Page Comparison

...

Code Block

language	java
title	Code Sample __createUser()
linenumbers	true

    private Response    __createUser( User usr )
    {
        Response resp;
        try
        {
            DBConnector connector = DBConnector.getConnector();
            connector.loadAndConnect();

            UserHandler.getLoader().addUser(connector.getConnection(), usr);
            
            resp = Response.status(200).entity(usr).build();
        } catch (IOException ex)
        {
            resp = Response.status(200500).entity(new SimpleErrorMessage("CANNOT ADD USER - SERVER PROBLEM")).build();
            Logger.getLogger(UserRestServices.class.getName()).log(Level.SEVERE, null, ex);
        } catch (ResponseException ex)
        {
            Logger.getLogger(UserRestServices.class.getName()).log(Level.SEVERE, null, ex);
            resp = Response.status(200500).entity(ex.getResponse()).build();
        } catch (SQLException ex)
        {
            resp = Response.status(200409).entity(new SimpleErrorMessage(usr.getUserID() + " CANNOT BE ADDED - ALREADY EXIST")).build();
            Logger.getLogger(UserRestServices.class.getName()).log(Level.SEVERE, null, ex);
        }
        return resp;
    }

I didn't use Java 8 exception multi catch statements as I wanted to report different messages back to the client.

The call at line 6 is to a singleton. We could have used non singleton implementation and this would have worked to, but backend implementation works in a non webservice context too, such as with JSPs.

Notice the error codes that I am returning in the reponse, see http://www.restapitutorial.com/httpstatuscodes.html for valid codes

Client Code

Here we present several examples of client side code

Code Block

language	java
title	Code Sample invoking a POST - to find a user
linenumbers	true

package com.celestial.jaxrs.client;

import com.celestial.dbankbusinessobjects.User;
import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.WebResource;
import com.sun.jersey.api.client.config.ClientConfig;
import com.sun.jersey.api.client.config.DefaultClientConfig;
import com.sun.jersey.api.json.JSONConfiguration;

/**
 *
 * @author Selvyn
 */
public class TestServices
{
    public static void main(String[] args)
    {
        try
        {
            User usr = new User("David", "PP-WW-QQ");

            ClientConfig clientConfig = new DefaultClientConfig();

            clientConfig.getFeatures().put(
                    JSONConfiguration.FEATURE_POJO_MAPPING, Boolean.TRUE);

            Client client = Client.create(clientConfig);

            WebResource webResource = client
                    .resource("http://localhost:8084/dbwstier/dbrest/user/fu");

            ClientResponse response = webResource.accept("application/json")
                    .type("application/json").post(ClientResponse.class, usr);

            if (response.getStatus() != 201)
            {
                throw new RuntimeException("Failed : HTTP error code : "
                        + response.getStatus());
            }

            String output = response.getEntity(String.class);

            System.out.println("Server response .... \n");
            System.out.println(output);
        } catch (Exception e)
        {
            e.printStackTrace();
        }
    }
}

The next examples only show the body changed code

Code Block

language	java
firstline	26
title	Sample Code invoking a DELETE - to remove a user
linenumbers	true

            User us = new User("penny", "leonard");

            ClientConfig clientConfig = new DefaultClientConfig();

            clientConfig.getFeatures().put(
                    JSONConfiguration.FEATURE_POJO_MAPPING, Boolean.TRUE);

            Client client = Client.create(clientConfig);

            WebResource webResource = client
                    .resource("http://localhost:8084/dbwstier/dbrest/user/du");

            ClientResponse response = webResource.accept("application/json")
                    .type("application/json").delete(ClientResponse.class, us);

            if (response.getStatus() != 200)
            {
                throw new RuntimeException("Failed : HTTP error code : "
                        + response.getStatus());
            }

            String output = response.getEntity(String.class);

            System.out.println("Server response .... \n");
            System.out.println(output);

Code Block

language	java
title	Sample Code invoking a POST - add a user
linenumbers	true

            User us = new User("David", "");

            ClientConfig clientConfig = new DefaultClientConfig();

            clientConfig.getFeatures().put(
                    JSONConfiguration.FEATURE_POJO_MAPPING, Boolean.TRUE);

            Client client = Client.create(clientConfig);

            WebResource webResource = client
                    .resource("http://localhost:8084/dbwstier/dbrest/user/cu");

            ClientResponse response = webResource.accept("application/json")
                    .type("application/json").post(ClientResponse.class, us);

            if (response.getStatus() != 201)
            {
                throw new RuntimeException("Failed : HTTP error code : "
                        + response.getStatus());
            }

