Guice Intro (#1177)

* Add files via upload

* Update pom.xml

* Update RunGuice.java

* Update Communication.java

* Update CommunicationMode.java

* Update DefaultCommunicator.java

* Update EmailCommunicationMode.java

* Update IMCommunicationMode.java

* Update SMSCommunicationMode.java

* Update MessageLogger.java

* Update MessageSentLoggable.java

* Update AOPModule.java

* Update BasicModule.java

* Update CommunicationModel.java

* Update Communicator.java

* Update BasicModule.java

* Update RunGuice.java

* Update MessageLogger.java

* Update Communicator.java

* Update pom.xml

* Update pom.xml

* Update pom.xml

* Update pom.xml

guice-intro/pom.xml

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+<?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>
+    <groupId>com.baeldung.examples.guice</groupId>
+    <artifactId>guice-intro</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <packaging>jar</packaging>
+    <dependencies>
+        <dependency>
+            <groupId>com.google.inject</groupId>
+            <artifactId>guice</artifactId>
+            <version>${guice.version}</version>
+        </dependency>
+    </dependencies>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
+        <guice.version>4.1.0</guice.version>
+    </properties>
+    <name>guice-intro</name>
+</project>

guice-intro/src/main/java/com/baeldung/examples/RunGuice.java

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+
+package com.baeldung.examples;
+
+import com.baeldung.examples.guice.Communication;
+import com.baeldung.examples.guice.binding.AOPModule;
+import com.baeldung.examples.guice.modules.BasicModule;
+import com.google.inject.Guice;
+import com.google.inject.Injector;
+import java.util.Scanner;
+
+/**
+ *
+ * @author Baeldung
+ */
+public class RunGuice {
+
+    public static void main(String[] args) {
+        Injector injector = Guice.createInjector(new BasicModule(), new AOPModule());
+        Communication comms = injector.getInstance(Communication.class);
+        Scanner scanner = new Scanner(System.in);
+        System.out.println("Enter your message to be sent; press Q to quit and P to print the message log");
+        while (true) {
+            String input = scanner.nextLine();
+            if (input.equalsIgnoreCase("q")) {
+                System.exit(0);
+            }
+            if (input.equalsIgnoreCase("p")) {
+                comms.print();
+            } else {
+                comms.sendMessage(input);
+            }
+
+        }
+
+    }
+}

guice-intro/src/main/java/com/baeldung/examples/guice/Communication.java

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+
+package com.baeldung.examples.guice;
+
+import com.google.inject.Inject;
+import com.google.inject.name.Named;
+import java.util.Date;
+import java.util.LinkedList;
+import java.util.Queue;
+import java.util.logging.Logger;
+
+/**
+ *
+ * @author Baeldung
+ */
+public class Communication {
+
+    final Date start = new Date();
+
+    @Inject
+    private Logger logger;
+
+    private Queue<String> messageLog;
+
+    @Named("CommsUUID")
+    private String commsID;
+
+    @Inject
+    private DefaultCommunicator communicator;
+
+    public Communication(Boolean keepRecords) {
+        if (keepRecords) {
+            messageLog = new LinkedList();
+        }
+    }
+
+    public boolean sendMessage(String message) {
+        if (!message.isEmpty() && messageLog != null) {
+            messageLog.add(message);
+        }
+        return communicator.sendMessage(message);
+    }
+
+    public void print() {
+        if (messageLog != null) {
+            for (String message : messageLog) {
+                logger.info(message);
+            }
+        } else {
+            logger.info("Message logging wasn't enabled");
+        }
+    }
+
+    public DefaultCommunicator getCommunicator() {
+        return this.communicator;
+    }
+
+}

guice-intro/src/main/java/com/baeldung/examples/guice/CommunicationMode.java

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+
+package com.baeldung.examples.guice;
+
+import com.baeldung.examples.guice.constant.CommunicationModel;
+
+public interface CommunicationMode {
+
+    public CommunicationModel getMode();
+    
+    public boolean sendMessage(String message);
+
+}

