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How to write data in excel sheet in specific cell using servlet?

I'm New to Servlet please help me out. I have created a Servlet file in which one excel file contains some data from the user. data is printed through the string. Now, most of the data is printed as per the expectation but now I want to print array stored data in a specific cell of the excel sheet and in a specific format. please refer the provided photo for the format that what I'm expecting. and also refer my code for the more better understanding. the main goal is to print array stored data in the specific cell of excel sheet. Please help me with the code because I'm really new to the Servlets. refer this link
testExcel
#WebServlet("/testExcel")
public class testExcel extends HttpServlet {
private static final long serialVersionUID = 1L;
String emails = "xyz#gmail.com";
#Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
processRequest(req, resp);
}
protected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
OutputStream writer = response.getOutputStream();
// FileWriter writer =null;
ResultSet rs = null;
ResultSet rs1 = null;
Connection con = null;
ArrayList data_ar = new ArrayList();
String str = "";
PreparedStatement ps = null;
PreparedStatement ps1 = null;
try {
String fileName = emails + "data.csv";
System.out.println(fileName);
ServletContext context = getServletContext();
String mimeType = context.getMimeType(fileName);
if (mimeType == null) {
mimeType = "application/octet-stream";
}
response.setContentType(mimeType);
String headerKey = "Content-Disposition";
String headerValue = String.format("attachment; filename=\"%s\"", fileName);
response.setHeader(headerKey, headerValue);
ConnectionClass cn = new ConnectionClass();
con = cn.connectDb();
System.out.println("fileName" + fileName);
//Write the CSV file header
CSVUtil.writeLine(writer, Arrays.asList("NAME", "email", " ", " ", " ", "NAME AND EMAIL"));
ps = con.prepareStatement("select name,email from user");
rs = ps.executeQuery();
ps1 = con.prepareStatement("select name,email from user");
rs1 = ps1.executeQuery();
while (rs.next()) {
System.out.println(rs.getString("name"));
CSVUtil.writeLine(writer, Arrays.asList(rs.getString("name"), rs.getString("email")));
}
while (rs1.next()) {
data_ar.add(rs1.getString("name") + " " + rs1.getString("email") + "\n");
}
str = String.join(" ", data_ar);
CSVUtil.writeLine(writer, Arrays.asList(" ", " ", " ", " ", " ", str));
writer.flush();
writer.close();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
rs.close();
ps.close();
con.close();
} catch (Exception e) {
}
}
}
}
csvutil.java
public class CSVUtil {
private static final char DEFAULT_SEPARATOR = ',';
public static void writeLine(OutputStream w, List<String> values) throws IOException {
writeLine(w, values, DEFAULT_SEPARATOR, ' ');
}
public static void writeLine(OutputStream w, List<String> values, char separators) throws IOException {
writeLine(w, values, separators, ' ');
}
// https://tools.ietf.org/html/rfc4180
private static String followCVSformat(String value) {
String result = value;
if (result.contains("\"")) {
result = result.replace("\"", "\"\"");
}
return result;
}
public static void writeLine(OutputStream w, List<String> values, char separators, char customQuote) throws IOException {
boolean first = true;
// default customQuote is empty
if (separators == ' ') {
separators = DEFAULT_SEPARATOR;
}
StringBuilder sb = new StringBuilder();
for (String value : values) {
if (!first) {
sb.append(separators);
}
if (customQuote == ' ') {
sb.append(followCVSformat(value));
} else {
sb.append(customQuote).append(followCVSformat(value)).append(customQuote);
}
first = false;
}
sb.append("\n");
String str = sb.toString();
byte[] bytes = str.getBytes(Charset.forName("UTF-8"));
w.write(bytes);
}
}

