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How to mock DriverManager.getConnection?

How do I mock the DriverManager.getConnection() method?
I want to test my method setUpConnectiontoDB()
I tried it with PowerMock, easyMock and Mokito itself. I didn't find anything usefull.
My Code:
import java.io.FileInputStream;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;
public class MysqlDAO implements DAO {
private final Properties properties = new Properties();
public MysqlDAO(String configPath) {
loadProperties(configPath);
}
private Properties loadProperties(String configPath) {
try {
properties.load(new FileInputStream(configPath));
} catch (IOException e) {
e.printStackTrace();
}
return this.properties;
}
#Override
public Connection setUpConnectionToDB() {
try {
Class.forName("com.mysql.jdbc.Driver");
return DriverManager.getConnection(
properties.getProperty("url"),
properties.getProperty("user"),
properties.getProperty("passwd"));
} catch (ClassNotFoundException | SQLException e) {
e.printStackTrace();
}
return null;
}
}

Some notes on that:
Class.forName("com.mysql.jdbc.Driver");
This line is obsolete since JDBC 4.0. You should be able to run the code without. Or if you think you need it at least abstract it as well to do
Class.forName(properties.getProperty("dbdriver", "com.mysql.jdbc.Driver");
Once that's been taken care of, who says you have to mock it? It's much easier to actually run it.
You could just as well use an in memory database (like h2) for testing and check your code for that. All you'd change would be your url, user and passwd properties.
This would be some example properties for use with h2:
dbdriver = org.h2.Driver
url = jdbc:h2:mem:test
user = sa
passwd = sa
That way, you not only take care of your unit-test for setUpConnectionToDB() but could later use that connection for methods that expect some data in that database.

