分支名称：bean-definition-and-bean-definition-register
主要增加如下类：
- BeanDefinition，顾名思义，用于定义bean信息的类，包含bean的class类型、构造参数、属性值等信息，每个bean对应一个BeanDefinition的实例。简化BeanDefinition仅包含bean的class类型。
- BeanDefinitionRegistry，BeanDefinition注册表接口，定义注册BeanDefinition的方法。
- SingletonBeanRegistry及其实现类DefaultSingletonBeanRegistry，定义添加和获取单例bean的方法。
- BeanFactory, bean工厂接口，包含获取bean方法
bean容器(DefaultListableBeanFactory)作为BeanDefinitionRegistry和SingletonBeanRegistry的实现类，具备两者的能力。向bean容器中注册BeanDefinition后，使用bean时才会实例化。
public class TestBeanFactory {
@Test
public void beanDefinitionAndBeanRegisterTest() throws BeanException {
DefaultListableBeanFactory defaultListableBeanFactory = new DefaultListableBeanFactory();
BeanDefinition helloWorldBeanDefinition = new BeanDefinition(HelloWorldBean.class);
defaultListableBeanFactory.registerBeanDefinition("helloWorldBean",helloWorldBeanDefinition);
HelloWorldBean helloWorldBean = (HelloWorldBean)defaultListableBeanFactory.getBean("helloWorldBean");
Assert.assertEquals(helloWorldBean.hello(),"HelloWorldBean.hello");
}
}分支名称：instantiation-strategy
bean = beanClass.newInstance(); 仅适用无参构造bean的情况，需要完善实例化策略
主要增加如下类： 抽象出一个bean实例化策略的接口InstantiationStrategy，有两个实现类
- SimpleInstantiationStrategy，通过构造函数的方式进行实例化
- CglibSubClassingInstatiationStrategy，通过Cglib动态代理实现子类
分支名称：decorate-bean-with-property-values
BeanDefinition 中添加对应bean属性的PropertyValues 成员变量 PropertyValue 包括 name和value 两个属性
测试示例
public class BeanWithPropertyValuesTest {
@Test
public void testBeanWithPropertyValues() throws BeanException {
DefaultListableBeanFactory beanFactory = new DefaultListableBeanFactory();
PropertyValues propertyValues = new PropertyValues();
propertyValues.addPropertyValue(new PropertyValue("name","helloWorld"));
propertyValues.addPropertyValue(new PropertyValue("age",18));
BeanDefinition beanDefinition = new BeanDefinition(Person.class,propertyValues);
beanFactory.registerBeanDefinition("person",beanDefinition);
Person person = (Person)beanFactory.getBean("person");
Assertions.assertNotNull(person);
Assertions.assertEquals(person.getAge(),18);
Assertions.assertEquals(person.getName(),"helloWorld");
}
}分支: bean-with-bean
- 增加BeanReference类，表示一个bean对另一个bean的引用。如果beanA 的属性 PropertyValue#value为beanDefinition类型，依赖bean B，则先实例化 bean B,再作为PropertyValue属性注入。暂时不支持循环依赖.....
