Response.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.coyote;
import java.io.IOException;
import java.io.StringReader;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.util.Locale;
import java.util.Map;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.function.Supplier;
import javax.servlet.WriteListener;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.util.buf.B2CConverter;
import org.apache.tomcat.util.buf.MessageBytes;
import org.apache.tomcat.util.http.MimeHeaders;
import org.apache.tomcat.util.http.parser.MediaType;
import org.apache.tomcat.util.res.StringManager;
/**
* Response object.
*
* @author James Duncan Davidson [duncan@eng.sun.com]
* @author Jason Hunter [jch@eng.sun.com]
* @author James Todd [gonzo@eng.sun.com]
* @author Harish Prabandham
* @author Hans Bergsten [hans@gefionsoftware.com]
* @author Remy Maucherat
*/
public final class Response {
private static final StringManager sm = StringManager.getManager(Response.class);
private static final Log log = LogFactory.getLog(Response.class);
// ----------------------------------------------------- Class Variables
/**
* Default locale as mandated by the spec.
*/
private static final Locale DEFAULT_LOCALE = Locale.getDefault();
// ----------------------------------------------------- Instance Variables
/**
* Status code.
*/
int status = 200;
/**
* Status message.
*/
String message = null;
/**
* Response headers.
*/
final MimeHeaders headers = new MimeHeaders();
private Supplier<Map<String, String>> trailerFieldsSupplier = null;
/**
* Associated output buffer.
*/
OutputBuffer outputBuffer;
/**
* Notes.
*/
final Object notes[] = new Object[Constants.MAX_NOTES];
/**
* Committed flag.
*/
volatile boolean committed = false;
/**
* Action hook.
*/
volatile ActionHook hook;
/**
* HTTP specific fields.
*/
String contentType = null;
String contentLanguage = null;
Charset charset = null;
// Retain the original name used to set the charset so exactly that name is
// used in the ContentType header. Some (arguably non-specification
// compliant) user agents are very particular
String characterEncoding = null;
long contentLength = -1;
private Locale locale = DEFAULT_LOCALE;
// General information
private long contentWritten = 0;
private long commitTime = -1;
/**
* Holds response writing error exception.
*/
private Exception errorException = null;
/**
* With the introduction of async processing and the possibility of non-container threads calling sendError()
* tracking the current error state and ensuring that the correct error page is called becomes more complicated.
* This state attribute helps by tracking the current error state and informing callers that attempt to change state
* if the change was successful or if another thread got there first.
*
* <pre>
* The state machine is very simple:
*
* 0 - NONE
* 1 - NOT_REPORTED
* 2 - REPORTED
*
*
* -->---->-- >NONE
* | | |
* | | | setError()
* ^ ^ |
* | | \|/
* | |-<-NOT_REPORTED
* | |
* ^ | report()
* | |
* | \|/
* |----<----REPORTED
* </pre>
*/
private final AtomicInteger errorState = new AtomicInteger(0);
Request req;
// ------------------------------------------------------------- Properties
public Request getRequest() {
return req;
}
public void setRequest(Request req) {
this.req = req;
}
public void setOutputBuffer(OutputBuffer outputBuffer) {
this.outputBuffer = outputBuffer;
}
public MimeHeaders getMimeHeaders() {
return headers;
}
protected void setHook(ActionHook hook) {
this.hook = hook;
}
// -------------------- Per-Response "notes" --------------------
public void setNote(int pos, Object value) {
notes[pos] = value;
}
public Object getNote(int pos) {
return notes[pos];
}
// -------------------- Actions --------------------
public void action(ActionCode actionCode, Object param) {
if (hook != null) {
if (param == null) {
hook.action(actionCode, this);
} else {
hook.action(actionCode, param);
}
}
}
// -------------------- State --------------------
public int getStatus() {
return status;
}
/**
* Set the response status.
*
* @param status The status value to set
*/
public void setStatus(int status) {
this.status = status;
}
/**
* Get the status message.