guice-intro/src/main/java/com/baeldung/examples/guice/DefaultCommunicator.java

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+
+package com.baeldung.examples.guice;
+
+import com.baeldung.examples.guice.marker.Communicator;
+import com.google.inject.Inject;
+import com.google.inject.name.Named;
+
+
+public class DefaultCommunicator implements Communicator {
+
+    private CommunicationMode defaultCommsMode;
+    @Inject
+    @Named("SMSComms")
+    CommunicationMode smsCommsMode;
+    @Inject
+    @Named("EmailComms")
+    CommunicationMode emailCommsMode;
+    @Inject
+    @Named("IMComms")
+    CommunicationMode imCommsMode;
+
+    protected DefaultCommunicator(CommunicationMode defaultComms) {
+        this.defaultCommsMode = defaultComms;
+    }
+
+    public DefaultCommunicator() {
+
+    }
+
+    public boolean sendMessage(String message) {
+        boolean sent = false;
+        if (defaultCommsMode != null) {
+            sent = sendMessageByDefault(message);
+        } else {
+            sent = smsCommsMode.sendMessage(message);
+        }
+        return sent;
+    }
+
+    private boolean sendMessageByDefault(String message) {
+        boolean sent = false;
+        if (message != null && !message.trim().equals("")) {
+            return defaultCommsMode.sendMessage(message);
+        }
+        return sent;
+    }
+
+}

guice-intro/src/main/java/com/baeldung/examples/guice/EmailCommunicationMode.java

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+package com.baeldung.examples.guice;
+
+import com.baeldung.examples.guice.aop.MessageSentLoggable;
+import com.baeldung.examples.guice.constant.CommunicationModel;
+
+/**
+ *
+ * @author Baekdung
+ */
+public class EmailCommunicationMode implements CommunicationMode {
+
+    @Override
+    public CommunicationModel getMode() {
+        return CommunicationModel.EMAIL;
+    }
+
+    @Override
+    @MessageSentLoggable
+    public boolean sendMessage(String Message) {
+        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
+    }
+
+}

guice-intro/src/main/java/com/baeldung/examples/guice/IMCommunicationMode.java

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+
+package com.baeldung.examples.guice;
+
+import com.baeldung.examples.guice.aop.MessageSentLoggable;
+import com.baeldung.examples.guice.constant.CommunicationModel;
+import com.google.inject.Inject;
+import java.util.logging.Logger;
+
+/**
+ *
+ * @author Baeldung
+ */
+public class IMCommunicationMode implements CommunicationMode {
+
+    @Inject
+    private Logger logger;
+
+    @Override
+    public CommunicationModel getMode() {
+        return CommunicationModel.IM;
+    }
+
+    @Override
+    @MessageSentLoggable
+    public boolean sendMessage(String message) {
+        logger.info("IM Message Sent");
+        return true;
+    }
+
+}

guice-intro/src/main/java/com/baeldung/examples/guice/SMSCommunicationMode.java

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+package com.baeldung.examples.guice;
+
+import com.baeldung.examples.guice.aop.MessageSentLoggable;
+import com.baeldung.examples.guice.constant.CommunicationModel;
+import com.google.inject.Inject;
+import java.util.logging.Logger;
+
+/**
+ *
+ * @author Baeldung
+ */
+public class SMSCommunicationMode implements CommunicationMode {
+    
+    @Inject
+    private Logger logger;
+
+    @Override
+    public CommunicationModel getMode() {
+        return CommunicationModel.SMS;
+    }
+
+    @Override
+    @MessageSentLoggable
+    public boolean sendMessage(String message) {
+        logger.info("SMS message sent");
+        return true;
+    }
+
+}

guice-intro/src/main/java/com/baeldung/examples/guice/aop/MessageLogger.java

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+package com.baeldung.examples.guice.aop;
+
+import java.util.logging.Logger;
+import org.aopalliance.intercept.MethodInterceptor;
+import org.aopalliance.intercept.MethodInvocation;
+
+/**
+ *
+ * @author Baeldung
+ */
+public class MessageLogger implements MethodInterceptor {
+
+    @Override
+    public Object invoke(MethodInvocation invocation) throws Throwable {
+        Object[] objectArray = invocation.getArguments();
+        int i = 0;
+        for (Object object : objectArray) {
+            Logger.getAnonymousLogger().info("Sending message: " + object.toString());
+        }
+        return invocation.proceed();
+    }
+}

guice-intro/src/main/java/com/baeldung/examples/guice/aop/MessageSentLoggable.java

