Pmd: [java] CloseResource - NullPointerException: Cannot invoke "net.sourceforge.pmd.lang.java.ast.TypeNode.getType()" because "refType" is null

[jorsol]

Affects PMD Version:

6.27.0

Description:

With PMD 6.26.0 no warning is show, updating PMD to 6.27.0 throws this warning:

Exception Stacktrace:

[INFO] --- maven-pmd-plugin:3.13.0:pmd (pmd) @ cm-api ---
[WARNING] Exception applying rule CloseResource on file /cm-api/src/main/java/com/demo/ex/problem/DataAccessExceptionMapper.java, continuing with next rule
java.lang.NullPointerException: Cannot invoke "net.sourceforge.pmd.lang.java.ast.TypeNode.getType()" because "refType" is null
    at net.sourceforge.pmd.lang.java.rule.errorprone.CloseResourceRule.isResourceTypeOrSubtype (CloseResourceRule.java:336)
    at net.sourceforge.pmd.lang.java.rule.errorprone.CloseResourceRule.getResourceVariables (CloseResourceRule.java:178)
    at net.sourceforge.pmd.lang.java.rule.errorprone.CloseResourceRule.checkForResources (CloseResourceRule.java:159)
    at net.sourceforge.pmd.lang.java.rule.errorprone.CloseResourceRule.visit (CloseResourceRule.java:153)
    at net.sourceforge.pmd.lang.java.ast.ASTMethodDeclaration.jjtAccept (ASTMethodDeclaration.java:37)
    at net.sourceforge.pmd.lang.java.rule.AbstractJavaRule.visit (AbstractJavaRule.java:220)
    at net.sourceforge.pmd.lang.java.rule.AbstractJavaRule.visit (AbstractJavaRule.java:267)
    at net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceBodyDeclaration.jjtAccept (ASTClassOrInterfaceBodyDeclaration.java:44)
    at net.sourceforge.pmd.lang.java.rule.AbstractJavaRule.visit (AbstractJavaRule.java:220)
    at net.sourceforge.pmd.lang.java.rule.AbstractJavaRule.visit (AbstractJavaRule.java:262)
    at net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceBody.jjtAccept (ASTClassOrInterfaceBody.java:35)
    at net.sourceforge.pmd.lang.java.rule.AbstractJavaRule.visit (AbstractJavaRule.java:220)
    at net.sourceforge.pmd.lang.java.rule.AbstractJavaRule.visit (AbstractJavaRule.java:232)
    at net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceDeclaration.jjtAccept (ASTClassOrInterfaceDeclaration.java:56)
    at net.sourceforge.pmd.lang.java.rule.AbstractJavaRule.visit (AbstractJavaRule.java:220)
    at net.sourceforge.pmd.lang.java.rule.AbstractJavaRule.visit (AbstractJavaRule.java:417)
    at net.sourceforge.pmd.lang.java.ast.ASTTypeDeclaration.jjtAccept (ASTTypeDeclaration.java:39)
    at net.sourceforge.pmd.lang.java.rule.AbstractJavaRule.visit (AbstractJavaRule.java:220)
    at net.sourceforge.pmd.lang.java.rule.AbstractJavaRule.visit (AbstractJavaRule.java:392)
    at net.sourceforge.pmd.lang.java.ast.ASTCompilationUnit.jjtAccept (ASTCompilationUnit.java:44)
    at net.sourceforge.pmd.lang.java.rule.AbstractJavaRule.visitAll (AbstractJavaRule.java:163)
    at net.sourceforge.pmd.lang.java.rule.AbstractJavaRule.apply (AbstractJavaRule.java:157)
    at net.sourceforge.pmd.lang.rule.AbstractDelegateRule.apply (AbstractDelegateRule.java:336)
    at net.sourceforge.pmd.RuleSet.apply (RuleSet.java:575)
    at net.sourceforge.pmd.RuleSets.apply (RuleSets.java:148)
    at net.sourceforge.pmd.SourceCodeProcessor.processSource (SourceCodeProcessor.java:194)
    at net.sourceforge.pmd.SourceCodeProcessor.processSourceCodeWithoutCache (SourceCodeProcessor.java:107)
    at net.sourceforge.pmd.SourceCodeProcessor.processSourceCode (SourceCodeProcessor.java:89)
    at net.sourceforge.pmd.SourceCodeProcessor.processSourceCode (SourceCodeProcessor.java:51)
    at net.sourceforge.pmd.processor.PmdRunnable.call (PmdRunnable.java:78)
    at net.sourceforge.pmd.processor.PmdRunnable.call (PmdRunnable.java:24)
    at java.util.concurrent.FutureTask.run (FutureTask.java:264)
    at java.util.concurrent.Executors$RunnableAdapter.call (Executors.java:515)
    at java.util.concurrent.FutureTask.run (FutureTask.java:264)
    at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1130)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:630)
    at java.lang.Thread.run (Thread.java:832)
[WARNING] There are 1 PMD processing errors:
[WARNING] /cm-api/src/main/java/com/demo/ex/problem/DataAccessExceptionMapper.java: NullPointerException: Cannot invoke "net.sourceforge.pmd.lang.java.ast.TypeNode.getType()" because "refType" is null

