private PropertySource createPropertySource(AnnotationAttributes attributes, ConfigurableEnvironment environment, ResourceLoader resourceLoader, EncryptablePropertyResolver resolver, EncryptablePropertyFilter propertyFilter, List<PropertySourceLoader> loaders) throws Exception {
    String name = generateName(attributes.getString("name"));
    String[] locations = attributes.getStringArray("value");
    boolean ignoreResourceNotFound = attributes.getBoolean("ignoreResourceNotFound");
    CompositePropertySource compositePropertySource = new CompositePropertySource(name);
    Assert.isTrue(locations.length > 0, "At least one @PropertySource(value) location is required");
    for (String location : locations) {
        String resolvedLocation = environment.resolveRequiredPlaceholders(location);
        Resource resource = resourceLoader.getResource(resolvedLocation);
        if (!resource.exists()) {
            if (!ignoreResourceNotFound) {
                throw new IllegalStateException(String.format("Encryptable Property Source '%s' from location: %s Not Found", name, resolvedLocation));
            } else {
                log.info("Ignoring NOT FOUND Encryptable Property Source '{}' from locations: {}", name, resolvedLocation);
            }
        } else {
            String actualName = name + "#" + resolvedLocation;
            loadPropertySource(loaders, resource, actualName)
                    .ifPresent(psources -> psources.forEach(compositePropertySource::addPropertySource));
        }
    }
    return new EncryptableEnumerablePropertySourceWrapper<>(compositePropertySource, resolver, propertyFilter);
}
 

private void conditionallyExcludeRabbitAutoConfiguration() {
	if (appIsBoundToRabbitMQ()) {
		return;
	}

	Map<String, Object> properties = new LinkedHashMap<>();
	String existingExcludes = environment.getProperty(SPRING_AUTOCONFIGURE_EXCLUDE);
	if (existingExcludes == null) {
		properties.put(SPRING_AUTOCONFIGURE_EXCLUDE, RABBIT_AUTOCONFIG_CLASS);
	} else if (!existingExcludes.contains(RABBIT_AUTOCONFIG_CLASS)) {
		properties.put(SPRING_AUTOCONFIGURE_EXCLUDE, RABBIT_AUTOCONFIG_CLASS + "," + existingExcludes);
	}

	PropertySource<?> propertySource = new MapPropertySource("springCloudServicesRabbitAutoconfigExcluder",
			properties);
	environment.getPropertySources().addFirst(propertySource);
}
 

@Test
public void fromEnvironmentIsSuccessful() {

	ConfigurableEnvironment mockEnvironment = mock(ConfigurableEnvironment.class);

	MutablePropertySources propertySources = spy(new MutablePropertySources());

	PropertySource mockVcapPropertySource = mock(EnumerablePropertySource.class);

	when(mockEnvironment.getPropertySources()).thenReturn(propertySources);
	doReturn(mockVcapPropertySource).when(propertySources).get(eq("vcap"));
	when(mockVcapPropertySource.containsProperty(anyString())).thenReturn(true);
	when(mockVcapPropertySource.getName()).thenReturn("vcap");

	VcapPropertySource propertySource = VcapPropertySource.from(mockEnvironment);

	assertThat(propertySource).isNotNull();
	assertThat(propertySource.getSource()).isEqualTo(mockVcapPropertySource);

	verify(mockEnvironment, times(1)).getPropertySources();
	verify(propertySources, times(1)).get(eq("vcap"));
	verify(mockVcapPropertySource, times(1))
		.containsProperty(eq("vcap.application.name"));
	verify(mockVcapPropertySource, times(1))
		.containsProperty(eq("vcap.application.uris"));
}
 

@SuppressWarnings({ "rawtypes", "unchecked" })
@Override
public void updateFlatConfig() {
    super.updateFlatConfig();
    if(this.environment instanceof ConfigurableEnvironment) {
        ConfigurableEnvironment configurableEnv = ((ConfigurableEnvironment)environment);
        for(PropertySource<?> propertySource : configurableEnv.getPropertySources()) {
            if(propertySource instanceof EnumerablePropertySource) {
                EnumerablePropertySource<?> enumerablePropertySource = (EnumerablePropertySource)propertySource;
                for(String propertyName : enumerablePropertySource.getPropertyNames()) {
                    flatConfig.put(propertyName, enumerablePropertySource.getProperty(propertyName));
                }
            }
        }
    }
}
 

