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.
Related
I want to modify the HTML body tag when I open a Wicket-Bootstrap Modal. What I'm trying to achieve is <body class="modal-open"> instead of <body>
Using Wicket 8 M8 , I have this code:
owsImportDialog = new MyModalBootstrapDialog("owsImportDialog"
, new CompoundPropertyModel<>(new BopOwsTO())) {
#Override
void importOws(AjaxRequestTarget target, IModel<BopOwsTO> owsModel) {
appendCloseDialogJavaScript(target);
BopOwsTO owsTo = owsModel.getObject();
try {
importOwsCapabilities(owsTo);
owsViewDialog.header(Model.of("OWS anzeigen"))
.setModel(Model.of(owsTo.getServiceId()));
owsViewDialog.appendShowDialogJavaScript(target);
}
catch (OwsCapsImportException e) {
String localizedMessage = e.getLocalizedMessage();
importAlert.setModelObject(localizedMessage);
importAlert.appendShowDialogJavaScript(target);
error(localizedMessage);
}
finally {
target.appendJavaScript("document.getElementsByTagName('body')[0]" +
".setAttribute('class', 'modal-open');");
// target.appendJavaScript("document.body.setAttribute('class', 'modal-open');");
// target.prependJavaScript("document.body.setAttribute('class', 'modal-open');");
// target.appendJavaScript("alert('Hallo');");
// owsViewDialog is a child of owsView WebMarkupContainer
target.add(owsView, feedback);
}
}
#Override
void saveOws(AjaxRequestTarget target, IModel<BopOwsTO> owsModel)
{ }
#Override
void cancel(AjaxRequestTarget target)
{ }
};
If the line target.appendJavaScript("alert('Hallo');"); is active I actually see the alert window.
I also tried this code in the page class:
#Override
public void renderHead(IHeaderResponse response) {
super.renderHead(response);
PackageResourceReference resourceReference = new PackageResourceReference(
getClass(), "../css/BuiOwsPage.css");
CssReferenceHeaderItem cssRef = CssReferenceHeaderItem.forReference(resourceReference);
response.render(cssRef);
response.render(OnLoadHeaderItem
.forScript("document.body.setAttribute('class', 'modal-open');"));
}
But none of my attempts was succesful.
Update
The answer of #martin-g didn't solve the issue.
I'm quite sure that the problem is caused by the sequence of these statements:
{
appendCloseDialogJavaScript(target);
...
try {
owsViewDialog.appendShowDialogJavaScript(target);
....
}
catch { ... }
finally {
target.add(owsView, feedback);
}
}
When this modal is closed because of appendCloseDialogJavaScript() ,
the class modal-open is erased from the class attribute of the <body> .
Then owsViewDialog opens, but modal-open isn't inserted in class, no matter if I append the snippet jQuery(document.body).addClass('modal-open') or not. The missing modal-open means that the page can't be scrolled.
Since Wicket and Bootstrap are used then jQuery is also available. I would recommend you to use jQuery(document.body).addClass('modal-open').
There must be a reason why jQuery has both addClass() and attr()!
I am doing a small project with images using jsp/servlets.In that I generate some image dynamically(actually I'll decrypt two image shares as one).That decrypted image must be displayed directly to browser without saving it as file in filesystem.
Crypting c=new Crypting();
BufferedImage imgKey;
BufferedImage imgEnc;
imgKey = ImageIO.read(new File("E:/Netbeans Projects/banking/web/Key.png"));
imgEnc=ImageIO.read(new File("E:/Netbeans Projects/banking/build/web/upload/E.png"));
BufferedImage imgDec=Crypting.decryptImage(imgKey,imgEnc);
When I store it in filesystem and display it using <img> it does not show the image.When reloaded it shows the image.So it is problem with the backend work of IDE.
Any help pls...
Make a servlet to generate images.
Use html img tag with attribute src, as a path to your genarated resource.
Example in spring boot (QR Codes).
Servlet
public class QRCodeServlet extends HttpServlet {
#Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
String url = req.getParameter("url");
String format = req.getParameter("format");
QRCodeFormat formatParam = StringUtils.isNotEmpty(format) && format.equalsIgnoreCase("PDF") ?
QRCodeFormat.PDF : QRCodeFormat.JPG;
if(formatParam.equals(QRCodeFormat.PDF))
resp.setContentType("application/pdf");
else
resp.setContentType("image/jpeg");
if(StringUtils.isNotBlank(url)) {
ByteArrayOutputStream stream = QRCodeService.getQRCodeFromUrl(url, formatParam);
stream.writeTo(resp.getOutputStream());
}
}
}
Configuration:
#Configuration
public class WebMvcConfig {
#Bean
public ServletRegistrationBean qrCodeServletRegistrationBean(){
ServletRegistrationBean qrCodeBean =
new ServletRegistrationBean(new QRCodeServlet(), "/qrcode");
qrCodeBean.setLoadOnStartup(1);
return qrCodeBean;
}
}
Conroller:
String qrcodeServletPrefix = "http://localhost:8082/qrcode?url="
String encodedUrl = URLEncoder.encode("http://exmaple.com?param1=value1¶m2=value2", "UTF-8");
modelAndView.addObject("qrcodepage", qrcodeServletPrefix + encodedUrl);
modelAndView.setViewName("view");
view.jsp
<%# taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<img src="<c:url value='${qrcodepage}'/>" />
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)
I'm working a dynamic website with jsp.
