/*
* 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.catalina.connector;
import java.io.IOException;
import java.io.Writer;
import java.security.AccessController;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.HashMap;
import org.apache.coyote.ActionCode;
import org.apache.coyote.Response;
import org.apache.catalina.Globals;
import org.apache.tomcat.util.buf.ByteChunk;
import org.apache.tomcat.util.buf.C2BConverter;
/**
* The buffer used by Tomcat response. This is a derivative of the Tomcat 3.3
* OutputBuffer, with the removal of some of the state handling (which in
* Coyote is mostly the Processor's responsability).
*
* @author Costin Manolache
* @author Remy Maucherat
*/
public class OutputBuffer extends Writer
implements ByteChunk.ByteOutputChannel {
// -------------------------------------------------------------- Constants
public static final String DEFAULT_ENCODING =
org.apache.coyote.Constants.DEFAULT_CHARACTER_ENCODING;
public static final int DEFAULT_BUFFER_SIZE = 8*1024;
// ----------------------------------------------------- Instance Variables
/**
* The byte buffer.
*/
private ByteChunk bb;
/**
* State of the output buffer.
*/
private boolean initial = true;
/**
* Number of bytes written.
*/
private int bytesWritten = 0;
/**
* Number of chars written.
*/
private int charsWritten = 0;
/**
* Flag which indicates if the output buffer is closed.
*/
private boolean closed = false;
/**
* Do a flush on the next operation.
*/
private boolean doFlush = false;
/**
* Byte chunk used to output bytes.
*/
private ByteChunk outputChunk = new ByteChunk();
/**
* Encoding to use.
*/
private String enc;
/**
* Encoder is set.
*/
private boolean gotEnc = false;
/**
* List of encoders.
*/
protected HashMap encoders = new HashMap();
/**
* Current char to byte converter.
*/
protected C2BConverter conv;
/**
* Associated Coyote response.
*/
private Response coyoteResponse;
/**
* Suspended flag. All output bytes will be swallowed if this is true.
*/
private boolean suspended = false;
// ----------------------------------------------------------- Constructors
/**
* Default constructor. Allocate the buffer with the default buffer size.
*/
public OutputBuffer() {
this(DEFAULT_BUFFER_SIZE);
}
/**
* Alternate constructor which allows specifying the initial buffer size.
*
* @param size Buffer size to use
*/
public OutputBuffer(int size) {
bb = new ByteChunk(size);
bb.setLimit(size);
bb.setByteOutputChannel(this);
}
// ------------------------------------------------------------- Properties
/**
* Associated Coyote response.
*
* @param coyoteResponse Associated Coyote response
*/
public void setResponse(Response coyoteResponse) {
this.coyoteResponse = coyoteResponse;
}
/**
* Get associated Coyote response.
*
* @return the associated Coyote response
*/
public Response getResponse() {
return this.coyoteResponse;
}
/**
* Is the response output suspended ?
*
* @return suspended flag value
*/
public boolean isSuspended() {
return this.suspended;
}
/**
* Set the suspended flag.
*
* @param suspended New suspended flag value
*/
public void setSuspended(boolean suspended) {
this.suspended = suspended;
}
/**
* Is the response output closed ?
*
* @return closed flag value
*/
public boolean isClosed() {
return this.closed;
}
// --------------------------------------------------------- Public Methods
/**
* Recycle the output buffer.
*/
public void recycle() {
initial = true;
bytesWritten = 0;
charsWritten = 0;
bb.recycle();
closed = false;
suspended = false;
if (conv!= null) {
conv.recycle();
}
gotEnc = false;
enc = null;
}
/**
* Clear cached encoders (to save memory for Comet requests).
*/
public void clearEncoders() {
encoders.clear();
}
/**
* Close the output buffer. This tries to calculate the response size if
* the response has not been committed yet.
*
* @throws IOException An underlying IOException occurred
*/
public void close()
throws IOException {
if (closed)
return;
if (suspended)
return;
if ((!coyoteResponse.isCommitted())
&& (coyoteResponse.getContentLengthLong() == -1)) {
// If this didn't cause a commit of the response, the final content
// length can be calculated
if (!coyoteResponse.isCommitted()) {
coyoteResponse.setContentLength(bb.getLength());
}
}
doFlush(false);
closed = true;
coyoteResponse.finish();
}
/**
* Flush bytes or chars contained in the buffer.
*
* @throws IOException An underlying IOException occurred
*/
public void flush()
throws IOException {
doFlush(true);
}
/**
* Flush bytes or chars contained in the buffer.
