CODEWITHSUNDEEP
javaspringjavabeans
lisak
lisak

Reputation: 21981

java/spring printing out bean property values

does anybody have a simple way of printing out bean property values ? Without complicated instrospection constructs via getting propertyDescriptors etc. I'm talking about testing and checking that all properties have correct values, during development.

Upvotes: 4

Views: 9768

Answers (5)

user590444
user590444

Reputation: 4332

Add custom <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">

where 

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

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

    @Override
    protected String resolveSystemProperty(String key)

Upvotes: 0

Will
Will

Reputation: 6286

For a one liner can use the gson library.

new Gson().toJson(myObject)

For 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>

Upvotes: 0

Sean Patrick Floyd
Sean Patrick Floyd

Reputation: 299208

PropertyDescriptors are the way to go, but Spring makes using them a lot easier if you use the BeanWrapper interface.

Here's a stupid test class:

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;
    }
}

And here's a main method to inspect an instance of it:

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));
    }
}

Output:

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

Read this for reference:

Upvotes: 6

Jaydeep Patel
Jaydeep Patel

Reputation: 2423

BeanPostProcessor may be able to help you. postProcessBeforeInitialization() method will be called for each bean initialization and you can print values of properties there.

Post processor class:

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;
    }
}

Declare bean in bean file:

<bean class="ExampleBeanPostProcessor " />

Upvotes: 0

Roman
Roman

Reputation: 66216

JSR-305: Annotations for Software Defect Detection

Upvotes: 0

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