Apollo client integration with Spring

apollo-client/pom.xml

@@ -32,6 +32,12 @@
 			<groupId>org.slf4j</groupId>
 			<artifactId>slf4j-api</artifactId>
 		</dependency>
+		<!-- optional spring dependency -->
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-context</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<!-- test -->
 		<dependency>
 			<groupId>org.eclipse.jetty</groupId>

apollo-client/src/main/java/com/ctrip/framework/apollo/spring/annotation/ApolloAnnotationProcessor.java

@@ -0,0 +1,83 @@
+package com.ctrip.framework.apollo.spring.annotation;
+
+import com.google.common.base.Preconditions;
+
+import com.ctrip.framework.apollo.Config;
+import com.ctrip.framework.apollo.ConfigChangeListener;
+import com.ctrip.framework.apollo.ConfigService;
+import com.ctrip.framework.apollo.model.ConfigChangeEvent;
+
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.config.BeanPostProcessor;
+import org.springframework.core.annotation.AnnotationUtils;
+import org.springframework.util.ReflectionUtils;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+
+/**
+ * Apollo Annotation Processor for Spring Application
+ *
+ * @author Jason Song(song_s@ctrip.com)
+ */
+public class ApolloAnnotationProcessor implements BeanPostProcessor {
+  @Override
+  public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
+    Class clazz = bean.getClass();
+    processFields(bean, clazz.getDeclaredFields());
+    processMethods(bean, clazz.getDeclaredMethods());
+    return bean;
+  }
+
+  @Override
+  public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
+    return bean;
+  }
+
+  private void processFields(Object bean, Field[] declaredFields) {
+    for (Field field : declaredFields) {
+      ApolloConfig annotation = AnnotationUtils.getAnnotation(field, ApolloConfig.class);
+      if (annotation == null) {
+        continue;
+      }
+
+      Preconditions.checkArgument(Config.class.isAssignableFrom(field.getType()),
+          "Invalid type: %s for field: %s, should be Config", field.getType(), field);
+
+      String namespace = annotation.value();
+      Config config = ConfigService.getConfig(namespace);
+
+      ReflectionUtils.makeAccessible(field);
+      ReflectionUtils.setField(field, bean, config);
+    }
+  }
+
+  private void processMethods(final Object bean, Method[] declaredMethods) {
+    for (final Method method : declaredMethods) {
+      ApolloConfigChangeListener annotation = AnnotationUtils.findAnnotation(method, ApolloConfigChangeListener.class);
+      if (annotation == null) {
+        continue;
+      }
+
+      Class<?>[] parameterTypes = method.getParameterTypes();
+      Preconditions.checkArgument(parameterTypes.length == 1,
+          "Invalid number of parameters: %s for method: %s, should be 1", parameterTypes.length, method);
+      Preconditions.checkArgument(ConfigChangeEvent.class.isAssignableFrom(parameterTypes[0]),
+          "Invalid parameter type: %s for method: %s, should be ConfigChangeEvent", parameterTypes[0], method);
+
+      ReflectionUtils.makeAccessible(method);
+      String[] namespaces = annotation.value();
+      for (String namespace : namespaces) {
+        Config config = ConfigService.getConfig(namespace);
+
+        config.addChangeListener(new ConfigChangeListener() {
+          @Override
+          public void onChange(ConfigChangeEvent changeEvent) {
+            ReflectionUtils.invokeMethod(method, bean, changeEvent);
+          }
+        });
+      }
+    }
+  }
+
+}

apollo-client/src/main/java/com/ctrip/framework/apollo/spring/annotation/ApolloConfig.java

@@ -0,0 +1,31 @@
+package com.ctrip.framework.apollo.spring.annotation;
+
+import com.ctrip.framework.apollo.core.ConfigConsts;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Use this annotation to inject Apollo Config Instance.
+ *
+ * <p>Usage example:</p>
+ * <pre class="code">
+ * //Inject the config for "someNamespace"
+ * &#064;ApolloConfig("someNamespace")
+ * private Config config;
+ * </pre>
+ *
+ * @author Jason Song(song_s@ctrip.com)
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.FIELD)
+@Documented
+public @interface ApolloConfig {
+  /**
+   * Apollo namespace for the config, if not specified then default to application
+   */
+  String value() default ConfigConsts.NAMESPACE_APPLICATION;
+}

apollo-client/src/main/java/com/ctrip/framework/apollo/spring/annotation/ApolloConfigChangeListener.java