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+package com.baeldung.examples.guice.aop;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ *
+ * @author Baeldung
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.METHOD)
+public @interface MessageSentLoggable {
+
+}

guice-intro/src/main/java/com/baeldung/examples/guice/binding/AOPModule.java

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+package com.baeldung.examples.guice.binding;
+
+import com.baeldung.examples.guice.aop.MessageLogger;
+import com.baeldung.examples.guice.aop.MessageSentLoggable;
+import com.google.inject.AbstractModule;
+import com.google.inject.matcher.Matchers;
+
+/**
+ *
+ * @author Baeldung
+ */
+public class AOPModule extends AbstractModule {
+
+    @Override
+    protected void configure() {
+        bindInterceptor(Matchers.any(),
+                Matchers.annotatedWith(MessageSentLoggable.class),
+                new MessageLogger()
+        );
+    }
+
+}

guice-intro/src/main/java/com/baeldung/examples/guice/binding/BasicModule.java

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+package com.baeldung.examples.guice.binding;
+
+import com.baeldung.examples.guice.Communication;
+import com.baeldung.examples.guice.CommunicationMode;
+import com.baeldung.examples.guice.DefaultCommunicator;
+import com.baeldung.examples.guice.EmailCommunicationMode;
+import com.baeldung.examples.guice.IMCommunicationMode;
+import com.baeldung.examples.guice.SMSCommunicationMode;
+import com.google.inject.AbstractModule;
+import com.google.inject.name.Names;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ *
+ * @author Baeldung
+ */
+public class BasicModule extends AbstractModule {
+
+    @Override
+    protected void configure() {
+        try {
+            bind(Communication.class).toConstructor(Communication.class.getConstructor(Boolean.TYPE));
+        } catch (NoSuchMethodException ex) {
+            Logger.getLogger(BasicModule.class.getName()).log(Level.SEVERE, null, ex);
+        } catch (SecurityException ex) {
+            Logger.getLogger(BasicModule.class.getName()).log(Level.SEVERE, null, ex);
+        }
+        bind(DefaultCommunicator.class).annotatedWith(Names.named("AnotherCommunicator")).to(DefaultCommunicator.class).asEagerSingleton();
+
+        bind(CommunicationMode.class).annotatedWith(Names.named("IMComms")).to(IMCommunicationMode.class);
+        bind(CommunicationMode.class).annotatedWith(Names.named("EmailComms")).to(EmailCommunicationMode.class);
+        bind(CommunicationMode.class).annotatedWith(Names.named("SMSComms")).to(SMSCommunicationMode.class);
+    }
+
+}

guice-intro/src/main/java/com/baeldung/examples/guice/constant/CommunicationModel.java

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+package com.baeldung.examples.guice.constant;
+
+/**
+ *
+ * @author Baeldung
+ */
+public enum CommunicationModel {
+
+    EMAIL("Email"), SMS("SMS"), IM("IM"), PHONE("Phone");
+
+    final String name;
+
+    CommunicationModel(String name) {
+        this.name = name;
+    }
+}

guice-intro/src/main/java/com/baeldung/examples/guice/marker/Communicator.java

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+package com.baeldung.examples.guice.marker;
+
+/**
+ *
+ * @author Baeldung
+ */
+public interface Communicator {
+    
+     public boolean sendMessage(String message);
+    
+}

guice-intro/src/main/java/com/baeldung/examples/guice/modules/BasicModule.java

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+package com.baeldung.examples.guice.modules;
+
+import com.baeldung.examples.guice.Communication;
+import com.baeldung.examples.guice.CommunicationMode;
+import com.baeldung.examples.guice.DefaultCommunicator;
+import com.baeldung.examples.guice.EmailCommunicationMode;
+import com.baeldung.examples.guice.IMCommunicationMode;
+import com.baeldung.examples.guice.SMSCommunicationMode;
+import com.google.inject.AbstractModule;
+import com.google.inject.name.Names;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ *
+ * @author Baeldung
+ */
+public class BasicModule extends AbstractModule {
+
+    @Override
+    protected void configure() {
+        try {
+            bind(Communication.class).toConstructor(Communication.class.getConstructor(Boolean.class));
+            bind(Boolean.class).toInstance(true);
+        } catch (NoSuchMethodException ex) {
+            Logger.getLogger(com.baeldung.examples.guice.binding.BasicModule.class.getName()).log(Level.SEVERE, null, ex);
+        } catch (SecurityException ex) {
+            Logger.getLogger(com.baeldung.examples.guice.binding.BasicModule.class.getName()).log(Level.SEVERE, null, ex);
+        }
+        bind(DefaultCommunicator.class).annotatedWith(Names.named("AnotherCommunicator")).to(DefaultCommunicator.class).asEagerSingleton();
+
+        bind(CommunicationMode.class).annotatedWith(Names.named("IMComms")).to(IMCommunicationMode.class);
+        bind(CommunicationMode.class).annotatedWith(Names.named("EmailComms")).to(EmailCommunicationMode.class);
+        bind(CommunicationMode.class).annotatedWith(Names.named("SMSComms")).to(SMSCommunicationMode.class);
+    }
+
+}