@Test
public void contextShouldLoadPropertiesInACorrectOrder() {
    assertThat(environment.getPropertySources())
        .extracting(PropertySource::getName)
        .containsExactly(
            "configurationProperties",
            "Inlined Test Properties",
            "systemProperties",
            "systemEnvironment",
            "random",
            "class path resource [db.properties]",
            "class path resource [engine.properties]",
            "applicationConfig: [classpath:/application.properties]",
            "flowableDefaultConfig: [classpath:/flowable-default.properties]",
            "flowable-liquibase-override",
            "Management Server"
        );
}
 

@Test
public void orderingIsCorrect() {
	refresher.refresh();
	MutablePropertySources propertySources = environment.getPropertySources();
	PropertySource<?> test1 = propertySources
			.get("bootstrapProperties-testContextRefresherOrdering1");
	PropertySource<?> test2 = propertySources
			.get("bootstrapProperties-testContextRefresherOrdering2");
	PropertySource<?> test3 = propertySources
			.get("bootstrapProperties-testContextRefresherOrdering3");
	int index1 = propertySources.precedenceOf(test1);
	int index2 = propertySources.precedenceOf(test2);
	int index3 = propertySources.precedenceOf(test3);
	assertThat(index1).as("source1 index not less then source2").isLessThan(index2);
	assertThat(index2).as("source2 index not less then source3").isLessThan(index3);
}
 

@Test
public void withNonEnumerablePropertySource() {
	DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
	bf.registerBeanDefinition("testBean",
			genericBeanDefinition(TestBean.class)
				.addPropertyValue("name", "${foo}")
				.getBeanDefinition());

	PropertySourcesPlaceholderConfigurer ppc = new PropertySourcesPlaceholderConfigurer();

	PropertySource<?> ps = new PropertySource<Object>("simplePropertySource", new Object()) {
		@Override
		public Object getProperty(String key) {
			return "bar";
		}
	};

	MockEnvironment env = new MockEnvironment();
	env.getPropertySources().addFirst(ps);
	ppc.setEnvironment(env);

	ppc.postProcessBeanFactory(bf);
	assertThat(bf.getBean(TestBean.class).getName(), equalTo("bar"));
}
 

/**
 * Create {@link PropertySource}s given {@link Environment} from the property
 * configuration.
 * @param environment must not be {@literal null}.
 * @return a {@link List} of ordered {@link PropertySource}s.
 */
protected List<PropertySource<?>> doCreatePropertySources(Environment environment) {

	Collection<SecretBackendMetadata> secretBackends = this.propertySourceLocatorConfiguration
			.getSecretBackends();
	List<SecretBackendMetadata> sorted = new ArrayList<>(secretBackends);
	List<PropertySource<?>> propertySources = new ArrayList<>();

	AnnotationAwareOrderComparator.sort(sorted);

	propertySources.addAll(doCreateKeyValuePropertySources(environment));

	for (SecretBackendMetadata backendAccessor : sorted) {

		PropertySource<?> vaultPropertySource = createVaultPropertySource(
				backendAccessor);
		propertySources.add(vaultPropertySource);
	}

	return propertySources;
}
 

public Map<String, Map<String, Object>> getAllEnv() {
	Map<String, Map<String, Object>> result = new LinkedHashMap<String, Map<String, Object>>();		
	for (Entry<String, PropertySource<?>> entry : getPropertySources().entrySet()) {
		PropertySource<?> source = entry.getValue();
		String sourceName = entry.getKey();
		if (source instanceof EnumerablePropertySource) {
			EnumerablePropertySource<?> enumerable = (EnumerablePropertySource<?>) source;
			Map<String, Object> properties = new LinkedHashMap<String, Object>();
			for (String name : enumerable.getPropertyNames()) {
				properties.put(name, sanitize(name, enumerable.getProperty(name)));
			}
			result.put(sourceName, properties);				
		}
	}
	return result;
}
 