Simple and Quick answer:
You should try to use Apache POI :
Maven dependancy :
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>3.15</version>
</dependency>
Simple class to write a list in excel file :
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
public class ApachePOIExcelWrite {
private static final String FILE_NAME = "/tmp/MyFirstExcel.xlsx";
public static void main(String[] args) {
XSSFWorkbook workbook = new XSSFWorkbook();
XSSFSheet sheet = workbook.createSheet("Datatypes in Java");
Object[][] datatypes = {
{"Datatype", "Type", "Size(in bytes)"},
{"int", "Primitive", 2},
{"float", "Primitive", 4},
{"double", "Primitive", 8},
{"char", "Primitive", 1},
{"String", "Non-Primitive", "No fixed size"}
};
int rowNum = 0;
System.out.println("Creating excel");
for (Object[] datatype : datatypes) {
Row row = sheet.createRow(rowNum++);
int colNum = 0;
for (Object field : datatype) {
Cell cell = row.createCell(colNum++);
if (field instanceof String) {
cell.setCellValue((String) field);
} else if (field instanceof Integer) {
cell.setCellValue((Integer) field);
}
}
}
try {
FileOutputStream outputStream = new FileOutputStream(FILE_NAME);
workbook.write(outputStream);
workbook.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
System.out.println("Done");
}
}

Append String to file with Callback

I'm reading data from a DB and like to appended each row of data from the DB using a Callback. I've managed to get the Callback working but I don't know how I will get it append the data to file. Here is my code.
Main
public class Main {
public static void main(String[] args) {
FileIO fileIO = new FileIO();
fileIO.writeRStoFile();
}
}
FileIO
public class FileIO implements DBAccess.CallBack {
public void writeRStoFile() {
DBAccess dbAccess = new DBAccess(this);
String fileName = "/result.csv";
try (FileWriter fw = new FileWriter(fileName)) {
System.out.println("Starting data download from DB...");
dbAccess.readDB();
// HERE I LIKE TO APPEND EACH ROW TO THE FILE
fw.append('\n');
System.out.println("Finished data download from DB...");
} catch (IOException e) {
e.printStackTrace();
}
}
#Override
public void iAmDone(String row) {
System.out.println("Row: " + row);
}
}
DBAccess
public class DBAccess {
public interface CallBack {
public void iAmDone(String row);
}
private final CallBack callBack;
public DBAccess(CallBack callBack) {
this.callBack = callBack;
}
public void readDB() {
String url = "jdbc:Cobol:////Dev/Project Files/DatAndCpyFiles";
try (Connection con = DriverManager.getConnection(url, "", "");
Statement stmt = con.createStatement())
{
stmt.setFetchSize(10);
Class.forName("com.hxtt.sql.cobol.CobolDriver").newInstance();
String sql = "select * from PROFS";
ResultSet rs = stmt.executeQuery(sql);
ResultSetMetaData resultSetMetaData = rs.getMetaData();
int iNumCols = resultSetMetaData.getColumnCount();
for (int i = 1; i <= iNumCols; i++) {
callBack.iAmDone(resultSetMetaData.getColumnLabel(i) + ";");
}
String field;
while (rs.next()) {
String row = "";
for (int i = 1; i <= iNumCols; i++) {
field = rs.getString(i);
field = field.trim() + ";";
row = row + field;
}
callBack.iAmDone(row);
}
rs.close();
} catch (Exception e) {
System.out.println(e.getMessage());
e.printStackTrace();
}
}
}
I'm not sure how I get the data from iAmDone() into the writeRStoFile() method. I'm able to print the data to the console.

One way that I can think of is to declare fw as a member variable in FileIO. That way you can call fw.append(...) in iAmDone. (You might have to change the try-with-resources then.)

