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minify html and js in jersey Interceptor

used jersey mvc and jsp, all requests to html or js files did through #Template or Viewable.
example;
#GET
#Path(JS_URL + "{type}")
#Template(name = "grid")
#Produces("application/javascript")
public Response buildJSGrid(#DefaultValue("") #PathParam("type") String type) {
Grid grid = new Grid(type);
....
return Response.ok(grid).build();
}
where grid is grid.jsp file with pure javascript inside
<%# page contentType="application/javascript;charset=UTF-8" language="java" %>
.....
also possible other variant with html and js, example;
#GET
#Path(FORM_URL + "{type}")
#Template(name = "form")
#Produces(MediaType.TEXT_HTML)
public Response buildAccountForm(#DefaultValue("") #PathParam("type") String type) {
Form form = new Form(type);
....
return Response.ok(form).build();
}
where form is form.jsp with html and js inside <script>..</script>
<%# page contentType="text/html;charset=UTF-8" language="java" %>
...
i need to minify result js and html/js before send to client, i try to use https://code.google.com/archive/p/htmlcompressor/ lib, but there need to pass String to htmlCompressor.compress(input);
tried use WriterInterceptor
public class MinifyJsInterceptor implements WriterInterceptor {
#Override
public void aroundWriteTo(WriterInterceptorContext context) throws IOException, WebApplicationException {
final OutputStream outputStream = context.getOutputStream();
// here need to convert outputStream to InputStream and after to String ?
// result string to htmlCompressor.compress(resultString);
// after that convert result minify string back to resultOutputStream and set to context ?
context.setOutputStream(new GZIPOutputStream(resultOutputStream));
is it correct way ? and i can`t converts that outputstream to string
thanks
--update
answer to questions;
html + js mean that in some jsp are html markup and js code
<div id="form" style="width: 500px; display: none">
<div class="w2ui-page page-0">
<div class="w2ui-field">
</div>....
<script type="text/javascript">
var uiElement = (function () {
var config = {
onOpen: function (event) {
event.onComplete = function () {
$('#formContainer').w2render('form');
}
...
}());
</script>
on client that file requested by
$('#tempContainer').load('that file name - also dynamic', function (data, status, xhr) {
uiElement.init();
w2ui[layout].content(layout_main, w2ui[uiElement.name]);
});
And do you really return js-files in you resource methods?
some js and html + js files are dynamic build, example;
grid.jsp contains inside
<%# page contentType="application/javascript;charset=UTF-8" language="java" %>
var uiElement = (function () {
var config = {
grid: {
name: ${it.name},
listUrl:'${it.entityListUrl}',
formUrl:'${it.entityFormUrl}',
columns: ${it.columns},
records: ${it.records},
}}
there are ${it..} values from el expression and setting in resource method
#GET
#Path(JS_URL + "{type}")
#Template(name = "grid")
#Produces("application/javascript")
public Response buildJSGrid(#DefaultValue("") #PathParam("type") String type) {
Grid grid = new Grid(type);
....
return Response.ok(grid).build();
}}
and from client that js 'file' called by
$.getScript('dynamic js file name' - it is dynamic too).done(function (script, status, xhr) {
//console.log(xhr.responseText);
uiElement.init();
w2ui[layout].content(layout_main, w2ui[uiElement.name]);
});
also some html blocks build dynamic
{
<c:if test="${it.recid != 0}">
<div class="w2ui-field">
<label>active:</label>
<div>
<input name="active" type="checkbox"/>
</div>
</div>
</c:if>
}
-- update description,
grid builder;
one resource and one template for build any grid,
#GET
#Path(GRID + "{type}")
#Template(name = W2UI_VIEW_PREFIX + "grid/grid")
#Produces(MEDIA_TYPE_APPLICATION_JAVASCRIPT)
public Response buildGrid(#DefaultValue("") #PathParam("type") String type) {
for (W2UI ui : W2UI.values()) {
if (type.equals(ui.getName())) {
W2UIElement grid = ui.getUI();
return Response.ok(grid).build();
}
}
return Response.noContent().build();
}
also possible different templates(jsp files) through Viewable(template, model)
somewhere in menu builder for menu.jsp template
List<MenuItem> items..
MenuItem item1 = new MenuItem(W2UI.TASK_GRID, W2UIService.GRID);
items.add(item1);
where
W2UIService.GRID is string url for client js request and for server method resource #Path() anno.
and
public enum W2UI {
TASK_GRID("task_grid", "tasks", Type.SCRIPT){
#Override
public W2UIElement getUI() {
return new TaskGrid(getName());
}
},
.....
}
TaskGrid is filled model for grid.jsp template with js code, so easy to add any type of grid with different sets of data and buttons.
type of component(Type.SCRIPT) processing on the client by $.getScript(), Type.HTML by $('#tempContainer').load()
---update factory and providers;
#Provider
#Priority(200)
#HtmlMinify
public class HtmlMinifyInterceptor implements WriterInterceptor {
#Inject private HtmlCompressor compressor;
...
public class HtmlMinifierFactory implements Factory<HtmlCompressor> {
private HtmlCompressor compressor;
#Override
public HtmlCompressor provide() {
if (null == compressor) compressor = new HtmlCompressor();
ClosureJavaScriptCompressor jsCompressor = new ClosureJavaScriptCompressor();
jsCompressor.setCompilationLevel(CompilationLevel.SIMPLE_OPTIMIZATIONS);
..
#ApplicationPath("/")
public class MainRsConfig extends ResourceConfig {
public MainRsConfig() {
..
register(new AbstractBinder() {
#Override
protected void configure() {
bindFactory(HtmlMinifierFactory.class).to(HtmlCompressor.class).in(Singleton.class);
}
});
..