@@ -0,0 +1,33 @@
+package com.ctrip.framework.apollo.spring.annotation;
+
+import com.ctrip.framework.apollo.core.ConfigConsts;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Use this annotation to register Apollo ConfigChangeListener.
+ *
+ * <p>Usage example:</p>
+ * <pre class="code">
+ * //Listener on namespaces of "someNamespace" and "anotherNamespace"
+ * &#064;ApolloConfigChangeListener({"someNamespace","anotherNamespace"})
+ * private void onChange(ConfigChangeEvent changeEvent) {
+ *     //handle change event
+ * }
+ * </pre>
+ *
+ * @author Jason Song(song_s@ctrip.com)
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.METHOD)
+@Documented
+public @interface ApolloConfigChangeListener {
+  /**
+   * Apollo namespace for the config, if not specified then default to application
+   */
+  String[] value() default {ConfigConsts.NAMESPACE_APPLICATION};
+}

apollo-client/src/main/java/com/ctrip/framework/apollo/spring/annotation/ApolloConfigRegistrar.java

@@ -0,0 +1,35 @@
+package com.ctrip.framework.apollo.spring.annotation;
+
+import com.google.common.collect.Lists;
+
+import com.ctrip.framework.apollo.spring.config.PropertySourcesProcessor;
+import com.ctrip.framework.apollo.spring.util.BeanRegistrationUtil;
+
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
+import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
+import org.springframework.core.annotation.AnnotationAttributes;
+import org.springframework.core.type.AnnotationMetadata;
+
+/**
+ * @author Jason Song(song_s@ctrip.com)
+ */
+public class ApolloConfigRegistrar implements ImportBeanDefinitionRegistrar {
+  @Override
+  public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
+    AnnotationAttributes attributes = AnnotationAttributes.fromMap(importingClassMetadata
+        .getAnnotationAttributes(EnableApolloConfig.class.getName()));
+    String[] namespaces = attributes.getStringArray("value");
+    int order = attributes.getNumber("order");
+    PropertySourcesProcessor.addNamespaces(Lists.newArrayList(namespaces), order);
+
+    BeanRegistrationUtil.registerBeanDefinitionIfNotExists(registry, PropertySourcesPlaceholderConfigurer.class.getName(),
+        PropertySourcesPlaceholderConfigurer.class);
+
+    BeanRegistrationUtil.registerBeanDefinitionIfNotExists(registry, PropertySourcesProcessor.class.getName(),
+        PropertySourcesProcessor.class);
+
+    BeanRegistrationUtil.registerBeanDefinitionIfNotExists(registry, ApolloAnnotationProcessor.class.getName(),
+        ApolloAnnotationProcessor.class);
+  }
+}

apollo-client/src/main/java/com/ctrip/framework/apollo/spring/annotation/EnableApolloConfig.java

@@ -0,0 +1,44 @@
+package com.ctrip.framework.apollo.spring.annotation;
+
+import com.ctrip.framework.apollo.core.ConfigConsts;
+
+import org.springframework.context.annotation.Import;
+import org.springframework.core.Ordered;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Use this annotation to register Apollo property sources when using Java Config.
+ *
+ * <p>Configuration example:</p>
+ * <pre class="code">
+ * &#064;Configuration
+ * &#064;EnableApolloConfig({"someNamespace","anotherNamespace"})
+ * public class AppConfig {
+ *
+ * }
+ * </pre>
+ *
+ * @author Jason Song(song_s@ctrip.com)
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+@Documented
+@Import(ApolloConfigRegistrar.class)
+public @interface EnableApolloConfig {
+  /**
+   * Apollo namespaces to inject configuration into Spring Property Sources.
+   */
+  String[] value() default {ConfigConsts.NAMESPACE_APPLICATION};
+
+  /**
+   * The order of the apollo config, default is {@link Ordered#LOWEST_PRECEDENCE}, which is Integer.MAX_VALUE.
+   * If there are properties with the same name in different apollo configs, the apollo config with smaller order wins.
+   * @return
+   */
+  int order() default Ordered.LOWEST_PRECEDENCE;
+}

apollo-client/src/main/java/com/ctrip/framework/apollo/spring/config/ConfigPropertySource.java

