////////////////////////////////////////////////////////////////////////////////
   // checkstyle: Checks Java source code for adherence to a set of rules.
   // Copyright (C) 2001-2019 the original author or authors.
   //
   // This library is free software; you can redistribute it and/or
   // modify it under the terms of the GNU Lesser General Public
   // License as published by the Free Software Foundation; either
   // version 2.1 of the License, or (at your option) any later version.
   //
  // This library is distributed in the hope that it will be useful,
  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  // Lesser General Public License for more details.
  //
  // You should have received a copy of the GNU Lesser General Public
  // License along with this library; if not, write to the Free Software
  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  ////////////////////////////////////////////////////////////////////////////////
  
  package com.puppycrawl.tools.checkstyle.checks.coding;
  
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.Set;
  import java.util.stream.Collectors;
  
  import com.puppycrawl.tools.checkstyle.StatelessCheck;
  import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
  import com.puppycrawl.tools.checkstyle.api.DetailAST;
  import com.puppycrawl.tools.checkstyle.api.FullIdent;
  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
  import com.puppycrawl.tools.checkstyle.utils.AnnotationUtil;
  import com.puppycrawl.tools.checkstyle.utils.CheckUtil;
  
  /**
   * <p>
   * This check can be used to ensure that types are not declared to be thrown.
   * Declaring that a method throws {@code java.lang.Error} or
   * {@code java.lang.RuntimeException} is almost never acceptable.
   * </p>
   * <ul>
   * <li>
   * Property {@code illegalClassNames} - Specify throw class names to reject.
   * Default value is {@code java.lang.Throwable, RuntimeException, Error, Throwable,
   * java.lang.Error, java.lang.RuntimeException}.
   * </li>
   * <li>
   * Property {@code ignoredMethodNames} - Specify names of methods to ignore.
   * Default value is {@code finalize}.
   * </li>
   * <li>
   * Property {@code ignoreOverriddenMethods} - allow to ignore checking overridden methods
   * (marked with {@code Override} or {@code java.lang.Override} annotation).
   * Default value is {@code true}.
   * </li>
   * </ul>
   * <p>
   * To configure the check:
   * </p>
   * <pre>
   * &lt;module name="IllegalThrows"/&gt;
   * </pre>
   * <p>
   * To configure the check rejecting throws NullPointerException from methods:
   * </p>
   * <pre>
   * &lt;module name="IllegalThrows"&gt;
   *   &lt;property name="illegalClassNames" value="NullPointerException"/&gt;
   * &lt;/module&gt;
   * </pre>
   * <p>
   * To configure the check ignoring method named "foo()":
   * </p>
   * <pre>
   * &lt;module name="IllegalThrows"&gt;
   *   &lt;property name="ignoredMethodNames" value="foo"/&gt;
   * &lt;/module&gt;
   * </pre>
   * <p>
   * To configure the check to warn on overridden methods:
   * </p>
   * <pre>
   * &lt;module name=&quot;IllegalThrows&quot;&gt;
   *   &lt;property name=&quot;ignoreOverriddenMethods&quot; value=&quot;false&quot;/&gt;
   * &lt;/module&gt;
   * </pre>
   *
   * @since 4.0
   */
  @StatelessCheck
  public final class IllegalThrowsCheck extends AbstractCheck {
  
      /**
       * A key is pointing to the warning message text in "messages.properties"
       * file.
       */
      public static final String MSG_KEY = "illegal.throw";
  
      /** Specify names of methods to ignore. */
     private final Set<String> ignoredMethodNames =
         Arrays.stream(new String[] {"finalize", }).collect(Collectors.toSet());
 
     /** Specify throw class names to reject. */
     private final Set<String> illegalClassNames = Arrays.stream(
         new String[] {"Error", "RuntimeException", "Throwable", "java.lang.Error",
                       "java.lang.RuntimeException", "java.lang.Throwable", })
         .collect(Collectors.toSet());
 
     /**
      * Allow to ignore checking overridden methods (marked with {@code Override}
      * or {@code java.lang.Override} annotation).
      */
     private boolean ignoreOverriddenMethods = true;
 
     /**
      * Setter to specify throw class names to reject.
      *
      * @param classNames
      *            array of illegal exception classes
      */
     public void setIllegalClassNames(final String... classNames) {
         illegalClassNames.clear();
         illegalClassNames.addAll(
                 CheckUtil.parseClassNames(classNames));
     }
 
     @Override
     public int[] getDefaultTokens() {
         return getRequiredTokens();
     }
 
     @Override
     public int[] getRequiredTokens() {
         return new int[] {TokenTypes.LITERAL_THROWS};
     }
 
     @Override
     public int[] getAcceptableTokens() {
         return getRequiredTokens();
     }
 
     @Override
     public void visitToken(DetailAST detailAST) {
         final DetailAST methodDef = detailAST.getParent();
         // Check if the method with the given name should be ignored.
         if (!isIgnorableMethod(methodDef)) {
             DetailAST token = detailAST.getFirstChild();
             while (token != null) {
                 if (token.getType() != TokenTypes.COMMA) {
                     final FullIdent ident = FullIdent.createFullIdent(token);
                     if (illegalClassNames.contains(ident.getText())) {
                         log(token, MSG_KEY, ident.getText());
                     }
                 }
                 token = token.getNextSibling();
             }
         }
     }
 
     /**
      * Checks if current method is ignorable due to Check's properties.
      * @param methodDef {@link TokenTypes#METHOD_DEF METHOD_DEF}
      * @return true if method is ignorable.
      */
     private boolean isIgnorableMethod(DetailAST methodDef) {
         return shouldIgnoreMethod(methodDef.findFirstToken(TokenTypes.IDENT).getText())
             || ignoreOverriddenMethods
                && (AnnotationUtil.containsAnnotation(methodDef, "Override")
                   || AnnotationUtil.containsAnnotation(methodDef, "java.lang.Override"));
     }
 
     /**
      * Check if the method is specified in the ignore method list.
      * @param name the name to check
      * @return whether the method with the passed name should be ignored
      */
     private boolean shouldIgnoreMethod(String name) {
         return ignoredMethodNames.contains(name);
     }
 
     /**
      * Setter to specify names of methods to ignore.
      * @param methodNames array of ignored method names
      */
     public void setIgnoredMethodNames(String... methodNames) {
         ignoredMethodNames.clear();
         Collections.addAll(ignoredMethodNames, methodNames);
     }
 
     /**
      * Setter to allow to ignore checking overridden methods
      * (marked with {@code Override} or {@code java.lang.Override} annotation).
      * @param ignoreOverriddenMethods Check's property.
      */
     public void setIgnoreOverriddenMethods(boolean ignoreOverriddenMethods) {
         this.ignoreOverriddenMethods = ignoreOverriddenMethods;
     }
 
 }