*
* @return The message associated with the current status
*/
public String getMessage() {
return message;
}
/**
* Set the status message.
*
* @param message The status message to set
*/
public void setMessage(String message) {
this.message = message;
}
public boolean isCommitted() {
return committed;
}
public void setCommitted(boolean v) {
if (v && !this.committed) {
this.commitTime = System.currentTimeMillis();
}
this.committed = v;
}
/**
* Return the time the response was committed (based on System.currentTimeMillis).
*
* @return the time the response was committed
*/
public long getCommitTime() {
return commitTime;
}
// -----------------Error State --------------------
/**
* Set the error Exception that occurred during the writing of the response processing.
*
* @param ex The exception that occurred
*/
public void setErrorException(Exception ex) {
if (errorException == null) {
errorException = ex;
}
}
/**
* Get the Exception that occurred during the writing of the response.
*
* @return The exception that occurred
*/
public Exception getErrorException() {
return errorException;
}
public boolean isExceptionPresent() {
return errorException != null;
}
/**
* Set the error flag.
*
* @return <code>false</code> if the error flag was already set
*
* @deprecated This method will be changed to return void in Tomcat 11 onwards
*/
@Deprecated
public boolean setError() {
return errorState.compareAndSet(0, 1);
}
/**
* Error flag accessor.
*
* @return <code>true</code> if the response has encountered an error
*/
public boolean isError() {
return errorState.get() > 0;
}
public boolean isErrorReportRequired() {
return errorState.get() == 1;
}
public boolean setErrorReported() {
return errorState.compareAndSet(1, 2);
}
public void resetError() {
errorState.set(0);
}
// -------------------- Methods --------------------
public void reset() throws IllegalStateException {
if (committed) {
throw new IllegalStateException();
}
recycle();
}
// -------------------- Headers --------------------
/**
* Does the response contain the given header. <br>
* Warning: This method always returns <code>false</code> for Content-Type and Content-Length.
*
* @param name The name of the header of interest
*
* @return {@code true} if the response contains the header.
*/
public boolean containsHeader(String name) {
return headers.getHeader(name) != null;
}
public void setHeader(String name, String value) {
char cc = name.charAt(0);
if (cc == 'C' || cc == 'c') {
if (checkSpecialHeader(name, value)) {
return;
}
}
headers.setValue(name).setString(value);
}
public void addHeader(String name, String value) {
addHeader(name, value, null);
}
public void addHeader(String name, String value, Charset charset) {
char cc = name.charAt(0);
if (cc == 'C' || cc == 'c') {
if (checkSpecialHeader(name, value)) {
return;
}
}
MessageBytes mb = headers.addValue(name);
if (charset != null) {
mb.setCharset(charset);
}
mb.setString(value);
}
public void setTrailerFields(Supplier<Map<String, String>> supplier) {
AtomicBoolean trailerFieldsSupported = new AtomicBoolean(false);
action(ActionCode.IS_TRAILER_FIELDS_SUPPORTED, trailerFieldsSupported);
if (!trailerFieldsSupported.get()) {
throw new IllegalStateException(sm.getString("response.noTrailers.notSupported"));
}
this.trailerFieldsSupplier = supplier;
}
public Supplier<Map<String, String>> getTrailerFields() {
return trailerFieldsSupplier;
}
/**
* Set internal fields for special header names. Called from set/addHeader. Return true if the header is special, no
* need to set the header.
*/
private boolean checkSpecialHeader(String name, String value) {
// XXX Eliminate redundant fields !!!
// ( both header and in special fields )
if (name.equalsIgnoreCase("Content-Type")) {
setContentType(value);
return true;
}
if (name.equalsIgnoreCase("Content-Length")) {
try {
long cL = Long.parseLong(value);
setContentLength(cL);
return true;
} catch (NumberFormatException ex) {
// Do nothing - the spec doesn't have any "throws"
// and the user might know what they're doing
return false;
}
}
return false;
}
/**
* Signal that we're done with the headers, and body will follow. Any implementation needs to notify ContextManager,
* to allow interceptors to fix headers.