You can use a custom implementation of a ByteArrayOutputStream as a wrapper to the OutputStream of the WriterInterceptorContext:
import com.googlecode.htmlcompressor.compressor.Compressor;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
public class HtmlMinifyOutputStream extends ByteArrayOutputStream {
private OutputStream origOut;
private Compressor compressor;
public HtmlMinifyOutputStream(OutputStream origOut, Compressor compressor) {
this.origOut = origOut;
this.compressor = compressor;
}
public void close() throws IOException {
super.close();
String compressedBody = compressor.compress(new String(this.buf));
this.origOut.write(compressedBody.getBytes());
this.origOut.close();
}
}
The HtmlMinifyOutputStream can be used in the WriterInterceptor implementation. The HtmlCompressor instance is injected:
import com.googlecode.htmlcompressor.compressor.Compressor;
import javax.inject.Inject;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.ext.Provider;
import javax.ws.rs.ext.WriterInterceptor;
import javax.ws.rs.ext.WriterInterceptorContext;
import java.io.*;
#Provider
#HtmlMinify
public class MinifyHtmlInterceptor implements WriterInterceptor {
#Inject
private Compressor compressor;
#Override
public void aroundWriteTo(WriterInterceptorContext context) throws IOException, WebApplicationException {
final OutputStream outputStream = context.getOutputStream();
context.setOutputStream(new HtmlMinifyOutputStream(outputStream, compressor));
context.proceed();
}
}
#HtmlMinify is a NameBinding annotation, used to activate the MinifyHtmlInterceptor on specific resource methods. (see https://jersey.java.net/documentation/latest/filters-and-interceptors.html#d0e9988):
import javax.ws.rs.NameBinding;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
#NameBinding
#Retention(value = RetentionPolicy.RUNTIME)
public #interface HtmlMinify {}
The HtmlCompressor can be created only once per application and used concurrently, because:
HtmlCompressor and XmlCompressor classes are considered thread safe* and can be used in multi-thread environment (https://code.google.com/archive/p/htmlcompressor/)
Here is a HK2 factory (see: Implementing Custom Injection Provider) which creates the compressor instance and enables inline css and javascript compression:
import com.googlecode.htmlcompressor.compressor.Compressor;
import com.googlecode.htmlcompressor.compressor.HtmlCompressor;
import org.glassfish.hk2.api.Factory;
public class HtmlCompressorFactory implements Factory<Compressor> {
private HtmlCompressor compressor;
#Override
public Compressor provide() {
if(compressor == null) {
compressor = new HtmlCompressor();
}
compressor.setCompressJavaScript(true);
compressor.setCompressCss(true);
return compressor;
}
#Override
public void dispose(Compressor compressor) {}
}
The factory is registered with an AbstractBinder:
final ResourceConfig rc = new ResourceConfig().packages("com.example");
rc.register(new AbstractBinder() {
#Override
protected void configure() {
bindFactory(HtmlCompressorFactory.class).to(Compressor.class).in(Singleton.class);
}
});
If inline javascript or inline css compression is enabled:
HTML compressor with default settings doesn't require any dependencies. Inline CSS compression requires YUI compressor library.Inline JavaScript compression requires either YUI compressor library (by default) or Google Closure Compiler library. (https://code.google.com/archive/p/htmlcompressor/)
I use maven, so I added this dependency to my pom.xml:
<dependency>
<groupId>com.yahoo.platform.yui</groupId>
<artifactId>yuicompressor</artifactId>
<version>2.4.8</version>
</dependency>
If you want to use the Google Closure Compiler use this dependency:
<dependency>
<groupId>com.google.javascript</groupId>
<artifactId>closure-compiler</artifactId>
<version>r2388</version>
</dependency>
and activate it:
compressor.setJavaScriptCompressor(new ClosureJavaScriptCompressor());
compressor.setCompressJavaScript(true);
compressor.setCssCompressor(new YuiCssCompressor());
compressor.setCompressCss(true);
return compressor;
If you want to compress pure JavaScript or CSS files, you cannot use the htmlcompressor. This library supports only HTML files with inline CSS/JS. But you could implement a MinifyJsInterceptor or MinifyCssInterceptor analog to the MinifyHtmlInterceptor, which uses the YUI-Compressor and/or Google Closure libraries directly.
For gzip compression you should implement another interceptor. So it is possible to configure the minification and compression separately. If you activate multiple interceptors, use javax.annotation.Priority to controll the order of execution. (see: https://jersey.java.net/documentation/latest/filters-and-interceptors.html#d0e9927)

