I have this url
private static final String PRODUCTS_URL = "http://localhost:3007/catalog/products/";
And this methods:
public JSONObject getProductByIdFromMicroservice(String id) throws IOException, JSONException {
return getProductsFromProductMicroservice(PRODUCTS_URL + id);
}
public JSONObject getProductsFromProductMicroservice(String url) throws IOException, JSONException {
CloseableHttpClient productClient = HttpClients.createDefault();
HttpGet getProducts = new HttpGet(url);
CloseableHttpResponse microserviceResponse = productClient.execute(getProducts);
HttpEntity entity = microserviceResponse.getEntity();
BufferedReader br = new BufferedReader(new InputStreamReader((entity.getContent())));
StringBuilder sb = new StringBuilder();
String line;
while ((line = br.readLine()) != null) {
sb.append(line);
}
br.close();
System.out.println(sb.toString());
JSONObject obj = new JSONObject(sb.toString());
System.out.println(obj);
return obj;
}
I want to put the port and host in a separate property file. I have already seen examples using properties and the yml file. But I do not understand how then my methods will work using this port when creating an instance of the class, which I will indicate in the properties file. Can you tell?
You can put your properties in a properties file in the resource directory for example
PRODUCTS_URL="http://localhost:3007/catalog/products/"
and add #PropertySource("YOUR_RESOURCE_FILE_HERE.properties") in your main class (Application.java)
#SpringBootApplication
#PropertySource("products.properties")
public class Application {...}
and then use #Value("${YOUR_PROPERTY_NAME}") to load it:
#Value("${PRODUCTS_URL}")
private String PRODUCTS_URL;
Check this tutorial
This is how i do it :
CONFIG FILE
#Database Server Properties
dbUrl=jdbc:sqlserver://localhost:1433;database=Something;
dbUser=sa
dbPassword=SomePassword
Then i annotate a config class with this :
#PropertySource("file:${ENV_VARIABLE_TO_PATH}/config.properties")
Then autowire this field :
#Autowired
private Environment environment;
Then create the data source :
#Bean
public DataSource dataSource()
{
HikariDataSource dataSource = new HikariDataSource();
try
{
dataSource.setDriverClassName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
dataSource.setConnectionTestQuery("SELECT 1");
dataSource.setMaximumPoolSize(100);
String dbUrl = environment.getProperty("dbUrl");
if (dbUrl != null)
{
dataSource.setJdbcUrl(dbUrl);
}
else
{
throw new PropertyNotFoundException("The dbUrl property is missing from the config file!");
}
String dbUser = environment.getProperty("dbUser");
if (dbUser != null)
{
dataSource.setUsername(dbUser);
}
else
{
throw new PropertyNotFoundException("The dbUser property is missing from the config file!");
}
String dbPassword = environment.getProperty("dbPassword");
if (dbPassword != null)
{
dataSource.setPassword(dbPassword);
}
else
{
throw new PropertyNotFoundException("The dbPassword property is missing from the config file!");
}
logger.debug("Successfully initialized datasource");
}
catch (PropertyNotFoundException ex)
{
logger.fatal("Error initializing datasource : " + ex.getMessage());
}
return dataSource;
}
I know this is not exactly your scenario but perhaps you can find inspiration from this code to suit your specific needs?
Other answers here mention using #PropertySource annotation to specify path of config files. Also if this is a test code (unit/integration) you can also make use of another annotation #TestPropertySource.
With this, we can define configuration sources that have higher precedence than any other source used in the project.
See here: https://www.baeldung.com/spring-test-property-source
Sample spring configuration is as below.
<int-mail:imap-idle-channel-adapter id="mailAdapter"
store-uri="imaps://${"username"}:${"password"}#imap-server:993/INBOX"
java-mail-properties="javaMailProperties"
channel="emails"
should-delete-messages="false"
should-mark-messages-as-read="true">
</int-mail:imap-idle-channel-adapter>
I wish to keep the password field encrypted in properties file and decrypt it in the code. I am not sure on how to set mailReceiver property of ImapIdleChannelAdapter to my custom version of ImapMailReceiver.
Please let me know if there is any way to do this.
All of my configurations are in XML as described above.
Above solution of adding the defifnation did not work may be I am doing something wrong. Then I tried using XML + Java configuration, as below.