Continuously getting content from table database

I have a code here:
package testcode;
import java.sql.*;
import javax.jms.ConnectionFactory;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;
import org.apache.activemq.ActiveMQConnection;
import org.apache.activemq.ActiveMQConnectionFactory;
public class ProducerClear2 {
public static String vardbserver;
public static String vardbuser;
public static String vardbpassword;
public static String vardbname;
public static void main(String[] args) {
vardbserver = "TestDBtoMQ";
vardbuser = "postgresql";
vardbpassword = "admin";
ConnectionFactory factory = null;
javax.jms.Connection connection = null;
Session session = null;
Destination destination = null;
MessageProducer producer = null;
try {
factory = new ActiveMQConnectionFactory(ActiveMQConnection.DEFAULT_BROKER_URL);
connection = factory.createConnection();
connection.start();
session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
destination = session.createQueue("TestQueue");
producer = session.createProducer(destination);
Class.forName("org.postgresql.Driver");
System.out.println("----------------------------");
try (Connection c = DriverManager.getConnection("jdbc:postgresql://localhost:5432/" + vardbserver, vardbuser, vardbpassword);
PreparedStatement stmt = c.prepareStatement("SELECT * FROM MESSAGES where xmin::varchar::bigint > ? and xmin::varchar::bigint < ? ");
PreparedStatement max = c.prepareStatement("select max(xmin::varchar::bigint) as txid from messages")
) {
c.setAutoCommit(false);
Long previousTxId = 0L;
Long nextTxId = 0L;
while (true) {
stmt.clearParameters();
try (ResultSet rs = max.executeQuery()) {
if (rs.next()) {
nextTxId = rs.getLong(1);
}
}
stmt.setLong(1, previousTxId);
stmt.setLong(2, nextTxId + 1);
try (ResultSet rs = stmt.executeQuery()) {
while (rs.next()) {
String message = rs.getString("MESSAGE");
System.out.println("Message = " + message);
TextMessage mssg = session.createTextMessage(message);
System.out.println("Sent: " + mssg.getText());
producer.send(mssg);
}
previousTxId = nextTxId;
}
Thread.sleep(5000);
}
}
} catch (JMSException e) {
e.printStackTrace();
} catch (Exception e) {
System.err.println(e.getClass().getName() + ": " + e.getMessage());
} finally {
if (session != null) {
try {
session.close();
} catch (JMSException ex) {
// ignore
}
}
if (connection != null) {
try {
connection.close();
} catch (JMSException ex) {
// ignore
}
}
}
System.out.println("----------------------------");
System.out.println("Message sent successfully");
}
}
Basically, the app works to get contents inside a database's table and sent it to ActiveMQ. And when the table updated, it will sent the content that just updated (not sending the past that was sent). But this code only works on PostgreSQL
Then i'm planning to create an "if" function. So i can use another database to getting the data (Oracle and MySQL).
Is the xmin still works for Oracle and MySQL? So i just need to change the server URL? Or i need to change the code for Oracle and MySQL?

Simply found the answer, using limit, save it's every limit row to a file and use a date for every daily file....
if(vardbtype.equals("MYSQL")){
Class.forName("com.mysql.jdbc.Driver");
System.out.println("----------------------------");
int limitrowmysql = 0;
LocalDate now = LocalDate.now();
Path path = FileSystems.getDefault().getPath("C:\\Users\\NN\\Documents\\Test\\RowMYSQL\\RowIDMYSQL_" + now.format(DateTimeFormatter.ISO_LOCAL_DATE) + ".txt");
if (Files.exists(path)) {
String latestRowIdFromFile = Files.lines(path).max((e1, e2) -> {
if (((String)e1).isEmpty() || ((String)e2).isEmpty()) {
return -1;
}
return new Long(e1).compareTo(new Long(e2));
}).get(); // read latestRowId from file
if (latestRowIdFromFile != null && !latestRowIdFromFile.isEmpty()) {
limitrowmysql = Integer.valueOf(latestRowIdFromFile);
}
} else {
limitrowmysql = 0;
}
Connection c = DriverManager.getConnection("jdbc:mysql://localhost:3306/"+ vardbserver, vardbuser, vardbpassword);
while(true) {
Statement stmts = c.createStatement();
int countrowmysql = 0;
String sql = ("SELECT * FROM "+ vardbname +" LIMIT "+ limitrowmysql +", 18446744073709551615");
ResultSet rss = stmts.executeQuery(sql);
while(rss.next()) {
String message = rss.getString("MESSAGE");
System.out.println("Message = " + message);
TextMessage mssg = session.createTextMessage(message);
System.out.println("Sent: " + mssg.getText());
producer.send(mssg);
countrowmysql = countrowmysql + 1;
}
rss.close();
stmts.close();
Thread.sleep(batchperiod2);
limitrowmysql = limitrowmysql + countrowmysql;
Files.write(path, ("\n" + limitrowmysql).getBytes()); // write latestRowId to file
}
}

