package com.prgguru.com;
public class Constants {
public static String dbClass = "com.mysql.jdbc.Driver";
private static String dbName= "myapp";
public static String dbUrl = "jdbc:mysql://localhost:3306/"+dbName;
public static String dbUser = "root";
public static String dbPwd = "";
}

package com.prgguru.com;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class DBConnection {
/**
 * Method to create DB Connection
 *
 * @return
 * @throws Exception
 */
@SuppressWarnings("finally")
public static Connection createConnection() throws Exception {
    Connection con = null;
    try {
        Class.forName(Constants.dbClass);
        con = DriverManager.getConnection(Constants.dbUrl, Constants.dbUser, Constants.dbPwd);
    } catch (Exception e) {
        throw e;
    } finally {
        return con;
    }
}
/**
 * Method to check whether uname and pwd combination are correct
 *
 * @param uname
 * @param pwd
 * @return
 * @throws Exception
 */
public static boolean checkLoginStudent(String uname, String pwd) throws Exception {
    boolean isUserAvailable = false;
    Connection dbConn = null;
    try {
        try {
            dbConn = DBConnection.createConnection();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        Statement stmt = dbConn.createStatement();
        String query = "SELECT * FROM student WHERE stuid = '" + uname
                + "' AND pass=" + "'" + pwd + "'";
        //System.out.println(query);
        ResultSet rs = stmt.executeQuery(query);
        while (rs.next()) {
            //System.out.println(rs.getString(1) + rs.getString(2) + rs.getString(3));
            isUserAvailable = true;
        }
    } catch (SQLException sqle) {
        throw sqle;
    } catch (Exception e) {
        // TODO Auto-generated catch block
        if (dbConn != null) {
            dbConn.close();
        }
        throw e;
    } finally {
        if (dbConn != null) {
            dbConn.close();
        }
    }
    return isUserAvailable;
}

public static boolean checkLoginTeacher(String uname, String pwd) throws Exception {
    boolean isUserAvailable = false;
    Connection dbConn = null;
    try {
        try {
            dbConn = DBConnection.createConnection();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        Statement stmt = dbConn.createStatement();
        String query = "SELECT * FROM teacher WHERE teacherid = '" + uname
                + "' AND pass=" + "'" + pwd + "'";
        //System.out.println(query);
        ResultSet rs = stmt.executeQuery(query);
        while (rs.next()) {
            //System.out.println(rs.getString(1) + rs.getString(2) + rs.getString(3));
            isUserAvailable = true;
        }
    } catch (SQLException sqle) {
        throw sqle;
    } catch (Exception e) {
        // TODO Auto-generated catch block
        if (dbConn != null) {
            dbConn.close();
        }
        throw e;
    } finally {
        if (dbConn != null) {
            dbConn.close();
        }
    }
    return isUserAvailable;
}
/**
 * Method to insert uname and pwd in DB
 *
 * @param name
 * @param uname
 * @param pwd
 * @return
 * @throws SQLException
 * @throws Exception
 */
public static boolean insertStudent(String stuid,String fname,String lname ,String email ,String pass ,String department ,String stream) throws SQLException, Exception {
    boolean insertStatus = false;
    Connection dbConn = null;
    try {
        try {
            dbConn = DBConnection.createConnection();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        Statement stmt = dbConn.createStatement();
        String query = "INSERT into student(stuid, firstname, lastname, email, mobileno, pass, department, stream, yearofstudy) values('"+stuid+"',"+"'"+fname+"'"+ ", '"+lname+ "'"+", '"+email+ "'"+", '"+""+"'"+", '"+pass+"'"+ ", '"+department+"'"+ ", '"+stream+"'"+", '"+""+"')";
        //System.out.println(query);
        int records = stmt.executeUpdate(query);
        //System.out.println(records);
        //When record is successfully inserted
        if (records > 0) {
            insertStatus = true;
        }
    } catch (SQLException sqle) {
        //sqle.printStackTrace();
        throw sqle;
    } catch (Exception e) {
        //e.printStackTrace();
        // TODO Auto-generated catch block
        if (dbConn != null) {
            dbConn.close();
        }
        throw e;
    } finally {
        if (dbConn != null) {
            dbConn.close();
        }
    }
    return insertStatus;
}