#Configuration
public class EmailConfiguration {
#Bean
public ImapIdleChannelAdapter customAdapter() {
ImapIdleChannelAdapter adapter = new ImapIdleChannelAdapter(mailReceiver());
adapter.setOutputChannel(outputChannel());
adapter.setErrorChannel(errorChannel());
adapter.setAutoStartup(true);
adapter.setShouldReconnectAutomatically(true);
adapter.setTaskScheduler(taskScheduler());
return adapter;
}
#Bean
public TaskImapMailReceiver mailReceiver() {
TaskImapMailReceiver mailReceiver = new TaskImapMailReceiver("imaps://[username]:[password]#imap.googlemail.com:993/inbox");
mailReceiver.setShouldDeleteMessages(false);
mailReceiver.setShouldMarkMessagesAsRead(true);
//mailReceiver.setJavaMailProperties(javaMailProperties());
mailReceiver.setMaxFetchSize(Integer.MAX_VALUE);
return mailReceiver;
}
}
Also created empty errorChannel,outputChannel etc. I observed that Spring creates two instances one with xml config and other with java #Configuration. Where it was expected to use only java configuration. If I remove the xml config tag
then it provides sigle imap instance with my mailReceiver but runs only once does not go periodic. also does not show IMAPS logs.
Just wondering if I need to do so much to encrypt the password. Is somthing wrong with my approach.
Use Java configuration instead of XML...
#Configuration
public class MyConfigClass {
#Bean
public MyMailReceiver receiver() {
...
}
#Bean
public ImapIdleChannelAdapter adapter() {
ImapIdleChannelAdapter adapter = new ImapIdleChannelAdapter(receiver());
...
return adapter;
}
}
If you are using XML for everything else, simply add this class as a <bean/> to your XML.
EDIT
Here's an example that works fine for me...
#SpringBootApplication
public class So42298254Application {
public static void main(String[] args) {
SpringApplication.run(So42298254Application.class, args);
}
#Bean
public TestMailServer.ImapServer imapServer() {
return TestMailServer.imap(0);
}
#Bean
public ImapMailReceiver receiver() {
ImapMailReceiver imapMailReceiver = new ImapMailReceiver(imapUrl("user", "pw"));
imapMailReceiver.setHeaderMapper(new DefaultMailHeaderMapper()); // converts the MimeMessage to a String
imapMailReceiver.setUserFlag("testSIUserFlag"); // needed by the SI test server
Properties javaMailProperties = new Properties();
javaMailProperties.put("mail.debug", "true");
imapMailReceiver.setJavaMailProperties(javaMailProperties);
return imapMailReceiver;
}
private String imapUrl(String user, String pw) {
return "imap://"
+ user + ":" + pw
+ "#localhost:" + imapServer().getPort() + "/INBOX";
}
#Bean
public ImapIdleChannelAdapter adapter() {
ImapIdleChannelAdapter adapter = new ImapIdleChannelAdapter(receiver());
adapter.setOutputChannelName("handleMail");
return adapter;
}
#ServiceActivator(inputChannel = "handleMail")
public void handle(String mail, #Header(MailHeaders.FROM) Object from) {
System.out.println(mail + " from:" + from);
imapServer().resetServer(); // so we'll get the email again
}
}
My intention was to use encrypted passwords in properties files.
So I changed my approach of getting into email receiving classes. I added inherited PropertyPlaceholderConfigurer and implemented method convertPropertyValue() as below.
public class EncryptationAwarePropertyPlaceholderConfigurer extends PropertyPlaceholderConfigurer {
private static final Logger logger = LoggerFactory.getLogger(EncryptationAwarePropertyPlaceholderConfigurer.class);
#Override
protected String convertPropertyValue(String originalValue) {
if (originalValue.contains("{<ENC>}") && originalValue.contains("{</ENC>}")) {
String encryptedTaggedValue = originalValue.substring(originalValue.indexOf("{<ENC>}"), originalValue.indexOf("{</ENC>}") + 8);
String encryptedValue = originalValue.substring(originalValue.indexOf("{<ENC>}") + 7, originalValue.indexOf("{</ENC>}"));
try {
String decryptedValue = EncrypDecriptUtil.decrypt(encryptedValue);//EncrypDecriptUtil is my class for encription and decryption
originalValue = originalValue.replace(encryptedTaggedValue, decryptedValue);
} catch (GeneralSecurityException e) {
logger.error("failed to decrypt property returning original value as in properties file.", e);
}
}
return originalValue;
}
}
And changed properties file to enclose encrypted value in custuom ENC tag
as
mail.imap.task.url=imap://username:{<ENC>}encryptedPassword{</ENC>}#imap.googlemail.com:993/inbox
I am working with Spring-websocket and I have the following problem:
I am trying to put a placeholder inside a #MessageMapping annotation in order to get the url from properties. It works with #RequestMapping but not with #MessageMapping.