@Override
public PropertySource<?> createPropertySource(String name, EncodedResource resource) throws IOException {
    PropertySource<?> propSource = null;
    String propName = name;
    if (StringUtils.isEmpty(propName)) {
        propName = getNameForResource(resource.getResource());
    }
    if (resource.getResource().exists()) {
        String fileName = resource.getResource().getFilename();
        for (PropertySourceLoader loader : loaders) {
            if (checkFileType(fileName, loader.getFileExtensions())) {
                List<PropertySource<?>> propertySources = loader.load(propName, resource.getResource());
                if (!propertySources.isEmpty()) {
                    propSource = propertySources.get(0);
                }
            }
        }
    } else {
        throw new FileNotFoundException(propName + "对应文件'" + resource.getResource().getFilename() + "'不存在");
    }
    return propSource;
}
 

public Map<String, Map<String, Object>> getAllEnv() {  
	Map<String, Map<String, Object>> result = new LinkedHashMap<String, Map<String, Object>>();		
	for (Entry<String, PropertySource<?>> entry : getPropertySources().entrySet()) {
		PropertySource<?> source = entry.getValue();
		String sourceName = entry.getKey();
		if (source instanceof EnumerablePropertySource) {
			EnumerablePropertySource<?> enumerable = (EnumerablePropertySource<?>) source;
			Map<String, Object> properties = new LinkedHashMap<String, Object>();
			for (String name : enumerable.getPropertyNames()) {
				properties.put(name, sanitize(name, enumerable.getProperty(name)));
			}
			result.put(sourceName, properties);				
		}
	}
	return result;
}
 

@Override
public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {

    PropertySource<?> system = environment.getPropertySources()
        .get(SYSTEM_ENVIRONMENT_PROPERTY_SOURCE_NAME);

    Map<String, Object> prefixed = new LinkedHashMap<>();

    if (!hasOurPriceProperties(system)) {
        // Baeldung-internal code so this doesn't break other examples
        logger.warn("System environment variables [calculation_mode,gross_calculation_tax_rate] not detected, fallback to default value [calcuation_mode={},gross_calcuation_tax_rate={}]", CALCUATION_MODE_DEFAULT_VALUE,
            GROSS_CALCULATION_TAX_RATE_DEFAULT_VALUE);
        prefixed = names.stream()
            .collect(Collectors.toMap(this::rename, this::getDefaultValue));
        environment.getPropertySources()
            .addAfter(SYSTEM_ENVIRONMENT_PROPERTY_SOURCE_NAME, new MapPropertySource("prefixer", prefixed));
        return;
    }

    prefixed = names.stream()
        .collect(Collectors.toMap(this::rename, system::getProperty));
    environment.getPropertySources()
        .addAfter(SYSTEM_ENVIRONMENT_PROPERTY_SOURCE_NAME, new MapPropertySource("prefixer", prefixed));

}
 

public PropertySource<?> load(String name, Resource resource, String profile) throws IOException {

		logger.info("load PropertySource -> name:{},profile:{}", name, profile);
		if (profile == null) {
			Properties properties = loadProperties(name,resource);
			if (profiles == null) {
				profiles = properties.getProperty("spring.profiles.active");
			} else {
				logger.info("spring.profiles.active = " + profiles + ",ignore load remote config");
			}
			// 如果指定了profile，则也不加载远程配置
			if (profiles == null && ccContext.isRemoteEnabled() && !ccContext.isProcessed()) {
				ccContext.init(properties, true);
				ccContext.mergeRemoteProperties(properties);
			}

			if (!properties.isEmpty()) {
				return new PropertiesPropertySource(name, properties);
			}
		}
		return null;
	}
 

@Test
public void shouldLocateLeaseAwareSources() {

	RequestedSecret rotating = RequestedSecret.rotating("secret/rotating");
	DefaultSecretBackendConfigurer configurer = new DefaultSecretBackendConfigurer();
	configurer.add(rotating);
	configurer.add("database/mysql/creds/readonly");

	this.propertySourceLocator = new LeasingVaultPropertySourceLocator(
			new VaultProperties(), configurer, this.secretLeaseContainer);

	PropertySource<?> propertySource = this.propertySourceLocator
			.locate(this.configurableEnvironment);

	assertThat(propertySource).isInstanceOf(CompositePropertySource.class);

	verify(this.secretLeaseContainer).addRequestedSecret(rotating);
	verify(this.secretLeaseContainer).addRequestedSecret(
			RequestedSecret.renewable("database/mysql/creds/readonly"));
}
 

private void logActiveProperties(ConfigurableEnvironment env) {
    List<MapPropertySource> propertySources = new ArrayList<>();

    for (PropertySource<?> source : env.getPropertySources()) {
        if (source instanceof MapPropertySource && source.getName().contains("applicationConfig")) {
            propertySources.add((MapPropertySource) source);
        }
    }

    propertySources.stream()
        .map(propertySource -> propertySource.getSource().keySet())
        .flatMap(Collection::stream)
        .distinct()
        .sorted()
        .forEach(key -> {
            try {
                log.debug(key + "=" + env.getProperty(key));
            } catch (Exception e) {
                log.warn("{} -> {}", key, e.getMessage());
            }
        });
}
 