*/
public void sendHeaders() {
action(ActionCode.COMMIT, this);
setCommitted(true);
}
// -------------------- I18N --------------------
public Locale getLocale() {
return locale;
}
/**
* Called explicitly by user to set the Content-Language and the default encoding.
*
* @param locale The locale to use for this response
*/
public void setLocale(Locale locale) {
if (locale == null) {
this.locale = null;
this.contentLanguage = null;
return;
}
// Save the locale for use by getLocale()
this.locale = locale;
// Set the contentLanguage for header output
contentLanguage = locale.toLanguageTag();
}
/**
* Return the content language.
*
* @return The language code for the language currently associated with this response
*/
public String getContentLanguage() {
return contentLanguage;
}
/**
* Overrides the character encoding used in the body of the response. This method must be called prior to writing
* output using getWriter().
*
* @param characterEncoding The name of character encoding.
*
* @throws UnsupportedEncodingException If the specified name is not recognised
*/
public void setCharacterEncoding(String characterEncoding) throws UnsupportedEncodingException {
if (isCommitted()) {
return;
}
if (characterEncoding == null) {
this.charset = null;
this.characterEncoding = null;
return;
}
this.characterEncoding = characterEncoding;
this.charset = B2CConverter.getCharset(characterEncoding);
}
public Charset getCharset() {
return charset;
}
/**
* @return The name of the current encoding
*/
public String getCharacterEncoding() {
return characterEncoding;
}
/**
* Sets the content type. This method must preserve any response charset that may already have been set via a call
* to response.setContentType(), response.setLocale(), or response.setCharacterEncoding().
*
* @param type the content type
*/
public void setContentType(String type) {
if (type == null) {
this.contentType = null;
return;
}
MediaType m = null;
try {
m = MediaType.parseMediaType(new StringReader(type));
} catch (IOException e) {
// Ignore - null test below handles this
}
if (m == null) {
// Invalid - Assume no charset and just pass through whatever
// the user provided.
this.contentType = type;
return;
}
this.contentType = m.toStringNoCharset();
String charsetValue = m.getCharset();
if (charsetValue == null) {
// No charset and we know value is valid as parser was successful
// Pass-through user provided value in case user-agent is buggy and
// requires specific format
this.contentType = type;
} else {
// There is a charset so have to rebuild content-type without it
this.contentType = m.toStringNoCharset();
charsetValue = charsetValue.trim();
if (charsetValue.length() > 0) {
try {
charset = B2CConverter.getCharset(charsetValue);
} catch (UnsupportedEncodingException e) {
log.warn(sm.getString("response.encoding.invalid", charsetValue), e);
}
}
}
}
public void setContentTypeNoCharset(String type) {
this.contentType = type;
}
public String getContentType() {
String ret = contentType;
if (ret != null && charset != null) {
ret = ret + ";charset=" + characterEncoding;
}
return ret;
}
public void setContentLength(long contentLength) {
this.contentLength = contentLength;
}
public int getContentLength() {
long length = getContentLengthLong();
if (length < Integer.MAX_VALUE) {
return (int) length;
}
return -1;
}
public long getContentLengthLong() {
return contentLength;
}
/**
* Write a chunk of bytes.
*
* @param chunk The ByteBuffer to write
*
* @throws IOException If an I/O error occurs during the write
*/
public void doWrite(ByteBuffer chunk) throws IOException {
int len = chunk.remaining();
outputBuffer.doWrite(chunk);
contentWritten += len - chunk.remaining();
}
// --------------------
public void recycle() {
contentType = null;
contentLanguage = null;
locale = DEFAULT_LOCALE;
charset = null;
characterEncoding = null;
contentLength = -1;
status = 200;
message = null;
committed = false;
commitTime = -1;
errorException = null;
resetError();
headers.recycle();
trailerFieldsSupplier = null;
// Servlet 3.1 non-blocking write listener
listener = null;
synchronized (nonBlockingStateLock) {
fireListener = false;
registeredForWrite = false;
}
// update counters
contentWritten = 0;
}
/**
* Bytes written by application - i.e. before compression, chunking, etc.
