Talk about DubboDefaultPropertiesEnvironmentPostProcessor

sequence

In this paper, we study the DubboDefaultPropertiesEnvironmentPostProcessor

DubboDefaultPropertiesEnvironmentPostProcessor

Dubbo – spring – the boot – project – 2.7.3 / dubbo – spring – the boot – compatible/autoconfigure/SRC/main/Java/org/apache/dubbo/spring/boot/en v/DubboDefaultPropertiesEnvironmentPostProcessor.java

public class DubboDefaultPropertiesEnvironmentPostProcessor implements EnvironmentPostProcessor, Ordered {

    /**
     * The name of default {@link PropertySource} defined in SpringApplication#configurePropertySources method.
     */
    public static final String PROPERTY_SOURCE_NAME = "defaultProperties";

    /**
     * The property name of "spring.main.allow-bean-definition-overriding". * both Please refer to: https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-2.1-Release-Notes#bean-overriding
     */
    public static final String ALLOW_BEAN_DEFINITION_OVERRIDING_PROPERTY = "spring.main.allow-bean-definition-overriding";

    @Override
    public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
        MutablePropertySources propertySources = environment.getPropertySources();
        Map<String, Object> defaultProperties = createDefaultProperties(environment);
        if(! CollectionUtils.isEmpty(defaultProperties)) { addOrReplace(propertySources, defaultProperties); } } @Override public intgetOrder() {
        return LOWEST_PRECEDENCE;
    }

    private Map<String, Object> createDefaultProperties(ConfigurableEnvironment environment) {
        Map<String, Object> defaultProperties = new HashMap<String, Object>();
        setDubboApplicationNameProperty(environment, defaultProperties);
        setDubboConfigMultipleProperty(defaultProperties);
        setDubboApplicationQosEnableProperty(defaultProperties);
        setAllowBeanDefinitionOverriding(defaultProperties);
        return defaultProperties;
    }

    private void setDubboApplicationNameProperty(Environment environment, Map<String, Object> defaultProperties) {
        String springApplicationName = environment.getProperty(SPRING_APPLICATION_NAME_PROPERTY);
        if(StringUtils.hasLength(springApplicationName) && ! environment.containsProperty(DUBBO_APPLICATION_NAME_PROPERTY)) { defaultProperties.put(DUBBO_APPLICATION_NAME_PROPERTY, springApplicationName); } } private voidsetDubboConfigMultipleProperty(Map<String, Object> defaultProperties) {
        defaultProperties.put(DUBBO_CONFIG_MULTIPLE_PROPERTY, Boolean.TRUE.toString());
    }

    private void setDubboApplicationQosEnableProperty(Map<String, Object> defaultProperties) {
        defaultProperties.put(DUBBO_APPLICATION_QOS_ENABLE_PROPERTY, Boolean.FALSE.toString());
    }

    /**
     * Set {@link #ALLOW_BEAN_DEFINITION_OVERRIDING_PROPERTY "spring.main.allow-bean-definition-overriding"} to be
     * <code>true</code> as default.
     *
     * @param defaultProperties the default {@link Properties properties}
     * @see #ALLOW_BEAN_DEFINITION_OVERRIDING_PROPERTY
     * @since 2.7.1
     */
    private void setAllowBeanDefinitionOverriding(Map<String, Object> defaultProperties) {
        defaultProperties.put(ALLOW_BEAN_DEFINITION_OVERRIDING_PROPERTY, Boolean.TRUE.toString());
    }

    /**
     * Copy from BusEnvironmentPostProcessor#addOrReplace(MutablePropertySources, Map)
     *
     * @param propertySources {@link MutablePropertySources}
     * @param map             Default Dubbo Properties
     */
    private void addOrReplace(MutablePropertySources propertySources,
                              Map<String, Object> map) {
        MapPropertySource target = null;
        if(propertySources.contains(PROPERTY_SOURCE_NAME)) { PropertySource<? >source = propertySources.get(PROPERTY_SOURCE_NAME);
            if (source instanceof MapPropertySource) {
                target = (MapPropertySource) source;
                for (String key : map.keySet()) {
                    if(! target.containsProperty(key)) { target.getSource().put(key, map.get(key)); }}}}if (target == null) {
            target = new MapPropertySource(PROPERTY_SOURCE_NAME, map);
        }
        if(! propertySources.contains(PROPERTY_SOURCE_NAME)) { propertySources.addLast(target); }}}Copy the code

• DubboDefaultPropertiesEnvironmentPostProcessor implements EnvironmentPostProcessor Ordered interface; The postProcessEnvironment method first gets MutablePropertySources from the Environment and then creates the default configuration defaultProperties(By default, DUBBO_APPLICATION_NAME_PROPERTY is set to springApplicationName, DUBBO_CONFIG_MULTIPLE_PROPERTY to true, and DUBBO_APPLICATION_QOS_E NABLE_PROPERTY to false), and finally, the addOrReplace method overwrites the defaultProperties to the propertySources. The getOrder method returns LOWEST_PRECEDENCE

