| /* |
| * 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.IOException; |
| import java.io.PrintWriter; |
| import java.util.Locale; |
| |
| /** |
| * Defines an object to assist a servlet in sending a response to the client. |
| * The servlet container creates a <code>ServletResponse</code> object and |
| * passes it as an argument to the servlet's <code>service</code> method. |
| * <p> |
| * To send binary data in a MIME body response, use the |
| * {@link ServletOutputStream} returned by {@link #getOutputStream}. To send |
| * character data, use the <code>PrintWriter</code> object returned by |
| * {@link #getWriter}. To mix binary and text data, for example, to create a |
| * multipart response, use a <code>ServletOutputStream</code> and manage the |
| * character sections manually. |
| * <p> |
| * The charset for the MIME body response can be specified explicitly using the |
| * {@link #setCharacterEncoding} and {@link #setContentType} methods, or |
| * implicitly using the {@link #setLocale} method. Explicit specifications take |
| * precedence over implicit specifications. If no charset is specified, |
| * ISO-8859-1 will be used. The <code>setCharacterEncoding</code>, |
| * <code>setContentType</code>, or <code>setLocale</code> method must be called |
| * before <code>getWriter</code> and before committing the response for the |
| * character encoding to be used. |
| * <p> |
| * See the Internet RFCs such as <a href="http://www.ietf.org/rfc/rfc2045.txt"> |
| * RFC 2045</a> for more information on MIME. Protocols such as SMTP and HTTP |
| * define profiles of MIME, and those standards are still evolving. |
| * |
| * @see ServletOutputStream |
| */ |
| public interface ServletResponse { |
| |
| /** |
| * Returns the name of the character encoding (MIME charset) used for the |
| * body sent in this response. The character encoding may have been |
| * specified explicitly using the {@link #setCharacterEncoding} or |
| * {@link #setContentType} methods, or implicitly using the |
| * {@link #setLocale} method. Explicit specifications take precedence over |
| * implicit specifications. Calls made to these methods after |
| * <code>getWriter</code> has been called or after the response has been |
| * committed have no effect on the character encoding. If no character |
| * encoding has been specified, <code>ISO-8859-1</code> is returned. |
| * <p> |
| * See RFC 2047 (http://www.ietf.org/rfc/rfc2047.txt) for more information |
| * about character encoding and MIME. |
| * |
| * @return a <code>String</code> specifying the name of the character |
| * encoding, for example, <code>UTF-8</code> |
| */ |
| public String getCharacterEncoding(); |
| |
| /** |
| * Returns the content type used for the MIME body sent in this response. |
| * The content type proper must have been specified using |
| * {@link #setContentType} before the response is committed. If no content |
| * type has been specified, this method returns null. If a content type has |
| * been specified and a character encoding has been explicitly or implicitly |
| * specified as described in {@link #getCharacterEncoding}, the charset |
| * parameter is included in the string returned. If no character encoding |
| * has been specified, the charset parameter is omitted. |
| * |
| * @return a <code>String</code> specifying the content type, for example, |
| * <code>text/html; charset=UTF-8</code>, or null |
| * @since 2.4 |
| */ |
| public String getContentType(); |
| |
| /** |
| * Returns a {@link ServletOutputStream} suitable for writing binary data in |
| * the response. The servlet container does not encode the binary data. |
| * <p> |
| * Calling flush() on the ServletOutputStream commits the response. Either |
| * this method or {@link #getWriter} may be called to write the body, not |
| * both. |
| * |
| * @return a {@link ServletOutputStream} for writing binary data |
| * @exception IllegalStateException |
| * if the <code>getWriter</code> method has been called on |
| * this response |
| * @exception IOException |
| * if an input or output exception occurred |
| * @see #getWriter |
| */ |
| public ServletOutputStream getOutputStream() throws IOException; |
| |
| /** |
| * Returns a <code>PrintWriter</code> object that can send character text to |
| * the client. The <code>PrintWriter</code> uses the character encoding |
| * returned by {@link #getCharacterEncoding}. If the response's character |
| * encoding has not been specified as described in |
| * <code>getCharacterEncoding</code> (i.e., the method just returns the |
| * default value <code>ISO-8859-1</code>), <code>getWriter</code> updates it |
| * to <code>ISO-8859-1</code>. |
| * <p> |
| * Calling flush() on the <code>PrintWriter</code> commits the response. |
| * <p> |
| * Either this method or {@link #getOutputStream} may be called to write the |