NoClassDefFoundError: com/google/common/reflect/TypeToken

I have been using this api. The API is a Java wrapper for Mailchimp API with maven dependency.
<dependency>
<groupId>com.ecwid</groupId>
<artifactId>ecwid-mailchimp</artifactId>
<version>2.0.1.0</version>
</dependency>
I didn’t have trouble working with their API so far. But now I see this strange exception:
Exception in thread "Timer-2" java.lang.NoClassDefFoundError: com/google/common/reflect/TypeToken
at com.ziprealty.subscription.MailChimpNewsSubscriptionProcessor.updateAllUnSubscribedEmails(MailChimpNewsSubscriptionProcessor.java:84)
at com.ziprealty.job.MailChimpSubscriptionProcessor.processTask(MailChimpSubscriptionProcessor.java:29)
at com.ziprealty.job.JobBase.run(JobBase.java:96)
at java.util.TimerThread.mainLoop(Timer.java:555)
at java.util.TimerThread.run(Timer.java:505)
Caused by: java.lang.ClassNotFoundException: com.google.common.reflect.TypeToken
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1305)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1157)
... 5 more
And here is the code for updateAllUnSubscribedEmails
public void updateAllUnSubscribedEmails( Date lastRunDate, String brandCode,Logger logger){
logger.log(Level.SEVERE, "Entering mail chimp subscription processor in boardwalk for :" + brandCode);
logger.log(Level.SEVERE, "Last run date is :" + lastRunDate);
System.out.println("Entering mail chimp subscription processor in boardwalk for :" + brandCode);
try {
MailChimpSubscriptionDAO subscriptionDAO = MailChimpSubscriptionDAO.INSTANCE;
MailChimpSubscription subscription= subscriptionDAO.getMailChimpSubscriptionByBrandCode(brandCode);
logger.log(Level.SEVERE,"Subscription object is :"+ subscription);
**ListMembersMethod listMembersMethod= new ListMembersMethod();**
logger.log(Level.SEVERE,"listMembersMethod object is :"+ listMembersMethod);
listMembersMethod.status= MemberStatus.unsubscribed;
logger.log(Level.SEVERE,"listMembersMethod.status object is :"+ listMembersMethod.status);
listMembersMethod.apikey=mailChimpApiKey;
logger.log(Level.SEVERE,"listMembersMethod.apikey object is :"+ listMembersMethod.apikey);
listMembersMethod.id=subscription.getEmailListId();
logger.log(Level.SEVERE,"listMembersMethod.id object is :"+ listMembersMethod.id);
listMembersMethod.since= lastRunDate;
.
.
.
.
} catch (IOException e) {
e.printStackTrace();
System.out.println(e.getMessage());
logger.log(Level.SEVERE, e.getMessage());
} catch (MailChimpException e) {
e.printStackTrace();
System.out.println(e.getMessage());
logger.log(Level.SEVERE, e.getMessage());
}
catch (Exception e){
e.printStackTrace();
System.out.println(e.getMessage());
logger.log(Level.SEVERE, e.getMessage());
}
finally {
logger.log(Level.SEVERE,"Finally block ...Try catch block ended");
}
logger.log(Level.SEVERE,"After finally Try catch block without exception ");
}
The code stops working at this line :
ListMembersMethod listMembersMethod= new ListMembersMethod();
It doesn’t even go to the Exceptions block at all. Only to the finally block.
This is the generated code by Intelij IDEA for the class ListMembersMethod:
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//
package com.ecwid.mailchimp.method.v1_3.list;
import com.ecwid.mailchimp.MailChimpAPIVersion;
import com.ecwid.mailchimp.MailChimpMethod.Method;
import com.ecwid.mailchimp.MailChimpObject.Field;
import com.ecwid.mailchimp.method.v1_3.list.HasListIdMethod;
import com.ecwid.mailchimp.method.v1_3.list.ListMembersResult;
import com.ecwid.mailchimp.method.v1_3.list.MemberStatus;
import java.util.Date;
#Method(
name = "listMembers",
version = MailChimpAPIVersion.v1_3
)
public class ListMembersMethod extends HasListIdMethod<ListMembersResult> {
#Field
public MemberStatus status;
#Field
public Date since;
#Field
public Integer start;
#Field
public Integer limit;
public ListMembersMethod() {
}
}
Intelij Idea has also generated the following code for hasHasListIdMethod :
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//
package com.ecwid.mailchimp.method.v1_3.list;
import com.ecwid.mailchimp.MailChimpMethod;
import com.ecwid.mailchimp.MailChimpObject.Field;
public abstract class HasListIdMethod<R> extends MailChimpMethod<R> {
#Field
public String id;
public HasListIdMethod() {
}
}
The MailChimpMethod has the following code where it contains TypeToken
:
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//
package com.ecwid.mailchimp;
import com.ecwid.mailchimp.MailChimpAPIVersion;
import com.ecwid.mailchimp.MailChimpObject;
import com.ecwid.mailchimp.MailChimpObject.Field;
import com.google.common.reflect.TypeToken;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
public abstract class MailChimpMethod<R> extends MailChimpObject {
private final TypeToken<R> resultTypeToken = new TypeToken(this.getClass()) {
};
#Field
public String apikey;
public MailChimpMethod() {
}
public final MailChimpMethod.Method getMetaInfo() {
for(Class c = this.getClass(); c != null; c = c.getSuperclass()) {
MailChimpMethod.Method a = (MailChimpMethod.Method)c.getAnnotation(MailChimpMethod.Method.class);
if(a != null) {
return a;
}
}
throw new IllegalArgumentException("Neither " + this.getClass() + " nor its superclasses are annotated with " + MailChimpMethod.Method.class);
}
public final Type getResultType() {
Type type = this.resultTypeToken.getType();
if(!(type instanceof Class) && !(type instanceof ParameterizedType) && !(type instanceof GenericArrayType)) {
throw new IllegalArgumentException("Cannot resolve result type: " + this.resultTypeToken);
} else {
return type;
}
}
#Documented
#Retention(RetentionPolicy.RUNTIME)
#Target({ElementType.TYPE})
public #interface Method {
MailChimpAPIVersion version();
String name();
}
}
I would really appreciate your help on this. Couldn't figure out what the fix would be.

