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.
https://www.thetechnojournals.com/2020/03/cors-implementation-using-java-filter.html

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){
        super(req);
        setContentType("true".equals(req.getParameter("json"))
            ?"application/json" : req.getContentType());
    }
    @Override
    public String getContentType(){
        return contentType;
    }
    
    @Override
    public String getHeader(String name){
        if("Content-Type".equalsIgnoreCase(name))
            return contentType;
        else
            return super.getHeader(name);
    }

    @Override
    public Enumeration<String> getHeaders(String name){
        if("Content-Type".equalsIgnoreCase(name))
            return Collections.enumeration(Arrays.asList(contentType));
        else
            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;
        ....
        .....
        
        if("OPTIONS".equalsIgnoreCase(request.getMethod())){
            response.setStatus(HttpServletResponse.SC_ACCEPTED);
            return;
        }
        chain.doFilter(request, response);
    }
}

Comments

  1. There are many apps that let the apk website Android users stream movies and TV shows on their devices for free. Here, I am listing some of the topmost apps, which will put hundreds of movies and countless TV shows at your fingertips.

    ReplyDelete
  2. Download Apk Latest Version of getcontact pro MOD, The Social Apps of Android, This Pro Apk Includes Unlocked All Premium, No Ads. Get Your Apk Now!

    ReplyDelete
  3. I explore many web pages in such form and I definitely always learn more about these important programming languages. Last night I found perfect point to study lot more.

    ReplyDelete
  4. I read the above article and got some knowledge from your article which is about..... It's actually great and useful data for us. Thanks for sharing it.web development

    ReplyDelete
  5. I read the article you linked to above, and I learned a little something from it. For us, the information is genuinely quite good and helpful. We appreciate you sharing it.hire programmers in india

    ReplyDelete
  6. I am attracted by the info which you have provided in the above post. It is genuinely good and beneficial info for us. Continue posting, Thank you. web development company in bangalore

    ReplyDelete
  7. I read the article you linked to above, and I learned a little something from it. We can really utilise this information, it's amazing. We appreciate you sharing it.app development

    ReplyDelete

Post a Comment

Popular Posts

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=&

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 "property.name" 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

Why HashMap key should be immutable in java

HashMap is used to store the data in key, value pair where key is unique and value can be store or retrieve using the key. Any class can be a candidate for the map key if it follows below rules. 1. Overrides hashcode() and equals() method.   Map stores the data using hashcode() and equals() method from key. To store a value against a given key, map first calls key's hashcode() and then uses it to calculate the index position in backed array by applying some hashing function. For each index position it has a bucket which is a LinkedList and changed to Node from java 8. Then it will iterate through all the element and will check the equality with key by calling it's equals() method if a match is found, it will update the value with the new value otherwise it will add the new entry with given key and value. In the same way it check for the existing key when get() is called. If it finds a match for given key in the bucket with given hashcode(), it will return the value other

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