Write Time In MySQL

I'm using Java code to randomly create pins for 6000 entries. Currently its taking 3 min 27 sec to write to the database. I would like to know if you can decrease the write time to the database
Database has an auto_increment field as well as a pin field which is a string.
public class DonkeyInsert {
/**
* #param args the command line arguments
* #throws java.sql.SQLException
*/
public static void main(String[] args) throws SQLException {
// TODO code application logic here
Connection conn = new DBConnection().connect();
for (int i = 1; i <= 6000; i++) {
Random rand = new Random();
// create a Statement from the connection
Statement statement = conn.createStatement();
// insert the data
int k = rand.nextInt(Integer.SIZE - 1);
k = (k + 1) * 9999;
String pin = Integer.toString(k);
try {
String sql = "INSERT INTO login (login_id,pin) VALUES (" + i + "," + pin + ");";
statement.executeUpdate(sql);
} catch (SQLException se) {
System.out.println(se);
}
}
}
}

Try this and see if it's faster. The changes I've made should help:
package persistence;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Random;
/**
* DonkeyInsert changes
* #author Michael
* #link https://stackoverflow.com/questions/32551895/write-time-in-mysql?noredirect=1#comment52959887_32551895
* #since 9/13/2015 12:49 PM
*/
public class DonkeyInsert {
public static final int DEFAULT__RECORD_COUNT = 6000;
private Random random;
public DonkeyInsert() {
this.random = new Random();
}
public DonkeyInsert(long seed) {
this.random = new Random(seed);
}
public static void main(String[] args) {
// I'd externalize these so I could change the database without recompiling.
String driver = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://hostname:3306/dbname";
String username = "username";
String password = "password";
Connection connection = null;
try {
DonkeyInsert donkeyInsert = new DonkeyInsert();
connection = createConnection(driver, url, username, password);
int numRowsInserted = donkeyInsert.insertPins(connection, DEFAULT__RECORD_COUNT);
System.out.println(String.format("# pins inserted: %d", numRowsInserted));
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
} finally {
close(connection);
}
}
private static final String INSERT_SQL = "INSERT INTO login(pin) VALUES(?) ";
public int insertPins(Connection connection, int count) {
int numInserted = 0;
if (count > 0) {
PreparedStatement ps = null;
try {
ps = connection.prepareStatement(INSERT_SQL);
for (int i = 0; i < count; ++i) {
ps.setString(1, this.createRandomPin());
ps.addBatch();
}
int [] counts = ps.executeBatch();
for (int rowCount : counts) {
numInserted += rowCount;
}
} catch (SQLException e) {
throw new RuntimeException("SQL exception caught while inserting pins", e);
} finally {
close(ps);
}
}
return numInserted;
}
public String createRandomPin() {
// Changed it a bit. Didn't understand your requirement.
int k = this.random.nextInt(Integer.MAX_VALUE);
return Integer.toString(k);
}
public static Connection createConnection(String driver, String url, String username, String password) throws ClassNotFoundException, SQLException {
Class.forName(driver);
if ((username == null) || (password == null) || (username.trim().length() == 0) || (password.trim().length() == 0)) {
return DriverManager.getConnection(url);
} else {
return DriverManager.getConnection(url, username, password);
}
}
public static void close(Connection connection) {
try {
if (connection != null) {
connection.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
public static void close(Statement st) {
try {
if (st != null) {
st.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}

Display Records From MySQL Database using JTable in Java

I want to connect a JTable to a ResultSet from a MySQL database so I can view the data.
I am looking for some links or code snippets describing this task. I'm using the Netbeans IDE..