The MailChimp API Wrapper 2.0.1.0 depends on Guava 16.0.1 (see mvnrepository.com/artifact/com.ecwid/ecwid-mailchimp/2.0.1.0). The com.google.common.reflect.TypeToken class is part of Guava 16.0.1 (see central.maven.org/maven2/com/google/guava/guava/16.0.1/guava-16.0.1.jar).
Do you use Maven to build your project and if this is the case, can you compile/test your code without issues? Is Guava downloaded for the project? What do you see when running mvn dependency:tree -Dverbose?

It took me sometime but I found the issue. I was working on two independent projects which are dependent on MailChimp API. However, I didn't have the maven dependency on one of the project and that was causing the problem.
So included the maven dependency on both projects, and it worked like a charm!
<dependency>
<groupId>com.ecwid</groupId>
<artifactId>ecwid-mailchimp</artifactId>
<version>2.0.1.0</version>
</dependency>

jdbc dynamic class loading

hello i am trying to load my jdbc diver through classloader
here i am code but why i get this error if possible than give me some example
i don not what to set class path variable
i am making a database application and this application need to connect database again and again and i want to give this application to my friend but my friend not know about class path he is like normal user ,
my application can connect 4 type of database MS-Access,MySQL,Oracle,SQLlite...
in user system i have to set 5 class path variable and provide 5 jar file
if i give this application 100 people than they have set set class path variable
i can include jar file with my application but how can i set class path dynamically ....
please provide some example...
package classload;
import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class ClassLoad {
static Connection con;
public static void main(String[] args) {
File jar = new File("C:\\query\\Driver.jar").getAbsoluteFile();
if(jar.exists()){
System.out.print("File exits");
}
URL urls[] = null;
try {
urls = new URL[] {
jar.toURI().toURL()
};
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
ClassLoader cl = new URLClassLoader(urls);
try {
Class.forName("com.mysql.jdbc.Driver", true, cl);
con=DriverManager.getConnection("jdbc:mysql://localhost", "root", "anil");
Statement stm=con.createStatement();
ResultSet result=stm.executeQuery("select *from actor");
while(result.next()){
System.out.print(result.getInt(1)+" "+result.getString(2)+" "+result.getString(3));
System.out.println("");
}
} catch (SQLException e) {
System.out.println(e);
}catch(ClassNotFoundException e){
System.out.println(e);
}
}
}
exception is
java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost

Just use One-Jar to package the application and all of the dependencies into single fat jar. Your solution is no good. Your friend would have to use the same folder structure as you are in order for it to work.

This error is coming probably because the required jar file mysql-connector has not been included in your project. Try including jar file as shown here. And try this code to load Driver class:
Class.forName("com.mysql.jdbc.Driver");
con=DriverManager.getConnection("jdbc:mysql://localhost:3306/jlcstudents","root","password");

How to make MongoDB Service Available?

