shawn 01/10/24 21:31:36
Modified: jsptl/conf jr.tld jx.tld
jsptl/src/org/apache/taglibs/jsptl/tag/common
NullAttributeException.java
Added: jsptl/examples/web/import Absolute.jsp ContextRelative.jsp
ExposeString.jsp ExposeStringRelative.jsp
LocalSample.jsp Relative.jsp
jsptl/src/org/apache/taglibs/jsptl/tag/common
ImportSupport.java
jsptl/src/org/apache/taglibs/jsptl/tag/jr ImportTag.java
jsptl/src/org/apache/taglibs/jsptl/tag/jx
ExpressionUtil.java ImportTag.java
Log:
Initial version of <import> tag for 'jr' and 'jx', including TLD modifications,
and several examples. Some other related changes and minor typo fixes too.
Not yet thoroughly tested.
Revision Changes Path
1.2 +35 -0 jakarta-taglibs/jsptl/conf/jr.tld
Index: jr.tld
===================================================================
RCS file: /home/cvs/jakarta-taglibs/jsptl/conf/jr.tld,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- jr.tld 2001/07/08 16:27:34 1.1
+++ jr.tld 2001/10/25 04:31:35 1.2
@@ -76,6 +76,41 @@
</tag>
<tag>
+ <name>import</name>
+ <tag-class>org.apache.taglibs.jsptl.tag.jr.ImportTag</tag-class>
+ <body-content>JSP</body-content>
+ <description>
+ Retrieves an absolute or relative URL and exposes its contents
+ to either the page, a String in 'var', or a Reader in 'varReader'.
+ </description>
+ <attribute>
+ <name>url</name>
+ <required>true</required>
+ <rtexprvalue>true</rtexprvalue>
+ </attribute>
+ <attribute>
+ <name>var</name>
+ <required>false</required>
+ <rtexprvalue>false</rtexprvalue>
+ </attribute>
+ <attribute>
+ <name>varReader</name>
+ <required>false</required>
+ <rtexprvalue>false</rtexprvalue>
+ </attribute>
+ <attribute>
+ <name>context</name>
+ <required>false</required>
+ <rtexprvalue>true</rtexprvalue>
+ </attribute>
+ <attribute>
+ <name>charEncoding</name>
+ <required>false</required>
+ <rtexprvalue>true</rtexprvalue>
+ </attribute>
+ </tag>
+
+ <tag>
<name>forEach</name>
<tag-class>org.apache.taglibs.jsptl.tag.jr.ForEachTag</tag-class>
<tei-class>org.apache.taglibs.jsptl.tei.ForEachTEI</tei-class>
1.2 +35 -0 jakarta-taglibs/jsptl/conf/jx.tld
Index: jx.tld
===================================================================
RCS file: /home/cvs/jakarta-taglibs/jsptl/conf/jx.tld,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- jx.tld 2001/07/08 16:27:34 1.1
+++ jx.tld 2001/10/25 04:31:35 1.2
@@ -145,6 +145,41 @@
</tag>
<tag>
+ <name>import</name>
+ <tag-class>org.apache.taglibs.jsptl.tag.jx.ImportTag</tag-class>
+ <body-content>JSP</body-content>
+ <description>
+ Retrieves an absolute or relative URL and exposes its contents
+ to either the page, a String in 'var', or a Reader in 'varReader'.
+ </description>
+ <attribute>
+ <name>url</name>
+ <required>true</required>
+ <rtexprvalue>false</rtexprvalue>
+ </attribute>
+ <attribute>
+ <name>var</name>
+ <required>false</required>
+ <rtexprvalue>false</rtexprvalue>
+ </attribute>
+ <attribute>
+ <name>varReader</name>
+ <required>false</required>
+ <rtexprvalue>false</rtexprvalue>
+ </attribute>
+ <attribute>
+ <name>context</name>
+ <required>false</required>
+ <rtexprvalue>false</rtexprvalue>
+ </attribute>
+ <attribute>
+ <name>charEncoding</name>
+ <required>false</required>
+ <rtexprvalue>false</rtexprvalue>
+ </attribute>
+ </tag>
+
+ <tag>
<name>forEach</name>
<tag-class>org.apache.taglibs.jsptl.tag.jx.ForEachTag</tag-class>
<tei-class>org.apache.taglibs.jsptl.tei.ForEachTEI</tei-class>
1.1 jakarta-taglibs/jsptl/examples/web/import/Absolute.jsp
Index: Absolute.jsp
===================================================================
<%@ taglib prefix="jx" uri="http://java.sun.com/jsptl/ea/jx"; %>
<html>
<head>
<title>JSPTL: I/O Support -- Absolute URL Example</title>
</head>
<body bgcolor="#FFFFFF">
<h3>Absolute URL</h3>
<h4>CNN's RSS XML feed:</h4>
<blockquote>
<pre>
<jx:import url="http://www.cnn.com/cnn.rss"/>
</pre>
</blockquote>
</body>
</html>
1.1 jakarta-taglibs/jsptl/examples/web/import/ContextRelative.jsp
Index: ContextRelative.jsp
===================================================================
<%@ taglib prefix="jx" uri="http://java.sun.com/jsptl/ea/jx"; %>
<html>
<head>
<title>JSPTL: I/O Support -- Context-relative URL example</title>
</head>
<body bgcolor="#FFFFFF">
Assuming you have the "examples" webapp installed, here's a file from it...