Below is a class which will accomplish the very basics of what you want to do when reading data from a MySQL database into a JTable in Java.
import java.awt.*;
import java.sql.*;
import java.util.*;
import javax.swing.*;
import javax.swing.table.*;
public class TableFromMySqlDatabase extends JFrame
{
public TableFromMySqlDatabase()
{
ArrayList columnNames = new ArrayList();
ArrayList data = new ArrayList();
// Connect to an MySQL Database, run query, get result set
String url = "jdbc:mysql://localhost:3306/yourdb";
String userid = "root";
String password = "sesame";
String sql = "SELECT * FROM animals";
// Java SE 7 has try-with-resources
// This will ensure that the sql objects are closed when the program
// is finished with them
try (Connection connection = DriverManager.getConnection( url, userid, password );
Statement stmt = connection.createStatement();
ResultSet rs = stmt.executeQuery( sql ))
{
ResultSetMetaData md = rs.getMetaData();
int columns = md.getColumnCount();
// Get column names
for (int i = 1; i <= columns; i++)
{
columnNames.add( md.getColumnName(i) );
}
// Get row data
while (rs.next())
{
ArrayList row = new ArrayList(columns);
for (int i = 1; i <= columns; i++)
{
row.add( rs.getObject(i) );
}
data.add( row );
}
}
catch (SQLException e)
{
System.out.println( e.getMessage() );
}
// Create Vectors and copy over elements from ArrayLists to them
// Vector is deprecated but I am using them in this example to keep
// things simple - the best practice would be to create a custom defined
// class which inherits from the AbstractTableModel class
Vector columnNamesVector = new Vector();
Vector dataVector = new Vector();
for (int i = 0; i < data.size(); i++)
{
ArrayList subArray = (ArrayList)data.get(i);
Vector subVector = new Vector();
for (int j = 0; j < subArray.size(); j++)
{
subVector.add(subArray.get(j));
}
dataVector.add(subVector);
}
for (int i = 0; i < columnNames.size(); i++ )
columnNamesVector.add(columnNames.get(i));
// Create table with database data
JTable table = new JTable(dataVector, columnNamesVector)
{
public Class getColumnClass(int column)
{
for (int row = 0; row < getRowCount(); row++)
{
Object o = getValueAt(row, column);
if (o != null)
{
return o.getClass();
}
}
return Object.class;
}
};
JScrollPane scrollPane = new JScrollPane( table );
getContentPane().add( scrollPane );
JPanel buttonPanel = new JPanel();
getContentPane().add( buttonPanel, BorderLayout.SOUTH );
}
public static void main(String[] args)
{
TableFromMySqlDatabase frame = new TableFromMySqlDatabase();
frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
frame.pack();
frame.setVisible(true);
}
}
In the NetBeans IDE which you are using - you will need to add the MySQL JDBC Driver in Project Properties as I display here:
Otherwise the code will throw an SQLException stating that the driver cannot be found.
Now in my example, yourdb is the name of the database and animals is the name of the table that I am performing a query against.
Here is what will be output:
Parting note:
You stated that you were a novice and needed some help understanding some of the basic classes and concepts of Java. I will list a few here, but remember you can always browse the docs on Oracle's site.
ArrayList
Vector
Try-with-resources statement

this is the easy way to do that you just need to download the jar file "rs2xml.jar" add it to your project
and do that :
1- creat a connection
2- statment and resultset
3- creat a jtable
4- give the result set to DbUtils.resultSetToTableModel(rs)
as define in this methode you well get your jtable so easy.
public void afficherAll(String tableName){
String sql="select * from "+tableName;
try {
stmt=con.createStatement();
rs=stmt.executeQuery(sql);
tbContTable.setModel(DbUtils.resultSetToTableModel(rs));
} catch (SQLException e) {
// TODO Auto-generated catch block
JOptionPane.showMessageDialog(null, e);
}
}

