/**
* BSD-style license; for more info see http://pmd.sourceforge.net/license.html
*/
package net.sourceforge.pmd.lang.java.rule.logging;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import org.apache.commons.lang3.StringUtils;
import net.sourceforge.pmd.lang.java.ast.ASTArgumentList;
import net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceBody;
import net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceType;
import net.sourceforge.pmd.lang.java.ast.ASTExpression;
import net.sourceforge.pmd.lang.java.ast.ASTFieldDeclaration;
import net.sourceforge.pmd.lang.java.ast.ASTLiteral;
import net.sourceforge.pmd.lang.java.ast.ASTMethodDeclaration;
import net.sourceforge.pmd.lang.java.ast.ASTName;
import net.sourceforge.pmd.lang.java.ast.ASTPrimaryExpression;
import net.sourceforge.pmd.lang.java.ast.ASTPrimaryPrefix;
import net.sourceforge.pmd.lang.java.ast.ASTPrimarySuffix;
import net.sourceforge.pmd.lang.java.ast.ASTVariableDeclarator;
import net.sourceforge.pmd.lang.java.ast.ASTVariableDeclaratorId;
import net.sourceforge.pmd.lang.java.ast.AbstractJavaTypeNode;
import net.sourceforge.pmd.lang.java.rule.AbstractJavaRule;
import net.sourceforge.pmd.lang.java.symboltable.VariableNameDeclaration;
import net.sourceforge.pmd.lang.symboltable.NameDeclaration;
public class InvalidSlf4jMessageFormatRule extends AbstractJavaRule {
private static final Set<String> LOGGER_LEVELS;
private static final String LOGGER_CLASS = "org.slf4j.Logger";
static {
LOGGER_LEVELS = Collections
.unmodifiableSet(new HashSet<String>(Arrays.asList("trace", "debug", "info", "warn", "error")));
}
@Override
public Object visit(final ASTName node, final Object data) {
final NameDeclaration nameDeclaration = node.getNameDeclaration();
// ignore imports or methods
if (nameDeclaration == null || !(nameDeclaration instanceof VariableNameDeclaration)) {
return super.visit(node, data);
}
// ignore non slf4j logger
Class<?> type = ((VariableNameDeclaration) nameDeclaration).getType();
if (type == null || !type.getName().equals(LOGGER_CLASS)) {
return super.visit(node, data);
}
// get the node that contains the logger
final ASTPrimaryExpression parentNode = node.getFirstParentOfType(ASTPrimaryExpression.class);
// get the log level
final String method = parentNode.getFirstChildOfType(ASTPrimaryPrefix.class).getFirstChildOfType(ASTName.class)
.getImage().replace(nameDeclaration.getImage() + ".", "");
// ignore if not a log level
if (!LOGGER_LEVELS.contains(method)) {
return super.visit(node, data);
}
// find the arguments
final List<ASTExpression> argumentList = parentNode.getFirstChildOfType(ASTPrimarySuffix.class)
.getFirstDescendantOfType(ASTArgumentList.class).findChildrenOfType(ASTExpression.class);
final List<ASTPrimaryExpression> params = new ArrayList<ASTPrimaryExpression>(argumentList.size());
for (final ASTExpression astExpression : argumentList) {
ASTPrimaryExpression primaryExpression = astExpression.getFirstChildOfType(ASTPrimaryExpression.class);
if (primaryExpression != null) {
params.add(primaryExpression);
}
}
if (params.isEmpty()) {
// no params we could analyze
return super.visit(node, data);
}
final ASTPrimaryExpression messageParam = params.get(0);
// remove the message parameter
params.remove(0);
final int expectedArguments = expectedArguments(messageParam);
if (expectedArguments == 0) {
// ignore if we are not expecting arguments to format the message
// or if we couldn't analyze the message parameter
return super.visit(node, data);
}
// Remove throwable param, since it is shown separately.
// But only, if it is not used as a placeholder argument
if (params.size() > expectedArguments) {
removeThrowableParam(params);
}
if (params.size() < expectedArguments) {
addViolationWithMessage(data, node, "Missing arguments," + getExpectedMessage(params, expectedArguments));
} else if (params.size() > expectedArguments) {
addViolationWithMessage(data, node, "Too many arguments," + getExpectedMessage(params, expectedArguments));
}
return super.visit(node, data);
}
private boolean isNewThrowable(ASTPrimaryExpression last) {
// in case a new exception is created or the exception class is
// mentioned.
