JAVA-1526: Copy three @Value related articles to spring-boot-properties-2

spring-boot-modules/spring-boot-properties-2/README.md

@@ -4,3 +4,6 @@ This module contains articles about Properties in Spring Boot.
 
 ### Relevant Articles:
 - [Load Spring Boot Properties From a JSON File](https://www.baeldung.com/spring-boot-json-properties)
+- [A Quick Guide to Spring @Value](https://www.baeldung.com/spring-value-annotation)
+- [Using Spring @Value with Defaults](https://www.baeldung.com/spring-value-defaults)
+- [How to Inject a Property Value Into a Class Not Managed by Spring?](https://www.baeldung.com/inject-properties-value-non-spring-class)

spring-boot-modules/spring-boot-properties-2/src/main/java/com/baeldung/properties/value/ClassNotManagedBySpring.java

@@ -0,0 +1,28 @@
+package com.baeldung.properties.value;
+
+public class ClassNotManagedBySpring {
+
+    private String customVariable;
+    private String anotherCustomVariable;
+
+    public ClassNotManagedBySpring(String someInitialValue, String anotherManagedValue) {
+        this.customVariable = someInitialValue;
+        this.anotherCustomVariable = anotherManagedValue;
+    }
+
+    public String getCustomVariable() {
+        return customVariable;
+    }
+
+    public void setCustomVariable(String customVariable) {
+        this.customVariable = customVariable;
+    }
+
+    public String getAnotherCustomVariable() {
+        return anotherCustomVariable;
+    }
+
+    public void setAnotherCustomVariable(String anotherCustomVariable) {
+        this.anotherCustomVariable = anotherCustomVariable;
+    }
+}

spring-boot-modules/spring-boot-properties-2/src/main/java/com/baeldung/properties/value/CollectionProvider.java

@@ -0,0 +1,27 @@
+package com.baeldung.properties.value;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.PropertySource;
+import org.springframework.stereotype.Component;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+@Component
+@PropertySource("classpath:values.properties")
+public class CollectionProvider {
+
+    private final List<String> values = new ArrayList<>();
+
+    public Collection<String> getValues() {
+        return Collections.unmodifiableCollection(values);
+    }
+
+    @Autowired
+    public void setValues(@Value("#{'${listOfValues}'.split(',')}") List<String> values) {
+        this.values.addAll(values);
+    }
+}

spring-boot-modules/spring-boot-properties-2/src/main/java/com/baeldung/properties/value/InitializerBean.java

@@ -0,0 +1,21 @@
+package com.baeldung.properties.value;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+
+@Component
+public class InitializerBean {
+
+    private String someInitialValue;
+    private String anotherManagedValue;
+
+    public InitializerBean(@Value("someInitialValue") String someInitialValue, @Value("anotherValue") String anotherManagedValue) {
+        this.someInitialValue = someInitialValue;
+        this.anotherManagedValue = anotherManagedValue;
+    }
+
+    public ClassNotManagedBySpring initClass() {
+        return new ClassNotManagedBySpring(this.someInitialValue, this.anotherManagedValue);
+    }
+
+}

spring-boot-modules/spring-boot-properties-2/src/main/java/com/baeldung/properties/value/PriorityProvider.java

@@ -0,0 +1,22 @@
+package com.baeldung.properties.value;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.PropertySource;
+import org.springframework.stereotype.Component;
+
+@Component
+@PropertySource("classpath:values.properties")
+public class PriorityProvider {
+
+    private final String priority;
+
+    @Autowired
+    public PriorityProvider(@Value("${priority:normal}") String priority) {
+        this.priority = priority;
+    }
+
+    public String getPriority() {
+        return priority;
+    }
+}

spring-boot-modules/spring-boot-properties-2/src/main/java/com/baeldung/properties/value/SomeBean.java

@@ -0,0 +1,17 @@
+package com.baeldung.properties.value;
+
+public class SomeBean {
+    private int someValue;
+
+    public SomeBean(int someValue) {
+        this.someValue = someValue;
+    }
+
+    public int getSomeValue() {
+        return someValue;
+    }
+
+    public void setSomeValue(int someValue) {
+        this.someValue = someValue;
+    }
+}

spring-boot-modules/spring-boot-properties-2/src/main/java/com/baeldung/properties/value/ValuesApp.java