If I use this placeholder, the URL is null. Any idea or suggestion?
Example:
#RequestMapping(value= "${myProperty}")
#MessageMapping("${myProperty}")
Rossen Stoyanchev added placeholder support for #MessageMapping and #SubscribeMapping methods.
See Jira issue: https://jira.spring.io/browse/SPR-13271
Spring allows you to use property placeholders in #RequestMapping, but not in #MessageMapping. This is 'cause the MessageHandler. So, we need to override the default MessageHandler to do this.
WebSocketAnnotationMethodMessageHandler does not support placeholders and you need add this support yourself.
For simplicity I just created another WebSocketAnnotationMethodMessageHandler class in my project at the same package of the original, org.springframework.web.socket.messaging, and override getMappingForMethod method from SimpAnnotationMethodMessageHandler with same content, changing only how SimpMessageMappingInfo is contructed using this with this methods (private in WebSocketAnnotationMethodMessageHandler):
private SimpMessageMappingInfo createMessageMappingCondition(final MessageMapping annotation) {
return new SimpMessageMappingInfo(SimpMessageTypeMessageCondition.MESSAGE, new DestinationPatternsMessageCondition(
this.resolveAnnotationValues(annotation.value()), this.getPathMatcher()));
}
private SimpMessageMappingInfo createSubscribeCondition(final SubscribeMapping annotation) {
final SimpMessageTypeMessageCondition messageTypeMessageCondition = SimpMessageTypeMessageCondition.SUBSCRIBE;
return new SimpMessageMappingInfo(messageTypeMessageCondition, new DestinationPatternsMessageCondition(
this.resolveAnnotationValues(annotation.value()), this.getPathMatcher()));
}
These methods now will resolve value considering properties (calling resolveAnnotationValues method), so we need use something like this:
private String[] resolveAnnotationValues(final String[] destinationNames) {
final int length = destinationNames.length;
final String[] result = new String[length];
for (int i = 0; i < length; i++) {
result[i] = this.resolveAnnotationValue(destinationNames[i]);
}
return result;
}
private String resolveAnnotationValue(final String name) {
if (!(this.getApplicationContext() instanceof ConfigurableApplicationContext)) {
return name;
}
final ConfigurableApplicationContext applicationContext = (ConfigurableApplicationContext) this.getApplicationContext();
final ConfigurableBeanFactory configurableBeanFactory = applicationContext.getBeanFactory();
final String placeholdersResolved = configurableBeanFactory.resolveEmbeddedValue(name);
final BeanExpressionResolver exprResolver = configurableBeanFactory.getBeanExpressionResolver();
if (exprResolver == null) {
return name;
}
final Object result = exprResolver.evaluate(placeholdersResolved, new BeanExpressionContext(configurableBeanFactory, null));
return result != null ? result.toString() : name;
}
You still need to define a PropertySourcesPlaceholderConfigurer bean in your configuration.
