context:component-scan

<context:component-scan/> 配置项不但启用了对类包进行扫描以实施注释驱动 Bean 定义的功能,同时还启用了注释驱动自动注入的功能(即还隐式地在内部注册了 AutowiredAnnotationBeanPostProcessor 和 CommonAnnotationBeanPostProcessor),因此当使用 <context:component-scan/> 后,就可以将 <context:annotation-config/> 移除了。

<context:component-scan/> 的 base-package 属性指定了需要扫描的类包,类包及其递归子包中所有的类都会被处理。
相关阅读: spring组件扫描<context:component-scan/>使用详解
name-generator:指定产生规则
当一个 Bean 被自动检测到时,会根据那个扫描器的 BeanNameGenerator 策略生成它的 bean 名称。默认情况下,对于包含 name 属性的 @Component、@Repository、 @Service 和 @Controller,会把 name 取值作为 Bean 的名字。如果这个注解不包含 name 值或是其他被自定义过滤器发现的组件,默认 Bean 名称会是小写开头的非限定类名。如果你不想使用默认 bean 命名策略,可以提供一个自定义的命名策略。

If you do not want to rely on the default bean-naming strategy, you can provide a custom
bean-naming strategy. First, implement the BeanNameGenerator interface, and be sure to
include a default no-arg constructor. Then, provide the fully-qualified class name when
configuring the scanner:
<beans>
<context:component-scan base-package="org.example"
name-generator="org.example.MyNameGenerator" />
</beans>
实行示例
package pub.spring;

import org.springframework.beans.factory.annotation.AnnotatedBeanDefinition;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.context.annotation.AnnotationBeanNameGenerator;
import org.springframework.core.type.AnnotationMetadata;


public class BeanNameGenerator extends AnnotationBeanNameGenerator {

	private String BASE_PACKAGE_NAME;

	private String convertJavaNameToUrlName(String name) {
		StringBuilder sb = new StringBuilder();
		for (int n = 0; n < name.length(); n++) {
			char c = name.charAt(n);
			if (Character.isUpperCase(c)) {
				if (n > 0) {
					sb.append('_');
				}
				c = Character.toLowerCase(c);
			}
			sb.append(c);
		}
		return sb.toString();
	}

	@Override
	public String generateBeanName(BeanDefinition definition, BeanDefinitionRegistry registry) {
		String name;
		String className = definition.getBeanClassName();

		final String CONTROLLER_POSTFIX = "Action";
		if (className.endsWith(CONTROLLER_POSTFIX)) {

			String suffix = null;

			AnnotatedBeanDefinition annotatedDef = (AnnotatedBeanDefinition) definition;
			AnnotationMetadata amd = annotatedDef.getMetadata();

			final String controllerAnnotation = "org.springframework.stereotype.Controller";
			String controllerName = (String) amd.getAnnotationAttributes(controllerAnnotation).get("value");
			if (controllerName != null && controllerName.length() > 0) {
				// explicit specified postfix
				if (controllerName.charAt(0) == '.') {
					suffix = controllerName;
				}
				// for backword compatible
				// explicit specified struts uri
				else if (controllerName.indexOf('.') == -1) {
					return controllerName + ".do";
				}
				// explicit specified uri
				else {
					return controllerName;
				}
			}

			if (BASE_PACKAGE_NAME == null) {
				BASE_PACKAGE_NAME = className.substring(0,
					className.indexOf(".web.") + ".web".length());
			}

			int pos = className.lastIndexOf('.');
			String namePart = className.substring(pos + 1,
				className.length() - CONTROLLER_POSTFIX.length());
			namePart = convertJavaNameToUrlName(namePart);

			String packagePart = className.substring(BASE_PACKAGE_NAME.length(), pos);
			if (packagePart.indexOf('_') != -1) {
				packagePart = packagePart.replace("_.", ".");
			}
			assert packagePart.endsWith(".action");
			packagePart = packagePart.substring(0, packagePart.length() - ".action".length());

			name = packagePart + '.' + namePart;

			if (name.startsWith(".app.")) {
				name = name.substring(".app".length());
			}

			// postfix specified
			if (suffix != null) {
				// do nothing
			}
			// common .do actions
			else if (name.endsWith(".operate") ||
				name.endsWith(".functions")) {
				suffix = ".do";
			}
			//fall back to html
			else {
				suffix = ".html";
			}
			name = name.replace('.', '/') + suffix;
		}
		else {
			name = super.generateBeanName(definition, registry);
		}
		return name;
	}

}


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