package com.boot.condition.bootconditionconfig.converter;

/**

 * 编码格式转换器接口

 */

public interface EncodingConverter {

}

package com.boot.condition.bootconditionconfig.converter;

public class GBKEncodingConverter implements EncodingConverter {

}

package com.boot.condition.bootconditionconfig.converter;

public class UTF8EncodingConverter implements EncodingConverter {

}

package com.boot.condition.bootconditionconfig.config;

import com.boot.condition.bootconditionconfig.condition.GBKCondition;

import com.boot.condition.bootconditionconfig.condition.UTF8Condition;

import com.boot.condition.bootconditionconfig.converter.EncodingConverter;

import com.boot.condition.bootconditionconfig.converter.GBKEncodingConverter;

import com.boot.condition.bootconditionconfig.converter.UTF8EncodingConverter;

import org.springframework.boot.SpringBootConfiguration;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Conditional;

/**

 * 使用按照条件装配的过程:

 * 1、@Conditional [value值必须是实现Condition接口的类]

 * 2、根据接口中的matches方法的返回结果确定是否装配bean对象到spring容器中

 *    false 不装配 ， true 就会装配到spring容器中

 */

@SpringBootConfiguration

// @Conditional(UTF8Condition.class)

public class EncodingConverterConfig {

    @Bean

    @Conditional(UTF8Condition.class)

    public EncodingConverter createUTF8Converter() {

        return new UTF8EncodingConverter();

    }

    @Bean

    @Conditional(GBKCondition.class)

    public EncodingConverter createGBKConverter() {

        return new GBKEncodingConverter();

    }

}

package com.boot.condition.bootconditionconfig.condition;

import org.springframework.context.annotation.Condition;

import org.springframework.context.annotation.ConditionContext;

import org.springframework.core.type.AnnotatedTypeMetadata;

public class GBKCondition implements Condition {

    @Override

    public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {

        String encoding = System.getProperty("file.encoding");

        if ("gbk".equals(encoding.toLowerCase())) {

            return true;

        }

        return false;

    }

}

package com.boot.condition.bootconditionconfig.condition;

import org.springframework.context.annotation.Condition;

import org.springframework.context.annotation.ConditionContext;

import org.springframework.core.type.AnnotatedTypeMetadata;

public class UTF8Condition implements Condition {

    @Override

    public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {

        String encoding = System.getProperty("file.encoding");

        if ("utf-8".equals(encoding.toLowerCase())) {

            return true;

        }

        return false;

    }

}

package com.boot.condition.bootconditionconfig;

import com.boot.condition.bootconditionconfig.converter.EncodingConverter;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.context.ConfigurableApplicationContext;

import java.util.Map;

@SpringBootApplication

public class BootConditionConfigApplication {

    public static void main(String[] args) {

        ConfigurableApplicationContext context =

                SpringApplication.run(BootConditionConfigApplication.class, args);

        Map<String, EncodingConverter> beansOfType = context.getBeansOfType(EncodingConverter.class);

        System.out.println(beansOfType);

        // 使用获取系统的编码格式的系统变量的key

        System.out.println(System.getProperty("file.encoding"));

        context.close();

    }

}