*
* @return The total number of bytes written to the response by the application. This will not be the number of
* bytes written to the network which may be more or less than this value.
*/
public long getContentWritten() {
return contentWritten;
}
/**
* Bytes written to socket - i.e. after compression, chunking, etc.
*
* @param flush Should any remaining bytes be flushed before returning the total? If {@code false} bytes remaining
* in the buffer will not be included in the returned value
*
* @return The total number of bytes written to the socket for this response
*/
public long getBytesWritten(boolean flush) {
if (flush) {
action(ActionCode.CLIENT_FLUSH, this);
}
return outputBuffer.getBytesWritten();
}
/*
* State for non-blocking output is maintained here as it is the one point easily reachable from the
* CoyoteOutputStream and the Processor which both need access to state.
*/
volatile WriteListener listener;
// Ensures listener is only fired after a call is isReady()
private boolean fireListener = false;
// Tracks write registration to prevent duplicate registrations
private boolean registeredForWrite = false;
// Lock used to manage concurrent access to above flags
private final Object nonBlockingStateLock = new Object();
public WriteListener getWriteListener() {
return listener;
}
public void setWriteListener(WriteListener listener) {
if (listener == null) {
throw new NullPointerException(sm.getString("response.nullWriteListener"));
}
if (getWriteListener() != null) {
throw new IllegalStateException(sm.getString("response.writeListenerSet"));
}
// Note: This class is not used for HTTP upgrade so only need to test
// for async
AtomicBoolean result = new AtomicBoolean(false);
action(ActionCode.ASYNC_IS_ASYNC, result);
if (!result.get()) {
throw new IllegalStateException(sm.getString("response.notAsync"));
}
this.listener = listener;
// The container is responsible for the first call to
// listener.onWritePossible(). If isReady() returns true, the container
// needs to call listener.onWritePossible() from a new thread. If
// isReady() returns false, the socket will be registered for write and
// the container will call listener.onWritePossible() once data can be
// written.
if (isReady()) {
synchronized (nonBlockingStateLock) {
// Ensure we don't get multiple write registrations if
// ServletOutputStream.isReady() returns false during a call to
// onDataAvailable()
registeredForWrite = true;
// Need to set the fireListener flag otherwise when the
// container tries to trigger onWritePossible, nothing will
// happen
fireListener = true;
}
action(ActionCode.DISPATCH_WRITE, null);
if (!req.isRequestThread()) {
// Not on a container thread so need to execute the dispatch
action(ActionCode.DISPATCH_EXECUTE, null);
}
}
}
public boolean isReady() {
if (listener == null) {
if (log.isDebugEnabled()) {
log.debug(sm.getString("response.notNonBlocking"));
}
return false;
}
// Assume write is not possible
boolean ready = false;
synchronized (nonBlockingStateLock) {
if (registeredForWrite) {
fireListener = true;
return false;
}
ready = checkRegisterForWrite();
fireListener = !ready;
}
return ready;
}
public boolean checkRegisterForWrite() {
AtomicBoolean ready = new AtomicBoolean(false);
synchronized (nonBlockingStateLock) {
if (!registeredForWrite) {
action(ActionCode.NB_WRITE_INTEREST, ready);
registeredForWrite = !ready.get();
}
}
return ready.get();
}
public void onWritePossible() throws IOException {
// Any buffered data left over from a previous non-blocking write is
// written in the Processor so if this point is reached the app is able
// to write data.
boolean fire = false;
synchronized (nonBlockingStateLock) {
registeredForWrite = false;
if (fireListener) {
fireListener = false;
fire = true;
}
}
if (fire) {
listener.onWritePossible();
}
}
}