Skip to main content

How to handle exceptions in REST services (JAX-RS and SpringBoot)

Exception handling is vital aspect of any application or service. Exceptions should be handled properly and appropriate messages must be generated to end user or service in case of any exception. Same applies to REST services also whether they are used by some front-end application or some other service uses it to perform some operations.
It becomes tricky when we deal with REST services as we need to expose all the supported status codes for both success and error response which our service can generate, so client application or service can handle them appropriately.  Below are some samples of the status code.
200 - OK (API processes the request perfectly)
404 - Not found (Request URI or resource is not available)
500 - Internal server error (Request failed  due to some error at runtime at service side)

There are multiple ways to handle the exceptions which we will see in below sections.

Manual exception handling

We can handle the exception manually also like using try-catch combination but we need to do that at each service level. May be we will be ending up with lot of duplicate code for some common exceptions and fair chances to miss it also in some places

Exception handling in SpringBoot with JAX-RS Rest service

JAX-RS uses ExceptionMapper to convert the exception to response. An exception mapper class need to be created by implementing ExceptionMapper interface and override the "toResponse()" method. It also should be annotated with @Provider so JAX-RS can find it during provider scanning phase and when a particular exception is thrown at runtime, JAX-RS will convert it to HTTP response as per mapper to send it to the requester.

Mapper class implementation

public class MyExceptionHandler implements ExceptionMapper<Throwable>{

    public Response toResponse(Throwable arg0) {
        return Response.status(Response.Status.BAD_REQUEST).entity(arg0.getMessage())

JAX-RS integration with SpringBoot

To implement the JAX-RS services with Spring we need to register the Jersey resource configuration. below code is for achieving the same purpose with SpringBoot. In below code we have registered the package "" where we keeping all our jax-rs code like REST endpoint classes, Providers etc.
public class AppConfig{

    public ResourceConfig jaxrsResourceConfig(){
        return new ResourceConfig().packages("");

Service class implementation

public class JaxDemoRestService {

    public String welcome(@PathParam("name") String name) {
            throw new RuntimeException("\"error\" can't be used as a name.");
        return "Hello "+name;
Now run the application and hit below URL in browser.
You will get the below response and status code.
Status Code: 400
Response: "error" can't be used as a name.

Exception handling in SpringBoot Rest service

It is very easy to implement the exception handling in Spring boot using @ControllerAdvice and @ExceptionHandler annotations. By default the handlers defined in @ControllerAdvice annotated class are applied globally but we can change it to point to some specific packages using "basePackages" attribute. We can define many handler methods to handle the different exceptions using @ExceptionHandler annotation.

Controller Advice

public class ErrorHandlerConfig {
    public ResponseEntity<String> handleRunTimeException(RuntimeException e) {
        return new ResponseEntity<>(e.getMessage(), BAD_REQUEST);

Service class

public class HelloService {
    public String welcome(@PathVariable("name") String name) {
            throw new RuntimeException("\"error\" can't be used as a name.");
        return "Welcome "+name;

Now run the application and hit below URL in browser.
You will get the below response and status code.
Status Code: 400
Response: "error" can't be used as a name.


Popular Posts

Asynchronous REST service implementation in Spring boot

In this tutorial we will see how to create an asynchronous REST service endpoint using Spring boot application. Asynchronous service works in a way that it will not block the client request and do the processing in separate thread. When work is complete the response returned to the client so our service will be able to handle more client requests at the same time, compare to synchronous processing model. Let's understand how it is working in synchronous mode. In such server/client application at server side it has a pool of threads which are serving the request. If a request received by a thread then it will be blocked until it send the response back to client. In this case if processing doesn't take much time it will be able to process it quickly and accept other client requests but there could be one situation when all threads are busy and not able to accept the new client requests. To overcome of such problems, asynchronous processing model introduced for REST service

SpringBoot - @ConditionalOnProperty example for conditional bean initialization

@ConditionalOnProperty annotation is used to check if specified property available in the environment or it matches some specific value so it can control the execution of some part of code like bean creation. It may be useful in many cases for example enable/disable service if specific property is available. Below are the attributes which can be used for property check. havingValue - Provide the value which need to check against specified property otherwise it will check that value should not be false. matchIfMissing - If true it will match the condition and execute the annotated code when property itself is not available in environment. name - Name of the property to be tested. If you want to test single property then you can directly put the property name as string like "" and if you have multiple properties to test then you can put the names like {"prop.name1","prop.name2"} prefix - It can be use when you want to apply some prefix to

Setting up kerberos in Mac OS X

Kerberos in MAC OS X Kerberos authentication allows the computers in same domain network to authenticate certain services with prompting the user for credentials. MAC OS X comes with Heimdal Kerberos which is an alternate implementation of the kerberos and uses LDAP as identity management database. Here we are going to learn how to setup a kerberos on MAC OS X which we will configure latter in our application. Installing Kerberos In MAC we can use Homebrew for installing any software package. Homebrew makes it very easy to install the kerberos by just executing a simple command as given below. brew install krb5 Once installation is complete, we need to set the below export commands in user's profile which will make the kerberos utility commands and compiler available to execute from anywhere. Open user's bash profile: vi ~/.bash_profile Add below lines: export PATH=/usr/local/opt/krb5/bin:$PATH export PATH=/usr/local/opt/krb5/sbin:$PATH export LDFLAGS=&

Entity to DTO conversion in Java using Jackson

It's very common to have the DTO class for a given entity in any application. When persisting data, we use entity objects and when we need to provide the data to end user/application we use DTO class. Due to this we may need to have similar properties on DTO class as we have in our Entity class and to share the data we populate DTO objects using entity objects. To do this we may need to call getter on entity and then setter on DTO for the same data which increases number of code line. Also if number of DTOs are high then we need to write lot of code to just get and set the values or vice-versa. To overcome this problem we are going to use Jackson API and will see how to do it with minimal code only. Maven dependency <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.9.9</version> </dependency> Entity class Below is