DubboDefaultPropertiesEnvironmentPostProcessorTest

Dubbo – spring – the boot – project – 2.7.3 / dubbo – spring – the boot – autoconfigure/SRC/test/Java/org/apache/dubbo/spring/boot/env/DubboDefa ultPropertiesEnvironmentPostProcessorTest.java

public class DubboDefaultPropertiesEnvironmentPostProcessorTest { private DubboDefaultPropertiesEnvironmentPostProcessor  instance = new DubboDefaultPropertiesEnvironmentPostProcessor(); private SpringApplication springApplication = new SpringApplication(); @Test public voidtestOrder() {
        Assert.assertEquals(Ordered.LOWEST_PRECEDENCE, instance.getOrder());
    }

    @Test
    public void testPostProcessEnvironment() {
        MockEnvironment environment = new MockEnvironment();
        // Case 1 : Not Any property
        instance.postProcessEnvironment(environment, springApplication);
        // Get PropertySources
        MutablePropertySources propertySources = environment.getPropertySources();
        // Nothing to change
        PropertySource defaultPropertySource = propertySources.get("defaultProperties");
        Assert.assertNotNull(defaultPropertySource);
        Assert.assertEquals("true", defaultPropertySource.getProperty("dubbo.config.multiple"));
        Assert.assertEquals("false", defaultPropertySource.getProperty("dubbo.application.qos-enable"));

        // Case 2 :  Only set property "spring.application.name"
        environment.setProperty("spring.application.name"."demo-dubbo-application");
        instance.postProcessEnvironment(environment, springApplication);
        defaultPropertySource = propertySources.get("defaultProperties");
        Object dubboApplicationName = defaultPropertySource.getProperty("dubbo.application.name");
        Assert.assertEquals("demo-dubbo-application", dubboApplicationName);

        // Case 3 : Only set property "dubbo.application.name"
        // Rest environment
        environment = new MockEnvironment();
        propertySources = environment.getPropertySources();
        environment.setProperty("dubbo.application.name"."demo-dubbo-application");
        instance.postProcessEnvironment(environment, springApplication);
        defaultPropertySource = propertySources.get("defaultProperties");
        Assert.assertNotNull(defaultPropertySource);
        dubboApplicationName = environment.getProperty("dubbo.application.name");
        Assert.assertEquals("demo-dubbo-application", dubboApplicationName);

        // Case 4 : If "defaultProperties" PropertySource is present in PropertySources
        // Rest environment
        environment = new MockEnvironment();
        propertySources = environment.getPropertySources();
        propertySources.addLast(new MapPropertySource("defaultProperties", new HashMap<String, Object>()));
        environment.setProperty("spring.application.name"."demo-dubbo-application");
        instance.postProcessEnvironment(environment, springApplication);
        defaultPropertySource = propertySources.get("defaultProperties");
        dubboApplicationName = defaultPropertySource.getProperty("dubbo.application.name");
        Assert.assertEquals("demo-dubbo-application", dubboApplicationName);

        // Case 5 : Rest dubbo.config.multiple and dubbo.application.qos-enable
        environment = new MockEnvironment();
        propertySources = environment.getPropertySources();
        propertySources.addLast(new MapPropertySource("defaultProperties", new HashMap<String, Object>()));
        environment.setProperty("dubbo.config.multiple"."false");
        environment.setProperty("dubbo.application.qos-enable"."true");
        instance.postProcessEnvironment(environment, springApplication);
        Assert.assertEquals("false", environment.getProperty("dubbo.config.multiple"));
        Assert.assertEquals("true", environment.getProperty("dubbo.application.qos-enable")); }}Copy the code

• TestPostProcessEnvironment method is verified by MockEnvironment DubboDefaultPropertiesEnvironmentPostProcessor addOrReplace method

summary

DubboDefaultPropertiesEnvironmentPostProcessor implements EnvironmentPostProcessor Ordered interface; The postProcessEnvironment method first gets the MutablePropertySources from the Environment, Then create the default configuration defaultProperties with createDefaultProperties (where DUBBO_APPLICATION_NAME_PROPERTY is springApplicationName and DUBBO_CO by default) NFIG_MULTIPLE_PROPERTY is true, DUBBO_APPLICATION_QOS_ENABLE_PROPERTY is false), Finally, the addOrReplace method overwrites the defaultProperties to the propertySources; The getOrder method returns LOWEST_PRECEDENCE

doc

• DubboDefaultPropertiesEnvironmentPostProcessor