Java/Spring打印bean属性值

PropertyDescriptor是一种方法,但是如果使用 BeanWrapper 接口。

这是一个愚蠢的测试班:

public class Thingy{
    private final String foo = "hey";
    private final int bar = 123;
    private final List<String> grr = Arrays.asList("1", "2", "3");

    public String getFoo(){
        return this.foo;
    }
    public int getBar(){
        return this.bar;
    }
    public List<String> getGrr(){
        return this.grr;
    }
}

下面是检查它的一个实例的主要方法:

public static void main(final String[] args) throws Exception{
    final Thingy thingy = new Thingy();
    final BeanWrapper wrapper = new BeanWrapperImpl(thingy);
    for(final PropertyDescriptor descriptor : wrapper.getPropertyDescriptors()){
        System.out.println(descriptor.getName() + ":"
            + descriptor.getReadMethod().invoke(thingy));
    }
}

输出:

bar:123
class:class com.mypackage.Thingy
foo:hey
grr:[1, 2, 3]

阅读本文件以供参考:

• Bean manipulation and the BeanWrapper

JSR-305: Annotations for Software Defect Detection

BeanPostProcessor 也许能帮助你。将为每个bean初始化调用postprocessbeforeinitialization()方法,您可以在那里打印属性值。

后处理器类:

public class ExampleBeanPostProcessor implements BeanPostProcessor {
    public Object postProcessBeforeInitialization(Object bean, String beanName)
        throws BeansException {
        if (bean instanceof YourBean)
            System.out.println((YourBean) bean).getSomeProp());
        return bean;
    }
    public Object postProcessAfterInitialization(Object bean, String beanName)
        throws BeansException {
        return bean;
    }
}

在bean文件中声明bean:

<bean class="ExampleBeanPostProcessor " />

对于一个内衬,可以使用 gson 图书馆。

new Gson().toJson(myObject)

对于Maven:

<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
    <version>2.1</version>
    <scope>test</scope> <!-- remove you use gson in production -->
</dependency>

添加自定义 <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">

在哪里?

 @Override
    protected String resolvePlaceholder(String placeholder, Properties props) 

@Override
    protected String resolvePlaceholder(String placeholder, Properties props, int             systemPropertiesMode) 

    @Override
    protected String resolveSystemProperty(String key)