            String output = response.getEntity(String.class);

            System.out.println("Server response .... \n");
            System.out.println(output);

To update a record we are going to use HTTP PUT command

Code Block

language	java
firstline	26
title	Sample Code invoking a PUT - update a user
linenumbers	true

            User oldUser = new User("David", "ppp");
            User newUser = new User("David", "PP-XX-YY");
            UserMap umap = new UserMap( oldUser, newUser );

            ClientConfig clientConfig = new DefaultClientConfig();

            clientConfig.getFeatures().put(
                    JSONConfiguration.FEATURE_POJO_MAPPING, Boolean.TRUE);

            Client client = Client.create(clientConfig);

            WebResource webResource = client
                    .resource("http://localhost:8084/dbwstier/dbrest/user/uu");

            ClientResponse response = webResource.accept("application/json")
                    .type("application/json").put(ClientResponse.class, umap);

            if (response.getStatus() != 200)
            {
                throw new RuntimeException("Failed : HTTP error code : "
                        + response.getStatus());
            }

            String output = response.getEntity(String.class);

            System.out.println("Server response .... \n");
            System.out.println(output);

Notice the new class UserMap at line 28

Code Block

language	java
title	Code Sample - UserMap

public class UserMap
{
    public  User    oldUser;
    public  User    newUser;
    
    public  UserMap(){}
    
    public  UserMap( User oldU, User newU )
    {
        oldUser = oldU;
        newUser = newU;
    }
}

This will be a carrier object, holding two objects of type User.

Let's see the full server side service interface

Code Block

language	java
title	Code Sample - UserRestService
linenumbers	true
collapse	true

package dbk.webservices;

/**
 *
 * @author Selvyn
 */
import com.celestial.dbankbusinessobjects.User;
import com.celestial.dbankbusinessobjects.UserMap;
import com.celestial.util.objects.SimpleErrorMessage;
import dbk.dbutils.DBConnector;
import dbk.dbutils.ResponseException;
import dbk.dbutils.UserHandler;
import java.io.IOException;
import java.sql.SQLException;
import java.util.Random;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.ws.rs.Consumes;
import javax.ws.rs.DELETE;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.PUT;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;

@Path("/user")
public class UserRestServices
{

    private String genPassword()
    {
        String result = "";
        Random gen = new Random();

        for (int x = 0; x < 8; x++)
        {
            result += (char) (gen.nextInt(26) + 'A');
        }

        return result;
    }

    @GET
    @Path("/sayhello")
    @Produces(MediaType.TEXT_HTML)
    public String sayHtmlHelloTest()
    {
        return "<html> " + "<title>" + "Hello World" + "</title>"
                + "<body><h1>" + "Hello from the Deutsche Bank DB Tier" + "</h1></body>" + "</html> ";
    }

    @GET
    @Path("/cu/{user}")
    @Produces(MediaType.APPLICATION_JSON)
    public Response createUser(@PathParam("user") String userId)
    {
        User usr = new User(userId, genPassword());
        
        return __createUser(usr);
    }

    @POST
    @Path("/cu")
    @Consumes(MediaType.APPLICATION_JSON)
    public Response createUserFromObject(User usr)
    {
        usr.setUserPwd(genPassword());
        return __createUser(usr);
    }
    
    private Response    __createUser( User usr )
    {
        Response resp;
        try
        {
            DBConnector connector = DBConnector.getConnector();
            connector.loadAndConnect();

            UserHandler.getLoader().addUser(connector.getConnection(), usr);
            
            resp = Response.status(201).entity(usr).build();
        } catch (IOException ex)
        {
            resp = Response.status(500).entity(new SimpleErrorMessage("CANNOT ADD USER - SERVER PROBLEM")).build();
            Logger.getLogger(UserRestServices.class.getName()).log(Level.SEVERE, null, ex);
        } catch (ResponseException ex)
        {
            Logger.getLogger(UserRestServices.class.getName()).log(Level.SEVERE, null, ex);
            resp = Response.status(500).entity(ex.getResponse()).build();
        } catch (SQLException ex)
        {
            resp = Response.status(409).entity(new SimpleErrorMessage(usr.getUserID() + " CANNOT BE ADDED - ALREADY EXIST")).build();
            Logger.getLogger(UserRestServices.class.getName()).log(Level.SEVERE, null, ex);
        }
        return resp;
    }

    @DELETE
    @Path("/du")
    @Consumes(MediaType.APPLICATION_JSON)
    public Response deleteUser(User usr)
    {
        Response resp;
        try
        {
            DBConnector connector = DBConnector.getConnector();
            connector.loadAndConnect();

