Setting Up the Java Development Environment

Preparing Tools

• Maven

  Apache Maven 3.0.3 or later can be downloaded from the Maven official website.

• JDK

  Java Development Kit1.8.111 or later can be downloaded from the Oracle official website.

  After the installation, configure the Java environment variables.

• IntelliJ IDEA

  IntelliJ IDEA can be downloaded from the IntelliJ IDEA official website and be installed.

Procedure

1. Download the demo package.

   Decompress the package to obtain the following files.

   Table 1 Files in the demo package

   File	Directory	Description
   DmsConsumer.java	.\src\main\java\com\dms\consumer	API for consuming messages
   DmsProducer.java	.\src\main\java\com\dms\producer	API for producing messages
   dms.sdk.consumer.properties	.\src\main\resources	Configuration information for consuming messages
   dms.sdk.producer.properties	.\src\main\resources	Configuration information for producing messages
   client.truststore.jks	.\src\main\resources	SSL certificate, used for SASL connection
   DmsConsumerTest.java	.\src\test\java\com\dms\consumer	Test code of consuming messages
   DmsProducerTest.java	.\src\test\java\com\dms\producer	Test code of producing messages
   pom.xml	.\	Maven configuration file, containing the Kafka client dependencies

2. In IntelliJ IDEA, import the demo project.
   The demo project is a Java project built in Maven. Therefore, you need the JDK and the Maven plugin in IDEA.

   Figure 1 Click Import Project.
   

   Figure 2 Choose Maven.
   
   Figure 3 Select the JDK.
   

   You can select other options or retain the default settings. Click Finish.

   The demo project has been imported.

   

3. Configure Maven.

   Choose Files > Settings, set Maven home directory correctly, and select the required settings.xml file.

   

4. Specify Kafka configurations.

   The following is a configuration example for producing messages. Replace the information in bold with the actual values.

   #The information in bold is specific to different Kafka instances and must be modified. Other parameters can also be added.
   #The topic name is in the specific production and consumption code.
   #######################
   #Information about Kafka brokers. ip:port are the connection addresses and ports used by the instance. The values can be obtained by referring to the "Collecting Connection Information" section. Example: bootstrap.servers=100.xxx.xxx.87:909x,100.xxx.xxx.69:909x,100.xxx.xxx.155:909x
   bootstrap.servers=ip1:port1,ip2:port2,ip3:port3
   #Producer acknowledgement
   acks=all
   #Method of turning the key into bytes
   key.serializer=org.apache.kafka.common.serialization.StringSerializer
   #Method of turning the value into bytes
   value.serializer=org.apache.kafka.common.serialization.StringSerializer
   #Memory available to the producer for buffering
   buffer.memory=33554432
   #Number of retries
   retries=0
   #######################
   #Comment out the following parameters if SASL access is not enabled.
   #######################
   # Set the SASL authentication mechanism, username, and password.
   # sasl.mechanism indicates the SASL authentication mechanism. username and password indicate the username and password of SASL_SSL. Obtain them by referring to "Collecting Connection Information."
   # If the SASL mechanism is PLAIN, the configuration is as follows:
   sasl.mechanism=PLAIN
   sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule required \
       username="username" \
       password="password";
   # If the SASL mechanism is SCRAM-SHA-512, the configuration is as follows:
   sasl.mechanism=SCRAM-SHA-512
   sasl.jaas.config=org.apache.kafka.common.security.scram.ScramLoginModule required \
       username="username" \
       password="password";
   
   # Set security.protocol.
   # If the security protocol is SASL_SSL, the configuration is as follows:
   security.protocol=SASL_SSL
   # ssl truststore.location is the path for storing the SSL certificate. The following code uses the path format in Windows as an example. Change the path format based on the actual running environment.
   ssl.truststore.location=E:\\temp\\client.truststore.jks
   # ssl truststore.password is the password of the server certificate. This password is used for accessing the JKS file generated by Java.
   ssl.truststore.password=dms@kafka
   # ssl.endpoint.identification.algorithm indicates whether to verify the certificate domain name. This parameter must be left blank, which indicates disabling domain name verification.
   ssl.endpoint.identification.algorithm=
   # If the security protocol is SASL_PLAINTEXT, the configuration is as follows:
   security.protocol=SASL_PLAINTEXT

5. In the down left corner of IDEA, click Terminal. In terminal, run the mvn test command to see how the demo project goes.
   Figure 4 Opening terminal in IDEA
   

   The following information is displayed for the producer:

   -------------------------------------------------------
    T E S T S
   -------------------------------------------------------
   Running com.dms.producer.DmsProducerTest
   produce msg:The msg is 0
   produce msg:The msg is 1
   produce msg:The msg is 2
   produce msg:The msg is 3
   produce msg:The msg is 4
   produce msg:The msg is 5
   produce msg:The msg is 6
   produce msg:The msg is 7
   produce msg:The msg is 8
   produce msg:The msg is 9
   Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 138.877 sec

   The following information is displayed for the consumer:

   -------------------------------------------------------
    T E S T S
   -------------------------------------------------------
   Running com.dms.consumer.DmsConsumerTest
   the numbers of topic:0
   the numbers of topic:0
   the numbers of topic:6
   ConsumerRecord(topic = topic-0, partition = 2, offset = 0, CreateTime = 1557059377179, serialized key size = -1, serialized value size = 12, headers = RecordHeaders(headers = [], isReadOnly = false), key = null, value = The msg is 2)
   ConsumerRecord(topic = topic-0, partition = 2, offset = 1, CreateTime = 1557059377195, serialized key size = -1, serialized value size = 12, headers = RecordHeaders(headers = [], isReadOnly = false), key = null, value = The msg is 5)