Login, Browse and Upload In A Web Using Apache HTTPClient 4.3

This is my notes about using Apache HTTPClient library (version 4.3) to perform login, browse and upload in a website. At first I'm using an older version of jars and that makes some of my codes got deprecated warning when I upgrade the library. So here in my example I write two kind of codes, the deprecated and the new one.

Preparation

• Download Apache HTTPClient 4.3 jars in here
• Add the jars into your classpath project

Codes (deprecated)

	package com.hari.mynotes.httpclientexample;
	import java.io.File;
	import java.io.InputStream;
	import java.util.ArrayList;
	import java.util.List;
	import org.apache.http.HttpEntity;
	import org.apache.http.HttpResponse;
	import org.apache.http.NameValuePair;
	import org.apache.http.client.CookieStore;
	import org.apache.http.client.entity.UrlEncodedFormEntity;
	import org.apache.http.client.methods.HttpGet;
	import org.apache.http.client.methods.HttpPost;
	import org.apache.http.client.protocol.ClientContext;
	import org.apache.http.entity.mime.MultipartEntity;
	import org.apache.http.entity.mime.content.FileBody;
	import org.apache.http.entity.mime.content.StringBody;
	import org.apache.http.impl.client.BasicCookieStore;
	import org.apache.http.impl.client.DefaultHttpClient;
	import org.apache.http.message.BasicNameValuePair;
	import org.apache.http.protocol.BasicHttpContext;
	import org.apache.http.protocol.HttpContext;
	import org.apache.http.util.EntityUtils;
	import com.hari.mynotes.httpclientexample.MyRedirectStrategy;
	public class HTTPClientExample {
	private static CookieStore cookieStore;
	private static final MyRedirectStrategy redirectStrategy = new MyRedirectStrategy();
	private static final String BASE_URL = "http://example.com";
	private static final String USER_AGENT = "Mozilla/5.0";
	// Login method
	public static boolean login(String user, String password) {
	// Instantiate HttpClient object
	DefaultHttpClient client = new DefaultHttpClient();
	try {
	// Handle if request got specific redirect response
	client.setRedirectStrategy(redirectStrategy);
	// Instantiate a cookies
	cookieStore = new BasicCookieStore();
	// Add a cookies into http context
	HttpContext context = new BasicHttpContext();
	context.setAttribute(ClientContext.COOKIE_STORE, cookieStore);
	// Instantiate POST request
	HttpPost post = new HttpPost(BASE_URL);
	// Add user agent into the POST header
	post.setHeader("User-Agent", USER_AGENT);
	// Add parameters into the POST request
	// Note that we have to know the name of the parameters that we want to send
	List<NameValuePair> params = new ArrayList<NameValuePair>();
	params.add(new BasicNameValuePair("action", "loginAction"));
	params.add(new BasicNameValuePair("nameinput", user));
	params.add(new BasicNameValuePair("passinput", password));
	post.setEntity(new UrlEncodedFormEntity(params));
	// Execute the request and get the response
	HttpResponse response = client.execute(post, context);
	// Get the response entity
	HttpEntity resEntity = response.getEntity();
	// Check response status
	// Do something if it's OK
	int responseStatus = response.getStatusLine().getStatusCode();
	if (responseStatus==200) {
	String responseLocation = response.getLastHeader("location").getValue();
	InputStream is = resEntity.getContent();
	// Write codes here to check whether the response is as expected
	// We can check via the location or the content
	return true;
	}
	EntityUtils.consume(resEntity);
	} catch(Exception e) {
	e.printStackTrace();
	} finally {
	try {
	// Close the connection
	client.getConnectionManager().shutdown();
	} catch (Exception e ){e.printStackTrace();}
	}
	return false;
	}
	// Browse a secure page method (need cookies from the success login)
	public static void browse(String pageUrl) {
	// Instantiate HttpClient object
	DefaultHttpClient client = new DefaultHttpClient();
	try {
	// Add the cookies into request
	client.setCookieStore(cookieStore);
	// Add the cookies into http context
	HttpContext context = new BasicHttpContext();
	context.setAttribute(ClientContext.COOKIE_STORE, cookieStore);
	// Instantiate GET request
	HttpGet request = new HttpGet(pageUrl);
	// Add user agent into the GET header
	request.setHeader("User-Agent", USER_AGENT);
	// Execute the request and get the response
	HttpResponse response = client.execute(request, context);
	// Get the response entity
	HttpEntity resEntity = response.getEntity();
	// Check response status
	// Do something if it's OK
	int responseStatus = response.getStatusLine().getStatusCode();
	if (responseStatus==200) {
	// bla.. bla.. bla..
	}
	} catch(Exception e) {
	e.printStackTrace();
	} finally {
	try {
	// Close the connection
	client.getConnectionManager().shutdown();
	} catch (Exception e ){e.printStackTrace();}
	}
	}
	// Upload file method
	public static void upload(File file) {
	// Instantiate HttpClient object
	DefaultHttpClient client = new DefaultHttpClient();
	try {
	// Add the cookies into request
	client.setCookieStore(cookieStore);
	// Add the cookies into http context
	HttpContext context = new BasicHttpContext();
	context.setAttribute(ClientContext.COOKIE_STORE, cookieStore);
	// Instantiate POST request
	HttpPost post = new HttpPost(BASE_URL);
	// Add user agent into the POST header
	post.setHeader("User-Agent", USER_AGENT);
	// Add parameters into the POST request
	MultipartEntity entity = new MultipartEntity();
	entity.addPart("action", new StringBody("uploadAction")) ;
	// Prepare the File
	// Note that we have to know the name attribute of the input file
	FileBody fileBody = new FileBody(file, "application/vnd.ms-excel") ;
	entity.addPart("excelFile", fileBody) ;
	// Set the entity into the POST request
	post.setEntity(entity);
	// Execute the request and get the response
	HttpResponse response = client.execute(post, context);
	// Get the response entity
	HttpEntity resEntity = response.getEntity();
	// Check response status
	// Do something if it's OK
	int responseStatus = response.getStatusLine().getStatusCode();
	if (responseStatus==200) {
	// bla.. bla.. bla..
	}
	EntityUtils.consume(resEntity);
	} catch(Exception e) {
	e.printStackTrace();
	} finally {
	try {
	// Close the connection
	client.getConnectionManager().shutdown();
	} catch (Exception e ){e.printStackTrace();}
	}
	}
	}