<blockquote>
<pre>
<jx:import url="/jsp/simpletag/foo.jsp" context="/examples"/>
</pre>
</blockquote>
</body>
</html>
1.1 jakarta-taglibs/jsptl/examples/web/import/ExposeString.jsp
Index: ExposeString.jsp
===================================================================
<%@ taglib prefix="jx" uri="http://java.sun.com/jsptl/ea/jx"; %>
<html>
<head>
<title>JSPTL: I/O Support -- String exposure</title>
</head>
<body bgcolor="#FFFFFF">
<h3>String exposure</h3>
<jx:import var="cnn" url="http://www.cnn.com/cnn.rss"/>
<h4>CNN's RSS XML feed:</h4>
<blockquote>
<pre>
<jx:expr value="$cnn"/>
</pre>
</blockquote>
</body>
</html>
1.1
jakarta-taglibs/jsptl/examples/web/import/ExposeStringRelative.jsp
Index: ExposeStringRelative.jsp
===================================================================
<%@ taglib prefix="jx" uri="http://java.sun.com/jsptl/ea/jx"; %>
<html>
<head>
<title>JSPTL: I/O Support -- String exposure for relative URL</title>
</head>
<body bgcolor="#FFFFFF">
<h3>String exposure for relative URL</h3>
<jx:import var="cnn" url="LocalSample.jsp"/>
<jx:expr value="$cnn"/>
</body>
</html>
1.1 jakarta-taglibs/jsptl/examples/web/import/LocalSample.jsp
Index: LocalSample.jsp
===================================================================
<%@ taglib prefix="jx" uri="http://java.sun.com/jsptl/ea/jx"; %>
<html>
<head>
<title>JSPTL: I/O Support -- Simple static example to be included
in other pages</title>
</head>
<body bgcolor="#FFFFFF">
<h3>Local example target page</h3>
<h4>• This output comes from LocalSample.jsp • </h4>
</body>
</html>
1.1 jakarta-taglibs/jsptl/examples/web/import/Relative.jsp
Index: Relative.jsp
===================================================================
<%@ taglib prefix="jx" uri="http://java.sun.com/jsptl/ea/jx"; %>
<html>
<head>
<title>JSPTL: I/O Support -- Relative URL Example</title>
</head>
<body bgcolor="#FFFFFF">
<h3>Relative URL</h3>
<h4>Import from current directory:</h4>
<blockquote>
<pre>
<jx:import url="LocalSample.jsp"/>
</pre>
</blockquote>
</body>
</html>
1.2 +1 -1
jakarta-taglibs/jsptl/src/org/apache/taglibs/jsptl/tag/common/NullAttributeException.java
Index: NullAttributeException.java
===================================================================
RCS file:
/home/cvs/jakarta-taglibs/jsptl/src/org/apache/taglibs/jsptl/tag/common/NullAttributeException.java,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- NullAttributeException.java 2001/07/08 16:27:12 1.1
+++ NullAttributeException.java 2001/10/25 04:31:35 1.2
@@ -68,7 +68,7 @@
public class NullAttributeException extends JspTagException {
/**
- * Constructs a ExpressionException with appropriate information.
+ * Constructs a NullAttributeException with appropriate information.
*
* @param tag The name of the tag in which the error occurred.
* @param att The attribute value for which the error occurred.