If you are using XML based configuration, include something like this:
<context:property-placeholder location="classpath:/META-INF/spring/url-mapping-config.properties" />
If you are using Java based configuration, you can try in this way:
#Configuration
#PropertySources(value = #PropertySource("classpath:/META-INF/spring/url-mapping-config.properties"))
public class URLMappingConfig {
#Bean
public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
return new PropertySourcesPlaceholderConfigurer();
}
}
Obs.: in this case, url-mapping-config.properties file are in a gradle/maven project in src\main\resources\META-INF\spring folder and content look like this:
myPropertyWS=urlvaluews
This is my sample controller:
#Controller
public class WebSocketController {
#SendTo("/topic/test")
#MessageMapping("${myPropertyWS}")
public String test() throws Exception {
Thread.sleep(4000); // simulated delay
return "OK";
}
}
With default MessageHandler startup log will print something like this:
INFO: Mapped "{[/${myPropertyWS}],messageType=[MESSAGE]}" onto public java.lang.String com.brunocesar.controller.WebSocketController.test() throws java.lang.Exception
And with our MessageHandler now print this:
INFO: Mapped "{[/urlvaluews],messageType=[MESSAGE]}" onto public java.lang.String com.brunocesar.controller.WebSocketController.test() throws java.lang.Exception
See in this gist the full WebSocketAnnotationMethodMessageHandler implementation.
EDIT: this solution resolves the problem for versions before 4.2 GA. For more information, see this jira.
Update :
Now I understood what you mean, but I think that is not possible(yet).
Documentation does not mention anything related to Path mapping URIs.
Old answer
Use
#MessageMapping("/handler/{myProperty}")
instead of
#MessageMapping("/handler/${myProperty}")
And use it like this:
#MessageMapping("/myHandler/{username}")
public void handleTextMessage(#DestinationVariable String username,Message message) {
//do something
}
#MessageMapping("/chat/{roomId}")
public Message handleMessages(#DestinationVariable("roomId") String roomId, #Payload Message message, Traveler traveler) throws Exception {
System.out.println("Message received for room: " + roomId);
System.out.println("User: " + traveler.toString());
// store message in database
message.setAuthor(traveler);
message.setChatRoomId(Integer.parseInt(roomId));
int id = MessageRepository.getInstance().save(message);
message.setId(id);
return message;
}
I am using annotations to configure my spring environment like this:
#Configuration
...
#PropertySource("classpath:/config/default.properties")
...
public class GeneralApplicationConfiguration implements WebApplicationInitializer
{
#Autowired
Environment env;
}
This leads to my properties from default.properties being part of the Environment. I want to use the #PropertySource mechanism here, because it already provides the possibility to overload properties through several fallback layers and different dynamic locations, based on the environment settings (e.g. config_dir location). I just stripped the fallback to make the example easier.
However, my problem now is that I want to configure for example my datasource properties in default.properties. You can pass the settings to the datasource without knowing in detail what settings the datasource expects using
Properties p = ...
datasource.setProperties(p);
However, the problem is, the Environment object is neither a Properties object nor a Map nor anything comparable. From my point of view it is simply not possible to access all values of the environment, because there is no keySet or iterator method or anything comparable.
Properties p <=== Environment env?
Am I missing something? Is it possible to access all entries of the Environment object somehow? If yes, I could map the entries to a Map or Properties object, I could even filter or map them by prefix - create subsets as a standard java Map ... This is what I would like to do. Any suggestions?
You need something like this, maybe it can be improved. This is a first attempt:
...
import org.springframework.core.env.PropertySource;
import org.springframework.core.env.AbstractEnvironment;
import org.springframework.core.env.Environment;
import org.springframework.core.env.MapPropertySource;
...
#Configuration
...
#org.springframework.context.annotation.PropertySource("classpath:/config/default.properties")
...
public class GeneralApplicationConfiguration implements WebApplicationInitializer
{
#Autowired
Environment env;
public void someMethod() {
...
Map<String, Object> map = new HashMap();
for(Iterator it = ((AbstractEnvironment) env).getPropertySources().iterator(); it.hasNext(); ) {
PropertySource propertySource = (PropertySource) it.next();
if (propertySource instanceof MapPropertySource) {
map.putAll(((MapPropertySource) propertySource).getSource());
}
}
...
}
...
Basically, everything from the Environment that's a MapPropertySource (and there are quite a lot of implementations) can be accessed as a Map of properties.
This is an old question, but the accepted answer has a serious flaw. If the Spring Environment object contains any overriding values (as described in Externalized Configuration), there is no guarantee that the map of property values it produces will match those returned from the Environment object. I found that simply iterating through the PropertySources of the Environment did not, in fact, give any overriding values. Instead it produced the original value, the one that should have been overridden.
Here is a better solution. This uses the EnumerablePropertySources of the Environment to iterate through the known property names, but then reads the actual value out of the real Spring environment. This guarantees that the value is the one actually resolved by Spring, including any overriding values.
