Email API
Calendar API
Contacts API
Salesforce email integration
Google email & calendar integration
Outlook email & calendar integration
IMAP integration
Calendar management
Embedded contextual email
Scheduling automation
Automated outreach
Intelligent data extraction
Telehealth
Real estate
Financial technology
Educational technology
Customer relationship management
Applicant tracking system
Communications platform
Marketplaces
Document management
Docs
SDKs
Tutorials
API status
Changelog
Support
Blog
Events
Guides
Newsroom
Partners
Build vs. buy
Customer stories
Trust & security
Why Nylas
How to read email inbox data with Nylas Java SDK
• 11 min read
It can be challenging to programmatically analyze and extra data from Email as the data can be complex and unstructured. Thanks to the Nylas Connectivity APIs we can use different kinds of objects and filters that treat emails like first-class citizens, making this task easier.
To make things even easier for Java developers, we offer the Nylas Java SDK. Today we’re going to review how to read email inbox data using Java and the Nylas Java SDK.
If you’re interested in our other SDK offerings, we have you covered:
If you’re new to Java or new to Nylas, we would recommend you to read the post How to Send Emails with the Nylas Java SDK where everything is clearly explained.
Let’s name this project read_inbox and our main class ReadInbox.
This is going to be our pom.xml:
<?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>Nylas</groupId>
<artifactId>ReadInbox</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>17</maven.compiler.source>
<maven.compiler.target>17</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>com.nylas.sdk</groupId>
<artifactId>nylas-java-sdk</artifactId>
<version>1.16.0</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-jdk14</artifactId>
<version>1.7.25</version>
</dependency>
<dependency>
<groupId>io.github.cdimascio</groupId>
<artifactId>dotenv-java</artifactId>
<version>2.2.4</version>
</dependency>
</dependencies>
<build>
<pluginManagement>
<plugins>
<plugin>
<!-- Build an executable JAR -->
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>3.1.0</version>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>ReadInbox</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>ReadInbox</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<version>1.2.1</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>java</goal>
</goals>
</execution>
</executions>
<configuration>
<mainClass>ReadInbox</mainClass>
<cleanupDaemonThreads>false</cleanupDaemonThreads>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
And here’s our source code:
//Import Java Utilities
import java.io.IOException;
import java.util.List;
//Import Nylas Packages
import com.nylas.NylasAccount;
import com.nylas.NylasClient;
import com.nylas.RequestFailedException;
import com.nylas.Message;
import com.nylas.Messages;
import com.nylas.RemoteCollection;
//Import DotEnv to handle .env files
import io.github.cdimascio.dotenv.Dotenv;
import io.github.cdimascio.dotenv.DotenvException;
public class ReadInbox {
public static void main(String[] args) throws RequestFailedException,
IOException{
Dotenv dotenv = Dotenv.load();
// Create the client object
NylasClient client = new NylasClient();
// Connect it to Nylas using the Access Token from the .env file
NylasAccount account = client.account(dotenv.get("ACCESS_TOKEN"));
//Access the messages endpoint
Messages messages = account.messages();
//Read all messages
RemoteCollection<Message> messageList = messages.list();
//Loop through the emails
for(Message email : messageList){
//Print the subject and who’s sending the email
System.out.print("Subject: " + email.getSubject() + " | " +
"From: " + email.getFrom().get(0).getEmail() +
" |\n\n");
}
}
}
In order to run our project, we need to compile it first. We can open a Terminal window, go to our project’s root folder and type the following maven command:
$ mvn package
Now, we can run this command to execute our application:
$ mvn exec:java -Dexec.mainClass=”ReadInbox” -Dexec.cleanupDaemonThreads=false
This will display the first 100 emails in your mailbox.
If we would like to compile this as JAR file, we can use the following maven command:
$ mvn clean compile assembly:single
And run the JAR file like this:
$ java -jar target/ReadInbox-1.0-SNAPSHOT-jar-with-dependencies.jar
Just keep in mind that if the ACCESS_TOKEN expires, you will need to generate a new one and update the JAR file.
We might notice we’re getting more messages than expected in the response: all emails in the box are separated into “folders” using “labels”. As we’re not specifying any particular source, we’re getting Inbox but also Sent, Spam, and Trash messages.
We can easily fix this, by adding new MessageQuery().in(“inbox”) on line 21:
RemoteCollection<Message> messageList = messages.list(new MessageQuery().in("inbox"));
This will get only the emails that are in our inbox only.
If we want to only read the first 3 emails, we can just add .limit(3).
RemoteCollection<Message> messageList = messages.list(new MessageQuery().in("inbox").limit(3));
And add this to your list of imports:
import com.nylas.MessageQuery;
We’re just adding an extra property to our messages.list() function.
We know how to read emails from the account, specifying the source folder with .where, and setting a limit on the number of messages to read with .limit(). There’s a lot more you can configure when reading messages. Have a look at our documentation to see what else you can do.
A thread is a message shared between 2 or more people. It consists of the original message with its corresponding replies.
For this example, we’re going to limit the results to three threads. We’re going to call this project Reading_Threads and our main class will be called ReadThreads.
