Currently, I am in the process of learning about REST API. My goal is to make a call to a POST service implemented in Java from Javascript using fetch. However, I have encountered an issue where the request fails to reach the service whenever the @Produces and @Consumes are set to MediaType.APPLICATION_JSON.
In the same API, I have successfully defined other simple POST and GET methods that work fine. It's only when dealing with sending and receiving JSON data that I face difficulties.
Here is the snippet of my fetch call:
let options = {
method: "POST",
headers: new Headers({'content-type': 'application/json'}),
body: JSON.stringify({
"Title": "title"
})
};
const url = "http://localhost:8080/myserver/data/list";
return fetch(url, options);
Below is an excerpt of my REST API implementation:
@Path("/data")
public class Controller {
@POST
@Produces(MediaType.APPLICATION_JSON)
@Consumes(MediaType.APPLICATION_JSON)
@Path("/list")
public Response createList(CreateListJsonData data) throws IOException {
System.out.println("in create list");
return Response.status(200)
.entity("{\"dummykey\"}:\"dummyVal\"")
.header("Access-Control-Allow-Origin", "*")
.header("Access-Control-Allow-Methods", "GET, POST, DELETE, PUT")
.build();
}
The CreateListJsonData class definition looks like this:
@XmlRootElement
public class CreateListJsonData {
private String Title;
public String getTitle() {
return Title;
}
public void setTitle(String title) {
Title = title;
}
}
Here is also my web.xml configuration:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">
<display-name>myserver</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>Jersey Web Application</servlet-name>
<servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
<init-param>
<param-name>jersey.config.server.provider.packages</param-name>
<param-value>com.myserver</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Jersey Web Application</servlet-name>
<url-pattern>/*</url-pattern>
</servlet-mapping>
</web-app>
I am currently running the API on Tomcat within Eclipse. Upon triggering the request, the following messages appear on the console:
com.sun.jersey.server.wadl.generators.AbstractWadlGeneratorGrammarGenerator attachTypes
INFO: Couldn't find grammar element for class javax.ws.rs.core.Response
If anyone could offer assistance in identifying where I might be going wrong, it would be greatly appreciated.