*
* @throws IOException An underlying IOException occurred
*/
protected void doFlush(boolean realFlush)
throws IOException {
if (suspended)
return;
doFlush = true;
if (initial) {
coyoteResponse.sendHeaders();
initial = false;
}
if (bb.getLength() > 0) {
bb.flushBuffer();
}
doFlush = false;
if (realFlush) {
coyoteResponse.action(ActionCode.ACTION_CLIENT_FLUSH,
coyoteResponse);
// If some exception occurred earlier, or if some IOE occurred
// here, notify the servlet with an IOE
if (coyoteResponse.isExceptionPresent()) {
throw new ClientAbortException
(coyoteResponse.getErrorException());
}
}
}
// ------------------------------------------------- Bytes Handling Methods
/**
* Sends the buffer data to the client output, checking the
* state of Response and calling the right interceptors.
*
* @param buf Byte buffer to be written to the response
* @param off Offset
* @param cnt Length
*
* @throws IOException An underlying IOException occurred
*/
public void realWriteBytes(byte buf[], int off, int cnt)
throws IOException {
if (closed)
return;
if (coyoteResponse == null)
return;
// If we really have something to write
if (cnt > 0) {
// real write to the adapter
outputChunk.setBytes(buf, off, cnt);
try {
coyoteResponse.doWrite(outputChunk);
} catch (IOException e) {
// An IOException on a write is almost always due to
// the remote client aborting the request. Wrap this
// so that it can be handled better by the error dispatcher.
throw new ClientAbortException(e);
}
}
}
public void write(byte b[], int off, int len) throws IOException {
if (suspended)
return;
writeBytes(b, off, len);
}
private void writeBytes(byte b[], int off, int len)
throws IOException {
if (closed)
return;
bb.append(b, off, len);
bytesWritten += len;
// if called from within flush(), then immediately flush
// remaining bytes
if (doFlush) {
bb.flushBuffer();
}
}
public void writeByte(int b)
throws IOException {
if (suspended)
return;
bb.append((byte) b);
bytesWritten++;
}
// ------------------------------------------------- Chars Handling Methods
public void write(int c)
throws IOException {
if (suspended)
return;
conv.convert((char) c);
conv.flushBuffer();
charsWritten++;
}
public void write(char c[])
throws IOException {
if (suspended)
return;
write(c, 0, c.length);
}
public void write(char c[], int off, int len)
throws IOException {
if (suspended)
return;
conv.convert(c, off, len);
conv.flushBuffer();
charsWritten += len;
}
/**
* Append a string to the buffer
*/
public void write(String s, int off, int len)
throws IOException {
if (suspended)
return;
charsWritten += len;
if (s == null)
s = "null";
conv.convert(s, off, len);
conv.flushBuffer();
}
public void write(String s)
throws IOException {
if (suspended)
return;
if (s == null)
s = "null";
conv.convert(s);
conv.flushBuffer();
}
public void setEncoding(String s) {
enc = s;
}
public void checkConverter()
throws IOException {
if (!gotEnc)
setConverter();
}
protected void setConverter()
throws IOException {
if (coyoteResponse != null)
enc = coyoteResponse.getCharacterEncoding();
gotEnc = true;
if (enc == null)
enc = DEFAULT_ENCODING;
conv = (C2BConverter) encoders.get(enc);
if (conv == null) {
if (Globals.IS_SECURITY_ENABLED){
try{
conv = (C2BConverter)AccessController.doPrivileged(
new PrivilegedExceptionAction(){
public Object run() throws IOException{
return new C2BConverter(bb, enc);
}
}
);
}catch(PrivilegedActionException ex){
Exception e = ex.getException();
if (e instanceof IOException)
throw (IOException)e;
}
} else {
conv = new C2BConverter(bb, enc);
}
encoders.put(enc, conv);
}
}
// -------------------- BufferedOutputStream compatibility
/**
* Real write - this buffer will be sent to the client
*/
public void flushBytes()
throws IOException {
bb.flushBuffer();
}
public int getBytesWritten() {
return bytesWritten;
}
public int getCharsWritten() {
return charsWritten;
}
public int getContentWritten() {
return bytesWritten + charsWritten;
}
/**
* True if this buffer hasn't been used ( since recycle() ) -
* i.e. no chars or bytes have been added to the buffer.
*/
public boolean isNew() {
return (bytesWritten == 0) && (charsWritten == 0);
}
public void setBufferSize(int size) {
if (size > bb.getLimit()) {// ??????
bb.setLimit(size);
}
}
public void reset() {
bb.recycle();
bytesWritten = 0;
charsWritten = 0;
gotEnc = false;
enc = null;
initial = true;
}
public int getBufferSize() {
return bb.getLimit();
}
}
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