Running PMD through: Maven

[adangel]

Thanks for reporting. Would you mind to share the file /cm-api/src/main/java/com/demo/ex/problem/DataAccessExceptionMapper.java so that we can verify the fix on our side?

[jorsol]

Thanks for reporting. Would you mind to share the file /cm-api/src/main/java/com/demo/ex/problem/DataAccessExceptionMapper.java so that we can verify the fix on our side?

Sure, here is it:

package com.demo.ex.problem;

import java.net.URI;
import java.sql.SQLException;
import java.util.UUID;

import javax.ws.rs.core.Context;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.UriInfo;
import javax.ws.rs.ext.ExceptionMapper;
import javax.ws.rs.ext.Provider;

import org.jooq.exception.DataAccessException;
import org.postgresql.util.PSQLException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.zalando.problem.Problem;
import org.zalando.problem.ProblemBuilder;
import org.zalando.problem.Status;

@Provider
public class DataAccessExceptionMapper implements ExceptionMapper<DataAccessException> {

  private static final Logger log = LoggerFactory.getLogger(DataAccessExceptionMapper.class);

  @Context
  UriInfo uriInfo;

  @Override
  public Response toResponse(DataAccessException exception) {
    boolean uniqueViolation = false;
    var cause = exception.getCause();
    if (cause instanceof SQLException) {
      var sqlex = (SQLException) cause;
      uniqueViolation = sqlex.getSQLState().equals("23505");
    }

    ProblemBuilder builder = Problem.builder()
        .withStatus(uniqueViolation ? Status.CONFLICT : Status.INTERNAL_SERVER_ERROR)
        .withTitle(uniqueViolation ? "Duplicate resource creation" : "A data access error occurred")
        .withInstance(URI.create(uriInfo.getPath()));

    UUID uuid = UUID.randomUUID();
    if (log.isDebugEnabled()) {
      String format = "Code %s: %s";
      if (exception.getCause() != null) {
        if (exception.getCause().getCause() != null) {
          builder.withDetail(String.format(format, uuid,
              exception.getCause().getCause().getMessage()));
        } else {
          builder.withDetail(String.format(format, uuid,
              exception.getCause().getMessage()));
        }
      } else {
        builder.withDetail(String.format(format, uuid,
            exception.getMessage()));
      }
    } else {
      builder.withDetail(String.format("Code: %s", uuid));
    }

    if (log.isInfoEnabled()) {
      String logMessage = "[{}] Data access error occurred: {}";
      if (cause instanceof PSQLException) {
        var pgsqlex = (PSQLException) cause;
        log.info(logMessage, uuid, pgsqlex.getServerErrorMessage());
      } else {
        log.info(logMessage, uuid, cause.getMessage());
      }
    }

    return ProblemResponse.toResponse(builder.build());
  }

}

[adangel]

It turns out, this is actually a duplicate of #2755
It's the same NPE (at at net.sourceforge.pmd.lang.java.rule.errorprone.CloseResourceRule.isResourceTypeOrSubtype (CloseResourceRule.java:336)).
I just was confused about the new NPE message from jdk14 (JEP 358: Helpful NullPointerExceptions) ...