view raw Apache HTTPClient 4.3 Deprecated Codes hosted with ❤ by GitHub

You will notice that we have some deprecated problems here. They are :

• DefaultHttpClient class
• ClientContext class
• MultipartEntity class
• StringBody(String) constructor
• FileBody(File,String) constructor 

Somehow, after trial & errors I solved the problem.
Codes (new style)

	package com.hari.mynotes.httpclientexample;
	import java.io.File;
	import java.io.InputStream;
	import java.util.ArrayList;
	import java.util.List;
	import org.apache.http.HttpEntity;
	import org.apache.http.HttpResponse;
	import org.apache.http.NameValuePair;
	import org.apache.http.client.CookieStore;
	import org.apache.http.client.HttpClient;
	import org.apache.http.client.entity.UrlEncodedFormEntity;
	import org.apache.http.client.methods.HttpGet;
	import org.apache.http.client.methods.HttpPost;
	import org.apache.http.client.utils.HttpClientUtils;
	import org.apache.http.entity.ContentType;
	import org.apache.http.entity.mime.MultipartEntityBuilder;
	import org.apache.http.entity.mime.content.StringBody;
	import org.apache.http.impl.client.BasicCookieStore;
	import org.apache.http.impl.client.HttpClientBuilder;
	import org.apache.http.message.BasicNameValuePair;
	import org.apache.http.util.EntityUtils;
	import com.hari.mynotes.httpclientexample.MyRedirectStrategy;
	public class HTTPClientExampleNew {
	private static CookieStore cookieStore;
	private static final MyRedirectStrategy redirectStrategy = new MyRedirectStrategy();
	private static final String BASE_URL = "http://example.com";
	private static final String USER_AGENT = "Mozilla/5.0";
	// Login method
	public static boolean login(String user, String password) {
	// Instantiate a cookies
	cookieStore = new BasicCookieStore();
	// Instantiate HttpClient object via HttpClientBuilder
	// at the same time include the user agent, redirect strategy and cookies
	HttpClientBuilder clientBuilder = HttpClientBuilder
	.create()
	.setUserAgent(USER_AGENT)
	.setRedirectStrategy(redirectStrategy)
	.setDefaultCookieStore(cookieStore);
	HttpClient client = clientBuilder.build();
	try {
	// Instantiate POST request
	HttpPost post = new HttpPost(BASE_URL);
	// Add parameters into the POST request
	// Note that we have to know the name of the parameters that we want to send
	// There are no deprecated codes in this NameValuePair parameter list
	List<NameValuePair> params = new ArrayList<NameValuePair>();
	params.add(new BasicNameValuePair("action", "loginAction"));
	params.add(new BasicNameValuePair("nameinput", user));
	params.add(new BasicNameValuePair("passinput", password));
	post.setEntity(new UrlEncodedFormEntity(params));
	// Execute the request and get the response
	HttpResponse response = client.execute(post);
	// Get the response entity
	HttpEntity resEntity = response.getEntity();
	// Check response status
	// Do something if it's OK
	int responseStatus = response.getStatusLine().getStatusCode();
	if (responseStatus==200) {
	String responseLocation = response.getLastHeader("location").getValue();
	InputStream is = resEntity.getContent();
	// Write codes here to check whether the response is as expected
