public class SimpleFactoryBean implements FactoryBean<Cat> {
    @Override
    public Cat getObject() throws Exception {
        // 創(chuàng)建Cat對象并且返回
        return new Cat("Tom");
    }
    @Override
    public Class<?> getObjectType() {
        return Cat.class;
    }
}

其實這里就相當(dāng)于在配置文件里創(chuàng)建了一個bean標(biāo)簽。

<bean class="com.text.registrar.SimpleFactoryBean" id="cat"></bean>

?? 需要加載的類

public class Cat {
    String name;
    public Cat(String name) {
        this.name = name;
    }
}

?? 啟動類里面創(chuàng)建方法加載Bean

@SpringBootApplication
public class SpringbootApplication {
    public static void main(String[] args) {
        ConfigurableApplicationContext run = SpringApplication.run(SpringbootApplication.class, args);
    }
    // 等價于配置文件配置
    @Bean
    public SimpleFactoryBean catFactoryBean() {
        return new SimpleFactoryBean();
    }
}

二、高級使用

讓Spring容器通過FactoryBean創(chuàng)建指定接口的動態(tài)代理對象。

創(chuàng)建FactoryBean，可以生成任意接口的動態(tài)代理對象

?? 創(chuàng)建一個接口

public interface MyUserMapper {
    void select();
}

?? 創(chuàng)建一個FactoryBean實現(xiàn)類

可以通過傳入接口的全類名，創(chuàng)建動態(tài)代理對象。

public class MapperFactoryBean implements FactoryBean {
    /**
     * 用于保存接口的全類名
     */
    private String className;
    public MapperFactoryBean(String className) {
        this.className = className;
    }
    @Override
    public Object getObject() throws Exception {
        Class<?> interfaceClass = Class.forName(className);
        // 生成動態(tài)代理對象返回
        Object proxyInstance = Proxy.newProxyInstance(MapperFactoryBean.class.getClassLoader(), new Class[]{interfaceClass}, new InvocationHandler() {
            @Override
            public Object invoke(Object o, Method method, Object[] objects) throws Throwable {
                // 獲取當(dāng)前方法名
                System.out.println(method.getName());
                if ("select".equals((method.getName()))) {
                    System.out.println(className + "動態(tài)代理對象的select方法被執(zhí)行了??！");
                }
                return null;
            }
        });
        return proxyInstance;
    }
    @Override
    public Class<?> getObjectType() {
        try {
            Class<?> interfaceCLass = Class.forName(className);
            return interfaceCLass;
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        return null;
    }
}

?? 啟動類里面創(chuàng)建方法加載Bean

@SpringBootApplication
public class SpringbootApplication {
    public static void main(String[] args) {
        ConfigurableApplicationContext run = SpringApplication.run(SpringbootApplication.class, args);
        run.getBean(MyUserMapper.class);
    }
    // 等價于配置文件配置
    @Bean
    public MapperFactoryBean mapperFactoryBean() {
        return new MapperFactoryBean("com.test.registrar.MyUserMapper");
    }
}

到此這篇關(guān)于Spring詳細(xì)講解FactoryBean接口的使用的文章就介紹到這了,更多相關(guān)Spring FactoryBean內(nèi)容請搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！

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