I am currently learning Java EE, and I was asked to develop a backend RESTful Java API that will communicate with a database stored on a cloud solution (IBM Bluemix).
I currently use Eclipse Photon as IDE and I am not an admin user on the computer.
I was asked to test my code with IBM Was Liberty server plugin for eclipse, but I have some trouble setting up the server. I think I may have not understood how the plugin works and can't make it work as I want it to.
The problem is that I can't access the database stored on that server, be it with my api or admin center (can't even log on admin center).
Here is the java code I use (modified) and found on this site
package connection;
//STEP 1. Import required packages
import java.sql.*;
public class FirstExample {
// JDBC driver name and database URL
static final String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost:3306/ibm/api/validator/dataSource/SAMPLEDB";
// Database credentials
static final String USER = "admin";
static final String PASS = "admin";
public static void main(String[] args) {
Connection conn = null;
Statement stmt = null;
try{
//STEP 2: Register JDBC driver
Class.forName(JDBC_DRIVER);
//STEP 3: Open a connection
System.out.println("Connecting to database...");
conn = DriverManager.getConnection(DB_URL, USER, PASS);
//STEP 4: Execute a query
System.out.println("Creating statement...");
stmt = conn.createStatement();
String sql;
sql = "SELECT * FROM *";
ResultSet rs = stmt.executeQuery(sql);
//STEP 5: Extract data from result set
while(rs.next()){
//Retrieve by column name
String data = rs.getString("last");
//Display values
System.out.println("Data Retreived " + data);
}
//STEP 6: Clean-up environment
rs.close();
stmt.close();
conn.close();
}catch(SQLException se){
//Handle errors for JDBC
System.out.println("\nJDBC ERROR ! \n");
se.printStackTrace();
}catch(Exception e){
//Handle errors for Class.forName
System.out.println("\nClass.forName ERROR ! \n");
e.printStackTrace();
}finally{
//finally block used to close resources
try{
if(stmt!=null)
stmt.close();
}catch(SQLException se2){
System.out.println("\nSQL ERROR ! NOTHING TO DO \n");
}// nothing we can do
try{
if(conn!=null)
conn.close();
}catch(SQLException se){
System.out.println("\nJDBC ERROR ! MAYBE SOMETHING TO DO \n");
se.printStackTrace();
}//end finally try
}//end try
System.out.println("\nGoodbye!");
}//end main
}//end FirstExample
As for my Server.xml here is the updated code :
<server description="Liberty beta">
<featureManager>
<feature>webProfile-8.0</feature>
<feature>adminCenter-1.0</feature>
<feature>restConnector-2.0</feature>
<feature>transportSecurity-1.0</feature>
<feature>logstashCollector-1.1</feature>
<feature>validator-1.0</feature>
<feature>mpConfig-1.3</feature>
<feature>mpFaultTolerance-1.1</feature>
<feature>mpHealth-1.0</feature>
<feature>mpJwt-1.0</feature>
<feature>mpMetrics-1.1</feature>
<feature>mpOpenAPI-1.0</feature>
<feature>mpOpenTracing-1.0</feature>
<feature>mpRestClient-1.0</feature>
<feature>localConnector-1.0</feature>
<feature>jdbc-4.2</feature>
</featureManager>
<httpEndpoint id="defaultHttpEndpoint"
host="*"
httpPort="9080"
httpsPort="9443" />
<applicationManager autoExpand="true"/>
<keyStore id="defaultKeyStore"
password="Liberty" />
<basicRegistry id="userReg">
<user password="admin"
name="admin"
id="admin"></user>
</basicRegistry>
<administrator-role>
<user>admin</user>
</administrator-role>
<remoteFileAccess>
<writeDir>${server.config.dir}</writeDir>
</remoteFileAccess>
<dataSource id="DefaultDataSource" jndiName="jdbc/mySQL">
<jdbcDriver libraryRef="MySQLLib" />
<properties.microsoft.sqlserver databaseName="SAMPLEDB" serverName="localhost" portNumber="3306" user="admin" password="admin"/>
<connectionManager></connectionManager>
</dataSource>
<library id="MySQLLib">
<file name="C:/PUBLIC/tools/mysql-connector-java-8.0.12/mysql-connector-java-8.0.12/mysql-connector-java-8.0.12.jar" />
</library>
</server>
The problem I got now is that I can't seem to be able to communicate with my server.
here is the console error :
Connecting to database...
JDBC ERROR !
Goodbye!
com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:832)
at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:456)
at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240)
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:207)
at java.sql.DriverManager.getConnection(DriverManager.java:664)
at java.sql.DriverManager.getConnection(DriverManager.java:247)
at connection.FirstExample.main(FirstExample.java:23)
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151)
at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167)
at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:91)
at com.mysql.cj.NativeSession.connect(NativeSession.java:152)
at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:952)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:822)
... 6 more
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at com.mysql.cj.protocol.StandardSocketFactory.connect(StandardSocketFactory.java:173)
at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:65)
... 9 more