If you need to work a lot with database in your code and you know the structure of your table, I suggest you do it as follow:
First of all you can define a class which will help you to make objects capable of keeping your table rows data. For example in my project I created a class named Document.java to keep data of a single document from my database and I made an array list of these objects to keep data of my table which is gain by a query.
package financialdocuments;
import java.lang.*;
import java.util.HashMap;
/**
*
* #author Administrator
*/
public class Document {
private int document_number;
private boolean document_type;
private boolean document_status;
private StringBuilder document_date;
private StringBuilder document_statement;
private int document_code_number;
private int document_employee_number;
private int document_client_number;
private String document_employee_name;
private String document_client_name;
private long document_amount;
private long document_payment_amount;
HashMap<Integer,Activity> document_activity_hashmap;
public Document(int dn,boolean dt,boolean ds,String dd,String dst,int dcon,int den,int dcln,long da,String dena,String dcna){
document_date = new StringBuilder(dd);
document_date.setLength(10);
document_date.setCharAt(4, '.');
document_date.setCharAt(7, '.');
document_statement = new StringBuilder(dst);
document_statement.setLength(50);
document_number = dn;
document_type = dt;
document_status = ds;
document_code_number = dcon;
document_employee_number = den;
document_client_number = dcln;
document_amount = da;
document_employee_name = dena;
document_client_name = dcna;
document_payment_amount = 0;
document_activity_hashmap = new HashMap<>();
}
public Document(int dn,boolean dt,boolean ds, long dpa){
document_number = dn;
document_type = dt;
document_status = ds;
document_payment_amount = dpa;
document_activity_hashmap = new HashMap<>();
}
// Print document information
public void printDocumentInformation (){
System.out.println("Document Number:" + document_number);
System.out.println("Document Date:" + document_date);
System.out.println("Document Type:" + document_type);
System.out.println("Document Status:" + document_status);
System.out.println("Document Statement:" + document_statement);
System.out.println("Document Code Number:" + document_code_number);
System.out.println("Document Client Number:" + document_client_number);
System.out.println("Document Employee Number:" + document_employee_number);
System.out.println("Document Amount:" + document_amount);
System.out.println("Document Payment Amount:" + document_payment_amount);
System.out.println("Document Employee Name:" + document_employee_name);
System.out.println("Document Client Name:" + document_client_name);
}
}
Second of all, you can define a class to handle your database needs. For example I defined a class named DataBase.java which handles my connections to the database and my needed queries. And I instantiated an objected of it in my main class.
package financialdocuments;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
*
* #author Administrator
*/
public class DataBase {
/**
*
* Defining parameters and strings that are going to be used
*
*/
//Connection connect;
// Tables which their datas are extracted at the beginning
HashMap<Integer,String> code_table;
HashMap<Integer,String> activity_table;
HashMap<Integer,String> client_table;
HashMap<Integer,String> employee_table;
// Resultset Returned by queries
private ResultSet result;
// Strings needed to set connection
String url = "jdbc:mysql://localhost:3306/financial_documents?useUnicode=yes&characterEncoding=UTF-8";
String dbName = "financial_documents";
String driver = "com.mysql.jdbc.Driver";
String userName = "root";
String password = "";
public DataBase(){
code_table = new HashMap<>();
activity_table = new HashMap<>();
client_table = new HashMap<>();
employee_table = new HashMap<>();
Initialize();
}
/**
* Set variables and objects for this class.
*/
private void Initialize(){
System.out.println("Loading driver...");
try {
Class.forName(driver);
System.out.println("Driver loaded!");
} catch (ClassNotFoundException e) {
throw new IllegalStateException("Cannot find the driver in the classpath!", e);
}
System.out.println("Connecting database...");
try (Connection connect = DriverManager.getConnection(url,userName,password)) {
