Sabtu, 16 Mei 2015

JAVA - How To Populate a LinkedList From MySQL DataBase In Java

JAVA - How To Get Data From MySQL Database To LinkedList In Java

In this java Collection Tutorial we will see How To retrieve data from MySQL database
using LinkedList In Java NetBeans .

maybe you need to see:
- connect java to mysql.
- using LinkedList.

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Project Source Code:

package javaapp;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.LinkedList;
import java.util.logging.Level;
import java.util.logging.Logger;

// create a users class
class Users{
private int Id;
private String Fname;
private String Lname;
private int Age;

public Users(){}
public Users(int id, String fname,String lname,int age){
this.Id = id;
this.Fname = fname;
this.Lname = lname;
this.Age = age;
}

public int getId(){
return this.Id;
}

public String getFname(){
return this.Fname;
}

public String getLname(){
return this.Lname;
}

public int getAge(){
return this.Age;
}

// create a tostring methode to diplay data
public String ToString(){
return this.Id+" "+this.Fname+" "+this.Lname+" "+this.Age;
}
}

public class Work {

// create a methode to get the connection
public static Connection getConnection(){

Connection con = null;

try {
con = DriverManager.getConnection("jdbc:mysql://localhost/test_db", "root", "");
} catch (SQLException ex) {
Logger.getLogger(Work.class.getName()).log(Level.SEVERE, null, ex);
}

return con;
}

public static void main(String[] args){

// create the linkedlist

LinkedList<String> list = new LinkedList<String>();

Users u;

Connection con = getConnection();

Statement st = null;
ResultSet rs = null;

try{
st = con.createStatement();
rs = st.executeQuery("SELECT * FROM users");
while(rs.next()){
Integer id = rs.getInt("id");
String fname = rs.getString("fname");
String lname = rs.getString("lname");
int age = rs.getInt("age");

u = new Users(id, fname,lname,age);

// set data in the linkedlist with our tostring methode

list.add(u.ToString());
}
}catch(Exception ex){
ex.printStackTrace();
}

// display data from the LinkedList
for(String s : list)
System.out.println(s);

// now your data are displayed from mysql database using LinkedList
}
}

///////////////OUTPUT:

1 Fuser_1 Luser_1 56
2 Fuser_2 Luser_2 26
4 ftest ltest 43
5 DBB BDD 14
6 hgjk sdfr 25
7 some thing 32
8 white black 42
9 AAA1 BBB1 32
10 WOR HOME 54
13 java csharp 66
14 ASP.NET JAVAEE 11
15 FN LN 40