javax.servlet.ServletOutputStream Maven / Gradle / Ivy
/*
* 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 javax.servlet;
import java.io.CharConversionException;
import java.io.IOException;
import java.io.OutputStream;
import java.text.MessageFormat;
import java.util.ResourceBundle;
/**
* Provides an output stream for sending binary data to the client. A ServletOutputStream object is
* normally retrieved via the {@link ServletResponse#getOutputStream} method.
*
* This is an abstract class that the servlet container implements. Subclasses of this class must implement the
* java.io.OutputStream.write(int) method.
*
* @see ServletResponse
*/
public abstract class ServletOutputStream extends OutputStream {
private static final String LSTRING_FILE = "javax.servlet.LocalStrings";
private static final ResourceBundle lStrings = ResourceBundle.getBundle(LSTRING_FILE);
/**
* Does nothing, because this is an abstract class.
*/
protected ServletOutputStream() {
// NOOP
}
/**
* Writes a String to the client, without a carriage return-line feed (CRLF) character at the end.
*
* @param s the String to send to the client
*
* @exception IOException if an input or output exception occurred
*/
public void print(String s) throws IOException {
if (s == null) {
s = "null";
}
int len = s.length();
byte[] buffer = new byte[len];
for (int i = 0; i < len; i++) {
char c = s.charAt(i);
//
// XXX NOTE: This is clearly incorrect for many strings,
// but is the only consistent approach within the current
// servlet framework. It must suffice until servlet output
// streams properly encode their output.
//
if ((c & 0xff00) != 0) { // high order byte must be zero
String errMsg = lStrings.getString("err.not_iso8859_1");
Object[] errArgs = new Object[1];
errArgs[0] = Character.valueOf(c);
errMsg = MessageFormat.format(errMsg, errArgs);
throw new CharConversionException(errMsg);
}
buffer[i] = (byte) (c & 0xFF);
}
write(buffer);
}
/**
* Writes a boolean value to the client, with no carriage return-line feed (CRLF) character at the end.
*
* @param b the boolean value to send to the client
*
* @exception IOException if an input or output exception occurred
*/
public void print(boolean b) throws IOException {
String msg;
if (b) {
msg = lStrings.getString("value.true");
} else {
msg = lStrings.getString("value.false");
}
print(msg);
}
/**
* Writes a character to the client, with no carriage return-line feed (CRLF) at the end.
*
* @param c the character to send to the client
*
* @exception IOException if an input or output exception occurred
*/
public void print(char c) throws IOException {
print(String.valueOf(c));
}
/**
* Writes an int to the client, with no carriage return-line feed (CRLF) at the end.
*
* @param i the int to send to the client
*
* @exception IOException if an input or output exception occurred
*/
public void print(int i) throws IOException {
print(String.valueOf(i));
}
/**
* Writes a long value to the client, with no carriage return-line feed (CRLF) at the end.
*
* @param l the long value to send to the client
*
* @exception IOException if an input or output exception occurred
*/
public void print(long l) throws IOException {
print(String.valueOf(l));
}
/**
* Writes a float value to the client, with no carriage return-line feed (CRLF) at the end.
*
* @param f the float value to send to the client
*
* @exception IOException if an input or output exception occurred
*/
public void print(float f) throws IOException {
print(String.valueOf(f));
}
/**
* Writes a double value to the client, with no carriage return-line feed (CRLF) at the end.
*
* @param d the double value to send to the client
*
* @exception IOException if an input or output exception occurred
*/
public void print(double d) throws IOException {
print(String.valueOf(d));
}
/**
* Writes a carriage return-line feed (CRLF) to the client.
*
* @exception IOException if an input or output exception occurred
*/
public void println() throws IOException {
print("\r\n");
}
/**
* Writes a String to the client, followed by a carriage return-line feed (CRLF).
*
* @param s the String to write to the client
*
* @exception IOException if an input or output exception occurred
*/
public void println(String s) throws IOException {
StringBuilder sb = new StringBuilder();
sb.append(s);
sb.append("\r\n");
print(sb.toString());
}
/**
* Writes a boolean value to the client, followed by a carriage return-line feed (CRLF).
*
* @param b the boolean value to write to the client
*
* @exception IOException if an input or output exception occurred
*/
public void println(boolean b) throws IOException {
StringBuilder sb = new StringBuilder();
if (b) {
sb.append(lStrings.getString("value.true"));
} else {
sb.append(lStrings.getString("value.false"));
}
sb.append("\r\n");
print(sb.toString());
}
/**
* Writes a character to the client, followed by a carriage return-line feed (CRLF).
*
* @param c the character to write to the client
*
* @exception IOException if an input or output exception occurred
*/
public void println(char c) throws IOException {
println(String.valueOf(c));
}
/**
* Writes an int to the client, followed by a carriage return-line feed (CRLF) character.
*
* @param i the int to write to the client
*
* @exception IOException if an input or output exception occurred
*/
public void println(int i) throws IOException {
println(String.valueOf(i));
}
/**
* Writes a long value to the client, followed by a carriage return-line feed (CRLF).
*
* @param l the long value to write to the client
*
* @exception IOException if an input or output exception occurred
*/
public void println(long l) throws IOException {
println(String.valueOf(l));
}
/**
* Writes a float value to the client, followed by a carriage return-line feed (CRLF).
*
* @param f the float value to write to the client
*
* @exception IOException if an input or output exception occurred
*/
public void println(float f) throws IOException {
println(String.valueOf(f));
}
/**
* Writes a double value to the client, followed by a carriage return-line feed (CRLF).
*
* @param d the double value to write to the client
*
* @exception IOException if an input or output exception occurred
*/
public void println(double d) throws IOException {
println(String.valueOf(d));
}
/**
* Checks if a non-blocking write will succeed. If this returns false, it will cause a callback to
* {@link WriteListener#onWritePossible()} when the buffer has emptied. If this method returns false no
* further data must be written until the container calls {@link WriteListener#onWritePossible()}.
*
* @return true if data can be written, else false
*
* @since Servlet 3.1
*/
public abstract boolean isReady();
/**
* Sets the {@link WriteListener} for this {@link ServletOutputStream} and thereby switches to non-blocking IO. It
* is only valid to switch to non-blocking IO within async processing or HTTP upgrade processing.
*
* @param listener The non-blocking IO write listener
*
* @throws IllegalStateException If this method is called if neither async nor HTTP upgrade is in progress or if the
* {@link WriteListener} has already been set
* @throws NullPointerException If listener is null
*
* @since Servlet 3.1
*/
public abstract void setWriteListener(WriteListener listener);
}