	// We can check via the location or the content
	return true;
	}
	EntityUtils.consume(resEntity);
	} catch(Exception e) {
	e.printStackTrace();
	} finally {
	// Close the connection. Note that we don't need to try-catch-ing an exception
	HttpClientUtils.closeQuietly(client);
	}
	return false;
	}
	// Browse a secure page method (need cookies from the success login)
	public static void browse(String pageUrl) {
	// Instantiate HttpClient object via HttpClientBuilder
	// at the same time include the user agent, and the cookies
	HttpClientBuilder clientBuilder = HttpClientBuilder
	.create()
	.setUserAgent(USER_AGENT)
	.setDefaultCookieStore(cookieStore);
	HttpClient client = clientBuilder.build();
	try {
	// Instantiate GET request
	HttpGet request = new HttpGet(pageUrl);
	// Execute the request and get the response
	HttpResponse response = client.execute(request);
	// Get the response entity
	HttpEntity resEntity = response.getEntity();
	// Check response status
	// Do something if it's OK
	int responseStatus = response.getStatusLine().getStatusCode();
	if (responseStatus==200) {
	// bla.. bla.. bla..
	}
	} catch(Exception e) {
	e.printStackTrace();
	} finally {
	// Close the connection. No need try-catch
	HttpClientUtils.closeQuietly(client);
	}
	}
	// Upload file method
	public static void upload(File file) {
	// Instantiate HttpClient object via HttpClientBuilder
	// at the same time include the user agent, and the cookies
	HttpClientBuilder clientBuilder = HttpClientBuilder
	.create()
	.setUserAgent(USER_AGENT)
	.setDefaultCookieStore(cookieStore);
	HttpClient client = clientBuilder.build();
	try {
	// Instantiate POST request
	HttpPost post = new HttpPost(BASE_URL);
	// Prepare the parameter and the file into a HttpEntity
	HttpEntity entity = MultipartEntityBuilder.create()
	.addPart("action", new StringBody("uploadAction", ContentType.TEXT_PLAIN))
	.addBinaryBody("excelFile", file, ContentType.create("application/vnd.ms-excel"), file.getName())
	.build();
	// Add the entity into the POST request
	post.setEntity(entity);
	// Execute the request and get the response
	HttpResponse response = client.execute(post);
	// Get the response entity
	HttpEntity resEntity = response.getEntity();
	// Check response status
	// Do something if it's OK
	int responseStatus = response.getStatusLine().getStatusCode();
	if (responseStatus==200) {
	// bla.. bla.. bla..
	}
	EntityUtils.consume(resEntity);
	} catch(Exception e) {
	e.printStackTrace();
	} finally {
	// Close the connection. No need try-catch
	HttpClientUtils.closeQuietly(client);
	}
	}
	}

view raw Apache HTTPClient 4.3 (new style) hosted with ❤ by GitHub

That's it. Hope my notes helps.

Using HTMLUnit (Webcrawler Libs) For Login Into A Website

Notes :

• Note that my HTMLUnit example below is not a web crawler scenario, because we have to know first the specific structure and fields of the page of a website that we try to log.
• Note that HTMLUnit consume lot of memory. It's better to use other mechanism (not a crawler libs) such as Apache HTTPClient to complete the same task.

Preparation :

• First, download HTMLUnit jars in here: HTMLUnit 2.12 
• Put all the jars into your project's classpath.