@@ -0,0 +1,101 @@
+package com.baeldung.properties.value;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.PropertySource;
+
+import javax.annotation.PostConstruct;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+
+@Configuration
+@PropertySource(name = "myProperties", value = "values.properties")
+public class ValuesApp {
+
+    @Value("string value")
+    private String stringValue;
+
+    @Value("${value.from.file}")
+    private String valueFromFile;
+
+    @Value("${systemValue}")
+    private String systemValue;
+
+    @Value("${unknown_param:some default}")
+    private String someDefault;
+
+    @Value("${priority}")
+    private String prioritySystemProperty;
+
+    @Value("${listOfValues}")
+    private String[] valuesArray;
+
+    @Value("#{systemProperties['priority']}")
+    private String spelValue;
+
+    @Value("#{systemProperties['unknown'] ?: 'some default'}")
+    private String spelSomeDefault;
+
+    @Value("#{someBean.someValue}")
+    private Integer someBeanValue;
+
+    @Value("#{'${listOfValues}'.split(',')}")
+    private List<String> valuesList;
+	
+    @Value("#{${valuesMap}}")
+    private Map<String, Integer> valuesMap;
+
+    @Value("#{${valuesMap}.key1}")
+    private Integer valuesMapKey1;
+
+    @Value("#{${valuesMap}['unknownKey']}")
+    private Integer unknownMapKey;
+
+    @Value("#{${unknownMap : {key1:'1', key2 : '2'}}}")
+    private Map<String, Integer> unknownMap;
+
+    @Value("#{${valuesMap}['unknownKey'] ?: 5}")
+    private Integer unknownMapKeyWithDefaultValue;
+
+    @Value("#{${valuesMap}.?[value>'1']}")
+    private Map<String, Integer> valuesMapFiltered;
+
+    @Value("#{systemProperties}")
+    private Map<String, String> systemPropertiesMap;
+
+    public static void main(String[] args) {
+        System.setProperty("systemValue", "Some system parameter value");
+        System.setProperty("priority", "System property");
+        ApplicationContext applicationContext = new AnnotationConfigApplicationContext(ValuesApp.class);
+    }
+
+    @Bean
+    public SomeBean someBean() {
+        return new SomeBean(10);
+    }
+
+    @PostConstruct
+    public void afterInitialize() {
+        System.out.println(stringValue);
+        System.out.println(valueFromFile);
+        System.out.println(systemValue);
+        System.out.println(someDefault);
+        System.out.println(prioritySystemProperty);
+        System.out.println(Arrays.toString(valuesArray));
+        System.out.println(spelValue);
+        System.out.println(spelSomeDefault);
+        System.out.println(someBeanValue);
+        System.out.println(valuesList);
+        System.out.println(valuesMap);
+        System.out.println(valuesMapKey1);
+        System.out.println(unknownMapKey);
+        System.out.println(unknownMap);
+        System.out.println(unknownMapKeyWithDefaultValue);
+        System.out.println(valuesMapFiltered);
+        System.out.println(systemPropertiesMap);
+    }
+}

spring-boot-modules/spring-boot-properties-2/src/main/java/com/baeldung/properties/value/defaults/ValuesWithDefaultsApp.java

@@ -0,0 +1,71 @@
+package com.baeldung.properties.value.defaults;
+
+import org.apache.commons.lang3.ArrayUtils;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.PropertySource;
+import org.springframework.util.Assert;
+
+import javax.annotation.PostConstruct;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * Demonstrates setting defaults for @Value annotation.  Note that there are no properties 
+ * defined in the specified property source.  We also assume that the user here
+ * does not have a system property named some.key.
+ *
+ */
+@Configuration
+@PropertySource(name = "myProperties", value = "valueswithdefaults.properties")
+public class ValuesWithDefaultsApp {
+
+    @Value("${some.key:my default value}")
+    private String stringWithDefaultValue;
+
+    @Value("${some.key:}")
+    private String stringWithBlankDefaultValue;
+
+    @Value("${some.key:true}")
+    private boolean booleanWithDefaultValue;
+    
+    @Value("${some.key:42}")
+    private int intWithDefaultValue;  
+
+    @Value("${some.key:one,two,three}")
+    private String[] stringArrayWithDefaults;
+
+    @Value("${some.key:1,2,3}")
+    private int[] intArrayWithDefaults;
+
+    @Value("#{systemProperties['some.key'] ?: 'my default system property value'}")
+    private String spelWithDefaultValue;
+    
+
+    public static void main(String[] args) {
+        ApplicationContext applicationContext = new AnnotationConfigApplicationContext(ValuesWithDefaultsApp.class);
+    }
+
+    @PostConstruct
+    public void afterInitialize() {
+    	// strings
+    	Assert.isTrue(stringWithDefaultValue.equals("my default value"));
+    	Assert.isTrue(stringWithBlankDefaultValue.equals(""));
+    	
+    	// other primitives
+    	Assert.isTrue(booleanWithDefaultValue);
+    	Assert.isTrue(intWithDefaultValue == 42);
+    	
+    	// arrays
+        List<String> stringListValues = Arrays.asList("one", "two", "three");
+    	Assert.isTrue(Arrays.asList(stringArrayWithDefaults).containsAll(stringListValues));
+
+        List<Integer> intListValues = Arrays.asList(1, 2, 3);
+    	Assert.isTrue(Arrays.asList(ArrayUtils.toObject(intArrayWithDefaults)).containsAll(intListValues));
+
+    	// SpEL
+    	Assert.isTrue(spelWithDefaultValue.equals("my default system property value"));
+    }
+}