| * body, not both. |
| * |
| * @return a <code>PrintWriter</code> object that can return character data |
| * to the client |
| * @exception java.io.UnsupportedEncodingException |
| * if the character encoding returned by |
| * <code>getCharacterEncoding</code> cannot be used |
| * @exception IllegalStateException |
| * if the <code>getOutputStream</code> method has already |
| * been called for this response object |
| * @exception IOException |
| * if an input or output exception occurred |
| * @see #getOutputStream |
| * @see #setCharacterEncoding |
| */ |
| public PrintWriter getWriter() throws IOException; |
| |
| /** |
| * Sets the character encoding (MIME charset) of the response being sent to |
| * the client, for example, to UTF-8. If the character encoding has already |
| * been set by {@link #setContentType} or {@link #setLocale}, this method |
| * overrides it. Calling {@link #setContentType} with the |
| * <code>String</code> of <code>text/html</code> and calling this method |
| * with the <code>String</code> of <code>UTF-8</code> is equivalent with |
| * calling <code>setContentType</code> with the <code>String</code> of |
| * <code>text/html; charset=UTF-8</code>. |
| * <p> |
| * This method can be called repeatedly to change the character encoding. |
| * This method has no effect if it is called after <code>getWriter</code> |
| * has been called or after the response has been committed. |
| * <p> |
| * Containers must communicate the character encoding used for the servlet |
| * response's writer to the client if the protocol provides a way for doing |
| * so. In the case of HTTP, the character encoding is communicated as part |
| * of the <code>Content-Type</code> header for text media types. Note that |
| * the character encoding cannot be communicated via HTTP headers if the |
| * servlet does not specify a content type; however, it is still used to |
| * encode text written via the servlet response's writer. |
| * |
| * @param charset |
| * a String specifying only the character set defined by IANA |
| * Character Sets |
| * (http://www.iana.org/assignments/character-sets) |
| * @see #setContentType #setLocale |
| * @since 2.4 |
| */ |
| public void setCharacterEncoding(String charset); |
| |
| /** |
| * Sets the length of the content body in the response In HTTP servlets, |
| * this method sets the HTTP Content-Length header. |
| * |
| * @param len |
| * an integer specifying the length of the content being returned |
| * to the client; sets the Content-Length header |
| */ |
| public void setContentLength(int len); |
| |
| /** |
| * Sets the length of the content body in the response In HTTP servlets, |
| * this method sets the HTTP Content-Length header. |
| * |
| * @param length |
| * an integer specifying the length of the content being returned |
| * to the client; sets the Content-Length header |
| * |
| * @since Servlet 3.1 |
| */ |
| public void setContentLengthLong(long length); |
| |
| /** |
| * Sets the content type of the response being sent to the client, if the |
| * response has not been committed yet. The given content type may include a |
| * character encoding specification, for example, |
| * <code>text/html;charset=UTF-8</code>. The response's character encoding |
| * is only set from the given content type if this method is called before |
| * <code>getWriter</code> is called. |
| * <p> |
| * This method may be called repeatedly to change content type and character |
| * encoding. This method has no effect if called after the response has been |
| * committed. It does not set the response's character encoding if it is |
| * called after <code>getWriter</code> has been called or after the response |
| * has been committed. |
| * <p> |
| * Containers must communicate the content type and the character encoding |
| * used for the servlet response's writer to the client if the protocol |
| * provides a way for doing so. In the case of HTTP, the |
| * <code>Content-Type</code> header is used. |
| * |
| * @param type |
| * a <code>String</code> specifying the MIME type of the content |
| * @see #setLocale |
| * @see #setCharacterEncoding |
| * @see #getOutputStream |
| * @see #getWriter |
| */ |
| public void setContentType(String type); |
| |
| /** |
| * Sets the preferred buffer size for the body of the response. The servlet |
| * container will use a buffer at least as large as the size requested. The |
| * actual buffer size used can be found using <code>getBufferSize</code>. |
| * <p> |
| * A larger buffer allows more content to be written before anything is |
| * actually sent, thus providing the servlet with more time to set |
| * appropriate status codes and headers. A smaller buffer decreases server |
| * memory load and allows the client to start receiving data more quickly. |
| * <p> |
