Skip to main content

Allowing Cross domain POST request with JSON or XML content type in Java

Cross domain POST Request

Cross domain POST requests supports only below content types and other content type are not allowed by default.

  • application/x-www-form-urlencoded
  • multipart/form-data
  • text/plain

So, if we try to make an ajax request to such POST URLs with XML or JSON content type, it will not be able to make request and give CORS error.

Allowing Cross domain POST request with JSON or XML Content-Type

We have our service implemented in Java and we will use Servlet Filter & request wrapper to build our solution.
Please see my below POST to see how to implement CORS using java servlets which works well with GET methods or allowed content types with POST method.

In this POST I will explain only additional things required for our problem with POST request, so I request you to go through the above link first.

Request wrapper to change/ override the content-type to JSON or XML

Since, POST request is not allowing XML or JSON content-type and other types will fail when it need to match with our REST service's content type. We need to change the content-type at back-end before request reaching to REST service. Below is the code for Request wrapper class. Here we are doing a trick basis on request parameter "json". If this parameter is having value as "true" then we are changing the content type to "application/json" at backend before reaching to our service implementation which only accepts json content.
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.util.Arrays;
import java.util.Collections;
import java.util.Enumeration;

public class MyCorsServletRequestWrapper extends HttpServletRequestWrapper{
    private String contentType;
    public MyCorsServletRequestWrapper(HttpServletRequest req){
            ?"application/json" : req.getContentType());
    public String getContentType(){
        return contentType;
    public String getHeader(String name){
            return contentType;
            return super.getHeader(name);

    public Enumeration<String> getHeaders(String name){
            return Collections.enumeration(Arrays.asList(contentType));
            return super.getHeaders(name);

    public void setContentType(String contentType){
        this.contentType = contentType;

Changes required to Servlet Filter

Now we need to make below changes in our existing servlet filter which we have created in another post (link mentioned in above section). These changes are made to support preflight requests which made by the client to confirm with server whether server is accepting this CORS request and process properly.
public class CorsFilter extends Filter{
    public void doFilter(ServletRequest req, ServletResponse res,
        FilterChain chain) throws ServletException, IOException{

        MyCorsServletRequestWrapper request = new MyCorsServletRequestWrapper((HttpServletRequest) req);

        HttpServletResponse response = (HttpServletResponse) res;
        chain.doFilter(request, response);


Post a Comment

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=&

jaxb2-maven-plugin to generate java code from XSD schema

In this tutorial I will show how to generate the Java source code from XSD schema. I will use jaxb2-maven-plugin to generate the code using XSD file which will be declared in pom.xml to make it part of build, so when maven build is executed it will generate the java code using XSD. Class generation can be controlled in plugin configuration. Maven changes (pom.xml) Include below plugin in your pom.xml. Here we have done some configuration under configuration section as given below. schemaDirectory : This is the directory where I keep my schema (XSD file). outputDirectory : This is the java source location where I want to generate the Java files. If it is not given then by default it will be generate inside target folder. clearOutputDir : If this property is true then it will generate the classes on each build otherwise it will generate only if output directory is empty. <plugin> <groupId>org.codehaus.mojo</groupId> <artifactId>jaxb2-maven-plugin</art