spring-boot-modules/spring-boot-properties-2/src/main/resources/values.properties

@@ -0,0 +1,4 @@
+value.from.file=Value got from the file
+priority=high
+listOfValues=A,B,C
+valuesMap={key1:'1', key2 : '2', key3 : '3'}

spring-boot-modules/spring-boot-properties-2/src/test/java/com/baeldung/properties/value/ClassNotManagedBySpringIntegrationTest.java

@@ -0,0 +1,40 @@
+package com.baeldung.properties.value;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static junit.framework.TestCase.assertEquals;
+import static org.mockito.Mockito.when;
+
+@RunWith(SpringRunner.class)
+public class ClassNotManagedBySpringIntegrationTest {
+
+    @MockBean
+    private InitializerBean initializerBean;
+
+    @Before
+    public void init() {
+        when(initializerBean.initClass())
+          .thenReturn(new ClassNotManagedBySpring("This is only sample value", "Another configured value"));
+    }
+
+    @Test
+    public void givenInitializerBean_whenInvokedInitClass_shouldInitialize() throws Exception {
+
+        //given
+        ClassNotManagedBySpring classNotManagedBySpring = initializerBean.initClass();
+
+        //when
+        String initializedValue = classNotManagedBySpring.getCustomVariable();
+        String anotherCustomVariable = classNotManagedBySpring.getAnotherCustomVariable();
+
+        //then
+        assertEquals("This is only sample value", initializedValue);
+        assertEquals("Another configured value", anotherCustomVariable);
+
+    }
+
+}

spring-boot-modules/spring-boot-properties-2/src/test/java/com/baeldung/properties/value/CollectionProviderIntegrationTest.java

@@ -0,0 +1,22 @@
+package com.baeldung.properties.value;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(classes = CollectionProvider.class)
+public class CollectionProviderIntegrationTest {
+
+    @Autowired
+    private CollectionProvider collectionProvider;
+
+    @Test
+    public void givenPropertyFileWhenSetterInjectionUsedThenValueInjected() {
+        assertThat(collectionProvider.getValues()).contains("A", "B", "C");
+    }
+}

spring-boot-modules/spring-boot-properties-2/src/test/java/com/baeldung/properties/value/PriorityProviderIntegrationTest.java

@@ -0,0 +1,22 @@
+package com.baeldung.properties.value;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(classes = PriorityProvider.class)
+public class PriorityProviderIntegrationTest {
+
+    @Autowired
+    private PriorityProvider priorityProvider;
+
+    @Test
+    public void givenPropertyFileWhenConstructorInjectionUsedThenValueInjected() {
+        assertThat(priorityProvider.getPriority()).isEqualTo("high");
+    }
+}

spring-boot-modules/spring-boot-properties/README.md

@@ -7,9 +7,6 @@ This module contains articles about Properties in Spring Boot.
 - [Guide to @ConfigurationProperties in Spring Boot](https://www.baeldung.com/configuration-properties-in-spring-boot)
 - [Guide to @EnableConfigurationProperties](https://www.baeldung.com/spring-enable-config-properties)
 - [Properties with Spring and Spring Boot](https://www.baeldung.com/properties-with-spring) - checkout the `com.baeldung.properties` package for all scenarios of properties injection and usage
-- [A Quick Guide to Spring @Value](https://www.baeldung.com/spring-value-annotation)
 - [Spring YAML Configuration](https://www.baeldung.com/spring-yaml)
-- [Using Spring @Value with Defaults](https://www.baeldung.com/spring-value-defaults)
-- [How to Inject a Property Value Into a Class Not Managed by Spring?](https://www.baeldung.com/inject-properties-value-non-spring-class)
 - [Add Build Properties to a Spring Boot Application](https://www.baeldung.com/spring-boot-build-properties)
 - [IntelliJ – Cannot Resolve Spring Boot Configuration Properties Error](https://www.baeldung.com/intellij-resolve-spring-boot-configuration-properties)