public static boolean insertUser(String teacherid,String fname,String lname ,String email ,String pass ,String department) throws SQLException, Exception {
    boolean insertStatus = false;
    Connection dbConn = null;
    try {
        try {
            dbConn = DBConnection.createConnection();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        Statement stmt = dbConn.createStatement();
        String query = "INSERT into teacher(teacherid, firstname, lastname, email, mobileno, pass, department) values('"+teacherid+"',"+"'"+fname+"'"+ ", '"+lname+ "'"+", '"+email+ "'"+", '"+""+"'"+", '"+pass+"'"+ ", '"+department+"')";
        //System.out.println(query);
        int records = stmt.executeUpdate(query);
        //System.out.println(records);
        //When record is successfully inserted
        if (records > 0) {
            insertStatus = true;
        }
    } catch (SQLException sqle) {
        //sqle.printStackTrace();
        throw sqle;
    } catch (Exception e) {
        //e.printStackTrace();
        // TODO Auto-generated catch block
        if (dbConn != null) {
            dbConn.close();
        }
        throw e;
    } finally {
        if (dbConn != null) {
            dbConn.close();
        }
    }
    return insertStatus;
}

package com.prgguru.com;
import java.sql.SQLException;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.UriInfo;
import javax.ws.rs.core.Context;

import com.prgguru.com.DBConnection;
import com.prgguru.com.Utility;

 //Path: http://localhost/<appln-folder-name>/studentregister
@Path("/studentregister")
public class StudentRegister {
// HTTP Get Method
@GET
// Path: http://localhost/<appln-folder-name>/studentregister/doregister
@Path("/doregister")
// Produces JSON as response
@Produces(MediaType.APPLICATION_JSON)
// Query parameters are parameters: http://localhost/<appln-folder-name>/studentregister/doregister?stuid=abc&firstname=def&lastname=ghi&email=jkl&pass=mno&department=pq&stream=rs
public String doRegister(@Context UriInfo info){

    String response = "";
    int retCode;

    String stuid=  info.getQueryParameters().getFirst("stuid");
    String fname=info.getQueryParameters().getFirst("firstname");
    String lname=info.getQueryParameters().getFirst("lastname");
    String email=info.getQueryParameters().getFirst("email");
    String pass=info.getQueryParameters().getFirst("pass");
    String department=info.getQueryParameters().getFirst("department");
    String stream="";

    if(department.equals("BTech")){
        stream= info.getQueryParameters().getFirst("stream");
    }
    retCode = registerStudent(stuid,fname,lname,email,pass,department,stream);

    //System.out.println("Inside doLogin "+uname+"  "+pwd);

    if(retCode == 0){
        response = Utility.constructJSON("register",true);
    }else if(retCode == 1){
        response = Utility.constructJSON("register",false, "You are already registered");
    }else if(retCode == 2){
        response = Utility.constructJSON("register",false, "Special Characters are not allowed in Username and Password");
    }else if(retCode == 3){
        response = Utility.constructJSON("register",false, "Error occured");
    }
    return response;

}

private int registerStudent(String stuid, String fname, String lname , String email , String pass , String department , String stream){
    System.out.println("Inside checkCredentials");
    int result = 3;
    if(Utility.isNotNull(stuid) && Utility.isNotNull(fname) && Utility.isNotNull(lname) && Utility.isNotNull(email) && Utility.isNotNull(pass) && Utility.isNotNull(department) && Utility.isNotNull(stream)){
        try {
            if(DBConnection.insertStudent(stuid, fname, lname ,email ,pass ,department ,stream)){
                System.out.println("RegisterStudent if");
                result = 0;
            }
        } catch(SQLException sqle){
            System.out.println("RegisterStudent catch sqle");
            //When Primary key violation occurs that means user is already registered
            if(sqle.getErrorCode() == 1062){
                result = 1;
            }
            //When special characters are used in name,username or password
            else if(sqle.getErrorCode() == 1064){
                System.out.println(sqle.getErrorCode());
                result = 2;
            }
        }
        catch (Exception e) {
            // TODO Auto-generated catch block
            System.out.println("Inside checkCredentials catch e ");
            result = 3;
        }
    }else{
        System.out.println("Inside checkCredentials else");
        result = 3;
    }