@@ -0,0 +1,21 @@
+package com.ctrip.framework.apollo.spring.config;
+
+import com.ctrip.framework.apollo.Config;
+
+import org.springframework.core.env.PropertySource;
+
+/**
+ * Property source wrapper for Config
+ *
+ * @author Jason Song(song_s@ctrip.com)
+ */
+public class ConfigPropertySource extends PropertySource<Config> {
+  public ConfigPropertySource(String name, Config source) {
+    super(name, source);
+  }
+
+  @Override
+  public Object getProperty(String name) {
+    return this.source.getProperty(name, null);
+  }
+}

apollo-client/src/main/java/com/ctrip/framework/apollo/spring/config/ConfigPropertySourcesProcessor.java

@@ -0,0 +1,26 @@
+package com.ctrip.framework.apollo.spring.config;
+
+import com.ctrip.framework.apollo.spring.annotation.ApolloAnnotationProcessor;
+import com.ctrip.framework.apollo.spring.util.BeanRegistrationUtil;
+
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.beans.factory.support.BeanDefinitionRegistryPostProcessor;
+import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
+
+/**
+ * Apollo Property Sources processor for Spring XML Based Application
+ *
+ * @author Jason Song(song_s@ctrip.com)
+ */
+public class ConfigPropertySourcesProcessor extends PropertySourcesProcessor
+    implements BeanDefinitionRegistryPostProcessor {
+
+  @Override
+  public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) throws BeansException {
+    BeanRegistrationUtil.registerBeanDefinitionIfNotExists(registry, PropertySourcesPlaceholderConfigurer.class.getName(),
+        PropertySourcesPlaceholderConfigurer.class);
+    BeanRegistrationUtil.registerBeanDefinitionIfNotExists(registry, ApolloAnnotationProcessor.class.getName(),
+        ApolloAnnotationProcessor.class);
+  }
+}

apollo-client/src/main/java/com/ctrip/framework/apollo/spring/config/NamespaceHandler.java

@@ -0,0 +1,58 @@
+package com.ctrip.framework.apollo.spring.config;
+
+import com.google.common.base.Splitter;
+import com.google.common.base.Strings;
+
+import com.ctrip.framework.apollo.core.ConfigConsts;
+
+import org.springframework.beans.factory.support.BeanDefinitionBuilder;
+import org.springframework.beans.factory.xml.AbstractSingleBeanDefinitionParser;
+import org.springframework.beans.factory.xml.NamespaceHandlerSupport;
+import org.springframework.core.Ordered;
+import org.w3c.dom.Element;
+
+/**
+ * @author Jason Song(song_s@ctrip.com)
+ */
+public class NamespaceHandler extends NamespaceHandlerSupport {
+  private static final Splitter NAMESPACE_SPLITTER = Splitter.on(",").omitEmptyStrings().trimResults();
+
+  @Override
+  public void init() {
+    registerBeanDefinitionParser("config", new BeanParser());
+  }
+
+  static class BeanParser extends AbstractSingleBeanDefinitionParser {
+    @Override
+    protected Class<?> getBeanClass(Element element) {
+      return ConfigPropertySourcesProcessor.class;
+    }
+
+    @Override
+    protected boolean shouldGenerateId() {
+      return true;
+    }
+
+    @Override
+    protected void doParse(Element element, BeanDefinitionBuilder builder) {
+      String namespaces = element.getAttribute("namespaces");
+      //default to application
+      if (Strings.isNullOrEmpty(namespaces)) {
+        namespaces = ConfigConsts.NAMESPACE_APPLICATION;
+      }
+
+      int order = Ordered.LOWEST_PRECEDENCE;
+      String orderAttribute = element.getAttribute("order");
+
+      if (!Strings.isNullOrEmpty(orderAttribute)) {
+        try {
+          order = Integer.parseInt(orderAttribute);
+        } catch (Throwable ex) {
+          throw new IllegalArgumentException(
+              String.format("Invalid order: %s for namespaces: %s", orderAttribute, namespaces));
+        }
+      }
+      PropertySourcesProcessor.addNamespaces(NAMESPACE_SPLITTER.splitToList(namespaces), order);
+    }
+  }
+}