1.1
jakarta-taglibs/jsptl/src/org/apache/taglibs/jsptl/tag/common/ImportSupport.java
Index: ImportSupport.java
===================================================================
/*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact [EMAIL PROTECTED]
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.taglibs.jsptl.tag.common;
import java.io.*;
import java.net.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;
/**
* <p>Support for tag handlers for <import>, the general-purpose
* text-importing mechanism for JSPTL 1.0. The rtexprvalue and expression-
* evaluating libraries each have handlers that extend this class.</p>
*
* @author Shawn Bayern
*/
public abstract class ImportSupport extends BodyTagSupport
implements TryCatchFinally {
//*********************************************************************
// Public constants
/** <p>Valid characters in a scheme.</p>
* <p>RFC 1738 says the following:</p>
* <blockquote>
* Scheme names consist of a sequence of characters. The lower
* case letters "a"--"z", digits, and the characters plus ("+"),
* period ("."), and hyphen ("-") are allowed. For resiliency,
* programs interpreting URLs should treat upper case letters as
* equivalent to lower case in scheme names (e.g., allow "HTTP" as
* well as "http").
* </blockquote>
* <p>We treat as absolute any URL that begins with such a scheme name,
* followed by a colon.</p>
*/
public static final String VALID_SCHEME_CHARS =
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789+.-";
/** Default character encoding for response. */
public static final String DEFAULT_ENCODING = "ISO-8859-1";
//*********************************************************************
// Protected state
protected String url; // 'url' attribute
protected String var; // 'var' attribute
protected String varReader; // 'varReader' attribute
protected String context; // 'context' attribute
protected String charEncoding; // 'charEncoding' attrib.
//*********************************************************************
// Private state (implementation details)
Reader r; // exposed reader, if relevant
Object oldVarReader; // overwritten attribute
boolean isAbsoluteUrl; // is our URL absolute?
//*********************************************************************
// Constructor and initialization
public ImportSupport() {
super();
init();
}
private void init() {
url = var = varReader = context = charEncoding = null;
}
//*********************************************************************
// Tag logic
// determines what kind of import and variable exposure to perform
public int doStartTag() throws JspException {
// Sanity check
if (context != null
&& (!context.startsWith("/") || !url.startsWith("/"))) {
throw new JspException(
"In <import>, when 'context' attribute is specified, "
+ "values of both 'context' and 'url' must start with '/'.");
}
// Record whether our URL is absolute or relative
isAbsoluteUrl = isAbsoluteUrl();
try {
// If we need to expose a Reader, we've got to do it right away
if (varReader != null) {
r = acquireReader();
Object oldVarReader = pageContext.getAttribute(varReader);
pageContext.setAttribute(varReader, r);
}
} catch (IOException ex) {
throw new JspException(ex.getMessage());
} catch (ServletException ex) {
throw new JspException(ex.getMessage());
}
return EVAL_BODY_INCLUDE;
}
// manages connections as necessary (creating or destroying)
public int doEndTag() throws JspException {
try {
// If we didn't expose a Reader earlier...
if (varReader == null) {
// ... store it in 'var', if available ...
if (var != null)
pageContext.setAttribute(var, acquireString());
// ... or simply output it, if we have nowhere to expose it
else
pageContext.getOut().print(acquireString());
}
return EVAL_PAGE;
} catch (IOException ex) {
throw new JspException(ex.getMessage());
} catch (ServletException ex) {
throw new JspException(ex.getMessage());
}
}
// simply rethrows its exception
public void doCatch(Throwable t) throws Throwable {
throw t;
}
// cleans up if appropriate
public void doFinally() {
try {
// If we exposed a Reader in doStartTag(), close it.
if (varReader != null) {
r.close();
pageContext.setAttribute(varReader, oldVarReader);
}
} catch (IOException ex) {
// ignore it; close() failed, but there's nothing more we can do
}
}
// Releases any resources we may have (or inherit)
public void release() {
init();
super.release();
}
//*********************************************************************
// Tag attributes known at translation time
public void setVar(String var) {
this.var = var;
}
public void setVarReader(String varReader) {
this.varReader = varReader;
}
//*********************************************************************
// Collaboration with subtags
/**
* Adds a parameter to this tag's URL. The intent is that the
* <param> subtag will call this to register URL parameters.
* Assumes that 'name' and 'value' are appropriately encoded and do
* not contain any meaningful metacharacters; in order words, escaping
* is the responsibility of the caller.
