Inject #Parameter in different class in maven plugin - maven

I am writing a maven plugin and based on my previous experience i know that my mojo class will end up with a bunch of #Parameters to configure it. What I would like to do is instead of having those configuration parameters injected in the mojo class, I would like to have them injected in a second, configuration-only class. Is this possible?
The current way I do it is the mojo class just constructs a Configuration object where it passes all the injected parameters. Something like this
#Mojo
public class MyMojo extends AbstractMojo {
private MyConfig myConfig;
#Parameter
private String myArg1;
...
public void execute() {
myConfig = new MyConfig(myArg1, myArg2, ...);
}
}
But this is rather ugly. I want the DI to happen directly in Config

If MyConfig is a pojo, you can use the #Parameter here as well, However, you config will look like:
<configuration>
<myConfig>
<someField>value</someField>
</myConfig>
</configuration>
The second trick is to use setters, because an #Parameter-annotated field will use the matching public setter, if there is one.
private MyConfig myConfig = new MyConfig();
#Parameter
private String someField;
// matching setter for #parameter-annotated field
public void setSomeField( String field )
{
myConfig.setSomeField( field );
}

You can use your MyConfig POJO as #Parameter:
#Mojo
public class MyMojo extends AbstractMojo {
#Parameter
private MyConfig myConfig;
...
}
The rules for mapping complex objects are as follows:
There must be a private field that corresponds to name of the element being mapped. So in our case the person element must map to a person field in the mojo.
The object instantiated must be in the same package as the Mojo itself. So if your mojo is in com.mycompany.mojo.query then the mapping mechanism will look in that package for an object named Person. As you can see the mechanism will capitalize the first letter of the element name and use that to search for the object to instantiate.
Source
However, using the #Parameter for fields of MyConfig has no effect, see this thread.

Related

Copy properties from source to target class using beanutils.properties method

I have a source class Entity having some params and a target class Dto class.
Now, Entity class is having params of some other class but in dto class I'm using those params directly not using the other class reference in dto.
Problem is : while doing BeanUtils.copyProperties(source,target) those properties having reference to other class does not get copies to dto class.
Entity class:
Public class Entity{
private A a;
private String add;
}
Public class A{
private String name;
}
Dto class :
public class Dto{
private String add;
private String name; // here instead of class A i directly took the param of class A as per requirement.
}
How can I do BeanUtils.copyProperties(Entity,Dto); so that all properties get copied.
The entity class contains params from other entity class but dto does not contain the reference to other class instead directly having other class params.
Spring has the concept of Converters that are used automatically when it has to convert between classes. BeanUtils.copyProperties doesn't seem to use it, but it's should be difficult using BeanWrapper to write an alternative that loops over properties and attempts to use Converters (in this case a Converter from A to String) to copy the properties.
Alternatively there are other libraries that can do similar tasks: Dozer, ModelMapper, MapStruct just to name a few without any preference.

#Value annotation is only loading default - not using property file

Problem
I think that I havn't understood something properly because my #Value is always loading the default calue.
Java Code
So I have the following:
#Value("${disableQuerySecurityDebug:false}")
private boolean disableQuerySecurityDebug;
And this is set to false always.
Property file: application-disableQuerySecurityDebug.properties
I have a properties file called application-disableQuerySecurityDebug.properties.
And I have the following entry inside the file:
disableQuerySecurityDebugMne=true
And I run the application with the following profile: disableQuerySecurityDebugMne
I was expecting the value to be set to true, but it is always false.
Update
Based on deadpool's answer, I ended up with the following:
#Profile("disableQuerySecurityDebug") #Data
#Configuration
public class DisableSecurityConfig implements DisableQuerySecurityDebug {
#Value("${disableQuerySecurityDebug:true}")
private boolean securityDisabled;
}
#Profile("!disableQuerySecurityDebug") #Data
#Configuration
public class EnableSecurityConfig implements DisableQuerySecurityDebug{
#Value("${disableQuerySecurityDebug:false}")
private boolean securityDisabled;
}
public interface DisableQuerySecurityDebug{
public boolean isSecurityDisabled();
}
#Value annotation is only used to inject properties values into spring Beans from yml or properties file
This annotation can be used for injecting values into fields in Spring-managed beans and it can be applied at the field or constructor/method parameter level.
If you want to inject values based on profile specific then use #Profile on class
#Profile("disableQuerySecurityDebug")
#Configuration
public class Config {
#Value("${disableQuerySecurityDebug:false}")
private boolean disableQuerySecurityDebug;
}
You could also specify it on the command line by using the following switch:
java -jar demo.jar --spring.profiles.active=disableQuerySecurityDebug

How do I autowire a repository which has primitive type dependency injection?