ASTClassOrInterfaceType classOrInterface = last.getFirstDescendantOfType(ASTClassOrInterfaceType.class);
if (classOrInterface != null && classOrInterface.getType() != null
&& Throwable.class.isAssignableFrom(classOrInterface.getType())) {
return true;
}
return false;
}
private boolean hasTypeThrowable(ASTPrimaryExpression last) {
// if the type could be determined already
if (last.getType() != null && Throwable.class.isAssignableFrom(last.getType())) {
return true;
}
return false;
}
private boolean isReferencingThrowable(ASTPrimaryExpression last) {
// check the variable type, if there is a reference by name
ASTName variable = last.getFirstDescendantOfType(ASTName.class);
if (variable != null && variable.getNameDeclaration() != null
&& variable.getNameDeclaration() instanceof VariableNameDeclaration) {
VariableNameDeclaration declaration = (VariableNameDeclaration) variable.getNameDeclaration();
if (declaration.getType() != null && Throwable.class.isAssignableFrom(declaration.getType())) {
return true;
}
// convention: Exception type names should end with Exception
if (declaration.getTypeImage() != null && declaration.getTypeImage().endsWith("Exception")) {
return true;
}
}
return false;
}
private void removeThrowableParam(final List<ASTPrimaryExpression> params) {
// Throwable parameters are the last one in the list, if any.
if (params.isEmpty()) {
return;
}
int lastIndex = params.size() - 1;
ASTPrimaryExpression last = params.get(lastIndex);
if (isNewThrowable(last) || hasTypeThrowable(last) || isReferencingThrowable(last)) {
params.remove(lastIndex);
return;
}
}
private String getExpectedMessage(final List<ASTPrimaryExpression> params, final int expectedArguments) {
return " expected " + expectedArguments + (expectedArguments > 1 ? " arguments " : " argument ") + "but have "
+ params.size();
}
private int expectedArguments(final ASTPrimaryExpression node) {
int count = 0;
// look if the logger have a literal message
if (node.getFirstDescendantOfType(ASTLiteral.class) != null) {
count = countPlaceholders(node);
} else if (node.getFirstDescendantOfType(ASTName.class) != null) {
final String variableName = node.getFirstDescendantOfType(ASTName.class).getImage();
// look if the message is defined locally
final List<ASTVariableDeclarator> localValiables = node.getFirstParentOfType(ASTMethodDeclaration.class)
.findDescendantsOfType(ASTVariableDeclarator.class);
count = getAmountOfExpectedArguments(variableName, localValiables);
if (count == 0) {
// look if the message is defined in a field
final List<ASTFieldDeclaration> fieldlist = node.getFirstParentOfType(ASTClassOrInterfaceBody.class)
.findDescendantsOfType(ASTFieldDeclaration.class);
// only look for ASTVariableDeclarator that are Fields
final List<ASTVariableDeclarator> fields = new ArrayList<ASTVariableDeclarator>(fieldlist.size());
for (final ASTFieldDeclaration astFieldDeclaration : fieldlist) {
fields.add(astFieldDeclaration.getFirstChildOfType(ASTVariableDeclarator.class));
}
count = getAmountOfExpectedArguments(variableName, fields);
}
}
return count;
}
private int getAmountOfExpectedArguments(final String variableName, final List<ASTVariableDeclarator> variables) {
for (final ASTVariableDeclarator astVariableDeclarator : variables) {
if (astVariableDeclarator.getFirstChildOfType(ASTVariableDeclaratorId.class).getImage()
.equals(variableName)) {
return countPlaceholders(astVariableDeclarator);
}
}
return 0;
}
private int countPlaceholders(final AbstractJavaTypeNode node) {
int result = 0; // zero means, no placeholders, or we could not analyze the message parameter
ASTLiteral stringLiteral = node.getFirstDescendantOfType(ASTLiteral.class);
if (stringLiteral != null) {
result = StringUtils.countMatches(stringLiteral.getImage(), "{}");
}
return result;
}
}