Skip to content

WW-5602 Fix StreamResult contentCharSet handling and refactor for extensibility #1510

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
lukaszlenart merged 3 commits into from
Jan 14, 2026
+360 −80
Merged

WW-5602 Fix StreamResult contentCharSet handling and refactor for extensibility #1510

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
50a71c4
fix(core): WW-5602 fix StreamResult contentCharSet handling
lukaszlenart Jan 4, 2026
e14c4f7
refactor(core): extract methods and modernize StreamResult
lukaszlenart Jan 4, 2026
10afac4
fix(core): resolve setCharacterEncoding ambiguity for Jakarta EE 11
lukaszlenart Jan 4, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
211 changes: 131 additions & 80 deletions core/src/main/java/org/apache/struts2/result/StreamResult.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -18,23 +18,23 @@
*/
package org.apache.struts2.result;

import org.apache.struts2.ActionInvocation;
import org.apache.struts2.inject.Inject;
import org.apache.struts2.security.NotExcludedAcceptedPatternsChecker;
import jakarta.servlet.http.HttpServletResponse;
import org.apache.commons.lang3.StringUtils;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.struts2.ActionInvocation;
import org.apache.struts2.inject.Inject;
import org.apache.struts2.security.NotExcludedAcceptedPatternsChecker;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Serial;

/**
* A custom Result type for sending raw data (via an InputStream) directly to the
* HttpServletResponse. Very useful for allowing users to download content.
*
* <b>This result type takes the following parameters:</b>
*
* <ul>
* <li><b>contentType</b> - the stream mime-type as sent to the web browser
* (default = <code>text/plain</code>).</li>
Expand Down Expand Up @@ -80,13 +80,18 @@ public class StreamResult extends StrutsResultSupport {

public static final String DEFAULT_PARAM = "inputName";

protected String contentType = "text/plain";
public static final int DEFAULT_BUFFER_SIZE = 1024;
public static final String DEFAULT_CONTENT_TYPE = "text/plain";
public static final String DEFAULT_CONTENT_DISPOSITION = "inline";
public static final String DEFAULT_INPUT_NAME = "inputStream";

protected String contentType = DEFAULT_CONTENT_TYPE;
protected String contentLength;
protected String contentDisposition = "inline";
protected String contentDisposition = DEFAULT_CONTENT_DISPOSITION;
protected String contentCharSet;
protected String inputName = "inputStream";
protected String inputName = DEFAULT_INPUT_NAME;
protected InputStream inputStream;
protected int bufferSize = 1024;
protected int bufferSize = DEFAULT_BUFFER_SIZE;
protected boolean allowCaching = true;

private NotExcludedAcceptedPatternsChecker notExcludedAcceptedPatterns;
Expand Down Expand Up @@ -126,7 +131,7 @@ public void setAllowCaching(boolean allowCaching) {
* @return Returns the bufferSize.
*/
public int getBufferSize() {
return (bufferSize);
return bufferSize;
}

/**
Expand All @@ -140,7 +145,7 @@ public void setBufferSize(int bufferSize) {
* @return Returns the contentType.
*/
public String getContentType() {
return (contentType);
return contentType;
}

/**
Expand Down Expand Up @@ -196,7 +201,7 @@ public void setContentCharSet(String contentCharSet) {
* @return Returns the inputName.
*/
public String getInputName() {
return (inputName);
return inputName;
}

/**
Expand All @@ -209,87 +214,133 @@ public void setInputName(String inputName) {
/**
* @see StrutsResultSupport#doExecute(java.lang.String, ActionInvocation)
*/
@Override
protected void doExecute(String finalLocation, ActionInvocation invocation) throws Exception {
LOG.debug("Find the Response in context");