    return result;
}

package com.prgguru.com;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.UriInfo;

import com.prgguru.com.DBConnection;
import com.prgguru.com.Utility;

//Path: http://localhost/<appln-folder-name>/studentlogin
@Path("/studentlogin")

public class StudentLogin {

public class Login {
    // HTTP Get Method
    @GET
    // Path: http://localhost/<appln-folder-name>/studentlogin/dologin
    @Path("/dologin")
    // Produces JSON as response
    @Produces(MediaType.APPLICATION_JSON)
    // Query parameters are parameters: http://localhost/<appln-folder-name>/login/dologin?username=abc&password=xyz
    public String doLogin(@Context UriInfo info){
        String username=info.getQueryParameters().getFirst("username");
        String password=info.getQueryParameters().getFirst("password");
        String response = "";
        if(checkCredentials(username,password)){
            response = Utility.constructJSON("login",true);
        }else{
            response = Utility.constructJSON("login", false, "Incorrect UserId or Password");
        }
    return response;
    }

    /**
     * Method to check whether the entered credential is valid
     *
     * @param uname
     * @param pwd
     * @return
     */
    private boolean checkCredentials(String username, String password){
        //System.out.println("Inside checkCredentials");
        boolean result = false;
        if(Utility.isNotNull(username) && Utility.isNotNull(password)){
            try {
                    result = DBConnection.checkLoginStudent(username, password);
                }
                //System.out.println("Inside checkCredentials try "+result);
            catch (Exception e) {
                // TODO Auto-generated catch block
                //System.out.println("Inside checkCredentials catch");
                result = false;
            }
        }
        else{
            //System.out.println("Inside checkCredentials else");
            result = false;
        }

        return result;
    }

}

package com.prgguru.com;

import org.codehaus.jettison.json.JSONException;
import org.codehaus.jettison.json.JSONObject;

public class Utility {
/**
 * Null check Method
 *
 * @param txt
 * @return
 */
public static boolean isNotNull(String txt) {
    // System.out.println("Inside isNotNull");
    return txt != null && txt.trim().length() >= 0 ? true : false;
}

/**
 * Method to construct JSON
 *
 * @param tag
 * @param status
 * @return
 */
public static String constructJSON(String tag, boolean status) {
    JSONObject obj = new JSONObject();
    try {
        obj.put("tag", tag);
        obj.put("status", new Boolean(status));
    } catch (JSONException e) {
        // TODO Auto-generated catch block
    }
    return obj.toString();
}

/**
 * Method to construct JSON with Error Msg
 *
 * @param tag
 * @param status
 * @param err_msg
 * @return
 */
public static String constructJSON(String tag, boolean status,String err_msg) {
    JSONObject obj = new JSONObject();
    try {
        obj.put("tag", tag);
        obj.put("status", new Boolean(status));
        obj.put("error_msg", err_msg);
    } catch (JSONException e) {
        // TODO Auto-generated catch block
    }
    return obj.toString();
}

?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_2_5.xsd" id="WebApp_ID" version="2.5">
<display-name>Engine</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 REST Service</servlet-name>
<servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
<init-param>
  <param-name>com.sun.jersey.config.property.packages</param-name>
  <param-value>com.prgguru.com</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
<servlet-name>Jersey REST Service</servlet-name>
<url-pattern>/*</url-pattern>
</servlet-mapping>


</web-app>