*/
public void addParameter(String name, String value) {
// append a '?' or '&' as appropriate, followed by name=value
boolean firstParameter = url.indexOf('?') == -1;
if (firstParameter)
url += "?" + name + "=" + value;
else
url += "&" + name + "=" + value;
}
//*********************************************************************
// Actual URL importation logic
/*
* Overall strategy: we have two entry points, acquireString() and
* acquireReader(). The latter passes data through unbuffered if
* possible (but note that it is not always possible -- specifically
* for cases where we must use the RequestDispatcher. The remaining
* methods handle the common logic of loading either a URL or a local
* resource.
*
* We consider the 'natural' form of absolute URLs to be Readers and
* relative URLs to be Strings. Thus, to avoid doing extra work,
* acquireString() and acquireReader() delegate to one another as
* appropriate. (Perhaps I could have spelled things out more clearly,
* but I thought this implementation was instructive, not to mention
* somewhat cute...)
*/
private String acquireString() throws IOException, ServletException {
if (isAbsoluteUrl) {
// for absolute URLs, delegate to our peer
BufferedReader r = new BufferedReader(acquireReader());
StringBuffer sb = new StringBuffer();
int i;
// under JIT, testing seems to show this simple loop is as fast
// as any of the alternatives
while ((i = r.read()) != -1)
sb.append((char)i);
return sb.toString();
} else {
// handle relative URLs ourselves
// retrieve an appropriate ServletContext
ServletContext c = null;
String targetUrl = null;
if (context != null) {
c = pageContext.getServletContext().getContext(context);
// accept the URL wholesale; we know it starts with '/'
targetUrl = url;
} else {
c = pageContext.getServletContext();
// normalize the URL if we have an HttpServletRequest
if (pageContext.getRequest() instanceof HttpServletRequest
&& !url.startsWith("/")) {
String sp = ((HttpServletRequest)
pageContext.getRequest()).getServletPath();
targetUrl = sp.substring(0, sp.lastIndexOf('/'))
+ '/' + url;
}
}
// from this context, get a dispatcher
RequestDispatcher rd = c.getRequestDispatcher(targetUrl);
// include the resource, using our custom wrapper
ImportResponseWrapper irw =
new ImportResponseWrapper(
(HttpServletResponse) pageContext.getResponse());
rd.include(pageContext.getRequest(), irw);
// recover the response String from our wrapper
return irw.toString();
}
}
private Reader acquireReader() throws IOException, ServletException {
if (!isAbsoluteUrl) {
// for relative URLs, delegate to our peer
return new StringReader(acquireString());
} else {
// handle absolute URLs ourselves, using java.net.URL
URL u = new URL(url);
URLConnection uc = u.openConnection();
InputStream i = uc.getInputStream();
// okay, we've got a stream; encode it appropriately
Reader r = null;
if (charEncoding != null)
r = new InputStreamReader(i, charEncoding);
else {
String responseAdvisoryEncoding = uc.getContentEncoding();
if (responseAdvisoryEncoding != null)
r = new InputStreamReader(i, responseAdvisoryEncoding);
else
r = new InputStreamReader(i, DEFAULT_ENCODING);
}
return r;
}
}
/** Wraps responses to allow us to retrieve results as Strings. */
private static class ImportResponseWrapper
extends HttpServletResponseWrapper {
//************************************************************
// Data
/** The Writer we convey. */
private StringWriter s = new StringWriter();
/** A ServletOutputStream we convey, tied to this Writer. */
private ServletOutputStream sos = new ServletOutputStream() {
public void write(int b) throws IOException {
s.write(b);
}
};
//************************************************************
// Constructor and methods
/** Constructs a new ImportResponseWrapper. */
public ImportResponseWrapper(HttpServletResponse response) {
super(response);
}
/** Returns a Writer designed to buffer the output. */
public PrintWriter getWriter() {
return new PrintWriter(s);
}
/** Returns a ServletOutputStream designed to buffer the output. */
public ServletOutputStream getOutputStream() {
return sos;
}
/** Retrieves the buffered output. */
public String toString() {
return s.toString();
}
}
/** Returns <tt>true</tt> if our current URL is absolute,
* <tt>false</tt> otherwise.
