Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2013 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.internal.core; import java.util.Iterator; import org.eclipse.core.runtime.IStatus; import org.eclipse.jdt.core.Flags; import org.eclipse.jdt.core.ICompilationUnit; import org.eclipse.jdt.core.IImportDeclaration; import org.eclipse.jdt.core.IJavaElement; import org.eclipse.jdt.core.IJavaModelStatus; import org.eclipse.jdt.core.IJavaModelStatusConstants; import org.eclipse.jdt.core.IJavaProject; import org.eclipse.jdt.core.IType; import org.eclipse.jdt.core.JavaConventions; import org.eclipse.jdt.core.JavaCore; import org.eclipse.jdt.core.JavaModelException; import org.eclipse.jdt.core.compiler.CharOperation; import org.eclipse.jdt.core.dom.AST; import org.eclipse.jdt.core.dom.ASTNode; import org.eclipse.jdt.core.dom.CompilationUnit; import org.eclipse.jdt.core.dom.ImportDeclaration; import org.eclipse.jdt.core.dom.Name; import org.eclipse.jdt.core.dom.StructuralPropertyDescriptor; import org.eclipse.jdt.core.dom.rewrite.ASTRewrite; import org.eclipse.jdt.internal.core.util.Messages; /** * <p>This operation adds an import declaration to an existing compilation unit. * If the compilation unit already includes the specified import declaration, * the import is not generated (it does not generate duplicates). * Note that it is valid to specify both a single-type import and an on-demand import * for the same package, for example <code>"java.io.File"</code> and * <code>"java.io.*"</code>, in which case both are preserved since the semantics * of this are not the same as just importing <code>"java.io.*"</code>. * Importing <code>"java.lang.*"</code>, or the package in which the compilation unit * is defined, are not treated as special cases. If they are specified, they are * included in the result. * * <p>Required Attributes:<ul> * <li>Compilation unit * <li>Import name - the name of the import to add to the * compilation unit. For example: <code>"java.io.File"</code> or <code>"java.awt.*"</code> * </ul> */ @SuppressWarnings("rawtypes") public class CreateImportOperation extends CreateElementInCUOperation { /* * The name of the import to be created. */ protected String importName; /* * The flags of the import to be created (either Flags#AccDefault or Flags#AccStatic) */ protected int flags; /** * When executed, this operation will add an import to the given compilation unit. */ public CreateImportOperation(String importName, ICompilationUnit parentElement, int flags) { super(parentElement); this.importName = importName; this.flags = flags; } @Override protected StructuralPropertyDescriptor getChildPropertyDescriptor(ASTNode parent) { return CompilationUnit.IMPORTS_PROPERTY; } @Override protected ASTNode generateElementAST(ASTRewrite rewriter, ICompilationUnit cu) throws JavaModelException { // ensure no duplicate Iterator imports = this.cuAST.imports().iterator(); boolean onDemand = this.importName.endsWith(".*"); //$NON-NLS-1$ String importActualName = this.importName; if (onDemand) { importActualName = this.importName.substring(0, this.importName.length() - 2); } while (imports.hasNext()) { ImportDeclaration importDeclaration = (ImportDeclaration) imports.next(); if (importActualName.equals(importDeclaration.getName().getFullyQualifiedName()) && (onDemand == importDeclaration.isOnDemand()) && (Flags.isStatic(this.flags) == importDeclaration.isStatic())) { this.creationOccurred = false; return null; } } AST ast = this.cuAST.getAST(); ImportDeclaration importDeclaration = ast.newImportDeclaration(); importDeclaration.setStatic(Flags.isStatic(this.flags)); // split import name into individual fragments, checking for on demand imports char[][] charFragments = CharOperation.splitOn('.', importActualName.toCharArray(), 0, importActualName.length()); int length = charFragments.length; String[] strFragments = new String[length]; for (int i = 0; i < length; i++) { strFragments[i] = String.valueOf(charFragments[i]); } Name name = ast.newName(strFragments); importDeclaration.setName(name); if (onDemand) importDeclaration.setOnDemand(true); return importDeclaration; } /** * @see CreateElementInCUOperation#generateResultHandle */ @Override protected IJavaElement generateResultHandle() { return getCompilationUnit().getImport(this.importName); } /** * @see CreateElementInCUOperation#getMainTaskName() */ @Override public String getMainTaskName() { return Messages.operation_createImportsProgress; } /** * Sets the correct position for the new import:<ul> * <li> after the last import * <li> if no imports, before the first type * <li> if no type, after the package statement * <li> and if no package statement - first thing in the CU */ @Override protected void initializeDefaultPosition() { try { ICompilationUnit cu = getCompilationUnit(); IImportDeclaration[] imports = cu.getImports(); if (imports.length > 0) { createAfter(imports[imports.length - 1]); return; } IType[] types = cu.getTypes(); if (types.length > 0) { createBefore(types[0]); return; } IJavaElement[] children = cu.getChildren(); //look for the package declaration for (int i = 0; i < children.length; i++) { if (children[i].getElementType() == IJavaElement.PACKAGE_DECLARATION) { createAfter(children[i]); return; } } } catch (JavaModelException e) { // cu doesn't exit: ignore } } /** * Possible failures: <ul> * <li>NO_ELEMENTS_TO_PROCESS - the compilation unit supplied to the operation is * <code>null</code>. * <li>INVALID_NAME - not a valid import declaration name. * </ul> * @see IJavaModelStatus * @see JavaConventions */ @Override public IJavaModelStatus verify() { IJavaModelStatus status = super.verify(); if (!status.isOK()) { return status; } IJavaProject project = getParentElement().getJavaProject(); if (JavaConventions .validateImportDeclaration(this.importName, project.getOption(JavaCore.COMPILER_SOURCE, true), project.getOption(JavaCore.COMPILER_COMPLIANCE, true)) .getSeverity() == IStatus.ERROR) { return new JavaModelStatus(IJavaModelStatusConstants.INVALID_NAME, this.importName); } return JavaModelStatus.VERIFIED_OK; } }