001 /**
002 * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
003 */
004 package net.sourceforge.pmd.lang.java.typeresolution.rules;
005
006 import java.util.List;
007
008 import net.sourceforge.pmd.lang.ast.Node;
009 import net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceDeclaration;
010 import net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceType;
011 import net.sourceforge.pmd.lang.java.ast.ASTConstructorDeclaration;
012 import net.sourceforge.pmd.lang.java.ast.ASTExtendsList;
013 import net.sourceforge.pmd.lang.java.ast.ASTImplementsList;
014 import net.sourceforge.pmd.lang.java.ast.ASTImportDeclaration;
015 import net.sourceforge.pmd.lang.java.ast.ASTMethodDeclaration;
016 import net.sourceforge.pmd.lang.java.ast.ASTName;
017 import net.sourceforge.pmd.lang.java.rule.AbstractJavaRule;
018 import net.sourceforge.pmd.lang.rule.properties.BooleanProperty;
019
020 /**
021 * A method/constructor shouldn't explicitly throw java.lang.Exception, since it
022 * is unclear which exceptions that can be thrown from the methods. It might be
023 * difficult to document and understand the vague interfaces. Use either a class
024 * derived from RuntimeException or a checked exception. This version uses PMD's
025 * type resolution facilities, and can detect if the class implements or extends
026 * TestCase class
027 *
028 * @author <a mailto:trondandersen@c2i.net>Trond Andersen</a>
029 * @author acaplan
030 * @author Wouter Zelle
031 */
032 public class SignatureDeclareThrowsException extends AbstractJavaRule {
033
034 private static final BooleanProperty IGNORE_JUNIT_COMPLETELY_DESCRIPTOR = new BooleanProperty("IgnoreJUnitCompletely",
035 "Allow all methods in a JUnit testcase to throw Exceptions", false, 1.0f);
036
037 //Set to true when the class is determined to be a JUnit testcase
038 private boolean junitImported = false;
039
040 public SignatureDeclareThrowsException() {
041 definePropertyDescriptor(IGNORE_JUNIT_COMPLETELY_DESCRIPTOR);
042 }
043
044 @Override
045 public Object visit(ASTClassOrInterfaceDeclaration node, Object data) {
046 if (junitImported == true) {
047 return super.visit(node, data);
048 }
049
050 ASTImplementsList impl = node.getFirstChildOfType(ASTImplementsList.class);
051 if (impl != null && impl.jjtGetParent().equals(node)) {
052 for (int ix = 0; ix < impl.jjtGetNumChildren(); ix++) {
053 ASTClassOrInterfaceType type = (ASTClassOrInterfaceType) impl.jjtGetChild(ix);
054 if (isJUnitTest(type)) {
055 junitImported = true;
056 return super.visit(node, data);
057 }
058 }
059 }
060 if (node.jjtGetNumChildren() != 0 && node.jjtGetChild(0) instanceof ASTExtendsList) {
061 ASTClassOrInterfaceType type = (ASTClassOrInterfaceType) node.jjtGetChild(0).jjtGetChild(0);
062 if (isJUnitTest(type)) {
063 junitImported = true;
064 return super.visit(node, data);
065 }
066 }
067
068 return super.visit(node, data);
069 }
070
071 private boolean isJUnitTest(ASTClassOrInterfaceType type) {
072 Class<?> clazz = type.getType();
073 if (clazz == null) {
074 if ("junit.framework.Test".equals(type.getImage())) {
075 return true;
076 }
077 } else if (isJUnitTest(clazz)) {
078 return true;
079 } else {
080 while (clazz != null && !Object.class.equals(clazz)) {
081 for(Class<?> intf : clazz.getInterfaces()) {
082 if (isJUnitTest(intf)) {
083 return true;
084 }
085 }
086 clazz = clazz.getSuperclass();
087 }
088 }
089 return false;
090 }
091
092 private boolean isJUnitTest(Class<?> clazz) {
093 return clazz.getName().equals("junit.framework.Test");
094 }
095
096 @Override
097 public Object visit(ASTImportDeclaration node, Object o) {
098 if (node.getImportedName().indexOf("junit") != -1) {
099 junitImported = true;
100 }
101 return super.visit(node, o);
102 }
103
104
105 @Override
106 public Object visit(ASTMethodDeclaration methodDeclaration, Object o) {
107 if (junitImported && isAllowedMethod(methodDeclaration)) {
108 return super.visit(methodDeclaration, o);
109 }
110
111 checkExceptions(methodDeclaration, o);
112
113 return super.visit(methodDeclaration, o);
114 }
115
116 private boolean isAllowedMethod(ASTMethodDeclaration methodDeclaration) {
117 if (getProperty(IGNORE_JUNIT_COMPLETELY_DESCRIPTOR)) {
118 return true;
119 } else {
120 return methodDeclaration.getMethodName().equals("setUp") || methodDeclaration
121 .getMethodName().equals("tearDown");
122 }
123 }
124
125 @Override
126 public Object visit(ASTConstructorDeclaration constructorDeclaration, Object o) {
127 checkExceptions(constructorDeclaration, o);
128
129 return super.visit(constructorDeclaration, o);
130 }
131
132 /**
133 * Search the list of thrown exceptions for Exception
134 */
135 private void checkExceptions(Node method, Object o) {
136 List<ASTName> exceptionList = method.findDescendantsOfType(ASTName.class);
137 if (!exceptionList.isEmpty()) {
138 evaluateExceptions(exceptionList, o);
139 }
140 }
141
142 /**
143 * Checks all exceptions for possible violation on the exception declaration.
144 *
145 * @param exceptionList containing all exception for declaration
146 * @param context
147 */
148 private void evaluateExceptions(List<ASTName> exceptionList, Object context) {
149 for (ASTName exception: exceptionList) {
150 if (hasDeclaredExceptionInSignature(exception)) {
151 addViolation(context, exception);
152 }
153 }
154 }
155
156 /**
157 * Checks if the given value is defined as <code>Exception</code> and the parent is either
158 * a method or constructor declaration.
159 *
160 * @param exception to evaluate
161 * @return true if <code>Exception</code> is declared and has proper parents
162 */
163 private boolean hasDeclaredExceptionInSignature(ASTName exception) {
164 return exception.hasImageEqualTo("Exception") && isParentSignatureDeclaration(exception);
165 }
166
167 /**
168 * @param exception to evaluate
169 * @return true if parent node is either a method or constructor declaration
170 */
171 private boolean isParentSignatureDeclaration(ASTName exception) {
172 Node parent = exception.jjtGetParent().jjtGetParent();
173 return parent instanceof ASTMethodDeclaration || parent instanceof ASTConstructorDeclaration;
174 }
175 }
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