How to retrieve images from server to user using Struts 2

I have a Product entity, which has a imageUrl String field.
Products images after obtaining from user will be saved in directory:
System.getProperty("user.home") + "shop/data/product/"
And when user wants to see some Product I need to get this image from "user.home"+... to JSP page.
I've tried to read the image into the byte array, convert it to Base64 encoding, and then refer in JSP like this:
<img alt="image from user home" src="data:image/png, base64;${requestScope.image}">
But this solution is not working, and as far as I understand, it has a limitation on image size.
Could you suggest me a way how to do such thing?

Try this ( i think you have some typo )
<img alt="image from user home" src="data:image/png;base64,${requestScope.image}">
Also use this site: http://www.askapache.com/online-tools/base64-image-converter/ to make sure that your output Base64 code is correct.

There's an example of ImageAction that serves image from the file system. It's called
Struts 2 dynamic image example.
Instead of base64 encoding/decoding which increases the content length two times and slows down page loading you can use the action that returnes image bytes from the file. It could be a database, in this way it should fetch bytes from Blob.
In your <img> tag that is using src attribute can contain the URL to the action that returns response with a header Content-Type: image/jpeg and bytes written to the body.
This is the code of the ImageAction:
#Result(type = "stream", params = {"contentType", "${type}"})
public class ImageAction extends ActionSupport implements ServletRequestAware {
byte[] imageInByte = null;
String imageId;
private HttpServletRequest servletRequest;
private final static String type = "image/jpeg";
public getInputStream() { return new ByteArrayInputStream(getCustomImageInBytes()); }
public String getType() { return type; }
private String getFilename() {
return this.filename;
}
public String getImageId() {
return imageId;
}
public void setImageId(String imageId) {
this.imageId = imageId;
}
public ImageAction() {
System.out.println("ImageAction");
}
public byte[] getCustomImageInBytes() {
System.out.println("imageId" + imageId);
BufferedImage originalImage;
try {
originalImage = ImageIO.read(getImageFile(this.imageId));
// convert BufferedImage to byte array
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ImageIO.write(originalImage, "jpeg", baos);
baos.flush();
imageInByte = baos.toByteArray();
baos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return imageInByte;
}
private File getImageFile(String imageId) {
String filePath = servletRequest.getSession().getServletContext().getRealPath("/");
File file = new File(filePath + "/Image/", imageId);
System.out.println(file.toString());
return file;
}
#Override
public void setServletRequest(HttpServletRequest request) {
this.servletRequest = request;
}
}
This action supposed to have configuration created by convention-plugin. So it could be used in HTML like this
<img src="<s:url action='Image?imageId=darksouls.jpg' />" alt=""/>

So Alireza Fattahi was right that I had mistakes in my code. The first one is typo in img tag (see answer by Alireza Fattahi), the second one is after reading image to bytes array
byte[] image = ...;
I used
Base64.getEncoder().encode(image);
instead of
Base64.getEncoder().encodeToString(image));
So eventually this method with returning Base64 encoded image works. If there is a better choices - please left comments and answers.

Can't display StreamedContent in Primefaces media in JSF [duplicate]

I use the <p:media> to display static PDF content.
<p:media value="/resource/test.pdf"
width="100%" height="300px" player="pdf">
</p:media>
How can I change it to display dynamic content?

