Merge pull request #9135 from albanoj2/BAEL-3965

BAEL-3965: Created examples for instance and static factory methods.

pom.xml

@@ -652,6 +652,7 @@
                 <module>spring-core</module>
                 <module>spring-core-2</module>
                 <module>spring-core-3</module>
+                <module>spring-core-4</module>
                 <module>spring-cucumber</module>
 
                 <module>spring-data-rest</module>
@@ -1157,6 +1158,7 @@
                 <module>spring-core</module>
                 <module>spring-core-2</module>
                 <module>spring-core-3</module>
+                <module>spring-core-4</module>
                 <module>spring-cucumber</module>
 
                 <module>spring-data-rest</module>

spring-core-4/README.md

@@ -0,0 +1,7 @@
+## Spring Core
+
+This module contains articles about core Spring functionality
+
+## Relevant Articles:
+
+- More articles: [[<-- prev]](/spring-core-3)

spring-core-4/pom.xml

@@ -0,0 +1,63 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>spring-core-4</artifactId>
+    <name>spring-core-4</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-spring-5</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-spring-5</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-context</artifactId>
+            <version>${spring.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-core</artifactId>
+            <version>${spring.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-test</artifactId>
+            <version>${spring.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+            <version>${junit-jupiter.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <version>${junit-jupiter.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>${maven.surefire.version}</version>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <maven.surefire.version>2.22.1</maven.surefire.version>
+        <annotation-api.version>1.3.2</annotation-api.version>
+        <spring.boot.version>2.2.2.RELEASE</spring.boot.version>
+    </properties>
+
+</project>

spring-core-4/src/main/java/com/baeldung/factorymethod/Bar.java

@@ -0,0 +1,18 @@
+package com.baeldung.factorymethod;
+
+public class Bar {
+
+    private String name;
+
+    public Bar(String name) {
+        this.name = name;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+}

spring-core-4/src/main/java/com/baeldung/factorymethod/Foo.java

@@ -0,0 +1,5 @@
+package com.baeldung.factorymethod;
+
+public class Foo {
+
+}

spring-core-4/src/main/java/com/baeldung/factorymethod/InstanceBarFactory.java

@@ -0,0 +1,8 @@
+package com.baeldung.factorymethod;
+
+public class InstanceBarFactory {
+
+    public Bar createInstance(String name) {
+        return new Bar(name);
+    }
+}

spring-core-4/src/main/java/com/baeldung/factorymethod/InstanceFooFactory.java

@@ -0,0 +1,8 @@
+package com.baeldung.factorymethod;
+
+public class InstanceFooFactory {
+
+    public Foo createInstance() {
+        return new Foo();
+    }
+}

spring-core-4/src/main/java/com/baeldung/factorymethod/SingletonBarFactory.java

@@ -0,0 +1,11 @@
+package com.baeldung.factorymethod;
+
+public class SingletonBarFactory {
+
+    private static final Bar INSTANCE = new Bar("unnamed");
+    
+    public static Bar createInstance(String name) {
+        INSTANCE.setName(name);
+        return INSTANCE;
+    }
+}

spring-core-4/src/main/java/com/baeldung/factorymethod/SingletonFooFactory.java

@@ -0,0 +1,10 @@
+package com.baeldung.factorymethod;
+
+public class SingletonFooFactory {
+
+    private static final Foo INSTANCE = new Foo();
+    
+    public static Foo createInstance() {
+        return INSTANCE;
+    }
+}

spring-core-4/src/test/java/com/baeldung/factorymethod/InstanceBarFactoryIntegrationTest.java

@@ -0,0 +1,24 @@
+package com.baeldung.factorymethod;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration("/factorymethod/instance-bar-config.xml")
+public class InstanceBarFactoryIntegrationTest {
+
+    @Autowired
+    private Bar instance;
+    
+    @Test
+    public void givenValidInstanceFactoryConfig_whenCreateInstance_thenNameIsCorrect() {
+        assertNotNull(instance);
+        assertEquals("someName", instance.getName());
+    }
+}

spring-core-4/src/test/java/com/baeldung/factorymethod/InstanceFooFactoryIntegrationTest.java