OutputStream oOutput = null;

try {
String parsedInputName = conditionalParse(inputName, invocation);
boolean evaluated = parsedInputName != null && !parsedInputName.equals(inputName);
boolean reevaluate = !evaluated || isAcceptableExpression(parsedInputName);
if (inputStream == null && reevaluate) {
LOG.debug("Find the inputstream from the invocation variable stack");
inputStream = (InputStream) invocation.getStack().findValue(parsedInputName);
}

if (inputStream == null) {
String msg = ("Can not find a java.io.InputStream with the name [" + parsedInputName + "] in the invocation stack. " +
"Check the <param name=\"inputName\"> tag specified for this action is correct, not excluded and accepted.");
LOG.error(msg);
throw new IllegalArgumentException(msg);
}
resolveInputStream(invocation);
HttpServletResponse response = invocation.getInvocationContext().getServletResponse();

applyResponseHeaders(response, invocation);
applyContentLength(response, invocation);

LOG.debug("Streaming result [{}] of type [{}], length [{}], content-disposition [{}] with charset [{}]",
inputName, contentType, contentLength, contentDisposition, contentCharSet);

HttpServletResponse oResponse = invocation.getInvocationContext().getServletResponse();
try (InputStream in = inputStream; OutputStream out = response.getOutputStream()) {
streamContent(in, out);
}
}

LOG.debug("Set the content type: {};charset{}", contentType, contentCharSet);
if (contentCharSet != null && !contentCharSet.isEmpty()) {
oResponse.setContentType(conditionalParse(contentType, invocation) + ";charset=" + conditionalParse(contentCharSet, invocation));
} else {
oResponse.setContentType(conditionalParse(contentType, invocation));
}
/**
* Resolves the input stream from the action invocation.
* <p>
* This method can be overridden by subclasses to provide custom stream sources
* (e.g., from database, cloud storage, or generated content).
* </p>
*
* @param invocation the action invocation
* @throws IllegalArgumentException if the input stream cannot be found
*/
protected void resolveInputStream(ActionInvocation invocation) {
String parsedInputName = conditionalParse(inputName, invocation);
boolean evaluated = parsedInputName != null && !parsedInputName.equals(inputName);
boolean reevaluate = !evaluated || isAcceptableExpression(parsedInputName);

if (inputStream == null && reevaluate) {
LOG.debug("Find the inputstream from the invocation variable stack");
inputStream = (InputStream) invocation.getStack().findValue(parsedInputName);
}

LOG.debug("Set the content length: {}", contentLength);
if (contentLength != null) {
String translatedContentLength = conditionalParse(contentLength, invocation);
int contentLengthAsInt;
try {
contentLengthAsInt = Integer.parseInt(translatedContentLength);
if (contentLengthAsInt >= 0) {
oResponse.setContentLength(contentLengthAsInt);
}
} catch (NumberFormatException e) {
LOG.warn("failed to recognize {} as a number, contentLength header will not be set",
translatedContentLength, e);
}
}
if (inputStream == null) {
String msg = ("Can not find a java.io.InputStream with the name [" + parsedInputName + "] in the invocation stack. " +
"Check the <param name=\"inputName\"> tag specified for this action is correct, not excluded and accepted.");
LOG.error(msg);
throw new IllegalArgumentException(msg);
}
}

LOG.debug("Set the content-disposition: {}", contentDisposition);
if (contentDisposition != null) {
oResponse.addHeader("Content-Disposition", conditionalParse(contentDisposition, invocation));
}
/**
* Applies all response headers including content-type, charset, content-length,
* content-disposition, and cache control headers.
* <p>
* This method can be overridden by subclasses to add custom headers
* (e.g., ETag, X-Custom-Header) or modify caching behavior.
* </p>
*
* @param response the HTTP response
* @param invocation the action invocation
*/
protected void applyResponseHeaders(HttpServletResponse response, ActionInvocation invocation) {
String parsedContentType = conditionalParse(contentType, invocation);
String parsedContentCharSet = conditionalParse(contentCharSet, invocation);

response.setContentType(parsedContentType);
if (StringUtils.isEmpty(parsedContentCharSet)) {
LOG.debug("Set content type to: {} and reset character encoding to null", parsedContentType);
response.setCharacterEncoding((String) null);
} else {
LOG.debug("Set content type: {};charset={}", parsedContentType, parsedContentCharSet);
response.setCharacterEncoding(parsedContentCharSet);
}