Website login page source (login.html) :

	<html>
	<head>
	<title>example.com</title>
	....
	....
	</head>
	<body>
	...
	...
	<fieldset>
	<legend>Login</legend>
	<form id="form1" class="loginform" autocomplete="off" method="post" action="index.php?action=loginAction" enctype="multipart/form-data">
	<table border=0 style="padding-left: 150px">
	<tr>
	<td class="label">User Name</td>
	<td class="field"><input type="text" name="nameinput" id="nameinput" value="" class="required"></td>
	<td class="status"></td>
	</tr>
	<tr>
	<td class="label">Password</td>
	<td class="field"><input type="password" name="passinput" id="passinput" value="" class="required"></td>
	<td class="status"></td>
	</tr>
	<tr>
	<td colspan="2" align="right"><input type="submit" name="" class="ui-button ui-state-default ui-corner-all" value="Sign In"></td>
	</tr>
	<tr>
	<td colspan="2" align="right"><br/><a href="index.php?action=resetPassAction">Reset Password</a></td>
	</tr>
	</table>
	</form>
	</fieldset>
	...
	...
	</body>
	</html>

view raw login.html source example hosted with ❤ by GitHub

 
Login codes:

	package com.hari.mynotes.htmlunit;
	import com.gargoylesoftware.htmlunit.FailingHttpStatusCodeException;
	import com.gargoylesoftware.htmlunit.Page;
	import com.gargoylesoftware.htmlunit.WebClient;
	import com.gargoylesoftware.htmlunit.html.DomNode;
	import com.gargoylesoftware.htmlunit.html.HtmlElement;
	import com.gargoylesoftware.htmlunit.html.HtmlFileInput;
	import com.gargoylesoftware.htmlunit.html.HtmlForm;
	import com.gargoylesoftware.htmlunit.html.HtmlPage;
	import com.gargoylesoftware.htmlunit.html.HtmlPasswordInput;
	import com.gargoylesoftware.htmlunit.html.HtmlSubmitInput;
	import com.gargoylesoftware.htmlunit.html.HtmlTextInput;
	public class WebRobot {
	public static void login(String username, String password) {
	String loginUrl = "http://example.com";
	int loginFormNum = 1;
	String usernameInputName = "nameinput";
	String passwordInputName = "passinput";
	String submitLoginButtonValue = "Sign In";
	// create the HTMLUnit WebClient instance
	WebClient wclient = new WebClient();
	// configure WebClient based on your desired
	wclient.getOptions().setPrintContentOnFailingStatusCode(false);
	wclient.getOptions().setCssEnabled(false);
	wclient.getOptions().setThrowExceptionOnFailingStatusCode(false);
	wclient.getOptions().setThrowExceptionOnScriptError(false);
	try {
	// get the login page by connect to the URL
	final HtmlPage loginPage = (HtmlPage)wclient.getPage(loginUrl);
	// get the login form by its form number. mine is 1 (form[1])
	final HtmlForm loginForm = loginPage.getForms().get(loginFormNum);
	// get the text input field by the name and set the value
	final HtmlTextInput txtUser = loginForm.getInputByName(usernameInputName);
	txtUser.setValueAttribute(username);
	// get the password input field by the name and set the value
	final HtmlPasswordInput txtpass = loginForm.getInputByName(passwordInputName);
	txtpass.setValueAttribute(password);
	// get the submit button by the text value
	final HtmlSubmitInput submitLogin = loginForm.getInputByValue(submitLoginButtonValue);
	// after we set the name & password then we click the submit button
	// it will return a page (redirect or message alert or somethin, different sites different behaviour)
	// or it could throws an exception
	final HtmlPage returnPage = submitLogin.click();
	// we can analyze the return page based on the body
	// ex: mine is check if its body contains less than 5 elements
	final HtmlElement returnBody = returnPage.getBody();
	if (returnBody==null || returnBody.getChildElementCount()<5) {
	// bla.. bla.. bla..
	}
	} catch(FailingHttpStatusCodeException e) {
	e.printStackTrace();
	} catch(Exception e) {
	e.printStackTrace();
	}
	}
	}

view raw HTMLUnit login example hosted with ❤ by GitHub

That' its. Hope MyNotes helps.