I am developing OSGi Mongodb bundle I have also added the following dependencies
com.mongodb
org.apache.felix.fileinstal
org.amdatu.mongo
org.apache.felix.configadmin
and all the dependency managers but in gogo console I get the following error message
org.amdatu.mongo
org.osgi.service.cm.ManagedServiceFactory(service.pid=org.amdatu.mongo) registered
org.osgi.service.log.LogService service optional unavailable
[11] agenda.mongodb.mongo_gfs
agenda.mongo.inter.AgendaMongo() unregistered
org.amdatu.mongo.MongoDBService service required unavailable
the main problem is MongoDBService is not available I must require this service for solving this problem I have read the book according to them
From a development perspective, everything seems fine, but when you
run the appli‐ cation, it will complain that the MongoDBService is
unavailable. You can figure this out with the dmcommand in the shell.
We did however set up MongoDB on our system and deployed the necessary
dependencies in our runtime. Still, the MongoDBService was unable to
start. How come? This is because the MongoDBService needs some
mandatory configuration in order to know to what database to connect
to. The Amdatu MongoDB Serviceuses the Managed Service Factory pattern
(see Chapter 4), and in order to bootstrap it, we need to supply a
configuration file. In order to supply the configuration file, we need
to create a new folder in our agendaproject. Create a new folder
called load. This is the default name that the runtime will look for
in order to spot configuration files. Next, add an empty text file and
call it something like org.amdatu.mongo-demo.xml. The configuration
file needs at least the following information: dbName=demo
I have also apply this but its still unavailable.
This is interface:
package agenda.mongo.inter;
import java.io.InputStream;
public interface AgendaMongo {
public String store_in_db();
public InputStream getData(Object file_id);
}
This is the implementation for Mongodb:
package agenda.mongodb.gridfs;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.UnknownHostException;
import org.amdatu.mongo.MongoDBService;
import org.bson.types.ObjectId;
import agenda.mongo.inter.AgendaMongo;
import com.mongodb.DB;
import com.mongodb.DBCursor;
import com.mongodb.gridfs.GridFS;
import com.mongodb.gridfs.GridFSDBFile;
import com.mongodb.gridfs.GridFSInputFile;
public class Gridfs_Mongodb implements AgendaMongo{
GridFSInputFile gfsinput=null;
private volatile MongoDBService mongoservice;
public String store_in_db() {
/*try {
GridFS gfsHandler;
gfsHandler = new GridFS(mongoservice.getDB(), "rest_data");// database
File uri = new File("f:\\get1.jpg"); // name and
gfsinput = gfsHandler.createFile(uri);
gfsinput.saveChunks(1000);
gfsinput.setFilename("new file");
gfsinput.save();
//System.out.println(gfsinput.getId());
//save_filepath("file",gfsinput.getId());
Object get_id = gfsinput.getId();//get_filename();
//System.out.println(getData(get_id));
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
//System.out.println("Exception");
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
//System.out.println("Exception");
e.printStackTrace();
}*/
System.out.println("DB:" + mongoservice.getDB());
return mongoservice.getDB()+"";
}
/*
* Retrieving the file
*/
public InputStream getData(Object file_id) {
GridFS gfsPhoto = new GridFS(mongoservice.getDB(), "rest_data");
GridFSDBFile dataOutput = gfsPhoto.findOne((ObjectId) file_id);
DBCursor cursor = gfsPhoto.getFileList();
while (cursor.hasNext()) {
System.out.println(cursor.next());
}
System.out.println(dataOutput);
return dataOutput.getInputStream();
}
void start(){
System.out.println("hello");
System.out.println(store_in_db());
}
}
Here I was just trying to get database name because every thing can be done after that but I t was returning me NULL because MongoDBService is Unavailable.
At this is Activator class
package agenda.mongodb.gridfs;
import org.amdatu.mongo.MongoDBService;
import org.apache.felix.dm.DependencyActivatorBase;
import org.apache.felix.dm.DependencyManager;
import org.osgi.framework.BundleContext;
import agenda.mongo.inter.AgendaMongo;
public class Activator extends DependencyActivatorBase {
#Override
public void init(BundleContext arg0, DependencyManager manager)
throws Exception {
manager.add(createComponent()
.setInterface(AgendaMongo.class.getName(), null)
.setImplementation(Gridfs_Mongodb.class)
.add(createServiceDependency()
.setService(MongoDBService.class)
.setRequired(true)));
}
#Override
public void destroy(BundleContext arg0, DependencyManager arg1)
throws Exception {
// TODO Auto-generated method stub
}
}
The Interface package is an exported package and the implementation package is private.

The configuration file should have a .cfg extension (not .xml).