LOG.debug("Set the cache control headers if necessary: {}", allowCaching);
if (!allowCaching) {
oResponse.addHeader("Pragma", "no-cache");
oResponse.addHeader("Cache-Control", "no-cache");
}
LOG.debug("Set the content-disposition: {}", contentDisposition);
if (contentDisposition != null) {
response.addHeader("Content-Disposition", conditionalParse(contentDisposition, invocation));
}

oOutput = oResponse.getOutputStream();
LOG.debug("Set the cache control headers if necessary: {}", allowCaching);
if (!allowCaching) {
response.addHeader("Pragma", "no-cache");
response.addHeader("Cache-Control", "no-cache");
}
}

LOG.debug("Streaming result [{}] type=[{}] length=[{}] content-disposition=[{}] charset=[{}]",
inputName, contentType, contentLength, contentDisposition, contentCharSet);
/**
* Applies the content-length header to the response.
* <p>
* This method can be overridden by subclasses for custom length calculation
* or to skip setting the header for chunked transfer encoding.
* </p>
*
* @param response the HTTP response
* @param invocation the action invocation
*/
protected void applyContentLength(HttpServletResponse response, ActionInvocation invocation) {
if (contentLength == null) {
return;
}

LOG.debug("Streaming to output buffer +++ START +++");
byte[] oBuff = new byte[bufferSize];
int iSize;
while (-1 != (iSize = inputStream.read(oBuff))) {
LOG.debug("Sending stream ... {}", iSize);
oOutput.write(oBuff, 0, iSize);
LOG.debug("Set the content length: {}", contentLength);
String translatedContentLength = conditionalParse(contentLength, invocation);
try {
int length = Integer.parseInt(translatedContentLength);
if (length >= 0) {
response.setContentLength(length);
}
LOG.debug("Streaming to output buffer +++ END +++");
} catch (NumberFormatException e) {
LOG.warn("Failed to parse contentLength [{}], header will not be set", translatedContentLength, e);
}
}

// Flush
oOutput.flush();
} finally {
if (inputStream != null) {
inputStream.close();
}
if (oOutput != null) {
oOutput.close();
}
/**
* Streams content from the input stream to the output stream.
* <p>
* This method can be overridden by subclasses to implement custom streaming behavior
* such as progress tracking, compression, or encryption.
* </p>
*
* @param input the input stream to read from
* @param output the output stream to write to
* @throws IOException if an I/O error occurs
*/
protected void streamContent(InputStream input, OutputStream output) throws IOException {
LOG.debug("Streaming to output buffer +++ START +++");
byte[] buffer = new byte[bufferSize];
int bytesRead;
while ((bytesRead = input.read(buffer)) != -1) {
output.write(buffer, 0, bytesRead);
}
LOG.debug("Streaming to output buffer +++ END +++");
output.flush();
}

/**
Expand Down
19 changes: 19 additions & 0 deletions core/src/test/java/org/apache/struts2/result/StreamResultTest.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -120,6 +120,21 @@ public void testStreamResultWithCharSet2() throws Exception {
assertEquals("inline", response.getHeader("Content-disposition"));
}

public void testStreamResultWithNullCharSetExpression() throws Exception {
result.setParse(true);
result.setInputName("streamForImage");
result.setContentCharSet("${nullCharSetMethod}");

result.doExecute("helloworld", mai);

assertEquals(contentLength, response.getContentLength());
assertEquals("text/plain", result.getContentType());
// When expression evaluates to null, content-type should NOT include charset
assertEquals("text/plain", response.getContentType());
assertEquals("streamForImage", result.getInputName());
assertEquals("inline", response.getHeader("Content-disposition"));
}

public void testAllowCacheDefault() throws Exception {
result.setInputName("streamForImage");

Expand Down Expand Up @@ -310,6 +325,10 @@ public String getStreamForImageAsExpression() {
public String getContentCharSetMethod() {
return "UTF-8";
}

public String getNullCharSetMethod() {
return null;
}
}

}
Loading