/**
 * Attach a {@link ConfigurationPropertySource} support to the specified
 * {@link Environment}. Adapts each {@link PropertySource} managed by the environment
 * to a {@link ConfigurationPropertySource} and allows classic
 * {@link PropertySourcesPropertyResolver} calls to resolve using
 * {@link ConfigurationPropertyName configuration property names}.
 * <p>
 * The attached resolver will dynamically track any additions or removals from the
 * underlying {@link Environment} property sources.
 *
 * @param environment the source environment (must be an instance of
 *                    {@link ConfigurableEnvironment})
 * @see #get(Environment)
 */
public static void attach(Environment environment) {
    Assert.isInstanceOf(ConfigurableEnvironment.class, environment);
    MutablePropertySources sources = ((ConfigurableEnvironment) environment)
            .getPropertySources();
    PropertySource<?> attached = sources.get(ATTACHED_PROPERTY_SOURCE_NAME);
    if (attached != null && attached.getSource() != sources) {
        sources.remove(ATTACHED_PROPERTY_SOURCE_NAME);
        attached = null;
    }
    if (attached == null) {
        sources.addFirst(new ConfigurationPropertySourcesPropertySource(
                ATTACHED_PROPERTY_SOURCE_NAME,
                new SpringConfigurationPropertySources(sources)));
    }
}
 

@Override
protected PropertySource<?> toSimplePropertySource() {
    Properties props = new Properties();

    AtomicInteger index = new AtomicInteger(0);
    getProperties().getArchives().forEach(archive -> {
        props.setProperty("archives[" + index.get() + "]", archive);
        index.getAndIncrement();
    });

    copyIfSet(props, "git.branch");
    String commitId = getProperties().getGit().getShortCommitId();
    if (commitId != null) {
        props.put("git.commit.id", commitId);
    }
    copyIfSet(props, "git.commit.time");
    return new PropertiesPropertySource("launcher", props);
}
 

private static void addOrUpdateRemoteConfig(Environment env, boolean isUpdateOrNot) {
    StandardEnvironment environment = (StandardEnvironment) env;
    PropertySource propertySource = environment.getPropertySources().get("bootstrapProperties");
    if(propertySource == null) {
        return;
    }
    CompositePropertySource source = (CompositePropertySource) propertySource;
    for (String key: source.getPropertyNames()) {
        Object val = source.getProperty(key);
        if(val == null) {
            continue;
        }
        if(isUpdateOrNot) {
            logger.info("update remote config => " + key + " = " + source.getProperty(key));
            BDPConfiguration.set(key, val.toString());
        } else {
            logger.info("add remote config => " + key + " = " + source.getProperty(key));
            BDPConfiguration.setIfNotExists(key, val.toString());
        }
    }
}
 

private Function<ConfigurableApplicationContext, ConfigurableApplicationContext> newSpringSessionGemFirePropertiesConfigurationFunction() {

		return applicationContext -> {

			PropertySource springSessionGemFireProperties = new MockPropertySource("TestSpringSessionGemFireProperties")
				.withProperty(springSessionPropertyName("cache.client.region.shortcut"), "LOCAL")
				.withProperty(springSessionPropertyName("session.attributes.indexable"), "one, two")
				.withProperty(springSessionPropertyName("session.expiration.max-inactive-interval-seconds"), "600")
				.withProperty(springSessionPropertyName("cache.client.pool.name"), "MockPool")
				.withProperty(springSessionPropertyName("session.region.name"), "MockRegion")
				.withProperty(springSessionPropertyName("cache.server.region.shortcut"), "REPLICATE")
				.withProperty(springSessionPropertyName("session.serializer.bean-name"), "MockSessionSerializer");

			applicationContext.getEnvironment().getPropertySources().addFirst(springSessionGemFireProperties);

			return applicationContext;
		};
	}
 

private PropertySource<?> createVaultPropertySource(RequestedSecret secret,
		SecretBackendMetadata accessor) {

	if (accessor instanceof LeasingSecretBackendMetadata) {
		((LeasingSecretBackendMetadata) accessor).beforeRegistration(secret,
				this.secretLeaseContainer);
	}

