| /* |
| * Copyright 2004 The Apache Software Foundation |
| * |
| * Licensed 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. |
| * |
| * @author Various |
| * @version $Version$ |
| * |
| * @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 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 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. |
| * |
| * @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. If no locale has been specified, |
| * the container's default locale is returned. |
| * |
| * @see #setLocale |
| * |
| */ |
| |
| public Locale getLocale(); |
| |
| |
| |
| } |
| |
| |
| |
| |
| |
