Develop Reference

Tomcat and MYSQL porting to AWS

I have a working java 7 app that runs on tomcat 7 and MYSQL. I am trying to get it running on the basic (free tier) platform offered by Amazon AWS. I have succesfully loaded data to the RDS instance of MYSQL Community and set up an Elastic Beanstalk instance where basic JSPs are running correctly.
I am new to AWS so main problem should be my lack of knowledge.
I am not able to connect to the database from my code.
This is the code I am using to create the connection pool:
package com.authz.pap;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.sql.DataSource;
public class DBConnections {
private static DataSource dataSource;
private static final DBConnections instance = new DBConnections();
static
{
try
{
Context c = new InitialContext();
dataSource = (DataSource)c.lookup("java:comp/env/jdbc/authzDB");
}
catch (Exception e)
{
dataSource = null;
}
}
private DBConnections()
{
}
public static DBConnections getInstance()
{
return instance;
}
public static DataSource getGeoServDS() {
//if(dataSource==null) instance = new DBConnections();
return dataSource;
}
}
And this:
public DbCon() {
conn=null;
ProcessStatus stat = new ProcessStatus();
stat.function="DbCon.DbCon";
stat.message = "Initializing DB";
stat.retcode=0;
stat.record();
try {
conn=DBConnections.getGeoServDS().getConnection();
conn.setAutoCommit(false);
} catch (Exception e) {
stat.message = e.toString();
stat.retcode=-1;
stat.record();
}
}
And this is the content of the context.xml file:
<?xml version="1.0" encoding="UTF-8"?>
<Context antiJARLocking="true" path="/rest">
<Resource auth="Container" driverClassName="com.mysql.jdbc.Driver" maxActive="8" maxIdle="4" name="jdbc/authzDB" password="xxxx" type="javax.sql.DataSource" url="jdbc:mysql://x.x.x.x:3306/authzDB?autoReconnect=true&allowMultiQueries=true" username="root"/>
<ResourceLink global="jdbc/authzDB" name="jdbc/authzDB" type="javax.sql.DataSource"/>
</Context>
What I get is a java.lang.NullPointerException on DB initialization.
What am I doing wrong?
UPDATE:
This is the content of the web.xml file:
<?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" id="WebApp_ID" version="2.5">
<display-name>paprest</display-name>
<servlet>
<servlet-name>PAP rest interface</servlet-name>
<servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
<init-param>
<param-name>jersey.config.server.provider.packages</param-name>
<param-value>com.authz.pap.intfc</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>rest interface</servlet-name>
<url-pattern>/rest/*</url-pattern>
</servlet-mapping>
</web-app>

Double response:
1- I have not been able to use the data from context.xml file. I have ised a different solution:
private static Connection getRemoteConnection() {
ProcessStatus stat = new ProcessStatus();
try {
Class.forName("com.mysql.jdbc.Driver");
String dbName = "xxxxDB";
String userName = "xxxxx";
String password = "xxxxxx";
String hostname = "xxxxxxxx";
String port = "3306";
String jdbcUrl = "jdbc:mysql://" + hostname + ":" + port + "/" + dbName + "?user=" + userName + "&password=" + password + "&autoReconnect=true&allowMultiQueries=true";
Connection con = DriverManager.getConnection(jdbcUrl);
return con;
}
catch (ClassNotFoundException e) { stat.error(e.toString());}
catch (SQLException e) { stat.error(e.toString());}
return null;
}
2- I had a different problem, as the RDS instance is not to be created independently but related to the Elastic Beanstalk. This allows the comunication betwen tomcat and Mysql.