Lambdaj - Usage Examples

Lambdaj simplify your task to manipulate Collection in Java programming. Convert from List into Map, select and filtering collection, joining String, grouping, etc, those are Lambdaj expertise. 

To use it you have to import Lambdaj library into your classpath and then import Lambda as a static class into your java program like this :

import static ch.lambdaj.Lambda.*;

Dummy Class (Person.java)

class Person {
private int id;
private String name;
private int age;
private String city;

public Person() {}

public Person(int id, String name, int age, String city) {
this.id = id;
this.name = name;
this.age = age;
this.city = city;
}

public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public String getDetails() {
return "ID= "+id+"; Name= "+name+"; Age= "+age+"; City= "+city;
}
}

And these are my Lambdaj usage examples :

USE JOIN FOR BUILDING QUERY

List<String> list = Arrays.asList("hari1","hari2","hari3","hari4");
//-------------------------------------------------------------------------------------------
String result = join(list,"','");
String query = "select t from T_PERSON t where "+(result.length()>0 ? "t.name in ('"+result+"')" : "0=0");
//-------------------------------------------------------------------------------------------
System.out.println(query);

CONVERT LIST OBJECT INTO MAP

List<Person> persons = Arrays.asList(
new Person(13,"Steve",22,"London, UK"),
new Person(25,"Greg",28,"New York, USA"),
new Person(5,"Emily",22,"Bali, Indonesia"),
new Person(9,"Malih",14,"Jakarta, Indonesia"));

//-------------------------------------------------------------------------------------------
Map<Integer,Person> personMap = index(persons,on(Person.class).getId());
//-------------------------------------------------------------------------------------------
System.out.println("Person name with ID 5: " + personMap.get(5).getName());

EXTRACTING FIELDS INTO NEW LIST

List<String> personNames = extract(persons, on(Person.class).getName());
//-------------------------------------------------------------------------------------------
System.out.println("personNames: "+personNames);

SELECTING PERSON LIST WHERE CITY CONTAINS "Indonesia"

List<Person> filteredPerson = select(persons, having(on(Person.class).getCity(), StringContains.containsString("Indonesia")));
//-------------------------------------------------------------------------------------------
for (Person person : filteredPerson)  
            System.out.println(person.getDetails());

COMBINE EXTRACT AND SELECT

List<String> filteredPersonNames = extract(select(persons,having(on(Person.class).getAge(), IsEqual.equalTo(22))), on(Person.class).getName());

//-------------------------------------------------------------------------------------------
System.out.println("filteredPersonNames: "+filteredPersonNames);

GROUPING

Group<Person> groupAgeOfPerson = group(persons,by(on(Person.class).getAge()));
Set<String> groupAgeKeys  = groupAgeOfPerson.keySet();
//-------------------------------------------------------------------------------------------
System.out.println("groupAgeKeys: "+groupAgeKeys);
System.out.println("groupOfAge: "+groupAgeOfPerson.find(22));


for (String ageKey : groupAgeKeys) 
for (Person person : groupAgeOfPerson.find(ageKey))
System.out.println(person.getDetails());

Convert Wallet Into Keystore (OHS to Weblogic SSL) - Verse 2

Completing my previous notes about Converting Wallet into Keystore, this is other steps to do the convert and it is more simple than before. For Identity Keystore, I create an empty keystore, actually I create a keystore with dummy certificate and then delete the dummy certificate. And for the Trust Keystore I'm using Firefox browser convert the CAs.


So, the steps:

IDENTITY KEYSTORE

CREATE AN EMPTY JKS KEYSTORE
keytool -genkey -alias dummy -keystore identity_keystore.jks
keytool -delete -alias dummy -keystore identity_keystore.jks

IMPORT wallet_server.p12 INTO identity_keystore.jks
keytool -v -importkeystore -srckeystore wallet_server.p12 -srcstoretype PKCS12 -destkeystore identity_keystore.jks -deststoretype JKS


TRUST KEYSTORE

For CAs (which mine is in DER format), I tried a different way. I'm using Firefox browser to convert DER into PEM format.

