Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2019 IBM Corporation and others. * * This program and the accompanying materials * are made available under the terms of the Eclipse Public License 2.0 * which accompanies this distribution, and is available at * https://www.eclipse.org/legal/epl-2.0/ * * SPDX-License-Identifier: EPL-2.0 * * Contributors: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.jdt.core.dom; import java.util.ArrayList; import java.util.List; import org.eclipse.jdt.core.compiler.InvalidInputException; import org.eclipse.jdt.internal.compiler.parser.Scanner; import org.eclipse.jdt.internal.compiler.parser.TerminalTokens; import org.eclipse.jdt.internal.compiler.util.Util; /** * String literal nodes. * * @since 2.0 * @noinstantiate This class is not intended to be instantiated by clients. */ @SuppressWarnings("rawtypes") public class StringLiteral extends Expression { /** * The "escapedValue" structural property of this node type (type: {@link String}). * @since 3.0 */ public static final SimplePropertyDescriptor ESCAPED_VALUE_PROPERTY = new SimplePropertyDescriptor( StringLiteral.class, "escapedValue", String.class, MANDATORY); //$NON-NLS-1$ /** * A list of property descriptors (element type: * {@link StructuralPropertyDescriptor}), * or null if uninitialized. */ private static final List PROPERTY_DESCRIPTORS; static { List propertyList = new ArrayList(2); createPropertyList(StringLiteral.class, propertyList); addProperty(ESCAPED_VALUE_PROPERTY, propertyList); PROPERTY_DESCRIPTORS = reapPropertyList(propertyList); } /** * Returns a list of structural property descriptors for this node type. * Clients must not modify the result. * * @param apiLevel the API level; one of the * <code>AST.JLS*</code> constants * @return a list of property descriptors (element type: * {@link StructuralPropertyDescriptor}) * @since 3.0 */ public static List propertyDescriptors(int apiLevel) { return PROPERTY_DESCRIPTORS; } /** * The literal string, including quotes and escapes; defaults to the * literal for the empty string. */ private String escapedValue = "\"\"";//$NON-NLS-1$ /** * Creates a new unparented string literal node owned by the given AST. * By default, the string literal denotes the empty string. * <p> * N.B. This constructor is package-private. * </p> * * @param ast the AST that is to own this node */ StringLiteral(AST ast) { super(ast); } @Override final List internalStructuralPropertiesForType(int apiLevel) { return propertyDescriptors(apiLevel); } @Override final Object internalGetSetObjectProperty(SimplePropertyDescriptor property, boolean get, Object value) { if (property == ESCAPED_VALUE_PROPERTY) { if (get) { return getEscapedValue(); } else { setEscapedValue((String) value); return null; } } // allow default implementation to flag the error return super.internalGetSetObjectProperty(property, get, value); } @Override final int getNodeType0() { return STRING_LITERAL; } @Override ASTNode clone0(AST target) { StringLiteral result = new StringLiteral(target); result.setSourceRange(getStartPosition(), getLength()); result.setEscapedValue(getEscapedValue()); return result; } @Override final boolean subtreeMatch0(ASTMatcher matcher, Object other) { // dispatch to correct overloaded match method return matcher.match(this, other); } @Override void accept0(ASTVisitor visitor) { visitor.visit(this); visitor.endVisit(this); } /** * Returns the string value of this literal node to the given string * literal token. The token is the sequence of characters that would appear * in the source program, including enclosing double quotes and embedded * escapes. * * @return the string literal token, including enclosing double * quotes and embedded escapes */ public String getEscapedValue() { return this.escapedValue; } /** * Sets the string value of this literal node to the given string literal * token. The token is the sequence of characters that would appear in the * source program, including enclosing double quotes and embedded escapes. * For example, * <ul> * <li><code>""</code> <code>setLiteral("\"\"")</code></li> * <li><code>"hello world"</code> <code>setLiteral("\"hello world\"")</code></li> * <li><code>"boo\nhoo"</code> <code>setLiteral("\"boo\\nhoo\"")</code></li> * </ul> * * @param token the string literal token, including enclosing double * quotes and embedded escapes * @exception IllegalArgumentException if the argument is incorrect */ public void setEscapedValue(String token) { // update internalSetEscapedValue(String) if this is changed if (token == null) { throw new IllegalArgumentException("Token cannot be null"); //$NON-NLS-1$ } Scanner scanner = this.ast.scanner; char[] source = token.toCharArray(); scanner.setSource(source); scanner.resetTo(0, source.length); try { int tokenType = scanner.getNextToken(); switch (tokenType) { case TerminalTokens.TokenNameStringLiteral: break; default: throw new IllegalArgumentException("Invalid string literal : >" + token + "<"); //$NON-NLS-1$//$NON-NLS-2$ } } catch (InvalidInputException e) { throw new IllegalArgumentException("Invalid string literal : >" + token + "<");//$NON-NLS-1$//$NON-NLS-2$ } preValueChange(ESCAPED_VALUE_PROPERTY); this.escapedValue = token; postValueChange(ESCAPED_VALUE_PROPERTY); } /* (omit javadoc for this method) * This method is a copy of setEscapedValue(String) that doesn't do any validation. */ void internalSetEscapedValue(String token) { preValueChange(ESCAPED_VALUE_PROPERTY); this.escapedValue = token; postValueChange(ESCAPED_VALUE_PROPERTY); } /** * Returns the value of this literal node. * <p> * For example, * <pre> * StringLiteral s; * s.setEscapedValue("\"hello\\nworld\""); * assert s.getLiteralValue().equals("hello\nworld"); * </pre> * <p> * Note that this is a convenience method that converts from the stored * string literal token returned by <code>getEscapedLiteral</code>. * </p> * * @return the string value without enclosing double quotes and embedded * escapes * @exception IllegalArgumentException if the literal value cannot be converted */ public String getLiteralValue() { String s = getEscapedValue(); int len = s.length(); if (len < 2 || s.charAt(0) != '\"' || s.charAt(len - 1) != '\"') { throw new IllegalArgumentException(); } Scanner scanner = this.ast.scanner; char[] source = s.toCharArray(); scanner.setSource(source); scanner.resetTo(0, source.length); try { int tokenType = scanner.getNextToken(); switch (tokenType) { case TerminalTokens.TokenNameStringLiteral: return scanner.getCurrentStringLiteral(); default: throw new IllegalArgumentException(); } } catch (InvalidInputException e) { throw new IllegalArgumentException(); } } /** * Sets the value of this literal node. * <p> * For example, * <pre> * StringLiteral s; * s.setLiteralValue("hello\nworld"); * assert s.getEscapedValue().equals("\"hello\\nworld\""); * assert s.getLiteralValue().equals("hello\nworld"); * </pre> * <p> * Note that this is a convenience method that converts to the stored * string literal token acceptable to <code>setEscapedLiteral</code>. * </p> * * @param value the string value without enclosing double quotes and * embedded escapes * @exception IllegalArgumentException if the argument is incorrect */ public void setLiteralValue(String value) { if (value == null) { throw new IllegalArgumentException(); } int len = value.length(); StringBuffer b = new StringBuffer(len + 2); b.append("\""); // opening delimiter //$NON-NLS-1$ for (int i = 0; i < len; i++) { char c = value.charAt(i); Util.appendEscapedChar(b, c, true); } b.append("\""); // closing delimiter //$NON-NLS-1$ setEscapedValue(b.toString()); } @Override int memSize() { int size = BASE_NODE_SIZE + 1 * 4 + stringSize(this.escapedValue); return size; } @Override int treeSize() { return memSize(); } }