Jersey inject instance into Resource

I'm trying to create a Jersey Resource that allows me to reuse an ElasticSearch TransportClient. So I would like to use a single instance of TransportClient over all Resources that require it. So far I've got this:
Resource:
#Path("/request")
public class ConfigurationResource {
private final TransportClient transportClient;
#Inject
public ConfigurationResource(TransportClient transportClient)
{
this.transportClient = transportClient;
}
#GET
#Produces(MediaType.TEXT_PLAIN)
public String AlarmStatus(){
if(transportClient != null)
return "Not NULL! ID: ";
else
return "NULL :(";
}
}
Binding:
public class WebMainBinder extends AbstractBinder {
#Override
protected void configure() {
TransportClient transportClient = null;
try {
transportClient = TransportClient.builder().build()
.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("localhost"), 9300));
} catch (UnknownHostException e) {
e.printStackTrace();
return;
}
bind(transportClient).to(TransportClient.class);
}
}
Main Application:
#ApplicationPath("service")
public class WebMain extends ResourceConfig {
public WebMain(){
register(new WebMainBinder());
packages(true, "com.eniacdevelopment.EniacHome.Resources");
}
}
Web.xml:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
version="3.1">
<servlet>
<servlet-name>com.eniacdevelopment.EniacHome.Application.WebMain</servlet-name>
</servlet>
<servlet-mapping>
<servlet-name>com.eniacdevelopment.EniacHome.Application.WebMain</servlet-name>
<url-pattern>/service/*</url-pattern>
</servlet-mapping>
</web-app>
I've also tried using a factory like so:
public class TransportClientFactory implements Factory<TransportClient> {
private TransportClient transportClient;
#Override
public TransportClient provide() {
if(this.transportClient == null){
try {
transportClient = TransportClient.builder().build()
.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("localhost"), 9300));
} catch (UnknownHostException e) {
e.printStackTrace();
return null;
}
}
return transportClient;
}
#Override
public void dispose(TransportClient transportClient) {
}
}
And then binding it this way:
bindFactory(TransportClientFactory.class)
.to(TransportClient.class).in(Singleton.class);
But no success. I keep on getting Unsatisfied dependencies for type TransportClient with qualifiers #Default.
Help would be much appreciated!

I've found Jersey's DI container functionality pretty unpleasant. I prefer to use Guice for managing my DI, so if you're open to using Guice, you can see how to wire up Jersey and Guice to collaborate in this demo project: https://bitbucket.org/marshallpierce/guice-jaxrs-examples. The common subproject has the shared logic, and there are other subprojects for the jersey and resteasy specific parts.

Alright got it to work:
When I at first tried to deploy the app to glassfish it complained about some guava dependency. I swapped the Guava jar in glassfish/modules with the one maven had installed and got it to deploy. It may have something to do with that. No guarentees here.
I decided to drop the whole glassfish stuff and start from scratch. On the jersey introduction page there's this maven archetype that can be isntalled like so:
mvn archetype:generate -DarchetypeArtifactId=jersey-quickstart-grizzly2
-DarchetypeGroupId=org.glassfish.jersey.archetypes -DinteractiveMode=false -DgroupId=com.example -DartifactId=simple-service
-Dpackage=com.example
-DarchetypeVersion=2.24
Starting from there helped me out.

Ignoring web.xml when loading a WAR file with Jetty

I'm trying a self-executable WAR package with Jetty. It configures with web.xml by default. If a run-time option is given, I wanted to override web.xml by Java code-level configuration with ServletContextHandler#addServlet, #addEventListener, and ...
Can I ignore web.xml while loading a WAR package?
% java -jar foobar.jar # Use web.xml
% java -jar foobar.jar --customize=something # Use Java code to configure
// Example
WebAppContext webapp = new WebAppContext();
webapp.setWar(warLocation.toExternalForm());
webapp.setContextPath("/");
if ( /* has run-time options */ ) {
webapp.setWar(warLocation.toExternalForm()); // But, no load web.xml!
// Emulates web.xml.
webapp.addEventListener(...);
webapp.setInitParameter("resteasy.role.based.security", "true");
webapp.addFilter(...);
} else {
webapp.setWar(warLocation.toExternalForm()); // Loading web.xml.
}
Additional Question:
Before server.start() is called, classes under WEB-INF/ are not loaded. Can I do some configuration webapp.something() with some classes under WEB-INF/? (E.g. extend WebInfConfiguration or do a similar class-loading that WebInfConfiguration does?)
For example, I'd like to do something like:
webapp.addEventListener(new SomeClassUnderWebInf()));
webapp.addEventListener(someInjector.inject(SomeClassUnderWebInf.class));
before server.start().