Like as in <p:graphicImage>, the value attribute can point to a bean property returning StreamedContent. This only requires a special getter method for the reasons which is explained in detail in the following answer on using <p:graphicImage> with a dynamic resource from a database: Display dynamic image from database with p:graphicImage and StreamedContent.
In your particular example, it would look like this:
<p:media value="#{mediaManager.stream}" width="100%" height="300px" player="pdf">
<f:param name="id" value="#{bean.mediaId}" />
</p:media>
With
#ManagedBean
#ApplicationScoped
public class MediaManager {
#EJB
private MediaService service;
public StreamedContent getStream() throws IOException {
FacesContext context = FacesContext.getCurrentInstance();
if (context.getCurrentPhaseId() == PhaseId.RENDER_RESPONSE) {
// So, we're rendering the HTML. Return a stub StreamedContent so that it will generate right URL.
return new DefaultStreamedContent();
} else {
// So, browser is requesting the media. Return a real StreamedContent with the media bytes.
String id = context.getExternalContext().getRequestParameterMap().get("id");
Media media = service.find(Long.valueOf(id));
return new DefaultStreamedContent(new ByteArrayInputStream(media.getBytes()));
}
}
}

Using Flying Saucer to Render Images to PDF In Memory

I'm using Flying Saucer to convert XHTML to a PDF document. I've gotten the code to work with just basic HTML and in-line CSS, however, now I'm attempting to add an image as a sort of header to the PDF. What I'm wondering is if there is any way whatsoever to add the image by reading in an image file as a Java Image object, then adding that somehow to the PDF (or to the XHTML -- like it gets a virtual "url" representing the Image object that I can use to render the PDF). Has anyone ever done anything like this?
Thanks in advance for any help you can provide!

I had to do that last week so hopefully I will be able to answer you right away.
Flying Saucer
The easiest way is to add the image you want as markup in your HTML template before rendering with Flying Saucer. Within Flying Saucer you will have to implement a ReplacedElementFactory so that you can replace any markup before rendering with the image data.
/**
* Replaced element in order to replace elements like
* <tt><div class="media" data-src="image.png" /></tt> with the real
* media content.
*/
public class MediaReplacedElementFactory implements ReplacedElementFactory {
private final ReplacedElementFactory superFactory;
public MediaReplacedElementFactory(ReplacedElementFactory superFactory) {
this.superFactory = superFactory;
}
#Override
public ReplacedElement createReplacedElement(LayoutContext layoutContext, BlockBox blockBox, UserAgentCallback userAgentCallback, int cssWidth, int cssHeight) {
Element element = blockBox.getElement();
if (element == null) {
return null;
}
String nodeName = element.getNodeName();
String className = element.getAttribute("class");
// Replace any <div class="media" data-src="image.png" /> with the
// binary data of `image.png` into the PDF.
if ("div".equals(nodeName) && "media".equals(className)) {
if (!element.hasAttribute("data-src")) {
throw new RuntimeException("An element with class `media` is missing a `data-src` attribute indicating the media file.");
}
InputStream input = null;
try {
input = new FileInputStream("/base/folder/" + element.getAttribute("data-src"));
final byte[] bytes = IOUtils.toByteArray(input);
final Image image = Image.getInstance(bytes);
final FSImage fsImage = new ITextFSImage(image);
if (fsImage != null) {
if ((cssWidth != -1) || (cssHeight != -1)) {
fsImage.scale(cssWidth, cssHeight);
}
return new ITextImageElement(fsImage);
}
} catch (Exception e) {
throw new RuntimeException("There was a problem trying to read a template embedded graphic.", e);
} finally {
IOUtils.closeQuietly(input);
}
}
return this.superFactory.createReplacedElement(layoutContext, blockBox, userAgentCallback, cssWidth, cssHeight);
}
#Override
public void reset() {
this.superFactory.reset();
}
#Override
public void remove(Element e) {
this.superFactory.remove(e);
}
#Override
public void setFormSubmissionListener(FormSubmissionListener listener) {
this.superFactory.setFormSubmissionListener(listener);
}
}
You will notice that I have hardcoded here /base/folder which is the folder where the HTML file is located as it will be the root url for Flying Saucer for resolving medias. You may change it to the correct location, coming from anywhere you want (Properties for example).
HTML
Within your HTML markup you indicate somewhere a <div class="media" data-src="somefile.png" /> like so:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>My document</title>
<style type="text/css">
#logo { /* something if needed */ }
</style>
</head>
<body>
<!-- Header -->
<div id="logo" class="media" data-src="media/logo.png" style="width: 177px; height: 60px" />
...
</body>
</html>
Rendering
And finally you just need to indicate your ReplacedElementFactory to Flying-Saucer when rendering:
String content = loadHtml();
ITextRenderer renderer = new ITextRenderer();
renderer.getSharedContext().setReplacedElementFactory(new MediaReplacedElementFactory(renderer.getSharedContext().getReplacedElementFactory()));
renderer.setDocumentFromString(content.toString());
renderer.layout();
final ByteArrayOutputStream baos = new ByteArrayOutputStream();
renderer.createPDF(baos);
// baos.toByteArray();
I have been using Freemarker to generate the HTML from a template and then feeding the result to FlyingSaucer with great success. This is a pretty neat library.