Properties props = new Properties();
MutablePropertySources propSrcs = ((AbstractEnvironment) springEnv).getPropertySources();
StreamSupport.stream(propSrcs.spliterator(), false)
.filter(ps -> ps instanceof EnumerablePropertySource)
.map(ps -> ((EnumerablePropertySource) ps).getPropertyNames())
.flatMap(Arrays::<String>stream)
.forEach(propName -> props.setProperty(propName, springEnv.getProperty(propName)));
I had the requirement to retrieve all properties whose key starts with a distinct prefix (e.g. all properties starting with "log4j.appender.") and wrote following Code (using streams and lamdas of Java 8).
public static Map<String,Object> getPropertiesStartingWith( ConfigurableEnvironment aEnv,
String aKeyPrefix )
{
Map<String,Object> result = new HashMap<>();
Map<String,Object> map = getAllProperties( aEnv );
for (Entry<String, Object> entry : map.entrySet())
{
String key = entry.getKey();
if ( key.startsWith( aKeyPrefix ) )
{
result.put( key, entry.getValue() );
}
}
return result;
}
public static Map<String,Object> getAllProperties( ConfigurableEnvironment aEnv )
{
Map<String,Object> result = new HashMap<>();
aEnv.getPropertySources().forEach( ps -> addAll( result, getAllProperties( ps ) ) );
return result;
}
public static Map<String,Object> getAllProperties( PropertySource<?> aPropSource )
{
Map<String,Object> result = new HashMap<>();
if ( aPropSource instanceof CompositePropertySource)
{
CompositePropertySource cps = (CompositePropertySource) aPropSource;
cps.getPropertySources().forEach( ps -> addAll( result, getAllProperties( ps ) ) );
return result;
}
if ( aPropSource instanceof EnumerablePropertySource<?> )
{
EnumerablePropertySource<?> ps = (EnumerablePropertySource<?>) aPropSource;
Arrays.asList( ps.getPropertyNames() ).forEach( key -> result.put( key, ps.getProperty( key ) ) );
return result;
}
// note: Most descendants of PropertySource are EnumerablePropertySource. There are some
// few others like JndiPropertySource or StubPropertySource
myLog.debug( "Given PropertySource is instanceof " + aPropSource.getClass().getName()
+ " and cannot be iterated" );
return result;
}
private static void addAll( Map<String, Object> aBase, Map<String, Object> aToBeAdded )
{
for (Entry<String, Object> entry : aToBeAdded.entrySet())
{
if ( aBase.containsKey( entry.getKey() ) )
{
continue;
}
aBase.put( entry.getKey(), entry.getValue() );
}
}
Note that the starting point is the ConfigurableEnvironment which is able to return the embedded PropertySources (the ConfigurableEnvironment is a direct descendant of Environment). You can autowire it by:
#Autowired
private ConfigurableEnvironment myEnv;
If you not using very special kinds of property sources (like JndiPropertySource, which is usually not used in spring autoconfiguration) you can retrieve all properties held in the environment.
The implementation relies on the iteration order which spring itself provides and takes the first found property, all later found properties with the same name are discarded. This should ensure the same behaviour as if the environment were asked directly for a property (returning the first found one).
Note also that the returned properties are not yet resolved if they contain aliases with the ${...} operator. If you want to have a particular key resolved you have to ask the Environment directly again:
myEnv.getProperty( key );
The original question hinted that it would be nice to be able to filter all the properties based on a prefix. I have just confirmed that this works as of Spring Boot 2.1.1.RELEASE, for Properties or Map<String,String>. I'm sure it's worked for while now. Interestingly, it does not work without the prefix = qualification, i.e. I do not know how to get the entire environment loaded into a map. As I said, this might actually be what OP wanted to begin with. The prefix and the following '.' will be stripped off, which might or might not be what one wants:
#ConfigurationProperties(prefix = "abc")
#Bean
public Properties getAsProperties() {
return new Properties();
}
#Bean
public MyService createService() {
Properties properties = getAsProperties();
return new MyService(properties);
}
Postscript: It is indeed possible, and shamefully easy, to get the entire environment. I don't know how this escaped me:
#ConfigurationProperties
#Bean
public Properties getProperties() {
return new Properties();
}
As this Spring's Jira ticket, it is an intentional design. But the following code works for me.