| * This method must be called before any response body content is written; |
| * if content has been written or the response object has been committed, |
| * this method throws an <code>IllegalStateException</code>. |
| * |
| * @param size |
| * the preferred buffer size |
| * @exception IllegalStateException |
| * if this method is called after content has been written |
| * @see #getBufferSize |
| * @see #flushBuffer |
| * @see #isCommitted |
| * @see #reset |
| */ |
| public void setBufferSize(int size); |
| |
| /** |
| * Returns the actual buffer size used for the response. If no buffering is |
| * used, this method returns 0. |
| * |
| * @return the actual buffer size used |
| * @see #setBufferSize |
| * @see #flushBuffer |
| * @see #isCommitted |
| * @see #reset |
| */ |
| public int getBufferSize(); |
| |
| /** |
| * Forces any content in the buffer to be written to the client. A call to |
| * this method automatically commits the response, meaning the status code |
| * and headers will be written. |
| * |
| * @throws IOException if an I/O occurs during the flushing of the response |
| * |
| * @see #setBufferSize |
| * @see #getBufferSize |
| * @see #isCommitted |
| * @see #reset |
| */ |
| public void flushBuffer() throws IOException; |
| |
| /** |
| * Clears the content of the underlying buffer in the response without |
| * clearing headers or status code. If the response has been committed, this |
| * method throws an <code>IllegalStateException</code>. |
| * |
| * @see #setBufferSize |
| * @see #getBufferSize |
| * @see #isCommitted |
| * @see #reset |
| * @since 2.3 |
| */ |
| public void resetBuffer(); |
| |
| /** |
| * Returns a boolean indicating if the response has been committed. A |
| * committed response has already had its status code and headers written. |
| * |
| * @return a boolean indicating if the response has been committed |
| * @see #setBufferSize |
| * @see #getBufferSize |
| * @see #flushBuffer |
| * @see #reset |
| */ |
| public boolean isCommitted(); |
| |
| /** |
| * Clears any data that exists in the buffer as well as the status code and |
| * headers. If the response has been committed, this method throws an |
| * <code>IllegalStateException</code>. |
| * |
| * @exception IllegalStateException |
| * if the response has already been committed |
| * @see #setBufferSize |
| * @see #getBufferSize |
| * @see #flushBuffer |
| * @see #isCommitted |
| */ |
| public void reset(); |
| |
| /** |
| * Sets the locale of the response, if the response has not been committed |
| * yet. It also sets the response's character encoding appropriately for the |
| * locale, if the character encoding has not been explicitly set using |
| * {@link #setContentType} or {@link #setCharacterEncoding}, |
| * <code>getWriter</code> hasn't been called yet, and the response hasn't |
| * been committed yet. If the deployment descriptor contains a |
| * <code>locale-encoding-mapping-list</code> element, and that element |
| * provides a mapping for the given locale, that mapping is used. Otherwise, |
| * the mapping from locale to character encoding is container dependent. |
| * <p> |
| * This method may be called repeatedly to change locale and character |
| * encoding. The method has no effect if called after the response has been |
| * committed. It does not set the response's character encoding if it is |
| * called after {@link #setContentType} has been called with a charset |
| * specification, after {@link #setCharacterEncoding} has been called, after |
| * <code>getWriter</code> has been called, or after the response has been |
| * committed. |
| * <p> |
| * Containers must communicate the locale and the character encoding used |
| * for the servlet response's writer to the client if the protocol provides |
| * a way for doing so. In the case of HTTP, the locale is communicated via |
| * the <code>Content-Language</code> header, the character encoding as part |
| * of the <code>Content-Type</code> header for text media types. Note that |
| * the character encoding cannot be communicated via HTTP headers if the |
| * servlet does not specify a content type; however, it is still used to |
| * encode text written via the servlet response's writer. |
| * |
| * @param loc |
| * the locale of the response |
| * @see #getLocale |
| * @see #setContentType |
| * @see #setCharacterEncoding |
| */ |
| public void setLocale(Locale loc); |
| |
| /** |
| * Returns the locale specified for this response using the |
| * {@link #setLocale} method. Calls made to <code>setLocale</code> after the |
| * response is committed have no effect. |
| * |
| * @return The locale specified for this response using the |
| * {@link #setLocale} method. If no locale has been specified, the |
| * container's default locale is returned. |
| * |
| * @see #setLocale |
| */ |
| public Locale getLocale(); |
| |
| } |