what worked for me is putting it as a embedded image. So converting image to base64 first and then embed it:
byte[] image = ...
ITextRenderer renderer = new ITextRenderer();
renderer.setDocumentFromString("<html>\n" +
" <body>\n" +
" <h1>Image</h1>\n" +
" <div><img src=\"data:image/png;base64," + Base64.getEncoder().encodeToString(image) + "\"></img></div>\n" +
" </body>\n" +
"</html>");
renderer.layout();
renderer.createPDF(response.getOutputStream());

Thanks Alex for detailed solution. I'm using this solution and found there is another line to be added to make it work.
public ReplacedElement createReplacedElement(LayoutContext layoutContext, BlockBox blockBox, UserAgentCallback userAgentCallback, int cssWidth, int cssHeight) {
Element element = blockBox.getElement();
....
....
final Image image = Image.getInstance(bytes);
final int factor = ((ITextUserAgent)userAgentCallback).getSharedContext().getDotsPerPixel(); //Need to add this line
image.scaleAbsolute(image.getPlainWidth() * factor, image.getPlainHeight() * factor) //Need to add this line
final FSImage fsImage = new ITextFSImage(image);
....
....
We need to read the DPP from SharedContext and scale the image to display render the image on PDF.
Another suggestion:
We can directly extend ITextReplacedElement instead of implementing ReplacedElementFactory. In that case we can set the ReplacedElementFactory in the SharedContext as follows:
renderer.getSharedContext().setReplacedElementFactory(new MediaReplacedElementFactory(renderer.getOutputDevice());

JSP Custom Taglib: Nested Evaluation

Say I have my custom taglib:
<%# taglib uri="http://foo.bar/mytaglib" prefix="mytaglib"%>
<%# taglib uri="http://java.sun.com/jstl/core" prefix="c"%>
<mytaglib:doSomething>
Test
</mytaglib:doSomething>
Inside the taglib class I need to process a template and tell the JSP to re-evaluate its output, so for example if I have this:
public class MyTaglib extends SimpleTagSupport {
#Override public void doTag() throws JspException, IOException {
getJspContext().getOut().println("<c:out value=\"My enclosed tag\"/>");
getJspBody().invoke(null);
}
}
The output I have is:
<c:out value="My enclosed tag"/>
Test
When I actually need to output this:
My enclosed tag
Test
Is this feasible? How?
Thanks.

Tiago, I do not know how to solve your exact problem but you can interpret the JSP code from a file. Just create a RequestDispatcher and include the JSP:
public int doStartTag() throws JspException {
ServletRequest request = pageContext.getRequest();
ServletResponse response = pageContext.getResponse();
RequestDispatcher disp = request.getRequestDispatcher("/test.jsp");
try {
disp.include(request, response);
} catch (ServletException e) {
throw new JspException(e);
} catch (IOException e) {
throw new JspException(e);
}
return super.doStartTag();
}
I tested this code in a Liferay portlet, but I believe it should work in other contexts anyway. If it don't, I would like to know :)
HTH

what you really need to have is this:
<mytaglib:doSomething>
<c:out value="My enclosed tag"/>
Test
</mytaglib:doSomething>
and change your doTag to something like this
#Override public void doTag() throws JspException, IOException {
try {
BodyContent bc = getBodyContent();
String body = bc.getString();
// do something to the body here.
JspWriter out = bc.getEnclosingWriter();
if(body != null) {
out.print(buff.toString());
}
} catch(IOException ioe) {
throw new JspException("Error: "+ioe.getMessage());
}
}
make sure the jsp body content is set to jsp in the tld:
<bodycontent>JSP</bodycontent>

Why do you write a JSTL tag inside your doTag method?
The println is directly going into the compiled JSP (read: servlet) When this gets rendered in the browser it will be printed as it is since teh browser doesn't understand JSTL tags.
public class MyTaglib extends SimpleTagSupport {
#Override public void doTag() throws JspException, IOException {
getJspContext().getOut().println("My enclosed tag");
getJspBody().invoke(null);
}
}
You can optionally add HTML tags to the string.