public static Map<String, Object> getAllKnownProperties(Environment env) {
Map<String, Object> rtn = new HashMap<>();
if (env instanceof ConfigurableEnvironment) {
for (PropertySource<?> propertySource : ((ConfigurableEnvironment) env).getPropertySources()) {
if (propertySource instanceof EnumerablePropertySource) {
for (String key : ((EnumerablePropertySource) propertySource).getPropertyNames()) {
rtn.put(key, propertySource.getProperty(key));
}
}
}
}
return rtn;
}
Spring won't allow to decouple via java.util.Properties from Spring Environment.
But Properties.load() still works in a Spring boot application:
Properties p = new Properties();
try (InputStream is = getClass().getResourceAsStream("/my.properties")) {
p.load(is);
}
The other answers have pointed out the solution for the majority of cases involving PropertySources, but none have mentioned that certain property sources are unable to be casted into useful types.
One such example is the property source for command line arguments. The class that is used is SimpleCommandLinePropertySource. This private class is returned by a public method, thus making it extremely tricky to access the data inside the object. I had to use reflection in order to read the data and eventually replace the property source.
If anyone out there has a better solution, I would really like to see it; however, this is the only hack I have gotten to work.
Working with Spring Boot 2, I needed to do something similar. Most of the answers above work fine, just beware that at various phases in the app lifecycles the results will be different.
For example, after a ApplicationEnvironmentPreparedEvent any properties inside application.properties are not present. However, after a ApplicationPreparedEvent event they are.
For Spring Boot, the accepted answer will overwrite duplicate properties with lower priority ones. This solution will collect the properties into a SortedMap and take only the highest priority duplicate properties.
final SortedMap<String, String> sortedMap = new TreeMap<>();
for (final PropertySource<?> propertySource : env.getPropertySources()) {
if (!(propertySource instanceof EnumerablePropertySource))
continue;
for (final String name : ((EnumerablePropertySource<?>) propertySource).getPropertyNames())
sortedMap.computeIfAbsent(name, propertySource::getProperty);
}
I though I'd add one more way. In my case I supply this to com.hazelcast.config.XmlConfigBuilder which only needs java.util.Properties to resolve some properties inside the Hazelcast XML configuration file, i.e. it only calls getProperty(String) method. So, this allowed me to do what I needed:
#RequiredArgsConstructor
public class SpringReadOnlyProperties extends Properties {
private final org.springframework.core.env.Environment delegate;
#Override
public String getProperty(String key) {
return delegate.getProperty(key);
}
#Override
public String getProperty(String key, String defaultValue) {
return delegate.getProperty(key, defaultValue);
}
#Override
public synchronized String toString() {
return getClass().getName() + "{" + delegate + "}";
}
#Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
if (!super.equals(o)) return false;
SpringReadOnlyProperties that = (SpringReadOnlyProperties) o;
return delegate.equals(that.delegate);
}
#Override
public int hashCode() {
return Objects.hash(super.hashCode(), delegate);
}
private void throwException() {
throw new RuntimeException("This method is not supported");
}
//all methods below throw the exception
* override all methods *
}
P.S. I ended up not using this specifically for Hazelcast because it only resolves properties for XML file but not at runtime. Since I also use Spring, I decided to go with a custom org.springframework.cache.interceptor.AbstractCacheResolver#getCacheNames. This resolves properties for both situations, at least if you use properties in cache names.
To get ONLY properties, defined in my hibernate.properteies file:
#PropertySource(SomeClass.HIBERNATE_PROPERTIES)
public class SomeClass {
public static final String HIBERNATE_PROPERTIES = "hibernate.properties";
#Autowired
private Environment env;
public void someMethod() {
final Properties hibProps = asProperties(HIBERNATE_PROPERTIES);
}
private Properties asProperties(String fileName) {
return StreamSupport.stream(
((AbstractEnvironment) env).getPropertySources().spliterator(), false)
.filter(ps -> ps instanceof ResourcePropertySource)
.map(ps -> (ResourcePropertySource) ps)
.filter(rps -> rps.getName().contains(fileName))
.collect(
Properties::new,
(props, rps) -> props.putAll(rps.getSource()),
Properties::putAll);
}
}
A little helper to analyze the sources of a property, which sometimes drive me crazy . I used this discussion to write SpringConfigurableEnvironment.java on github.
