spring的ConversionService分析

左手的ㄟ右手 2022-11-11 14:54 139阅读 0赞

## 1：说明 ##

这是spring用来进行数据类型转化定义的接口，功能同[JDK的PropertyEditor简单使用  
][JDK_PropertyEditor_]，源码如下：

org.springframework.core.convert.ConversionService
    public interface ConversionService { 
    	// sourceType类型是否可以转换为targetType类型
    	boolean canConvert(@Nullable Class<?> sourceType, Class<?> targetType);
    	// sourceType的类型描述符，是否可以转换为targetType的类型描述符
    	boolean canConvert(@Nullable TypeDescriptor sourceType, TypeDescriptor targetType);
    	// 转换source为targetType
    	@Nullable
    	<T> T convert(@Nullable Object source, Class<T> targetType);
    	// 转换source+sourceType为targetType
    	@Nullable
    	Object convert(@Nullable Object source, @Nullable TypeDescriptor sourceType, TypeDescriptor targetType);
    }

## 1：测试 ##

@Test
    public void testConversionService() { 
        DefaultConversionService cs
                = new DefaultConversionService();
        // 检测int类型是否可以转换为String类型（true）
        boolean intToStringCanConvert = cs.canConvert(int.class, String.class);
        System.out.println("intToStringCanConvert: ");
        System.out.println(intToStringCanConvert);
        // 检测map类型是否可以转换为int类型
        boolean mapToIntCanConvert = cs.canConvert(Map.class, int.class);
        System.out.println("mapToIntCanConvert: ");
        System.out.println(mapToIntCanConvert);
        String intInStringType = "900";
        // 转换String为int类型结果
        Integer targetIntType = cs.convert(intInStringType, int.class);
        System.out.println("targetIntType: ");
        System.out.println(targetIntType);
    }

运行：

intToStringCanConvert: 
    true
    mapToIntCanConvert: 
    false
    targetIntType: 
    900
    
    Process finished with exit code 0

[JDK_PropertyEditor_]: https://blog.csdn.net/wang0907/article/details/115043257