IMPORT CA CERTIFICATES INTO FIREFOX
options -> Advanced -> Encryption -> View Certificates -> Import 

EXPORT THE CAs INTO PEM FORMAT (X.509 Certificate - PEM)

CREATE TRUSTED CA - CERTIFICATE CHAIN KEYSTORE

keytool -import -trustcacerts -file Inter1-CA.pem -keystore trust_keystore.jks -alias inter1

keytool -import -trustcacerts -file Inter2-CA.pem -keystore trust_keystore.jks -alias inter2

keytool -import -trustcacerts -file Root-CA.pem -keystore trust_keystore.jks -alias root


That's it, simple than the previous. Of course, there are many other ways to complete the task, but hope mine helps.

Convert Wallet Into Keystore (OHS to Weblogic SSL) - Verse 1

Recently I've been trying to migrate my SSL configuration from OHS (Oracle HTTP Server) to Weblogic Server. For information, OHS is using Wallet to store certificates for SSL authentication and at the other side, Weblogic using Keystore (Identity and Trusted Keystore). So, I need to convert my Wallet (PKCS12 format) into Keystore.

My certificates description :

• One Root CA (Root-CA)
• Two Intermediate CAs (inter1-CA and inter2-CA)
• A pair of certificate (public and private key) for Server
• inter1-CA issued by Root-CA
• inter2-CA issued by inter1-CA
• and a Wallet contain server certificate which issued by inter2-CA

Identity and Trust Keystore as Oracle documentation describes, Identity contains public and private key of the server and Trust contains trusted CA Certificates (mine is a chain: Root-CA, inter1CA and inter2-CA).

To complete this task I'm using this tools:

• Openssl
• Keytool
• Wallet Manager
• Class ImportKey which i got from http://www.agentbob.info/agentbob/79-AB.html (thanks for this helpful article)

More description:

• My certificates are in DER format
• Keytool only accept certificate in PEM format (hope I'm not wrong), so I have to convert it first before import it into the keystore
• Identity Keystore must fill with server public and private key, that's way I need ImportKey.class to do this task
• ImportKey class only accept DER format, so I have to convert it too using Openssl

So here it is, the steps:

IDENTITY KEYSTORE

SPLIT WALLET (PKCS12) INTO KEY AND CERT

openssl pkcs12 -nocerts -in wallet_server.p12 -out wallet_serverkey.pem -nodes

openssl pkcs12 -clcerts -nokeys -in wallet_server.p12 -out wallet_servercert.pem

openssl rsa -in wallet_serverkey.pem -out wallet_serverkey2.pem

CONVERT KEY AND CERT PEM FORMAT INTO DER FORMAT

openssl pkcs8 -topk8 -nocrypt -in wallet_serverkey2.pem -inform PEM -out wallet_serverkey.der -outform DER

openssl x509 -in wallet_servercert.pem -inform PEM -out wallet_servercert.der -outform DER

USING ImportKey.class TO IMPORT PRIVATE KEY INTO KEYSTORE

java ImportKey walletkey.der walletcert.der

RENAME KEYSTORE FILE keystore.importKey INTO identity_keystore.jks

CHANGE KEYSTORE PASSWORD importkey INTO somepass

keytool -keystore identity_keystore.jks -storepasswd

CHANGE CERTIFICATE PASSWORD importkey INTO somepass

keytool -keypasswd -keypass importkey -new somepass -alias importkey -keystore identity_keystore.jks

CHANGE ALIAS importkey INTO somekey

keytool -keystore identity_keystore.jks -keyclone -alias importkey -dest somekey

DELETE OLD ALIAS importkey

keytool -keystore identity_keystore.jks -delete -alias importkey 

TRUST KEYSTORE

USING WALLET MANAGER, EXPORT ALL CAs AND SAVE IT INTO YOUR LOCAL DISC

CONVERT CA CERTIFICATES DER TO PEM

openssl x509 -in Inter1-CA.cer -inform DER -out Inter1-CA.pem -outform PEM

openssl x509 -in Inter2-CA.cer -inform DER -out Inter2-CA.pem -outform PEM

openssl x509 -in Root-CA.cer -inform DER -out Root-CA.pem -outform PEM

CREATE TRUSTED CA - CERTIFICATE CHAIN KEYSTORE

keytool -import -trustcacerts -file Inter1-CA.pem -keystore trust_keystore.jks -alias inter1

keytool -import -trustcacerts -file Inter2-CA.pem -keystore trust_keystore.jks -alias inter2

keytool -import -trustcacerts -file Root-CA.pem -keystore trust_keystore.jks -alias root

That's it. Hope my notes helps.

By the way, there's a simple way to do the task, you can find it here.