Custom thread pool configuration in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a thread pool bean with a fixed size of 5 threads.

Spring Boot

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

@Configuration
public class ThreadPoolConfig {

    @Bean
    public ExecutorService taskExecutor() {
        return Executors.[1](5);
    }
}

Drag options to blanks, or click blank then click option'

AnewSingleThreadExecutor

BnewCachedThreadPool

CnewScheduledThreadPool

DnewFixedThreadPool

Attempts:

3 left

💡 Hint

Common Mistakes

Using newCachedThreadPool creates a pool that can grow dynamically.

Using newSingleThreadExecutor creates only one thread, not 5.

The newFixedThreadPool method creates a thread pool with a fixed number of threads, which is 5 here.

2fill in blank

medium

Complete the code to set the core pool size of the ThreadPoolTaskExecutor to 10.

Spring Boot

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;

@Configuration
public class ThreadPoolConfig {

    @Bean
    public ThreadPoolTaskExecutor taskExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize([1]);
        return executor;
    }
}

Drag options to blanks, or click blank then click option'

A15

B20

C10

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Setting the core pool size to a different number than requested.

Confusing core pool size with max pool size.

The setCorePoolSize method sets the number of core threads to 10 as required.

3fill in blank

hard

Fix the error in the code by completing the missing method to initialize the executor.

Spring Boot

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;

@Configuration
public class ThreadPoolConfig {

    @Bean
    public ThreadPoolTaskExecutor taskExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(5);
        executor.setMaxPoolSize(10);
        executor.[1]();
        return executor;
    }
}

Drag options to blanks, or click blank then click option'

Ainit

Bstart

Cinitialize

Drun

Attempts:

3 left

💡 Hint

Common Mistakes

Using start() or run() which are not methods of ThreadPoolTaskExecutor.

Forgetting to call initialize() causes the executor not to start properly.

The initialize() method initializes the ThreadPoolTaskExecutor so it is ready to use.

4fill in blank

hard

Fill both blanks to configure the thread name prefix and queue capacity.

Spring Boot

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;

@Configuration
public class ThreadPoolConfig {

    @Bean
    public ThreadPoolTaskExecutor taskExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setThreadNamePrefix([1]);
        executor.setQueueCapacity([2]);
        return executor;
    }
}

Drag options to blanks, or click blank then click option'

A"MyPool-"

B"Thread-"

C25

D50

Attempts:

3 left

💡 Hint

Common Mistakes

Using a number for thread name prefix instead of a string.

Setting queue capacity too low or forgetting to set it.

The thread name prefix is set to "MyPool-" to identify threads easily. The queue capacity is set to 50 to hold tasks waiting for execution.

5fill in blank

hard

Fill all three blanks to set core pool size, max pool size, and keep alive seconds.

Spring Boot

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;

@Configuration
public class ThreadPoolConfig {

    @Bean
    public ThreadPoolTaskExecutor taskExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize([1]);
        executor.setMaxPoolSize([2]);
        executor.setKeepAliveSeconds([3]);
        return executor;
    }
}

Drag options to blanks, or click blank then click option'

A5

B10

C60

D15

Attempts:

3 left

💡 Hint

Common Mistakes

Setting core pool size greater than max pool size.

Using keep alive seconds as zero or negative.

The core pool size is set to 10, max pool size to 15, and threads will be kept alive for 60 seconds when idle.