Database Connection via WebLogic

So I have a MySQL database, and I have a datasource on a local instance of WebLogic which is connected to that database. I am trying to write some client code which will simply connect and query. I am having issues with obtaining a connection from the datasource. Here's my code thus far. I am running WebLogic 12c.
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Hashtable;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.sql.DataSource;
public class ConnectionTest {
public static void main(String... args) {
ConnectionTest tCon = new ConnectionTest();
tCon.TestConnection();
}
public void TestConnection() {
Context ctx = null;
Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
try {
Hashtable<String, String> props = new Hashtable<String, String>();
props.put("java.naming.factory.initial",
"weblogic.jndi.WLInitialContextFactory");
props.put("java.naming.provider.url", "t3://localhost:7001");
props.put("java.naming.security.principal", "weblogic");
props.put("java.naming.security.credentials", "welcome1");
ctx = new InitialContext(props);
DataSource ds = (DataSource) ctx.lookup("RegexDB");
System.out.println(ds);
DAO dao = new DAO();
conn = ds.getConnection();
stmt = conn.createStatement();
stmt.execute("select * from regular_ex");
rs = stmt.getResultSet();
ArrayList<HashMap<String, Object>> results = dao
.resultSetToArrayList(rs);
dao.printArrayList(results);
stmt.close();
conn.close();
} catch (NamingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (stmt != null)
stmt.close();
if (conn != null)
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
This fails at ds.getConnection() with the following exception:
java.lang.ClassCastException: weblogic.jdbc.common.internal.ConnectionEnv cannot be cast to java.io.Serializable
at weblogic.iiop.IIOPOutputStream.writeObject(IIOPOutputStream.java:2285)
at weblogic.utils.io.ObjectStreamClass.writeFields(ObjectStreamClass.java:414)
at weblogic.corba.utils.ValueHandlerImpl.writeValueData(ValueHandlerImpl.java:235)
at weblogic.corba.utils.ValueHandlerImpl.writeValueData(ValueHandlerImpl.java:225)
at weblogic.corba.utils.ValueHandlerImpl.writeValue(ValueHandlerImpl.java:182)
at weblogic.iiop.IIOPOutputStream.write_value(IIOPOutputStream.java:1983)
at weblogic.iiop.IIOPOutputStream.write_value(IIOPOutputStream.java:2021)
at weblogic.iiop.IIOPOutputStream.writeObject(IIOPOutputStream.java:2285)
at weblogic.jdbc.common.internal.RmiDataSource_WLSkel.invoke(Unknown Source)
at weblogic.rmi.internal.BasicServerRef.invoke(BasicServerRef.java:695)
at weblogic.rmi.cluster.ClusterableServerRef.invoke(ClusterableServerRef.java:230)
at weblogic.rmi.internal.BasicServerRef$1.run(BasicServerRef.java:520)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:363)
at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:146)
at weblogic.rmi.internal.BasicServerRef.handleRequest(BasicServerRef.java:516)
at weblogic.rmi.internal.wls.WLSExecuteRequest.run(WLSExecuteRequest.java:118)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:256)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:221)
I have wlclient.jar, wlsafclient.jar, and weblogic.jar in my buildpath. I have tried all sorts of combinations of adding/removing these jars, but I still get the same error regardless of what I do. Any help would be greatly appreciated.

After doing some research, I am deleting my old answer and starting over.
There is a large table of client types in the Oracle Doc for WebLogic Standalone Clients. For each type of client, listed, the table shows the required jar files. For certain types of clients, you need to build an additional jar (wlfullclient.jar) and include that.
Hope this helps.

I have also face this problem and I tried to add "wlfullclient.jar" to my directory to fix it out but I didn't find this jar file in weblogic installation folder.
But at the last I have set all required jar files form weblogic by using setDomainEnv.cmd and it works fine. Here we don't have to care about which jar files required or not it'll simply set classpath for all required jar file for your program.
I am using Weblogic 11g.

In Weblogic 12c, copy the weblogic.jar file to some other directory. Rename the file to weblogic-classes.jar and then build the jar file using wljarbuilder.
Add the newly created wlfullclient.jar file to your Class Path in eclipse.

Build wlfullclient.jar and add just this jar to the build path.
It solved the problem for me.
By the way weblogic.jar from Weblogic 12 is missing some classes as compared to weblogic.jar from Weblogic 10.3