	LeaseAwareVaultPropertySource propertySource = new LeaseAwareVaultPropertySource(
			accessor.getName(), this.secretLeaseContainer, secret,
			accessor.getPropertyTransformer());

	if (accessor instanceof LeasingSecretBackendMetadata) {
		((LeasingSecretBackendMetadata) accessor).afterRegistration(secret,
				this.secretLeaseContainer);
	}

	return propertySource;
}
 

@Test
public void withNonEnumerablePropertySource() {
	DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
	bf.registerBeanDefinition("testBean",
			genericBeanDefinition(TestBean.class)
				.addPropertyValue("name", "${foo}")
				.getBeanDefinition());

	PropertySourcesPlaceholderConfigurer ppc = new PropertySourcesPlaceholderConfigurer();

	PropertySource<?> ps = new PropertySource<Object>("simplePropertySource", new Object()) {
		@Override
		public Object getProperty(String key) {
			return "bar";
		}
	};

	MockEnvironment env = new MockEnvironment();
	env.getPropertySources().addFirst(ps);
	ppc.setEnvironment(env);

	ppc.postProcessBeanFactory(bf);
	assertThat(bf.getBean(TestBean.class).getName(), equalTo("bar"));
}
 

private void mergeDefaultProperties(MutablePropertySources environment,
		MutablePropertySources bootstrap) {
	String name = DEFAULT_PROPERTIES;
	if (bootstrap.contains(name)) {
		PropertySource<?> source = bootstrap.get(name);
		if (!environment.contains(name)) {
			environment.addLast(source);
		}
		else {
			PropertySource<?> target = environment.get(name);
			if (target instanceof MapPropertySource && target != source
					&& source instanceof MapPropertySource) {
				Map<String, Object> targetMap = ((MapPropertySource) target)
						.getSource();
				Map<String, Object> map = ((MapPropertySource) source).getSource();
				for (String key : map.keySet()) {
					if (!target.containsProperty(key)) {
						targetMap.put(key, map.get(key));
					}
				}
			}
		}
	}
	mergeAdditionalPropertySources(environment, bootstrap);
}
 

static Collection<PropertySource<?>> locateCollection(PropertySourceLocator locator,
		Environment environment) {
	PropertySource<?> propertySource = locator.locate(environment);
	if (propertySource == null) {
		return Collections.emptyList();
	}
	if (CompositePropertySource.class.isInstance(propertySource)) {
		Collection<PropertySource<?>> sources = ((CompositePropertySource) propertySource)
				.getPropertySources();
		List<PropertySource<?>> filteredSources = new ArrayList<>();
		for (PropertySource<?> p : sources) {
			if (p != null) {
				filteredSources.add(p);
			}
		}
		return filteredSources;
	}
	else {
		return Arrays.asList(propertySource);
	}
}
 

@Override
@SuppressWarnings("unchecked")
public void initialize(ConfigurableApplicationContext configurableApplicationContext) {
    try {
        Resource resource = configurableApplicationContext.getResource("classpath:configprops.json");
        Map readValue = new ObjectMapper().readValue(resource.getInputStream(), Map.class);
        Set<Map.Entry> set = readValue.entrySet();
        List<MapPropertySource> propertySources = convertEntrySet(set, Optional.empty());
        for (PropertySource propertySource : propertySources) {
            configurableApplicationContext.getEnvironment()
                .getPropertySources()
                .addFirst(propertySource);
        }
    } catch (IOException e) {
        throw new RuntimeException(e);
    }
}
 

private ConfigurationPropertySource fetchNext() {
    if (this.next == null) {
        if (this.iterators.isEmpty()) {
            return null;
        }
        if (!this.iterators.peek().hasNext()) {
            this.iterators.pop();
            return fetchNext();
        }
        PropertySource<?> candidate = this.iterators.peek().next();
        if (candidate.getSource() instanceof ConfigurableEnvironment) {
            push((ConfigurableEnvironment) candidate.getSource());
            return fetchNext();
        }
        if (isIgnored(candidate)) {
            return fetchNext();
        }
        this.next = this.adapter.apply(candidate);
    }
    return this.next;
}
 

@Test
public void shouldLocatePropertySourcesInEachPathSpecifiedWhenApplicationNameContainsSeveral() {

	VaultKeyValueBackendProperties backendProperties = new VaultKeyValueBackendProperties();
	backendProperties.setApplicationName("wintermute,straylight,icebreaker/armitage");
	backendProperties.setProfiles(Arrays.asList("vermillion", "periwinkle"));

	this.propertySourceLocator = new VaultPropertySourceLocator(this.operations,
			new VaultProperties(),
			VaultPropertySourceLocatorSupport.createConfiguration(backendProperties));