I have three text files, they all contain data of the same type, but data is stored differently in each file.
I want to have one interface:
public interface ItemRepository() {
List<Item> getItems();
}
And instead of creating three implementations I want to create one implementation and use dependency injection to inject a path to the text file
and an analyser class for each text file:
public class ItemRepositoryImpl() implements ItemRepository {
Analyser analyser;
String path;
public ItemRepositoryImpl(Analyser analyser, String path) {
this.analyser = analyser;
this.path = path;
}
public List<Item> getItems() {
// Use injected analyser and a path to the text file to extract the data
}
}
How do I wire everything and inject the ItemRepositoryImpl into my controller?
I know I could simply do:
#Controller
public class ItemController {
#RequestMapping("/items1")
public List<Item> getItems1() {
ItemRepository itemRepository = new ItemRepositoryImpl(new Analyser1(), "file1.txt");
return itemRepository.getItems();
}
#RequestMapping("/items2")
public List<Item> getItems1() {
ItemRepository itemRepository = new ItemRepositoryImpl(new Analyser2(), "file2.txt");
return itemRepository.getItems();
}
#RequestMapping("/items3")
public List<Item> getItems1() {
ItemRepository itemRepository = new ItemRepositoryImpl(new Analyser3(), "file3.txt");
return itemRepository.getItems();
}
}
But I don't know how to configure Spring to autowire it.
You can achieve it in many different ways and it probably depends on your design.
One of them can be initialising 3 different analyzers in spring context and wiring all the three analyzers in ItemRepositoryImpl using '#Qualifier' annotation. With the help of an extra method parameter, ItemRepositoryImpl can decide which analyzer it should route the requests to.
For the path variable also you can follow a similar approach.
If your question is specific about how to wire the primitive type in the bean, check this post . It specifies how to initialize a String variable in spring context.

How do I mock an autowired #Value field in Spring with Mockito?

I'm using Spring 3.1.4.RELEASE and Mockito 1.9.5. In my Spring class I have:
#Value("#{myProps['default.url']}")
private String defaultUrl;
#Value("#{myProps['default.password']}")
private String defaultrPassword;
// ...
From my JUnit test, which I currently have set up like so:
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration({ "classpath:test-context.xml" })
public class MyTest
{
I would like to mock a value for my "defaultUrl" field. Note that I don't want to mock values for the other fields — I'd like to keep those as they are, only the "defaultUrl" field. Also note that I have no explicit "setter" methods (e.g. setDefaultUrl) in my class and I don't want to create any just for the purposes of testing.
Given this, how can I mock a value for that one field?
You can use the magic of Spring's ReflectionTestUtils.setField in order to avoid making any modifications whatsoever to your code.
The comment from Michał Stochmal provides an example:
use ReflectionTestUtils.setField(bean, "fieldName", "value"); before invoking your bean method during test.
Check out this tutorial for even more information, although you probably won't need it since the method is very easy to use
UPDATE
Since the introduction of Spring 4.2.RC1 it is now possible to set a static field without having to supply an instance of the class. See this part of the documentation and this commit.
It was now the third time I googled myself to this SO post as I always forget how to mock an #Value field. Though the accepted answer is correct, I always need some time to get the "setField" call right, so at least for myself I paste an example snippet here:
Production class:
#Value("#{myProps[‘some.default.url']}")
private String defaultUrl;
Test class:
import org.springframework.test.util.ReflectionTestUtils;
ReflectionTestUtils.setField(instanceUnderTest, "defaultUrl", "http://foo");
// Note: Don't use MyClassUnderTest.class, use the instance you are testing itself
// Note: Don't use the referenced string "#{myProps[‘some.default.url']}",
// but simply the FIELDs name ("defaultUrl")
You can use this magic Spring Test annotation :
#TestPropertySource(properties = { "my.spring.property=20" })
see
org.springframework.test.context.TestPropertySource
For example, this is the test class :
#ContextConfiguration(classes = { MyTestClass.Config.class })
#TestPropertySource(properties = { "my.spring.property=20" })
public class MyTestClass {
public static class Config {
#Bean
MyClass getMyClass() {
return new MyClass ();
}
}
#Resource
private MyClass myClass ;
#Test
public void myTest() {
...
And this is the class with the property :
#Component
public class MyClass {
#Value("${my.spring.property}")
private int mySpringProperty;
...
I'd like to suggest a related solution, which is to pass the #Value-annotated fields as parameters to the constructor, instead of using the ReflectionTestUtils class.
Instead of this:
public class Foo {
#Value("${foo}")
private String foo;
}
and
public class FooTest {
#InjectMocks
private Foo foo;
#Before
public void setUp() {
ReflectionTestUtils.setField(Foo.class, "foo", "foo");
}
#Test
public void testFoo() {
// stuff
}
}
Do this:
public class Foo {
private String foo;
public Foo(#Value("${foo}") String foo) {
this.foo = foo;
}
}
and
public class FooTest {
private Foo foo;
#Before
public void setUp() {
foo = new Foo("foo");
}
#Test
public void testFoo() {
// stuff
}
}
Benefits of this approach: 1) we can instantiate the Foo class without a dependency container (it's just a constructor), and 2) we're not coupling our test to our implementation details (reflection ties us to the field name using a string, which could cause a problem if we change the field name).
You can also mock your property configuration into your test class
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration({ "classpath:test-context.xml" })
public class MyTest
{
#Configuration
public static class MockConfig{
#Bean
public Properties myProps(){
Properties properties = new Properties();
properties.setProperty("default.url", "myUrl");
properties.setProperty("property.value2", "value2");
return properties;
}
}
#Value("#{myProps['default.url']}")
private String defaultUrl;
#Test
public void testValue(){
Assert.assertEquals("myUrl", defaultUrl);
}
}
I used the below code and it worked for me:
#InjectMocks
private ClassABC classABC;
#Before
public void setUp() {
ReflectionTestUtils.setField(classABC, "constantFromConfigFile", 3);
}
Reference: https://www.jeejava.com/mock-an-autowired-value-field-in-spring-with-junit-mockito/
Also note that I have no explicit "setter" methods (e.g. setDefaultUrl) in my class and I don't want to create any just for the purposes of testing.
One way to resolve this is change your class to use Constructor Injection, that can be used for testing and Spring injection. No more reflection :)
So, you can pass any String using the constructor:
class MySpringClass {
private final String defaultUrl;
private final String defaultrPassword;
public MySpringClass (
#Value("#{myProps['default.url']}") String defaultUrl,
#Value("#{myProps['default.password']}") String defaultrPassword) {
this.defaultUrl = defaultUrl;
this.defaultrPassword= defaultrPassword;
}
}
And in your test, just use it:
MySpringClass MySpringClass = new MySpringClass("anyUrl", "anyPassword");
Whenever possible, I set the field visibility as package-protected so it can be accessed from the test class. I document that using Guava's #VisibleForTesting annotation (in case the next guy wonders why it's not private). This way I don't have to rely on the string name of the field and everything stays type-safe.
I know it goes against standard encapsulation practices we were taught in school. But as soon as there is some agreement in the team to go this way, I found it the most pragmatic solution.
Another way is to use #SpringBootTest annotation properties field.
Here we override example.firstProperty property:
#SpringBootTest(properties = { "example.firstProperty=annotation" })
public class SpringBootPropertySourceResolverIntegrationTest {
#Autowired private PropertySourceResolver propertySourceResolver;
#Test
public void shouldSpringBootTestAnnotation_overridePropertyValues() {
String firstProperty = propertySourceResolver.getFirstProperty();
String secondProperty = propertySourceResolver.getSecondProperty();
Assert.assertEquals("annotation", firstProperty);
Assert.assertEquals("defaultSecond", secondProperty);
}
}
As you can see It overrides only one property. Properties not mentioned in #SpringBootTest stay untouched. Therefore, this is a great solution when we need to override only specific properties for the test.
For single property you can write it without braces:
#SpringBootTest(properties = "example.firstProperty=annotation")
Answer from: https://www.baeldung.com/spring-tests-override-properties#springBootTest
I also encourage you to whenever possible pass property as a parameter in constructor like in Dherik answer (https://stackoverflow.com/a/52955459/1673775) as it enables you to mock properties easily in unit tests.
However in integration tests you often don't create objects manually, but:
you use #Autowired
you want to modify property used in a class that is used in your integration test indirectly as it is deep dependency of some directly used class.
then this solution with #SpringBootTest might be helpful.

