Notes

package com.highradius.model;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse; // mapping,
import java.sql.Connection;
import java.sql.Date;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Timestamp;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import com.fasterxml.jackson.databind.ObjectMapper;
//import com.highradius.model.Prediction;
//@WebServlet("/Predict")
public class Predict extends HttpServlet {

private static final long serialVersionUID = 1L;
private static final Logger LOG = LogManager.getLogger(Predict.class);
/*private static final String SCHEMAURL = "jdbc:mysql://10.1.130.101:3306/1628004";
private static final String USERNAME = "1628004_user";
private static final String PASSWORD = "o7iueOP3KB";*/
private static final String SCHEMAURL = "jdbc:mysql://localhost:3306/1628006";
private static final String USERNAME = "devuser";
private static final String PASSWORD = "Demo@123";
private static final String DRIVERCLASS = "com.mysql.jdbc.Driver";
private Connection dbCon;
private PreparedStatement updateStatement,selectStatement;
private ResultSet result;

@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String dueQuery="SELECT due_date FROM acct_doc_hdr WHERE document_id = ? ;";
String updateQuery = "UPDATE acct_doc_hdr SET predicted_payment_date = ? WHERE document_id= ? ;";
ArrayList<String> dates=new ArrayList<>();
try {
Class.forName(DRIVERCLASS);
dbCon = DriverManager.getConnection(SCHEMAURL, USERNAME, PASSWORD);
dbCon.setAutoCommit(false);
selectStatement=dbCon.prepareStatement(dueQuery);
updateStatement=dbCon.prepareStatement(updateQuery);
ObjectMapper mapper = new ObjectMapper();
Prediction[] preds = mapper.readValue(request.getParameter("data"), Prediction[].class);
for(int i = 0; i < preds.length; i++) {
String doc=preds[i].getDocument_id();
String delay=preds[i].getPredictions();
System.out.println("doc,delay: "+doc+","+delay);
selectStatement.setInt(1, Integer.parseInt(doc));
result=selectStatement.executeQuery();
while(result.next()) {
Date date=result.getDate(1);
int d=(int) Math.round(Double.parseDouble(delay));
Calendar c=Calendar.getInstance();
c.setTime(date);
c.add(Calendar.DAY_OF_MONTH, d);
System.out.println("clear: "+c.getTime().toString());
updateStatement.setDate(1, new Date(c.getTimeInMillis()));
updateStatement.setInt(2, Integer.parseInt(doc));
updateStatement.addBatch();
}
}
updateStatement.executeBatch();
dbCon.commit();
updateStatement.clearBatch();
System.out.println("Done");
closeResources();
} catch (Exception e) {
e.printStackTrace();
}

}

private void closeResources() {
closeResource(result);
closeResource(updateStatement);
closeResource(dbCon);
}

private void closeResource(ResultSet rs) {
try {
if (rs != null)
rs.close();
} catch (Exception e) {
System.out.println("Error occurred in closing result set: " + e.toString());
}

}

private void closeResource(Connection dbCon) {
try {
if (dbCon != null)
dbCon.close();
} catch (Exception e) {
System.out.println("Error occurred in closing connection: " + e.toString());
}

}

private void closeResource(PreparedStatement statement) {
try {
if (statement != null)
statement.close();
} catch (Exception e) {
LOG.error("Error occurred in closing statement: " + e.toString());
}
}

}