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/* * Copyright (c) 1997-2018 Oracle and/or its affiliates. All rights reserved. * 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; /** * * Provides a convenient implementation of the ServletResponse interface that * can be subclassed by developers wishing to adapt the response from a Servlet. * This class implements the Wrapper or Decorator pattern. Methods default to * calling through to the wrapped response object. * * @author Various * @since Servlet 2.3 * * @see javax.servlet.ServletResponse */ public class ServletResponseWrapper implements ServletResponse { private ServletResponse response; /** * Creates a ServletResponse adaptor wrapping the given response object. * @throws java.lang.IllegalArgumentException if the response is null. * @param response the {@link ServletResponse} to be wrapped * */ public ServletResponseWrapper(ServletResponse response) { if (response == null) { throw new IllegalArgumentException("Response cannot be null"); } this.response = response; } /** * Return the wrapped ServletResponse object. * * @return the wrapped {@link ServletResponse} */ public ServletResponse getResponse() { return this.response; } /** * Sets the response being wrapped. * @throws java.lang.IllegalArgumentException if the response is null. * * @param response the {@link ServletResponse} to be installed */ public void setResponse(ServletResponse response) { if (response == null) { throw new IllegalArgumentException("Response cannot be null"); } this.response = response; } /** * The default behavior of this method is to call setCharacterEncoding(String charset) * on the wrapped response object. * * @since Servlet 2.4 */ public void setCharacterEncoding(String charset) { this.response.setCharacterEncoding(charset); } /** * The default behavior of this method is to return getCharacterEncoding() * on the wrapped response object. */ public String getCharacterEncoding() { return this.response.getCharacterEncoding(); } /** * The default behavior of this method is to return getOutputStream() * on the wrapped response object. */ public ServletOutputStream getOutputStream() throws IOException { return this.response.getOutputStream(); } /** * The default behavior of this method is to return getWriter() * on the wrapped response object. */ public PrintWriter getWriter() throws IOException { return this.response.getWriter(); } /** * The default behavior of this method is to call setContentLength(int len) * on the wrapped response object. */ public void setContentLength(int len) { this.response.setContentLength(len); } /** * The default behavior of this method is to call setContentLengthLong(long len) * on the wrapped response object. */ public void setContentLengthLong(long len) { this.response.setContentLengthLong(len); } /** * The default behavior of this method is to call setContentType(String type) * on the wrapped response object. */ public void setContentType(String type) { this.response.setContentType(type); } /** * The default behavior of this method is to return getContentType() * on the wrapped response object. * * @since Servlet 2.4 */ public String getContentType() { return this.response.getContentType(); } /** * The default behavior of this method is to call setBufferSize(int size) * on the wrapped response object. */ public void setBufferSize(int size) { this.response.setBufferSize(size); } /** * The default behavior of this method is to return getBufferSize() * on the wrapped response object. */ public int getBufferSize() { return this.response.getBufferSize(); } /** * The default behavior of this method is to call flushBuffer() * on the wrapped response object. */ public void flushBuffer() throws IOException { this.response.flushBuffer(); } /** * The default behavior of this method is to return isCommitted() * on the wrapped response object. */ public boolean isCommitted() { return this.response.isCommitted(); } /** * The default behavior of this method is to call reset() * on the wrapped response object. */ public void reset() { this.response.reset(); } /** * The default behavior of this method is to call resetBuffer() * on the wrapped response object. */ public void resetBuffer() { this.response.resetBuffer(); } /** * The default behavior of this method is to call setLocale(Locale loc) * on the wrapped response object. */ public void setLocale(Locale loc) { this.response.setLocale(loc); } /** * The default behavior of this method is to return getLocale() * on the wrapped response object. */ public Locale getLocale() { return this.response.getLocale(); } /** * Checks (recursively) if this ServletResponseWrapper wraps the given * {@link ServletResponse} instance. * * @param wrapped the ServletResponse instance to search for * * @return true if this ServletResponseWrapper wraps the * given ServletResponse instance, false otherwise * * @since Servlet 3.0 */ public boolean isWrapperFor(ServletResponse wrapped) { if (response == wrapped) { return true; } else if (response instanceof ServletResponseWrapper) { return ((ServletResponseWrapper) response).isWrapperFor(wrapped); } else { return false; } } /** * Checks (recursively) if this ServletResponseWrapper wraps a * {@link ServletResponse} of the given class type. * * @param wrappedType the ServletResponse class type to * search for * * @return true if this ServletResponseWrapper wraps a * ServletResponse of the given class type, false otherwise * * @throws IllegalArgumentException if the given class does not * implement {@link ServletResponse} * * @since Servlet 3.0 */ public boolean isWrapperFor(Class<?> wrappedType) { if (!ServletResponse.class.isAssignableFrom(wrappedType)) { throw new IllegalArgumentException("Given class " + wrappedType.getName() + " not a subinterface of " + ServletResponse.class.getName()); } if (wrappedType.isAssignableFrom(response.getClass())) { return true; } else if (response instanceof ServletResponseWrapper) { return ((ServletResponseWrapper) response).isWrapperFor(wrappedType); } else { return false; } } }