DCSJSON.java

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.*;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;

public class DCSJSON extends HttpServlet {
	private static final long serialVersionUID = 1L;
	
		
	// This sets up the JSON array for The final JSON object
        public String reportStrings(ResultSet rs, String columnName) throws SQLException{

		// Should use string buffer instead
		String resultantJSON = "[";

		//index for code that should run after first loop back
		int x = 0;
		while(rs.next()){
			if (x!=0) {resultantJSON += ",";}
			resultantJSON += "\"" + rs.getString(columnName) + "\"";
			x += 1;
		}
		resultantJSON += "]";
		return resultantJSON;
	} 
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		Context ctx = null;
		Connection con = null;
		Statement stmt = null;
		ResultSet rs = null;
		try{
			ctx = new InitialContext();
			DataSource ds = (DataSource) ctx.lookup("java:/comp/env/jdbc/LocalStudentAdminDB");
			con = ds.getConnection();
			stmt = con.createStatement();
			PrintWriter out = response.getWriter();
			rs = stmt.executeQuery("CALL getAllTermNames()");//SELECT * FROM SA_Development.TERM"
//			ResultSetMetaData rsmd = rs.getMetaData();
//			int columnCount = rsmd.getColumnCount();				
			String JSONEntity = "{\"TERM_NAME\":" + reportStrings(rs,"TERM_NAME") + ",\"CAMPUS_NAME\":";
			rs.close();
			rs = stmt.executeQuery("CALL getAllCampusNames()");
			JSONEntity += reportStrings(rs,"CAMPUS_NAME") + ",\"DEPARTMENT_NAME\":";
			rs.close();
			rs = stmt.executeQuery("CALL getAllDepartmentNames()");
			JSONEntity += reportStrings(rs,"DEPARTMENT_NAME") + "}";
			response.setContentType("application/json");
			out.print(JSONEntity);
		}catch(NamingException e){
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		}finally{
			try {
				rs.close();
				stmt.close();
				con.close();
				ctx.close();
			} catch (SQLException e) {
				System.out.println("Exception in closing DB resources");
			} catch (NamingException e) {
				System.out.println("Exception in closing Context");
			}
			
		}
	}
	public String extractDCSArgs(HttpServletRequest request) {
		String result = "CALL getCourseSearchResults('" + 
				request.getParameter("Term") + "','" + 
				request.getParameter("Campus") + "'," + 
				request.getParameter("Availability") + "," + 
				request.getParameter("Honors") + "," + 
				request.getParameter("Q") + "," + 
				request.getParameter("W") + "," + 
				"'00:00:00'," + 
				"'23:59:59','" + 
				request.getParameter("Department") + "'," + 
				request.getParameter("CourseNumber");
		return result;
	}
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		Context ctx = null;
		Connection con = null;
		Statement stmt = null;
		ResultSet classSearchRes = null;
		//out.println(extractDCSArgs(request));
		try{
			ctx = new InitialContext();
			DataSource ds = (DataSource) ctx.lookup("java:/comp/env/jdbc/LocalStudentAdminDB");
			con = ds.getConnection();
			stmt = con.createStatement();
			//add extractDCSArgs()
			PrintWriter out = response.getWriter();
			classSearchRes = stmt.executeQuery("CALL getCourseSearchResults('SPRING_2016','Storrs',0,0,0,0,'00:00:00','23:59:59','Computer Science and Engineering',1729)");
			ResultSetMetaData rsmd = classSearchRes.getMetaData();
			
			// DynamicClassSearchResult in JSON
			String DCSRJSON = "[";
			int addComma = 0;
			while(classSearchRes.next()) {
				if(addComma >= 1) {DCSRJSON += ",";}
				DCSRJSON += reportResultRow(classSearchRes,classSearchRes.getMetaData());
				addComma += 1;
			}
			DCSRJSON += "]";
			response.setContentType("application/json");
			out.print(DCSRJSON);
		}catch(NamingException e){
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		}finally{
			try {
				classSearchRes.close();
				stmt.close();
				con.close();
				ctx.close();
			} catch (SQLException e) {
				System.out.println("Exception in closing DB resources");
			} catch (NamingException e) {
				System.out.println("Exception in closing Context");
			}
			
		}
	}
	public String reportResultRow(ResultSet classSearchRes, ResultSetMetaData resTableMetaData) throws SQLException{
		String rowResultJSON = "{";
		int columnCount = resTableMetaData.getColumnCount();
		for(int i = 1;i <= columnCount;i++){
			if(i >= 1){rowResultJSON += ",";}
			rowResultJSON += "\"" + resTableMetaData.getColumnName(i) + "\":\"" + classSearchRes.getString(i) + "\"";
		}
		rowResultJSON += "}";
		return rowResultJSON;
	}
}