Util class for accesing a Service in Spring 3

In Spring 3 it is not possible to set #Autowired in either static fields or methods, so since I want to declare an utility class such as:
public class SchoolYearServiceUtil {
private static SchoolYearService schoolYearService;
public static SchoolYear getSchoolYear(Long id) {
return schoolYearService.get(id);
}
}
to avoid having to inject the schoolYearService everywhere (jsp, command class...) in which I need it. In this case, I don't need an interface to be implemented by SchoolYearServiceUtil.
I don't want to have to initialize the object through code but getting the same instance as the Spring's one.
Which would be the best option to implement the getSchoolYear as a static method?
Thanks.
Would this be conceptually wrong?:
#Component
public class SchoolYearServiceUtil {
private static SchoolYearService schoolYearService;
#Autowired(required = true)
private SchoolYearServiceUtil(#Qualifier("schoolYearServiceImpl") SchoolYearService schoolYearService) {
SchoolYearServiceUtil.schoolYearService = schoolYearService;
}
public static SchoolYearService getSchoolYearService() {
return schoolYearService;
}
public static SchoolYear getSchoolYear(Long id) {
return getSchoolYearService().get(id);
}
}
I would have to make sure that only Spring calls once the constructor and the constructor is called nowhere else, that's why I declared the constructor as private.
I fully support skaffman's comment. You don't need static fields with DI. You just define a bean of scope singleton (default).
There is a way to obtain a bean statically, but you should be aware that it is not to be used in regular situations. (there are some valid applications). It is to use the WebApplicationContextUtils.getRequiredWebApplicationContext(servletContext)
You notice that you need to pass a ServletContext argument.

Resources