@@ -0,0 +1,22 @@
+package com.baeldung.factorymethod;
+
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration("/factorymethod/instance-foo-config.xml")
+public class InstanceFooFactoryIntegrationTest {
+
+    @Autowired
+    private Foo foo;
+    
+    @Test
+    public void givenValidInstanceFactoryConfig_whenCreateFooInstance_thenInstanceIsNotNull() {
+        assertNotNull(foo);
+    }
+}

spring-core-4/src/test/java/com/baeldung/factorymethod/SingletonBarFactoryIntegrationTest.java

@@ -0,0 +1,24 @@
+package com.baeldung.factorymethod;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration("/factorymethod/static-bar-config.xml")
+public class SingletonBarFactoryIntegrationTest {
+
+    @Autowired
+    private Bar instance;
+    
+    @Test
+    public void givenValidStaticFactoryConfig_whenCreateInstance_thenNameIsCorrect() {
+        assertNotNull(instance);
+        assertEquals("someName", instance.getName());
+    }
+}

spring-core-4/src/test/java/com/baeldung/factorymethod/SingletonFooFactoryIntegrationTest.java

@@ -0,0 +1,22 @@
+package com.baeldung.factorymethod;
+
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration("/factorymethod/static-foo-config.xml")
+public class SingletonFooFactoryIntegrationTest {
+
+    @Autowired
+    private Foo singleton;
+    
+    @Test
+    public void givenValidStaticFactoryConfig_whenCreateInstance_thenInstanceIsNotNull() {
+        assertNotNull(singleton);
+    }
+}

spring-core-4/src/test/resources/factorymethod/instance-bar-config.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xmlns:util="http://www.springframework.org/schema/util"
+  xsi:schemaLocation="
+    http://www.springframework.org/schema/beans
+    http://www.springframework.org/schema/beans/spring-beans.xsd
+    http://www.springframework.org/schema/util
+    http://www.springframework.org/schema/util/spring-util.xsd">
+
+    <bean id="instanceBarFactory"
+      class="com.baeldung.factorymethod.InstanceBarFactory" />
+
+    <bean id="bar"
+      factory-bean="instanceBarFactory"
+      factory-method="createInstance">
+        <constructor-arg value="someName" />
+    </bean>
+
+</beans>

spring-core-4/src/test/resources/factorymethod/instance-foo-config.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xmlns:util="http://www.springframework.org/schema/util"
+  xsi:schemaLocation="
+    http://www.springframework.org/schema/beans
+    http://www.springframework.org/schema/beans/spring-beans.xsd
+    http://www.springframework.org/schema/util
+    http://www.springframework.org/schema/util/spring-util.xsd">
+
+    <bean id="instanceFooFactory"
+      class="com.baeldung.factorymethod.InstanceFooFactory" />
+
+    <bean id="foo"
+      factory-bean="instanceFooFactory"
+      factory-method="createInstance" />
+
+</beans>

spring-core-4/src/test/resources/factorymethod/static-bar-config.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xmlns:util="http://www.springframework.org/schema/util"
+  xsi:schemaLocation="
+    http://www.springframework.org/schema/beans
+    http://www.springframework.org/schema/beans/spring-beans.xsd
+    http://www.springframework.org/schema/util
+    http://www.springframework.org/schema/util/spring-util.xsd">
+
+    <bean id="bar"
+      class="com.baeldung.factorymethod.SingletonBarFactory"
+      factory-method="createInstance">
+        <constructor-arg value="someName" />
+    </bean>
+
+</beans>

spring-core-4/src/test/resources/factorymethod/static-foo-config.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xmlns:util="http://www.springframework.org/schema/util"
+  xsi:schemaLocation="
+    http://www.springframework.org/schema/beans
+    http://www.springframework.org/schema/beans/spring-beans.xsd
+    http://www.springframework.org/schema/util
+    http://www.springframework.org/schema/util/spring-util.xsd">
+
+    <bean id="foo"
+      class="com.baeldung.factorymethod.SingletonFooFactory"
+      factory-method="createInstance" />
+
+</beans>