Automatically Fill Username and Password Field in Web Pages using JAVA

So this is what i am trying to do, I need java to automatically open a webpage like mail.google.com and put in the username and password into respective boxes on click of a button. Now i know the code that opens up the browser and targets it to the specific url provided, i was just wondering if there was a way to tell java to fill in the username and password into respective boxes. By the way i am done with getting data from MYSQL database into string variables using JAVA...any help or suggestions??

Solution

Use Selenium. It's a good library where you can manipulate a web-page actions. i.e. selenium.isElementPresent("here comes the element's xpath"); will check if the element is loaded, and if it is you can use selenium.type("xpath", String/integer) in order to type in that field. Then by selenium.click("element"); you can click on an element such as submit button or something

This, for example (without checks for present elements), should open Google.com and search for "type some random text":

package com.example.tests;

import com.thoughtworks.selenium.*;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import static org.junit.Assert.*;
import java.util.regex.Pattern;

public class Googletest {
    private Selenium selenium;

    @Before
    public void setUp() throws Exception {
        selenium = new DefaultSelenium("localhost", 4444, "*chrome", "https://www.google.com/");
        selenium.start();
    }

    @Test
    public void testGoogletest() throws Exception {
        selenium.open("/");
        selenium.type("//div[@id='gs_lc0']/input", "type some random text");
        selenium.click("//div[@id='gbqfbw']/button");
    }

    @After
    public void tearDown() throws Exception {
        selenium.stop();
    }
}