            UserHandler.getLoader().deleteUser(connector.getConnection(), usr);
            resp = Response.status(200).entity( usr ).build();
        } catch (IOException ex)
        {
            resp = Response.status(500).entity(new SimpleErrorMessage("CANNOT DELETE USER - SERVER PROBLEM")).build();
            Logger.getLogger(UserRestServices.class.getName()).log(Level.SEVERE, null, ex);
        } catch (ResponseException ex)
        {
            Logger.getLogger(UserRestServices.class.getName()).log(Level.SEVERE, null, ex);
            resp = Response.status(200).entity(ex.getResponse()).build();
        } catch (SQLException ex)
        {
            resp = Response.status(409).entity(new SimpleErrorMessage(usr.getUserID() + " CANNOT BE DELETD - USER DOES NOT EXIST")).build();
            Logger.getLogger(UserRestServices.class.getName()).log(Level.SEVERE, null, ex);
        }
        return resp;
    }

    @PUT
    @Path("/uu")
    @Consumes(MediaType.APPLICATION_JSON)
    public Response updateUserFromObject(UserMap umap)
    {
        return __updateUser( umap );
    }

    @GET
    @Path("/uu/{oldid}/{oldpwd}/{newid}/{newpwd}")
    @Produces(MediaType.APPLICATION_JSON)
    public Response updateUser( @PathParam("oldid") String oldId, 
                                @PathParam("oldpwd") String oldpwd,
                                @PathParam("newid") String newId, 
                                @PathParam("newpwd") String newpwd)
    {
        User oldUser = new User( oldId, oldpwd );
        User newUser = new User( newId, newpwd );
        UserMap umap = new UserMap( oldUser, newUser );
        
        return __updateUser( umap );
    }
    
    private Response    __updateUser( UserMap umap )
    {
        Response resp;
        try
        {
            DBConnector connector = DBConnector.getConnector();
            connector.loadAndConnect();

            UserHandler.getLoader().updateUser(connector.getConnection(), umap.oldUser, umap.newUser);
            resp = Response.status(200).entity( umap ).build();
        } catch (IOException ex)
        {
            resp = Response.status(500).entity(new SimpleErrorMessage("CANNOT UPDATE USER - SERVER PROBLEM")).build();
            Logger.getLogger(UserRestServices.class.getName()).log(Level.SEVERE, null, ex);
        } catch (ResponseException ex)
        {
            Logger.getLogger(UserRestServices.class.getName()).log(Level.SEVERE, null, ex);
            resp = Response.status(200).entity(ex.getResponse()).build();
        } catch (SQLException ex)
        {
            resp = Response.status(409).entity(new SimpleErrorMessage(umap.oldUser.getUserID() + " CANNOT BE CHANGED - USER DOES NOT EXIST")).build();
            Logger.getLogger(UserRestServices.class.getName()).log(Level.SEVERE, null, ex);
        }
        return resp;
    }

    @POST
    @Path("/fu")
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    public Response findUser( User usr )
    {
        return __findUser( usr );
    }
    
    @GET
    @Path("/fu/{user}/{pwd}")
    @Produces(MediaType.APPLICATION_JSON)
    public Response findUser(@PathParam("user") String userId, @PathParam("pwd") String pwd)
    {
        User usr = new User( userId, pwd );
        return __findUser( usr );
    }
    
    private Response    __findUser( User requsr )
    {
        User usr = null;
        try
        {
            DBConnector connector = DBConnector.getConnector();
            connector.loadAndConnect();

            usr = UserHandler.getLoader().loadFromDB(connector.getConnection(), requsr.getUserID(), requsr.getUserPwd());
            if (usr != null)
            {
                return Response.status(200).entity(usr).build();
            } else
            {
                SimpleErrorMessage msg = new SimpleErrorMessage("USER NOT FOUND");
                return Response.status(200).entity(msg).build();
            }
        } catch (IOException ex)
        {
            Logger.getLogger(UserRestServices.class.getName()).log(Level.SEVERE, null, ex);
        } catch (ResponseException ex)
        {
            Logger.getLogger(UserRestServices.class.getName()).log(Level.SEVERE, null, ex);
            return Response.status(200).entity(ex.getResponse()).build();
        }

        SimpleErrorMessage msg = new SimpleErrorMessage("ERROR IN DB TIER");
        return Response.status(200).entity(msg).build();
    }
}

Versions Compared

Old Version 14

New Version Current

Key

Client Code