*/
private boolean isAbsoluteUrl() {
// do a fast, simple check first
int colonPos;
if ((colonPos = url.indexOf(":")) == -1)
return false;
// if we DO have a colon, make sure that every character
// leading up to it is a valid scheme character
for (int i = 0; i < colonPos; i++)
if (VALID_SCHEME_CHARS.indexOf(url.charAt(i)) == -1)
return false;
// otherwise, we've got ourselves an absolute url
return true;
}
}
1.1
jakarta-taglibs/jsptl/src/org/apache/taglibs/jsptl/tag/jr/ImportTag.java
Index: ImportTag.java
===================================================================
/*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact [EMAIL PROTECTED]
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.taglibs.jsptl.tag.jr;
import java.util.*;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;
import org.apache.taglibs.jsptl.tag.common.*;
/**
* <p>A handler for <import> that supports rtexprvalue-based
* attributes.</p>
*
* @author Shawn Bayern
*/
public class ImportTag extends ImportSupport {
//*********************************************************************
// Accessor methods
// for tag attribute
public void setUrl(String url) throws JspTagException {
this.url = url;
}
// for tag attribute
public void setContext(String context) throws JspTagException {
this.url = url;
}
// for tag attribute
public void setCharEncoding(String charEncoding) throws JspTagException {
this.url = url;
}
}
1.1
jakarta-taglibs/jsptl/src/org/apache/taglibs/jsptl/tag/jx/ExpressionUtil.java
Index: ExpressionUtil.java
===================================================================
/*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact [EMAIL PROTECTED]
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.taglibs.jsptl.tag.jx;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;
import javax.servlet.jsptl.ConditionalTagSupport;
import org.apache.taglibs.jsptl.tag.common.*;
import org.apache.taglibs.jsptl.lang.support.ExpressionEvaluatorManager;
/**
* <p>Contains some static utilities to facilitate common forms of
* expression evaluation.</p>
*
* @author Shawn Bayern
*/
public class ExpressionUtil {
/** Evaluates an expression if present, but does not allow the expression
* to evaluate to 'null', throwing a NullAttributeException if it
* does. The function <b>can</b> return null, however, if the
* expression itself is null.
*/
public static Object evalNotNull(String tagName,
String attributeName,
String expression,
Class expectedType,
Tag tag,
PageContext pageContext)
throws JspException {
if (expression != null) {
Object r = ExpressionEvaluatorManager.evaluate(
attributeName, expression, expectedType, tag, pageContext);
if (r == null)
throw new NullAttributeException(tagName, attributeName);
return r;
} else
return null;
}
}
1.1
jakarta-taglibs/jsptl/src/org/apache/taglibs/jsptl/tag/jx/ImportTag.java
Index: ImportTag.java
===================================================================
/*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact [EMAIL PROTECTED]
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.taglibs.jsptl.tag.jx;
import java.util.*;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;
import org.apache.taglibs.jsptl.tag.common.*;
/**
* <p>A handler for <import> that accepts attributes as Strings
* and evaluates them as expressions at runtime.</p>
*
* @author Shawn Bayern
*/
public class ImportTag extends ImportSupport {
//*********************************************************************
// 'Private' state (implementation details)
private String context_; // stores EL-based property
private String charEncoding_; // stores EL-based property
private String url_; // stores EL-based property
//*********************************************************************
// Constructor
/**
* Constructs a new ImportTag. As with TagSupport, subclasses
* should not provide other constructors and are expected to call
* the superclass constructor
*/
public ImportTag() {
super();
init();
}
//*********************************************************************
// Tag logic
// evaluates expression and chains to parent
public int doStartTag() throws JspException {
// evaluate any expressions we were passed, once per invocation
evaluateExpressions();
// chain to the parent implementation
return super.doStartTag();
}
// Releases any resources we may have (or inherit)
public void release() {
super.release();
init();
}
//*********************************************************************
// Accessor methods
// for EL-based attribute
public void setUrl(String url_) {
this.url_ = url_;
}
public void setContext(String context_) {
this.context_ = context_;
}
public void setCharEncoding(String charEncoding_) {
this.charEncoding_ = charEncoding_;
}
//*********************************************************************
// Private (utility) methods
// (re)initializes state (during release() or construction)
private void init() {
// null implies "no expression"
url_ = context_ = charEncoding_ = null;
}
/* Evaluates expressions as necessary */
private void evaluateExpressions() throws JspException {
/*
* Note: we don't check for type mismatches here; we assume
* the expression evaluator will return the expected type
* (by virtue of knowledge we give it about what that type is).
* A ClassCastException here is truly unexpected, so we let it
* propagate up.
*/
url = (String) ExpressionUtil.evalNotNull(
"import", "url", url_, String.class, this, pageContext);
context = (String) ExpressionUtil.evalNotNull(
"import", "context", context_, String.class, this, pageContext);
charEncoding = (String) ExpressionUtil.evalNotNull(
"import", "charEncoding", charEncoding_, String.class, this,
pageContext);
}
}