System.out.println("Database connected!");
//Get tables' information
selectCodeTableQueryArray(connect);
// System.out.println("HshMap Print:");
// printCodeTableQueryArray();
selectActivityTableQueryArray(connect);
// System.out.println("HshMap Print:");
// printActivityTableQueryArray();
selectClientTableQueryArray(connect);
// System.out.println("HshMap Print:");
// printClientTableQueryArray();
selectEmployeeTableQueryArray(connect);
// System.out.println("HshMap Print:");
// printEmployeeTableQueryArray();
connect.close();
}catch (SQLException e) {
throw new IllegalStateException("Cannot connect the database!", e);
}
}
/**
* Write Queries
* #param s
* #return
*/
public boolean insertQuery(String s){
boolean ret = false;
System.out.println("Loading driver...");
try {
Class.forName(driver);
System.out.println("Driver loaded!");
} catch (ClassNotFoundException e) {
throw new IllegalStateException("Cannot find the driver in the classpath!", e);
}
System.out.println("Connecting database...");
try (Connection connect = DriverManager.getConnection(url,userName,password)) {
System.out.println("Database connected!");
//Set tables' information
try {
Statement st = connect.createStatement();
int val = st.executeUpdate(s);
if(val==1){
System.out.print("Successfully inserted value");
ret = true;
}
else{
System.out.print("Unsuccessful insertion");
ret = false;
}
st.close();
} catch (SQLException ex) {
Logger.getLogger(DataBase.class.getName()).log(Level.SEVERE, null, ex);
}
connect.close();
}catch (SQLException e) {
throw new IllegalStateException("Cannot connect the database!", e);
}
return ret;
}
/**
* Query needed to get code table's data
* #param c
* #return
*/
private void selectCodeTableQueryArray(Connection c) {
try {
Statement st = c.createStatement();
ResultSet res = st.executeQuery("SELECT * FROM code;");
while (res.next()) {
int id = res.getInt("code_number");
String msg = res.getString("code_statement");
code_table.put(id, msg);
}
st.close();
} catch (SQLException ex) {
Logger.getLogger(DataBase.class.getName()).log(Level.SEVERE, null, ex);
}
}
private void printCodeTableQueryArray() {
for (HashMap.Entry<Integer ,String> entry : code_table.entrySet()){
System.out.println("Key : " + entry.getKey() + " Value : " + entry.getValue());
}
}
/**
* Query needed to get activity table's data
* #param c
* #return
*/
private void selectActivityTableQueryArray(Connection c) {
try {
Statement st = c.createStatement();
ResultSet res = st.executeQuery("SELECT * FROM activity;");
while (res.next()) {
int id = res.getInt("activity_number");
String msg = res.getString("activity_statement");
activity_table.put(id, msg);
}
st.close();
} catch (SQLException ex) {
Logger.getLogger(DataBase.class.getName()).log(Level.SEVERE, null, ex);
}
}
private void printActivityTableQueryArray() {
for (HashMap.Entry<Integer ,String> entry : activity_table.entrySet()){
System.out.println("Key : " + entry.getKey() + " Value : " + entry.getValue());
}
}
/**
* Query needed to get client table's data
* #param c
* #return
*/
private void selectClientTableQueryArray(Connection c) {
try {
Statement st = c.createStatement();
ResultSet res = st.executeQuery("SELECT * FROM client;");
while (res.next()) {
int id = res.getInt("client_number");
String msg = res.getString("client_full_name");
client_table.put(id, msg);
}
st.close();
} catch (SQLException ex) {
Logger.getLogger(DataBase.class.getName()).log(Level.SEVERE, null, ex);
}
}
private void printClientTableQueryArray() {
for (HashMap.Entry<Integer ,String> entry : client_table.entrySet()){
System.out.println("Key : " + entry.getKey() + " Value : " + entry.getValue());
}
}
/**
* Query needed to get activity table's data
* #param c
* #return
*/
private void selectEmployeeTableQueryArray(Connection c) {
try {
Statement st = c.createStatement();
ResultSet res = st.executeQuery("SELECT * FROM employee;");
while (res.next()) {
int id = res.getInt("employee_number");
String msg = res.getString("employee_full_name");
employee_table.put(id, msg);
}
st.close();
} catch (SQLException ex) {
Logger.getLogger(DataBase.class.getName()).log(Level.SEVERE, null, ex);
}
}
private void printEmployeeTableQueryArray() {
for (HashMap.Entry<Integer ,String> entry : employee_table.entrySet()){
System.out.println("Key : " + entry.getKey() + " Value : " + entry.getValue());
}
}
}
I hope this could be a little help.