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Tomcat example source code file (JspWriter.java)
The Tomcat JspWriter.java source code/* * 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.jsp; import java.io.IOException; /** * <p> * The actions and template data in a JSP page is written using the * JspWriter object that is referenced by the implicit variable out which * is initialized automatically using methods in the PageContext object. *<p> * This abstract class emulates some of the functionality found in the * java.io.BufferedWriter and java.io.PrintWriter classes, * however it differs in that it throws java.io.IOException from the print * methods while PrintWriter does not. * <p>Buffering * <p> * The initial JspWriter object is associated with the PrintWriter object * of the ServletResponse in a way that depends on whether the page is or * is not buffered. If the page is not buffered, output written to this * JspWriter object will be written through to the PrintWriter directly, * which will be created if necessary by invoking the getWriter() method * on the response object. But if the page is buffered, the PrintWriter * object will not be created until the buffer is flushed and * operations like setContentType() are legal. Since this flexibility * simplifies programming substantially, buffering is the default for JSP * pages. * <p> * Buffering raises the issue of what to do when the buffer is * exceeded. Two approaches can be taken: * <ul> * <li> * Exceeding the buffer is not a fatal error; when the buffer is * exceeded, just flush the output. * <li> * Exceeding the buffer is a fatal error; when the buffer is exceeded, * raise an exception. * </ul> * <p> * Both approaches are valid, and thus both are supported in the JSP * technology. The behavior of a page is controlled by the autoFlush * attribute, which defaults to true. In general, JSP pages that need to * be sure that correct and complete data has been sent to their client * may want to set autoFlush to false, with a typical case being that * where the client is an application itself. On the other hand, JSP * pages that send data that is meaningful even when partially * constructed may want to set autoFlush to true; such as when the * data is sent for immediate display through a browser. Each application * will need to consider their specific needs. * <p> * An alternative considered was to make the buffer size unbounded; but, * this had the disadvantage that runaway computations would consume an * unbounded amount of resources. * <p> * The "out" implicit variable of a JSP implementation class is of this type. * If the page directive selects autoflush="true" then all the I/O operations * on this class shall automatically flush the contents of the buffer if an * overflow condition would result if the current operation were performed * without a flush. If autoflush="false" then all the I/O operations on this * class shall throw an IOException if performing the current operation would * result in a buffer overflow condition. * * @see java.io.Writer * @see java.io.BufferedWriter * @see java.io.PrintWriter */ abstract public class JspWriter extends java.io.Writer { /** * Constant indicating that the Writer is not buffering output. */ public static final int NO_BUFFER = 0; /** * Constant indicating that the Writer is buffered and is using the * implementation default buffer size. */ public static final int DEFAULT_BUFFER = -1; /** * Constant indicating that the Writer is buffered and is unbounded; this * is used in BodyContent. */ public static final int UNBOUNDED_BUFFER = -2; /** * Protected constructor. * * @param bufferSize the size of the buffer to be used by the JspWriter * @param autoFlush whether the JspWriter should be autoflushing */ protected JspWriter(int bufferSize, boolean autoFlush) { this.bufferSize = bufferSize; this.autoFlush = autoFlush; } /** * Write a line separator. The line separator string is defined by the * system property <tt>line.separator, and is not necessarily a single * newline ('\n') character. * * @exception IOException If an I/O error occurs */ abstract public void newLine() throws IOException; /** * Print a boolean value. The string produced by <code>{@link * java.lang.String#valueOf(boolean)}</code> is written to the * JspWriter's buffer or, if no buffer is used, directly to the * underlying writer. * * @param b The <code>boolean to be printed * @throws java.io.IOException If an error occured while writing */ abstract public void print(boolean b) throws IOException; /** * Print a character. The character is written to the * JspWriter's buffer or, if no buffer is used, directly to the * underlying writer. * * @param c The <code>char to be printed * @throws java.io.IOException If an error occured while writing */ abstract public void print(char c) throws IOException; /** * Print an integer. The string produced by <code>{@link * java.lang.String#valueOf(int)}</code> is written to the * JspWriter's buffer or, if no buffer is used, directly to the * underlying writer. * * @param i The <code>int to be printed * @see java.lang.Integer#toString(int) * @throws java.io.IOException If an error occured while writing */ abstract public void print(int i) throws IOException; /** * Print a long integer. The string produced by <code>{@link * java.lang.String#valueOf(long)}</code> is written to the * JspWriter's buffer or, if no buffer is used, directly to the * underlying writer. * * @param l The <code>long to be printed * @see java.lang.Long#toString(long) * @throws java.io.IOException If an error occured while writing */ abstract public void print(long l) throws IOException; /** * Print a floating-point number. The string produced by <code>{@link * java.lang.String#valueOf(float)}</code> is written to the * JspWriter's buffer or, if no buffer is used, directly to the * underlying writer. * * @param f The <code>float to be printed * @see java.lang.Float#toString(float) * @throws java.io.IOException If an error occured while writing */ abstract public void print(float f) throws IOException; /** * Print a double-precision floating-point number. The string produced by * <code>{@link java.lang.String#valueOf(double)} is written to * the JspWriter's buffer or, if no buffer is used, directly to the * underlying writer. * * @param d The <code>double to be printed * @see java.lang.Double#toString(double) * @throws java.io.IOException If an error occured while writing */ abstract public void print(double d) throws IOException; /** * Print an array of characters. The characters are written to the * JspWriter's buffer or, if no buffer is used, directly to the * underlying writer. * * @param s The array of chars to be printed * * @throws NullPointerException If <code>s is Other Tomcat examples (source code examples)Here is a short list of links related to this Tomcat JspWriter.java source code file: |
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