Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2015 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.jdt.internal.debug.ui; import org.eclipse.core.runtime.CoreException; import org.eclipse.core.runtime.IAdaptable; import org.eclipse.debug.core.DebugException; import org.eclipse.debug.core.model.IVariable; import org.eclipse.debug.ui.DebugUITools; import org.eclipse.debug.ui.IDebugUIConstants; import org.eclipse.jdt.core.Flags; import org.eclipse.jdt.core.IClassFile; import org.eclipse.jdt.core.ICodeAssist; import org.eclipse.jdt.core.IField; import org.eclipse.jdt.core.IJavaElement; import org.eclipse.jdt.core.ILocalVariable; import org.eclipse.jdt.core.IMethod; import org.eclipse.jdt.core.ITypeRoot; import org.eclipse.jdt.core.JavaModelException; import org.eclipse.jdt.core.Signature; import org.eclipse.jdt.core.dom.AST; import org.eclipse.jdt.core.dom.ASTNode; import org.eclipse.jdt.core.dom.ASTParser; import org.eclipse.jdt.core.dom.FieldAccess; import org.eclipse.jdt.core.dom.NodeFinder; import org.eclipse.jdt.core.dom.QualifiedName; import org.eclipse.jdt.core.dom.StructuralPropertyDescriptor; import org.eclipse.jdt.core.dom.ThisExpression; import org.eclipse.jdt.debug.core.IJavaDebugTarget; import org.eclipse.jdt.debug.core.IJavaObject; import org.eclipse.jdt.debug.core.IJavaReferenceType; import org.eclipse.jdt.debug.core.IJavaStackFrame; import org.eclipse.jdt.debug.core.IJavaThread; import org.eclipse.jdt.debug.core.IJavaType; import org.eclipse.jdt.debug.core.IJavaValue; import org.eclipse.jdt.debug.core.IJavaVariable; import org.eclipse.jdt.internal.debug.core.JDIDebugPlugin; import org.eclipse.jdt.internal.debug.core.logicalstructures.JDIPlaceholderVariable; import org.eclipse.jdt.internal.debug.eval.ast.engine.ASTEvaluationEngine; import org.eclipse.jdt.ui.JavaUI; import org.eclipse.jdt.ui.SharedASTProvider; import org.eclipse.jdt.ui.text.java.hover.IJavaEditorTextHover; import org.eclipse.jface.preference.IPreferenceStore; import org.eclipse.jface.text.BadLocationException; import org.eclipse.jface.text.IDocument; import org.eclipse.jface.text.IInformationControlCreator; import org.eclipse.jface.text.IRegion; import org.eclipse.jface.text.ITextHoverExtension; import org.eclipse.jface.text.ITextHoverExtension2; import org.eclipse.jface.text.ITextViewer; import org.eclipse.ui.IEditorInput; import org.eclipse.ui.IEditorPart; public class JavaDebugHover implements IJavaEditorTextHover, ITextHoverExtension, ITextHoverExtension2 { private IEditorPart fEditor; /* (non-Javadoc) * @see org.eclipse.jdt.ui.text.java.hover.IJavaEditorTextHover#setEditor(org.eclipse.ui.IEditorPart) */ public void setEditor(IEditorPart editor) { fEditor = editor; } /* (non-Javadoc) * @see org.eclipse.jface.text.ITextHover#getHoverRegion(org.eclipse.jface.text.ITextViewer, int) */ public IRegion getHoverRegion(ITextViewer textViewer, int offset) { return JavaWordFinder.findWord(textViewer.getDocument(), offset); } /** * Returns the stack frame in which to search for variables, or <code>null</code> * if none. * * @return the stack frame in which to search for variables, or <code>null</code> * if none */ protected IJavaStackFrame getFrame() { IAdaptable adaptable = DebugUITools.getDebugContext(); if (adaptable != null) { return (IJavaStackFrame) adaptable.getAdapter(IJavaStackFrame.class); } return null; } /* (non-Javadoc) * @see org.eclipse.jface.text.ITextHover#getHoverInfo(org.eclipse.jface.text.ITextViewer, org.eclipse.jface.text.IRegion) */ public String getHoverInfo(ITextViewer textViewer, IRegion hoverRegion) { Object object = getHoverInfo2(textViewer, hoverRegion); if (object instanceof IVariable) { IVariable var = (IVariable) object; return getVariableText(var); } return null; } /** * Returns a local variable in the given frame based on the hover region * or <code>null</code> if none. * * @return local variable or <code>null</code> */ private IVariable resolveLocalVariable(IJavaStackFrame frame, ITextViewer textViewer, IRegion hoverRegion) { if (frame != null) { try { IDocument document = textViewer.getDocument(); if (document != null) { String variableName = document.get(hoverRegion.getOffset(), hoverRegion.getLength()); return findLocalVariable(frame, variableName); } } catch (BadLocationException x) { } } return null; } /** * Returns a local variable in the given frame based on the the given name * or <code>null</code> if none. * * @return local variable or <code>null</code> */ private IVariable findLocalVariable(IJavaStackFrame frame, String variableName) { if (frame != null) { try { return frame.findVariable(variableName); } catch (DebugException x) { if (x.getStatus().getCode() != IJavaThread.ERR_THREAD_NOT_SUSPENDED) { JDIDebugUIPlugin.log(x); } } } return null; } /** * Returns HTML text for the given variable */ private static String getVariableText(IVariable variable) { StringBuffer buffer = new StringBuffer(); JDIModelPresentation modelPresentation = getModelPresentation(); buffer.append("<p><pre>"); //$NON-NLS-1$ String variableText = modelPresentation.getVariableText((IJavaVariable) variable); buffer.append(replaceHTMLChars(variableText)); buffer.append("</pre></p>"); //$NON-NLS-1$ modelPresentation.dispose(); if (buffer.length() > 0) { return buffer.toString(); } return null; } /** * Replaces reserved HTML characters in the given string with * their escaped equivalents. This is to ensure that variable * values containing reserved characters are correctly displayed. */ private static String replaceHTMLChars(String variableText) { StringBuffer buffer = new StringBuffer(variableText.length()); char[] characters = variableText.toCharArray(); for (int i = 0; i < characters.length; i++) { char character = characters[i]; switch (character) { case '<': buffer.append("<"); //$NON-NLS-1$ break; case '>': buffer.append(">"); //$NON-NLS-1$ break; case '&': buffer.append("&"); //$NON-NLS-1$ break; case '"': buffer.append("""); //$NON-NLS-1$ break; default: buffer.append(character); } } return buffer.toString(); } /** * Returns a configured model presentation for use displaying variables. */ private static JDIModelPresentation getModelPresentation() { JDIModelPresentation presentation = new JDIModelPresentation(); String[][] booleanPrefs = { { IJDIPreferencesConstants.PREF_SHOW_QUALIFIED_NAMES, JDIModelPresentation.DISPLAY_QUALIFIED_NAMES } }; String viewId = IDebugUIConstants.ID_VARIABLE_VIEW; for (int i = 0; i < booleanPrefs.length; i++) { boolean preferenceValue = getBooleanPreferenceValue(viewId, booleanPrefs[i][0]); presentation.setAttribute(booleanPrefs[i][1], (preferenceValue ? Boolean.TRUE : Boolean.FALSE)); } return presentation; } /** * Returns the value of this filters preference (on/off) for the given * view. * * @param part * @return boolean */ public static boolean getBooleanPreferenceValue(String id, String preference) { String compositeKey = id + "." + preference; //$NON-NLS-1$ IPreferenceStore store = JDIDebugUIPlugin.getDefault().getPreferenceStore(); boolean value = false; if (store.contains(compositeKey)) { value = store.getBoolean(compositeKey); } else { value = store.getBoolean(preference); } return value; } /* (non-Javadoc) * @see org.eclipse.jface.text.ITextHoverExtension#getHoverControlCreator() */ public IInformationControlCreator getHoverControlCreator() { return new ExpressionInformationControlCreator(); } /* (non-Javadoc) * @see org.eclipse.jface.text.ITextHoverExtension2#getHoverInfo2(org.eclipse.jface.text.ITextViewer, org.eclipse.jface.text.IRegion) */ public Object getHoverInfo2(ITextViewer textViewer, IRegion hoverRegion) { IJavaStackFrame frame = getFrame(); if (frame != null) { // first check for 'this' - code resolve does not resolve java elements for 'this' IDocument document = textViewer.getDocument(); if (document != null) { try { String variableName = document.get(hoverRegion.getOffset(), hoverRegion.getLength()); if (variableName.equals("this")) { //$NON-NLS-1$ try { IJavaVariable variable = frame.findVariable(variableName); if (variable != null) { return variable; } } catch (DebugException e) { return null; } } } catch (BadLocationException e) { return null; } } ICodeAssist codeAssist = null; if (fEditor != null) { IEditorInput input = fEditor.getEditorInput(); Object element = JavaUI.getWorkingCopyManager().getWorkingCopy(input); if (element == null) { element = input.getAdapter(IClassFile.class); } if (element instanceof ICodeAssist) { codeAssist = ((ICodeAssist) element); } } if (codeAssist == null) { return resolveLocalVariable(frame, textViewer, hoverRegion); } IJavaElement[] resolve = null; try { resolve = codeAssist.codeSelect(hoverRegion.getOffset(), 0); } catch (JavaModelException e1) { resolve = new IJavaElement[0]; } try { for (int i = 0; i < resolve.length; i++) { IJavaElement javaElement = resolve[i]; if (javaElement instanceof IField) { IField field = (IField) javaElement; IJavaVariable variable = null; IJavaDebugTarget debugTarget = (IJavaDebugTarget) frame.getDebugTarget(); if (Flags.isStatic(field.getFlags())) { IJavaType[] javaTypes = debugTarget .getJavaTypes(field.getDeclaringType().getFullyQualifiedName()); if (javaTypes != null) { for (int j = 0; j < javaTypes.length; j++) { IJavaType type = javaTypes[j]; if (type instanceof IJavaReferenceType) { IJavaReferenceType referenceType = (IJavaReferenceType) type; variable = referenceType.getField(field.getElementName()); } if (variable != null) { break; } } } if (variable == null) { // the class is not loaded yet, but may be an in-lined primitive constant Object constant = field.getConstant(); if (constant != null) { IJavaValue value = null; if (constant instanceof Integer) { value = debugTarget.newValue(((Integer) constant).intValue()); } else if (constant instanceof Byte) { value = debugTarget.newValue(((Byte) constant).byteValue()); } else if (constant instanceof Boolean) { value = debugTarget.newValue(((Boolean) constant).booleanValue()); } else if (constant instanceof Character) { value = debugTarget.newValue(((Character) constant).charValue()); } else if (constant instanceof Double) { value = debugTarget.newValue(((Double) constant).doubleValue()); } else if (constant instanceof Float) { value = debugTarget.newValue(((Float) constant).floatValue()); } else if (constant instanceof Long) { value = debugTarget.newValue(((Long) constant).longValue()); } else if (constant instanceof Short) { value = debugTarget.newValue(((Short) constant).shortValue()); } else if (constant instanceof String) { value = debugTarget.newValue((String) constant); } if (value != null) { variable = new JDIPlaceholderVariable(field.getElementName(), value); } } if (variable == null) { return null; // class not loaded yet and not a constant } } } else { if (!frame.isStatic() && !frame.isNative()) { // ensure that we only resolve a field access on 'this': if (!(codeAssist instanceof ITypeRoot)) { return null; } ITypeRoot typeRoot = (ITypeRoot) codeAssist; ASTNode root = SharedASTProvider.getAST(typeRoot, SharedASTProvider.WAIT_NO, null); if (root == null) { ASTParser parser = ASTParser.newParser(AST.JLS4); parser.setSource(typeRoot); parser.setFocalPosition(hoverRegion.getOffset()); root = parser.createAST(null); } ASTNode node = NodeFinder.perform(root, hoverRegion.getOffset(), hoverRegion.getLength()); if (node == null) { return null; } StructuralPropertyDescriptor locationInParent = node.getLocationInParent(); if (locationInParent == FieldAccess.NAME_PROPERTY) { FieldAccess fieldAccess = (FieldAccess) node.getParent(); if (!(fieldAccess.getExpression() instanceof ThisExpression)) { return null; } } else if (locationInParent == QualifiedName.NAME_PROPERTY) { return null; } String typeSignature = Signature.createTypeSignature( field.getDeclaringType().getFullyQualifiedName(), true); typeSignature = typeSignature.replace('.', '/'); IJavaObject ths = frame.getThis(); if (ths != null) { variable = ths.getField(field.getElementName(), typeSignature); } } } if (variable != null) { return variable; } break; } if (javaElement instanceof ILocalVariable) { ILocalVariable var = (ILocalVariable) javaElement; IJavaElement parent = var.getParent(); while (!(parent instanceof IMethod) && parent != null) { parent = parent.getParent(); } if (parent instanceof IMethod) { IMethod method = (IMethod) parent; boolean equal = false; if (method.isBinary()) { // compare resolved signatures if (method.getSignature().equals(frame.getSignature())) { equal = true; } } else { // compare unresolved signatures if (((frame.isConstructor() && method.isConstructor()) || frame.getMethodName().equals(method.getElementName())) && frame.getDeclaringTypeName() .endsWith(method.getDeclaringType().getElementName()) && frame.getArgumentTypeNames().size() == method.getNumberOfParameters()) { equal = true; } else { // Finding variables in anonymous class int index = frame.getDeclaringTypeName().indexOf('$'); if (index > 0) { String name = frame.getDeclaringTypeName().substring(index + 1); try { Integer.getInteger(name); return findLocalVariable(frame, ASTEvaluationEngine.ANONYMOUS_VAR_PREFIX + var.getElementName()); } catch (NumberFormatException ex) { } } } } // find variable if equal or method is a Lambda Method if (equal || method.isLambdaMethod()) { return findLocalVariable(frame, var.getElementName()); } } break; } } } catch (CoreException e) { JDIDebugPlugin.log(e); } } return null; } /* (non-Javadoc) * @see org.eclipse.jface.text.ITextHoverExtension2#getInformationPresenterControlCreator() */ public IInformationControlCreator getInformationPresenterControlCreator() { return new ExpressionInformationControlCreator(); } }