Now my problem: when I use <%, to write my java, everything works perfectly fine.
<%
out.println("<p>test</p>");
%>
But when i use the <%! like this:
<%!
private void test() {
out.println("<p>test</p>");
}
%>
My output will get displayed in my code editors console and not on my website as expected.
As import I used <%# page import="static java.lang.System.out" %>. Is this the correct import or is the problem somewhere else?
If more information is needed please comment! :)
As you probably know, JSPs are turned into servlets on-the-fly by the Java EE container. In a <% ... %> block, out is a local variable in the generated _jspService (or similar) method in the generated servlet. It's a JspWriter for writing to the output for the page.
In a <%! ... %> block, you're outside that generated _jspService (or similar) method, and so your static import means your out reference is to System.out, which isn't where the page output should be sent.
If you want to define methods in your JSP in <%! ... %> blocks, you'll have to pass out into them:
<%!
private void test(JspWriter out) throws IOException {
out.println("<p>test</p>");
}
%>
About that JSP -> servlet thing, say we have this JSP:
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Example</title>
</head>
<body>
<%
out.println("The current date/time is " + new java.util.Date());
this.test(out, "Hi, Mom!");
%>
<%!
private void test(JspWriter out, String msg) throws java.io.IOException {
out.println(msg);
}
%>
</body>
</html>
Note that it has a <%...%> block and a <%! ... %> block.
The Java EE container turns that into something somewhat like the following. Note where our test method ended up, and where the code in our <%...%> block ended up (along with our raw JSP text/markup):
package org.apache.jsp;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.jsp.*;
public final class test_jsp extends org.apache.jasper.runtime.HttpJspBase
implements org.apache.jasper.runtime.JspSourceDependent {
private void test(JspWriter out, String msg) throws java.io.IOException {
out.println(msg);
}
/* ...lots of setup stuff omitted... */
public void _jspService(HttpServletRequest request, HttpServletResponse response)
throws java.io.IOException, ServletException {
PageContext pageContext = null;
HttpSession session = null;
ServletContext application = null;
ServletConfig config = null;
JspWriter out = null;
Object page = this;
JspWriter _jspx_out = null;
PageContext _jspx_page_context = null;
try {
response.setContentType("text/html");
pageContext = _jspxFactory.getPageContext(this, request, response,
null, true, 8192, true);
_jspx_page_context = pageContext;
application = pageContext.getServletContext();
config = pageContext.getServletConfig();
session = pageContext.getSession();
out = pageContext.getOut();
_jspx_out = out;
out.write("<!doctype html>\n");
out.write("<html>\n");
out.write("<head>\n");
out.write("<meta charset=\"utf-8\">\n");
out.write("<title>Example</title>\n");
out.write("</head>\n");
out.write("<body>\n");
out.println("The current date/time is " + new java.util.Date());
this.test(out, "Hi, Mom!");
out.write("\n");
out.write("</body>\n");
out.write("</html>\n");
} catch (Throwable t) {
if (!(t instanceof SkipPageException)){
out = _jspx_out;
if (out != null && out.getBufferSize() != 0)
try { out.clearBuffer(); } catch (java.io.IOException e) {}
if (_jspx_page_context != null) _jspx_page_context.handlePageException(t);
else log(t.getMessage(), t);
}
} finally {
_jspxFactory.releasePageContext(_jspx_page_context);
}
}
}
I just tried to add a custom taglib to my project, such that the testtaglib.tld file contains:
<taglib>
<tlibversion>1.0</tlibversion>
<jspversion>1.1</jspversion>
<shortname>name</shortname>
<tag>
<name>test</name>
<tagclass>taglib.TestTaglib</tagclass>
<bodycontent>empty</bodycontent>
<attribute>
<name>testCode</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
<type>java.lang.String</type>
</attribute>
</tag>
<taglib>
And then I added taglib class TestTaglib.java
public class TestTaglib extends TagSupport {
private String testCode;
public int doStartTag() throws JspException {
try {
JspWriter out = pageContext.getOut();
//doing some conversion with testCode
out.print(testCode);
return EVAL_PAGE;
} catch(IOException ioe) {
throw new JspException("Error: " + ioe.getMessage());
}
}
}
And then in .jsp file
<name:test testCode="${testCode}"/>
Okay the issue is:TestTaglib.java is recognizing values of testCode as ${testCode} and not the original value. Any suggestion?
Hi all inbuilt tag already handles the expression language. Just change your code as mentioned below and it will work fine.
public class TestTaglib extends TagSupport {
private String testCode;
public int doStartTag() throws JspException {
try {
JspWriter out = pageContext.getOut();
//doing some conversion with testCode
String value = (String) ExpressionUtil.evalNotNull("test", "testCode", testCode, String.class, this, pageContext);
out.print(value);
return EVAL_PAGE;
} catch(IOException ioe) {
throw new JspException("Error: " + ioe.getMessage());
}
}
}
ExpressionUtil is class provided under org.apache.taglibs.standard.tag.el.core package.
Here is short desc of evalNotNull method args
1) tagName : your tag name is test
2) tagAttribute: to eval in your case it is testCode
3) expression : which is el expression ${testCode}
4) Value: Class of expression value whether it is Boolean,String or any Object
5) tagClass: Reference of tag handler class so you can pass this
6) pageContext: which is coming from TagSupport