1 /** 2 * 3 * Copyright 2003-2004 The Apache Software Foundation 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 // 19 // This source code implements specifications defined by the Java 20 // Community Process. In order to remain compliant with the specification 21 // DO NOT add / change / or delete method signatures! 22 // 23 24 package javax.servlet.jsp; 25 26 import javax.servlet.Servlet; 27 import javax.servlet.ServletRequest; 28 import javax.servlet.ServletResponse; 29 30 /** 31 * <p> 32 * The JspFactory is an abstract class that defines a number of factory 33 * methods available to a JSP page at runtime for the purposes of creating 34 * instances of various interfaces and classes used to support the JSP 35 * implementation. 36 * <p> 37 * A conformant JSP Engine implementation will, during it's initialization 38 * instantiate an implementation dependent subclass of this class, and make 39 * it globally available for use by JSP implementation classes by registering 40 * the instance created with this class via the 41 * static <code> setDefaultFactory() </code> method. 42 * <p> 43 * The PageContext and the JspEngineInfo classes are the only implementation-dependent 44 * classes that can be created from the factory. 45 * <p> 46 * JspFactory objects should not be used by JSP page authors. 47 */ 48 49 public abstract class JspFactory { 50 51 private static JspFactory deflt = null; 52 53 /** 54 * Sole constructor. (For invocation by subclass constructors, 55 * typically implicit.) 56 */ 57 public JspFactory() { 58 } 59 60 /** 61 * <p> 62 * set the default factory for this implementation. It is illegal for 63 * any principal other than the JSP Engine runtime to call this method. 64 * </p> 65 * 66 * @param deflt The default factory implementation 67 */ 68 69 public static synchronized void setDefaultFactory(JspFactory deflt) { 70 JspFactory.deflt = deflt; 71 } 72 73 /** 74 * Returns the default factory for this implementation. 75 * 76 * @return the default factory for this implementation 77 */ 78 79 public static synchronized JspFactory getDefaultFactory() { 80 return deflt; 81 } 82 83 /** 84 * <p> 85 * obtains an instance of an implementation dependent 86 * javax.servlet.jsp.PageContext abstract class for the calling Servlet 87 * and currently pending request and response. 88 * </p> 89 * 90 * <p> 91 * This method is typically called early in the processing of the 92 * _jspService() method of a JSP implementation class in order to 93 * obtain a PageContext object for the request being processed. 94 * </p> 95 * <p> 96 * Invoking this method shall result in the PageContext.initialize() 97 * method being invoked. The PageContext returned is properly initialized. 98 * </p> 99 * <p> 100 * All PageContext objects obtained via this method shall be released 101 * by invoking releasePageContext(). 102 * </p> 103 * 104 * @param servlet the requesting servlet 105 * @param request the current request pending on the servlet 106 * @param response the current response pending on the servlet 107 * @param errorPageURL the URL of the error page for the requesting JSP, or null 108 * @param needsSession true if the JSP participates in a session 109 * @param buffer size of buffer in bytes, PageContext.NO_BUFFER if no buffer, 110 * PageContext.DEFAULT_BUFFER if implementation default. 111 * @param autoflush should the buffer autoflush to the output stream on buffer 112 * overflow, or throw an IOException? 113 * 114 * @return the page context 115 * 116 * @see javax.servlet.jsp.PageContext 117 */ 118 119 public abstract PageContext getPageContext(Servlet servlet, 120 ServletRequest request, 121 ServletResponse response, 122 String errorPageURL, 123 boolean needsSession, 124 int buffer, 125 boolean autoflush); 126 127 /** 128 * <p> 129 * called to release a previously allocated PageContext object. 130 * Results in PageContext.release() being invoked. 131 * This method should be invoked prior to returning from the _jspService() method of a JSP implementation 132 * class. 133 * </p> 134 * 135 * @param pc A PageContext previously obtained by getPageContext() 136 */ 137 138 public abstract void releasePageContext(PageContext pc); 139 140 /** 141 * <p> 142 * called to get implementation-specific information on the current JSP engine. 143 * </p> 144 * 145 * @return a JspEngineInfo object describing the current JSP engine 146 */ 147 148 public abstract JspEngineInfo getEngineInfo(); 149 }