gistfile1.txt

import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

import org.springframework.beans.FatalBeanException;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.GenericBeanDefinition;
import org.springframework.boot.bind.PropertiesConfigurationFactory;
import org.springframework.context.EnvironmentAware;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.Environment;
import org.springframework.core.type.AnnotationMetadata;
import org.springframework.jdbc.datasource.SingleConnectionDataSource;
import org.springframework.validation.BindException;

@Configuration
public class DynamicDataSourcesConfiguration implements ImportBeanDefinitionRegistrar, EnvironmentAware {
    private ConfigurableEnvironment environment;
    private static Map<String, Object> defaultDsProperties = new HashMap<String, Object>() {
        {
            put("suppressClose", true);
            put("username", "sa");
            put("password", "");
            put("driverClassName", "org.h2.Driver");
        }
    };

    @Override
    public void setEnvironment(Environment environment) {
        this.environment = (ConfigurableEnvironment)environment;
    }

    @Override
    public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
        DataSourceSettings settings = resolveSettings();
        for (Entry<String, String> entry : settings.clientDataSources().entrySet()) {
            createDsBean(registry, entry.getKey(), entry.getValue());
        }
    }

    private void createDsBean(BeanDefinitionRegistry registry, String beanName, String jdbcUrl) {
        GenericBeanDefinition beanDefinition = createBeanDefinition(SingleConnectionDataSource.class);
        beanDefinition.getPropertyValues().addPropertyValues(defaultDsProperties).addPropertyValue("url", jdbcUrl);
        registry.registerBeanDefinition(beanName, beanDefinition);
    }

    private GenericBeanDefinition createBeanDefinition(Class<?> beanClass) {
        GenericBeanDefinition beanDefinition = new GenericBeanDefinition();
        beanDefinition.setBeanClass(beanClass);
        beanDefinition.setAutowireMode(GenericBeanDefinition.AUTOWIRE_NO);
        return beanDefinition;
    }

    private DataSourceSettings resolveSettings() {
        DataSourceSettings settings = new DataSourceSettings();
        PropertiesConfigurationFactory<Object> factory = new PropertiesConfigurationFactory<Object>(settings);
        factory.setTargetName("ds");
        factory.setPropertySources(environment.getPropertySources());
        factory.setConversionService(environment.getConversionService());
        try {
            factory.bindPropertiesToTarget();
        }
        catch (BindException ex) {
            throw new FatalBeanException("Could not bind DataSourceSettings properties", ex);
        }
        return settings;
    }

}

gistfile2.txt

package io.loli.kan;

import org.springframework.beans.BeansException;
import org.springframework.beans.FatalBeanException;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.BeanDefinitionRegistryPostProcessor;
import org.springframework.boot.bind.PropertiesConfigurationFactory;
import org.springframework.context.EnvironmentAware;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.Environment;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import org.springframework.validation.BindException;

import java.util.Arrays;
import java.util.Collections;
import java.util.List;

@Component
public class DataSourcesBeanFactoryPostProcessor implements BeanDefinitionRegistryPostProcessor,
        EnvironmentAware {
    private ConfigurableEnvironment environment;

    @Override
    public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) throws BeansException {
        TestProperties testProperties = new TestProperties();
        PropertiesConfigurationFactory<Object> factory = new PropertiesConfigurationFactory<>(testProperties);
        factory.setPropertySources(environment.getPropertySources());
        factory.setConversionService(environment.getConversionService());

        try {
            factory.bindPropertiesToTarget();
        } catch (BindException ex) {
            throw new FatalBeanException("Could not bind DataSourceSettings properties", ex);
        }
        // 从配置文件中读取
        System.out.println(factory.getObjectType());
        for (String customerKey : testProperties.getCustomerNames()) {
            String beanName = customerKey;
            BeanDefinitionBuilder definitionBuilder =
                    BeanDefinitionBuilder.genericBeanDefinition(TestBean.class);
            definitionBuilder.addPropertyValue("name", customerKey);
            registry.registerBeanDefinition(beanName, definitionBuilder.getBeanDefinition());
        }
    }

    @Override
    public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
        // we actually only add new beans, but do not post process the existing definitions
    }

    private static List<String> parseCustomerKeys(String rawCustomerKeys) {
        if (StringUtils.isEmpty(rawCustomerKeys)) {
            throw new IllegalArgumentException("Property 'customerKeys' is undefined.");
        }
        return Collections.unmodifiableList(Arrays.asList(StringUtils.split(rawCustomerKeys, ",")));
    }

    @Override
    public void setEnvironment(Environment environment) {
        this.environment = (ConfigurableEnvironment) environment;
    }

    public static class TestProperties{
        private List<String> customerNames;

        public List<String> getCustomerNames() {
            return customerNames;
        }

        public void setCustomerNames(List<String> customerNames) {
            this.customerNames = customerNames;
        }
    }
}