Here’s our pom.xml file:
<?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>Nylas</groupId>
<artifactId>ReadThreads</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>17</maven.compiler.source>
<maven.compiler.target>17</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>com.nylas.sdk</groupId>
<artifactId>nylas-java-sdk</artifactId>
<version>1.16.0</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-jdk14</artifactId>
<version>1.7.25</version>
</dependency>
<dependency>
<groupId>io.github.cdimascio</groupId>
<artifactId>dotenv-java</artifactId>
<version>2.2.4</version>
</dependency>
</dependencies>
<build>
<pluginManagement>
<plugins>
<plugin>
<!-- Build an executable JAR -->
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>3.1.0</version>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>ReadThreads</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>ReadThreads</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<version>1.2.1</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>java</goal>
</goals>
</execution>
</executions>
<configuration>
<mainClass>ReadThreads</mainClass>
<cleanupDaemonThreads>false</cleanupDaemonThreads>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
And here’s our source code:
//Import Java Utilities
import java.io.IOException;
import java.util.List;
//Import Nylas Packages
import com.nylas.NylasAccount;
import com.nylas.NylasClient;
import com.nylas.RequestFailedException;
//Import DotEnv to handle .env files
import com.nylas.Thread;
import com.nylas.Threads;
import com.nylas.ThreadQuery;
import com.nylas.NameEmail;
import io.github.cdimascio.dotenv.Dotenv;
import io.github.cdimascio.dotenv.DotenvException;
public class ReadInbox {
public static void main(String[] args) throws RequestFailedException,
IOException{
Dotenv dotenv = Dotenv.load();
// Create the client object
NylasClient client = new NylasClient();
// Connect it to Nylas using the Access Token from the .env file
NylasAccount account = client.account(dotenv.get("ACCESS_TOKEN"));
Threads threads = account.threads();
List<Thread> thread = threads.list(new ThreadQuery().
in("inbox").limit(3)).fetchAll();
for(Thread message : thread){
List<NameEmail> participants = message.getParticipants();
for(NameEmail participant : participants){
System.out.println("Subject: " + message.getSubject() +
" | Participant: " + participant.getName() +
" | Email: " + participant.getEmail());
}
if(participants.size() != 0) {
System.out.println();
}
}
}
}
Let’s compile and run our application:
$ mvn package && mvn exec:java -Dexec.mainClass="ReadThreads"
We can link actions using the && command:
Let’s say we want to search the latest message sent by a particular email account. We can do this on either messages or threads, but for this example, we’re going to use messages. We’re going to call our project Search_Messages and the main class SearchMessages.
This is our pom.xml file:
<?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>Nylas</groupId>
<artifactId>Search_Messages</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>17</maven.compiler.source>
<maven.compiler.target>17</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>com.nylas.sdk</groupId>
<artifactId>nylas-java-sdk</artifactId>
<version>1.16.0</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-jdk14</artifactId>
<version>1.7.25</version>
</dependency>
<dependency>
<groupId>io.github.cdimascio</groupId>
<artifactId>dotenv-java</artifactId>
<version>2.2.4</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.12.0</version>
</dependency>
</dependencies>
<build>
<pluginManagement>
<plugins>
<plugin>
<!-- Build an executable JAR -->
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>3.1.0</version>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>SearchMessages</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>SearchMessages</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<version>1.2.1</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>java</goal>
</goals>
</execution>
</executions>
<configuration>
<mainClass>SearchMessages</mainClass>
<cleanupDaemonThreads>false</cleanupDaemonThreads>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
And here’s our source code:
//Import Java Utilities
import java.io.IOException;
import java.util.Arrays;
import java.util.List;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.StringUtils.*;
//Import Nylas Packages
import com.nylas.*;
//Import DotEnv to handle .env files
import io.github.cdimascio.dotenv.Dotenv;
import io.github.cdimascio.dotenv.DotenvException;
public class SearchMessages {
public static void main(String[] args) throws RequestFailedException,
IOException{
Dotenv dotenv = Dotenv.load();
// Create the client object
NylasClient client = new NylasClient();
// Connect it to Nylas using the Access Token from the .env file
NylasAccount account = client.account(dotenv.get("ACCESS_TOKEN"));
// Access the messages endpoint
Messages messages = account.messages();
// Filter messages by sender
RemoteCollection<Message> messageList =
messages.search("from:blag.nylas@gmail.com", 3, 0);
// Loop through messages
for(Message email : messageList){
// Print out the subject
System.out.print("Subject: " + email.getSubject() + " | ");
// Get attachments if there are any
List<File> attachments = email.getFiles();
// If we some attachment, let's get the names
if (attachments.size() != 0){
String attachs = "";
System.out.print("Attachments: ");
// Loop through the attachments
for(File attachment : attachments){
// Get the attachment name
attachs += attachment.getFilename() + ", ";
}
// Print out the attachment getting rid of the last ","
System.out.println(StringUtils.strip(attachs, ", "));
}else{
// No attachments found
System.out.println("Attachments: None");
}
}
}
}
Let’s compile and run our application:
$ mvn package && mvn exec:java -Dexec.mainClass="SearchMessages"
And that’s it. As you can see, by using the Nylas Java SDK, reading email inbox data becomes an easy task. If you want to learn more, visit our Documentation Page.
Create and read your Google webhooks using Ruby and Sinatra, and publish them using Koyeb. Here’s the full guide.
Learn how to build Mail Merge and Email Template functionality in your email workflow using TinyMCE Rich Text Editor.
Learn how to improve your email workflow using TinyMCE Rich Text Editor.
Blag aka Alvaro Tejada Galindo is a Senior Developer Advocate at Nylas. He loves learning about programming and sharing knowledge with the community. When he’s not coding, he’s spending time with his wife, daughter and son. He loves Punk Music and reading all sorts of books.