Handle the WebAppContext Configuration yourself.
Eg:
private static class SelfConfiguration extends AbstractConfiguration
{
#Override
public void configure(WebAppContext context) throws Exception
{
// Emulates web.xml.
webapp.addEventListener(...);
webapp.setInitParameter("resteasy.role.based.security", "true");
webapp.addFilter(...);
}
}
public static void main(String[] args) throws Exception
{
Server server = new Server(8080);
WebAppContext webapp = new WebAppContext();
webapp.setContextPath("/");
if (useWebXml)
{
webapp.setConfigurationClasses(WebAppContext.getDefaultConfigurationClasses());
}
else
{
webapp.setConfigurations(new Configuration[] {
new SelfConfiguration()
});
}
webapp.setWar("path/to/my/test.war");
webapp.setParentLoaderPriority(true);
server.setHandler(webapp);
server.start();
server.join();
}

injecting jetty spring servlet with guice(or changing it so I can inject it)

I cloned servlet:
https://github.com/eHarmony/vw-webservice . I want to start this servlet from my jetty code. I am using guice to add classes to jetty. It looks like I need to move applicationContext so it works as a jar, not war . I don't have experience with jetty or spring. I would love to hear what you think about it.
GuiceConfig.java
public class GuiceConfig extends GuiceServletContextListener
{
#Override
protected Injector getInjector()
{
return Guice.createInjector(new JerseyServletModule() {
#Override
protected void configureServlets() {
bind(ClassThatProcessRequest.class);
bind(InjecteeInterface.class).to(Injectee.class);
serve("/*").with(GuiceContainer.class);
}
});
}
}
and main.java
public class Main {
public static void main(String[] args) throws Exception {
Server server = new Server(8080);
ServletContextHandler root = new ServletContextHandler(server, "/", ServletContextHandler.SESSIONS);
root.addEventListener(new GuiceConfig());
root.addFilter(GuiceFilter.class, "/*", EnumSet.of(DispatcherType.REQUEST));
root.addServlet(EmptyServlet.class, "/*");
server.start();
}
}
When I start server I get
com.google.inject.CreationException: Guice creation errors:
No implementation for com.eharmony.matching.vw.webservice.core.exampleprocessor.ExampleProcessorFactory was bound.
here is applicationContext.xml and web.xml
https://github.com/eHarmony/vw-webservice/blob/master/vw-webservice-jersey/src/main/webapp/WEB-INF/applicationContext.xml
https://github.com/eHarmony/vw-webservice/blob/master/vw-webservice-jersey/src/main/webapp/WEB-INF/web.xml

How to register RPC service as servlet in web.xml

I have created RPC service in my existing application using the RPC tutorial mentioned on the page
http://www.gwtproject.org/doc/latest/tutorial/RPC.html#services. I am still getting the 404 no service found exception. Here is what I have done.
Created the service interface on client side.
#RemoteServiceRelativePath("searchportoutorder")
public interface SearchPortOutOrderService extends RemoteService {
List<SearchPortOutOrderModel> fetchMoreRecords();
}
Created the asynce interface on client.
public interface SearchPortOutOrderServiceAsync {
void fetchMoreRecords(AsyncCallback<List<SearchPortOutOrderModel>> async);
}
Create the service impl under package server.
public class SearchPortOutOrderServiceImpl extends RemoteServiceServlet implements SearchPortOutOrderService {
List<SearchPortOutOrderModel> models = new ArrayList<SearchPortOutOrderModel>();
private void initializeModel() {
for(int i=0;i<10000;i++){
SearchPortOutOrderModel model = new SearchPortOutOrderModel();
model.setOrderId("1234-132131-12312-12312");
model.setCustomer("ashish testing");
model.setOrderDate("2014-12-25");
model.setLastUpdated("2014-02-15");
model.setStatus("Completed");
models.add(model);
}
}
#Override public List<SearchPortOutOrderModel> fetchMoreRecords() {
initializeModel();
return models;
}
Update the web.xml file to involve the servlet.
<servlet>
<servlet-name>searchPortOutOrderService</servlet-name>
<servlet-class>com.inetwork.gwt.client.searchportoutorder.server.SearchPortOutOrderServiceImpl</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>searchPortOutOrderService</servlet-name>
<url-pattern>/report/searchportoutorder</url-pattern>
</servlet-mapping>
I am still getting 404 exception saying that the service is not found.Do I need to modified anything else in my code like .gwt.xml file.

if your gwt module name is not report
modify *.gwt.xml like this.
<module rename-to='report'>
or replace url-pattern in web.xml to your gwt-module-name.