It could be used in a test:
#SpringBootTest
public class SpringConfigurableEnvironmentTest {
#Autowired
private ConfigurableEnvironment springEnv;
#Test
public void testProperties() {
SpringConfigurableEnvironment properties = new SpringConfigurableEnvironment(springEnv);
SpringConfigurableEnvironment.PropertyInfo info = properties.get("profile.env");
assertEquals("default", properties.get(info.getValue());
assertEquals(
"Config resource 'class path resource [application.properties]' via location 'optional:classpath:/'",
info.getSourceList.get(0));
}
}
All answers above have pretty much covers everything, but be aware of overridden values from environment variables. They may have different key values.
For example, if a user override my.property[1].value using environment variable MY_PROPERTY[1]_VALUE, iterating through EnumerablePropertySources.getPropertyNames() would give you both my.property[1].value and MY_PROPERTY[1]_VALUE key values.
What even worse is that if my.property[1].value is not defined in applications.conf (or applications.yml), a MY_PROPERTY[1]_VALUE in environment variables would not give you my.property[1].value but only MY_PROPERTY[1]_VALUE key value from EnumerablePropertySources.getPropertyNames().
So it is developers' job to cover the those properties from environment variables. Unfortunately, there is no one-on-one mapping between environment variables schema vs the normal schema, see the source code of SystemEnvironmentPropertySource. For example, MY_PROPERTY[1]_VALUE could be either my.property[1].value or my-property[1].value
I am using a properties File to store some configuration properties, that are accessed this way:
#Value("#{configuration.path_file}")
private String pathFile;
Is it possible (with Spring 3) to use the same #Value annotation, but loading the properties from a database instead of a file ?
Assuming you have a table in your database stored key/value pairs:
Define a new bean "applicationProperties" - psuedo-code follows...
public class ApplicationProperties {
#AutoWired
private DataSource datasource;
public getPropertyValue(String key) {
// transact on your datasource here to fetch value for key
// SNIPPED
}
}
Inject this bean where required in your application. If you already have a dao/service layer then you would just make use of that.
Yes, you can keep your #Value annotation, and use the database source with the help of EnvironmentPostProcessor.
As of Spring Boot 1.3, we're able to use the EnvironmentPostProcessor to customize the application's Environment before application context is refreshed.
For example, create a class which implements EnvironmentPostProcessor:
public class ReadDbPropertiesPostProcessor implements EnvironmentPostProcessor {
private static final String PROPERTY_SOURCE_NAME = "databaseProperties";
private String[] CONFIGS = {
"app.version"
// list your properties here
};
#Override
public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
Map<String, Object> propertySource = new HashMap<>();
try {
// the following db connections properties must be defined in application.properties
DataSource ds = DataSourceBuilder
.create()
.username(environment.getProperty("spring.datasource.username"))
.password(environment.getProperty("spring.datasource.password"))
.url(environment.getProperty("spring.datasource.url"))
.driverClassName("com.mysql.jdbc.Driver")
.build();
try (Connection connection = ds.getConnection();
// suppose you have a config table storing the properties name/value pair
PreparedStatement preparedStatement = connection.prepareStatement("SELECT value FROM config WHERE name = ?")) {
for (int i = 0; i < CONFIGS.length; i++) {
String configName = CONFIGS[i];
preparedStatement.setString(1, configName);
ResultSet rs = preparedStatement.executeQuery();
while (rs.next()) {
propertySource.put(configName, rs.getString("value"));
}
// rs.close();
preparedStatement.clearParameters();
}
}
environment.getPropertySources().addFirst(new MapPropertySource(PROPERTY_SOURCE_NAME, propertySource));
} catch (Throwable e) {
throw new RuntimeException(e);
}
}
}
Finally, don't forget to put your spring.factories in META-INF. An example:
org.springframework.boot.autoconfigure.EnableAutoConfiguration=
com.baeldung.environmentpostprocessor.autoconfig.PriceCalculationAutoConfig
Although not having used spring 3, I'd assume you can, if you make a bean that reads the properties from the database and exposes them with getters.