protected void applyPropertyValues(String beanName, Object bean, BeanDefinition beanDefinition) throws BeanException {
try {
for (PropertyValue propertyValue : beanDefinition.getPropertyValues().getPropertyValueList()) {
String name = propertyValue.getName();
Object value = propertyValue.getValue();
//bean A 依赖bean B , 实例化bean B后再实例化bean A
if(value instanceof BeanReference){
BeanReference beanReference =(BeanReference)value;
value = getBean(beanReference.getBeanName());
}
//通过反射设置属性
BeanUtil.setFieldValue(bean, name, value);
}
} catch (Exception ex) {
throw new BeanException("Error setting property values for bean: " + beanName, ex);
}
}
测试示例
public class BeanWithPropertyValuesTest {
@Test
public void testPopulateBeanWithBean() throws Exception {
DefaultListableBeanFactory beanFactory = new DefaultListableBeanFactory();
//注册Plane实例
PropertyValues propertyValuesForPlane = new PropertyValues();
propertyValuesForPlane.addPropertyValue(new PropertyValue("nation", "CN"));
BeanDefinition planeBeanDefinition = new BeanDefinition(Plane.class, propertyValuesForPlane);
beanFactory.registerBeanDefinition("plane", planeBeanDefinition);
//注册Person实例
PropertyValues propertyValuesForPerson = new PropertyValues();
propertyValuesForPerson.addPropertyValue(new PropertyValue("name", "derek"));
propertyValuesForPerson.addPropertyValue(new PropertyValue("age", 18));
//Person实例依赖Plane实例
propertyValuesForPerson.addPropertyValue(new PropertyValue("plane", new BeanReference("plane")));
BeanDefinition beanDefinition = new BeanDefinition(Person.class, propertyValuesForPerson);
beanFactory.registerBeanDefinition("person", beanDefinition);
Person person = (Person) beanFactory.getBean("person");
System.out.println(person);
Assertions.assertEquals(person.getName(),"derek");
Assertions.assertEquals(person.getAge(),18);
Plane plane = person.getPlane();
Assertions.assertNotNull(plane);
//assertThat(car).isNotNull();
Assertions.assertEquals(plane.getNation(),"CN");
//assertThat(car.getBrand()).isEqualTo("porsche");
}
}分支名称：resource-and-resource-loader
- 新增 资源加载器ResourceLoader和资源的抽象和访问接口Resource 两个接口
- ClassPathResource 类路径下资源获取
- FileSystemResource 系统文件资源获取
- URLResource 网络资源获取 DefaultResourceLoader 资源加载器默认实现类
public class ResourceAndResourceLoaderTest {
@Test
public void testResourceLoader() throws IOException {
DefaultResourceLoader defaultResourceLoader = new DefaultResourceLoader();
// 加载classpath下的资源，classpath读取 resources文件夹下的文件
Resource resource = defaultResourceLoader.getResource("classpath:testMain.txt");
InputStream inputStream = resource.getInputStream();
String readUtf8 = IoUtil.readUtf8(inputStream);
System.out.println(readUtf8);
//加载网络URL资源
Resource urlResource = defaultResourceLoader.getResource("https://www.baidu.com");
Assertions.assertInstanceOf(URLResource.class,urlResource,"加载结果类型错误...");
InputStream urlResourceInputStream = urlResource.getInputStream();
String urlStream = IoUtil.readUtf8(urlResourceInputStream);
System.out.println(urlStream);
//加载系统文件
Resource fsResource = defaultResourceLoader.getResource("src/test/java/org/sunhb/testPath.java");
Assertions.assertInstanceOf(FileSystemResource.class,fsResource,"加载结果类型错误...");
InputStream fsResourceInputStream = fsResource.getInputStream();
String readUtf81 = IoUtil.readUtf8(fsResourceInputStream);
System.out.println(readUtf81);
}
}分支名称：xml-define-bean
xml中显式定义bean的信息，resourceloader加载xml文件，解析出bean信息后，加载进bean容器中
BeanDefinitionReader 是bean定义的读取接口，可以读取bean定义资源，包含ResourceLoader接口，AbstractBeanDefinitionReader 是BeanDefinitionReader的抽象实现类 XmlBeanDefinitionReader 是xml文件中读取bean的实现类。同时，BeanDefinitionReader 应该能够向容器中注入 BeanDefinition, 包含 BeanDefinitionRegister 接口。AbstractBeanDefinitionReader包含BeanDefinitionRegister 和 ResourceLoader 两个接口，是BeanDefinitionReader的抽象实现类。
public abstract class AbstractBeanDefinitionReader implements BeanDefinitionReader {
private final BeanDefinitionRegister register;
private ResourceLoader resourceLoader;
}
xml文件定义bean
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd">
<bean id="person" class="org.sunhb.bean.Person">
<property name="name" value="sunhb"/>
<property name="plane" ref="plane"/>
<property name="age" value="18"/>
</bean>
<bean id="plane" class="org.sunhb.bean.Plane">
<property name="nation" value="CN"/>
</bean>
</beans>测试示例
public class XMLFileDefineBeanTest {
@Test
public void testXmlFile(){
//构建beanFactory
DefaultListableBeanFactory beanFactory = new DefaultListableBeanFactory();
XmlBeanDefinitionReader beanDefinitionReader = new XmlBeanDefinitionReader(beanFactory);
beanDefinitionReader.loadBeanDefinitions("classpath:spring.xml");
Person person = (Person)beanFactory.getBean("person");
System.out.println(person);
}
}
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