	PropertySource<?> propertySource = this.propertySourceLocator
			.locate(this.configurableEnvironment);

	assertThat(propertySource).isInstanceOf(CompositePropertySource.class);

	CompositePropertySource composite = (CompositePropertySource) propertySource;
	assertThat(composite.getPropertySources()).extracting("name").contains(
			"secret/wintermute", "secret/straylight", "secret/icebreaker/armitage",
			"secret/wintermute/vermillion", "secret/wintermute/periwinkle",
			"secret/straylight/vermillion", "secret/straylight/periwinkle",
			"secret/icebreaker/armitage/vermillion",
			"secret/icebreaker/armitage/periwinkle");
}
 

/**
 * Create a new {@link SpringConfigurationPropertySource} implementation.
 *
 * @param propertySource       the source property source
 * @param mapper               the property mapper
 * @param containsDescendantOf function used to implement
 *                             {@link #containsDescendantOf(ConfigurationPropertyName)} (may be {@code null})
 */
SpringConfigurationPropertySource(PropertySource<?> propertySource,
                                  PropertyMapper mapper,
                                  Function<ConfigurationPropertyName, ConfigurationPropertyState> containsDescendantOf) {
    Assert.notNull(propertySource, "PropertySource must not be null");
    Assert.notNull(mapper, "Mapper must not be null");
    this.propertySource = propertySource;
    this.mapper = (mapper instanceof DelegatingPropertyMapper) ? mapper
            : new DelegatingPropertyMapper(mapper);
    this.containsDescendantOf = (containsDescendantOf != null) ? containsDescendantOf
            : (n) -> ConfigurationPropertyState.UNKNOWN;
}
 

/**
 * Creates a {@link CompositePropertySource}.
 * @param environment must not be {@literal null}.
 * @return the composite {@link PropertySource}.
 */
protected CompositePropertySource createCompositePropertySource(
		Environment environment) {

	List<PropertySource<?>> propertySources = doCreatePropertySources(environment);

	return doCreateCompositePropertySource(this.propertySourceName, propertySources);
}
 

@Override
protected PropertySource<?> toPropertySource(EurekaServiceInfo eurekaServiceInfo) {
	Map<String, Object> map = new LinkedHashMap<>();
	map.put(EUREKA_CLIENT + "serviceUrl.defaultZone", eurekaServiceInfo.getUri() + EUREKA_API_PREFIX);
	map.put(EUREKA_CLIENT + "region", DEFAULT_REGION);
	map.put(EUREKA_CLIENT_OAUTH2 + "clientId", eurekaServiceInfo.getClientId());
	map.put(EUREKA_CLIENT_OAUTH2 + "clientSecret", eurekaServiceInfo.getClientSecret());
	map.put(EUREKA_CLIENT_OAUTH2 + "accessTokenUri", eurekaServiceInfo.getAccessTokenUri());
	return new MapPropertySource(PROPERTY_SOURCE_NAME, map);
}
 

/**
 * Get prefixed {@link Properties}
 *
 * @param propertySources  {@link PropertySources}
 * @param propertyResolver {@link PropertyResolver} to resolve the placeholder if present
 * @param prefix           the prefix of property name
 * @return Map
 * @see Properties
 * @since 1.0.3
 */
public static Map<String, Object> getSubProperties(PropertySources propertySources, PropertyResolver propertyResolver, String prefix) {

    Map<String, Object> subProperties = new LinkedHashMap<String, Object>();

    String normalizedPrefix = normalizePrefix(prefix);

    Iterator<PropertySource<?>> iterator = propertySources.iterator();

    while (iterator.hasNext()) {
        PropertySource<?> source = iterator.next();
        if (source instanceof EnumerablePropertySource) {
            for (String name : ((EnumerablePropertySource<?>) source).getPropertyNames()) {
                if (!subProperties.containsKey(name) && name.startsWith(normalizedPrefix)) {
                    String subName = name.substring(normalizedPrefix.length());
                    if (!subProperties.containsKey(subName)) { // take first one
                        Object value = source.getProperty(name);
                        if (value instanceof String) {
                            // Resolve placeholder
                            value = propertyResolver.resolvePlaceholders((String) value);
                        }
                        subProperties.put(subName, value);
                    }
                }
            }
        }
    }

    return unmodifiableMap(subProperties);
}