="resources" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer" doc:name="Bean">
<property name="locations">
<list>
<value>dcm.properties</value>
<value>post_process.properties</value>
</list>
</property>
</bean>
The second one will load the .properties from the Spring Config Server :
<bean id="resources" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer" doc:name="Bean">
<property name="locations">
<list>
<value>http://localhost:8888/trunk/dcm-qa.properties</value>
</list>
</property>
</bean>
Everything that "just works" with Spring Boot is actually no more than some configuration. It's all just a Spring application at the end of the day. So I believe you can probably set everything up manually that Boot does for you automatically, but I'm not aware of anyone actually trying this particular angle. Creating a bootstrap application context is certainly the preferred approach, but depending on your use case you might get it to work with a single context if you make sure the property source locators are executed early enough.
Non Spring (or non Spring Boot) apps can access plain text or binary files in the config server. E.g. in Spring you could use a #PropertySource with a resource location that was a URL, like http://configserver/{app}/{profile}/{label}/application.properties or http://configserver/{app}-{profile}.properties. It's all covered in the user guide.
I found a solution for using spring-cloud-zookeeper without Spring Boot, based on the idea provided here https://wenku.baidu.com/view/493cf9eba300a6c30d229f49.html
It should be easily updated to match your needs and using a Spring Cloud Config Server (the CloudEnvironement class needs to be updated to load the file from the server instead of Zookeeper)
First, create a CloudEnvironement class that will create a PropertySource (ex from Zookeeper) :
CloudEnvironement.java
public class CloudEnvironment extends StandardServletEnvironment {
#Override
protected void customizePropertySources(MutablePropertySources propertySources) {
super.customizePropertySources(propertySources);
try {
propertySources.addLast(initConfigServicePropertySourceLocator(this));
}
catch (Exception ex) {
logger.warn("failed to initialize cloud config environment", ex);
}
}
private PropertySource<?> initConfigServicePropertySourceLocator(Environment environment) {
ZookeeperConfigProperties configProp = new ZookeeperConfigProperties();
ZookeeperProperties props = new ZookeeperProperties();
props.setConnectString("myzookeeper:2181");
CuratorFramework fwk = curatorFramework(exponentialBackoffRetry(props), props);
ZookeeperPropertySourceLocator propertySourceLocator = new ZookeeperPropertySourceLocator(fwk, configProp);
PropertySource<?> source= propertySourceLocator.locate(environment);
return source ;
}
private CuratorFramework curatorFramework(RetryPolicy retryPolicy, ZookeeperProperties properties) {
CuratorFrameworkFactory.Builder builder = CuratorFrameworkFactory.builder();
builder.connectString(properties.getConnectString());
CuratorFramework curator = builder.retryPolicy(retryPolicy).build();
curator.start();
try {
curator.blockUntilConnected(properties.getBlockUntilConnectedWait(), properties.getBlockUntilConnectedUnit());
}
catch (InterruptedException e) {
throw new RuntimeException(e);
}
return curator;
}
private RetryPolicy exponentialBackoffRetry(ZookeeperProperties properties) {
return new ExponentialBackoffRetry(properties.getBaseSleepTimeMs(),
properties.getMaxRetries(),
properties.getMaxSleepMs());
}
}
Then create a custom XmlWebApplicationContext class : it will enable to load the PropertySource from Zookeeper when your webapplication start and replace the bootstrap magic of Spring Boot:
MyConfigurableWebApplicationContext.java
public class MyConfigurableWebApplicationContext extends XmlWebApplicationContext {
#Override
protected ConfigurableEnvironment createEnvironment() {
return new CloudEnvironment();
}
}
Last, in your web.xml file add the following context-param for using your MyConfigurableWebApplicationContext class and bootstraping your CloudEnvironement.
<context-param>
<param-name>contextClass</param-name>
<param-value>com.kiabi.config.MyConfigurableWebApplicationContext</param-value>
</context-param>
If you use a standard property file configurer, it should still be loaded so you can have properties in both a local file and Zookeeper.
For all this to work you need to have spring-cloud-starter-zookeeper-config and curator-framework jar in your classpath with their dependancy, if you use maven you can add the following to your pom.xml
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-zookeeper-dependencies</artifactId>
<version>1.1.1.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-zookeeper-config</artifactId>
</dependency>
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-framework</artifactId>
</dependency>
</dependencies>
Posting as an answer because I don't have enough points to comment on Dave Syer's excellent answer. We have implemented his proposed solution in production and it is working as expected. Our newer apps are being written using Boot, while our legacy apps use Spring, but not boot. We were able to use Spring Cloud Config to create a property service that serves properties for both. The changes were minimal. I moved the legacy property files out of the war file to the property service git repository, and changed the property definition from a classpath reference to a URL as Dave describes and inserted our system environment variable just as we did for classpath. It was easy and effective.
<util:properties id="envProperties" location="https://properties.me.com/property-service/services-#{envName}.properties" />
<context:property-placeholder properties-ref="envProperties" ignore-resource-not-found="true" ignore-unresolvable="true" order="0" />
<util:properties id="defaultProperties" location="https://properties.me.com/property-service/services-default.properties" />
<context:property-placeholder properties-ref="defaultProperties" ignore-resource-not-found="true" ignore-unresolvable="true" order="10" />
I am updating an existing Java EE web application that uses Spring.
In my web.xml, there is a servlet defined as follows:
<servlet>
<display-name>My Example Servlet</display-name>
<servlet-name>MyExampleServlet</servlet-name>
<servlet-class>com.example.MyExampleServlet</servlet-class>
</servlet>
now, in this class I need to add an #Autowite annotation:
class MyExampleServlet extends HttpServlet {
#Autowired (required = true)
MyExampleBean myExampleBean;
[...]
}
the problem is that MyExampleBean is initialized by the Application Server
(in my case, weblogic.servlet.internal.WebComponentContributor.getNewInstance...)
so, Spring is not aware of that, and Spring does not have a chance to wire "myExampleBean".
How to solve that?
that is, how I need to modify web.xml or MyExampleServlet so that MyExampleServlet gets the reference to myExampleBean?
A possibility would be to add this init code inside MyExampleServlet,
but it requires a reference to servletContext. How to get a reference to servletContext?
ApplicationContext context = WebApplicationContextUtils.getWebApplicationContext(servletContext);
myExampleBean = (MyExampleBean) context.getBean("myExampleBean");
I see, HttpServlet/GenericServlet has a getServletContext() method,
(and the application server calls first the servlet's init(ServletConfig config), and config contains a reference to servletContext).
See http://tomcat.apache.org/tomcat-5.5-doc/servletapi/javax/servlet/GenericServlet.html
The code modified:
class MyExampleServlet extends HttpServlet {
MyExampleBean myExampleBean;
#Override
public void init() throws ServletException {
ApplicationContext context = WebApplicationContextUtils.getWebApplicationContext(getServletContext());
myExampleBean = (MyExampleBean) context.getBean("myExampleBean");
}
[...]
}
in your application context xml, you need something like
<bean id="myExampleBean" class="path/to/myExampleBean">