prometheus · zeitlinger · Aug 14, 2025 · Aug 14, 2025 · Aug 14, 2025 · Aug 14, 2025
@@ -267,7 +267,8 @@
              -Xep:MissingSummary:OFF
              -Xep:LongDoubleConversion:OFF
              -Xep:StringSplitter:OFF
-              -XepExcludedPaths:.*/generated/.*
+              -XepExcludedPaths:(.*/generated/.*|.*/src/test/java/.*|.*/examples/.*|.*/integration-tests/.*)
+              -XepOpt:NullAway:AnnotatedPackages=io.prometheus.metrics
            </arg>
          </compilerArgs>
          <annotationProcessorPaths>
@@ -276,6 +277,11 @@
              <artifactId>error_prone_core</artifactId>
              <version>2.41.0</version>
            </path>
+            <path>
+              <groupId>com.uber.nullaway</groupId>
+              <artifactId>nullaway</artifactId>
+              <version>0.12.8</version>
+            </path>
            <!-- Other annotation processors go here.

            If 'annotationProcessorPaths' is set, processors will no longer be

@@ -1,6 +1,7 @@
 package io.prometheus.metrics.config;

 import java.util.Map;
+import javax.annotation.Nullable;

 /** Properties starting with io.prometheus.exemplars */
 public class ExemplarsProperties {
@@ -10,14 +11,14 @@ public class ExemplarsProperties {
  private static final String MAX_RETENTION_PERIOD_SECONDS = "maxRetentionPeriodSeconds";
  private static final String SAMPLE_INTERVAL_MILLISECONDS = "sampleIntervalMilliseconds";

-  private final Integer minRetentionPeriodSeconds;
-  private final Integer maxRetentionPeriodSeconds;
-  private final Integer sampleIntervalMilliseconds;
+  @Nullable private final Integer minRetentionPeriodSeconds;
+  @Nullable private final Integer maxRetentionPeriodSeconds;
+  @Nullable private final Integer sampleIntervalMilliseconds;

  private ExemplarsProperties(
-      Integer minRetentionPeriodSeconds,
-      Integer maxRetentionPeriodSeconds,
-      Integer sampleIntervalMilliseconds) {
+      @Nullable Integer minRetentionPeriodSeconds,
+      @Nullable Integer maxRetentionPeriodSeconds,
+      @Nullable Integer sampleIntervalMilliseconds) {
    this.minRetentionPeriodSeconds = minRetentionPeriodSeconds;
    this.maxRetentionPeriodSeconds = maxRetentionPeriodSeconds;
    this.sampleIntervalMilliseconds = sampleIntervalMilliseconds;
@@ -28,6 +29,7 @@ private ExemplarsProperties(
   *
   * <p>Default see {@code ExemplarSamplerConfig.DEFAULT_MIN_RETENTION_PERIOD_SECONDS}
   */
+  @Nullable
  public Integer getMinRetentionPeriodSeconds() {
    return minRetentionPeriodSeconds;
  }
@@ -37,6 +39,7 @@ public Integer getMinRetentionPeriodSeconds() {
   *
   * <p>Default see {@code ExemplarSamplerConfig.DEFAULT_MAX_RETENTION_PERIOD_SECONDS}
   */
+  @Nullable
  public Integer getMaxRetentionPeriodSeconds() {
    return maxRetentionPeriodSeconds;
  }
@@ -48,6 +51,7 @@ public Integer getMaxRetentionPeriodSeconds() {
   *
   * <p>Default see {@code ExemplarSamplerConfig.DEFAULT_SAMPLE_INTERVAL_MILLISECONDS}
   */
+  @Nullable
  public Integer getSampleIntervalMilliseconds() {
    return sampleIntervalMilliseconds;
  }
@@ -108,9 +112,9 @@ public static Builder builder() {

  public static class Builder {

-    private Integer minRetentionPeriodSeconds;
-    private Integer maxRetentionPeriodSeconds;
-    private Integer sampleIntervalMilliseconds;
+    @Nullable private Integer minRetentionPeriodSeconds;
+    @Nullable private Integer maxRetentionPeriodSeconds;
+    @Nullable private Integer sampleIntervalMilliseconds;

    private Builder() {}


@@ -5,6 +5,7 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import javax.annotation.Nullable;

 /** Properties starting with io.prometheus.exporter.filter */
 public class ExporterFilterProperties {
@@ -15,16 +16,16 @@ public class ExporterFilterProperties {
  public static final String METRIC_NAME_MUST_NOT_START_WITH = "metricNameMustNotStartWith";
  private static final String PREFIX = "io.prometheus.exporter.filter";

-  private final List<String> allowedNames;
-  private final List<String> excludedNames;
-  private final List<String> allowedPrefixes;
-  private final List<String> excludedPrefixes;
+  @Nullable private final List<String> allowedNames;
+  @Nullable private final List<String> excludedNames;
+  @Nullable private final List<String> allowedPrefixes;
+  @Nullable private final List<String> excludedPrefixes;

  private ExporterFilterProperties(
-      List<String> allowedNames,
-      List<String> excludedNames,
-      List<String> allowedPrefixes,
-      List<String> excludedPrefixes) {
+      @Nullable List<String> allowedNames,
+      @Nullable List<String> excludedNames,
+      @Nullable List<String> allowedPrefixes,
+      @Nullable List<String> excludedPrefixes) {
    this.allowedNames =
        allowedNames == null ? null : Collections.unmodifiableList(new ArrayList<>(allowedNames));
    this.excludedNames =
@@ -39,18 +40,22 @@ private ExporterFilterProperties(
            : Collections.unmodifiableList(new ArrayList<>(excludedPrefixes));
  }

+  @Nullable
  public List<String> getAllowedMetricNames() {
    return allowedNames;
  }

+  @Nullable
  public List<String> getExcludedMetricNames() {
    return excludedNames;
  }

+  @Nullable
  public List<String> getAllowedMetricNamePrefixes() {
    return allowedPrefixes;
  }

+  @Nullable
  public List<String> getExcludedMetricNamePrefixes() {
    return excludedPrefixes;
  }
@@ -79,10 +84,10 @@ public static Builder builder() {

  public static class Builder {

-    private List<String> allowedNames;
-    private List<String> excludedNames;
-    private List<String> allowedPrefixes;
-    private List<String> excludedPrefixes;
+    @Nullable private List<String> allowedNames;
+    @Nullable private List<String> excludedNames;
+    @Nullable private List<String> allowedPrefixes;
+    @Nullable private List<String> excludedPrefixes;

    private Builder() {}


@@ -1,18 +1,20 @@
 package io.prometheus.metrics.config;

 import java.util.Map;
+import javax.annotation.Nullable;

 /** Properties starting with io.prometheus.exporter.httpServer */
 public class ExporterHttpServerProperties {

  private static final String PORT = "port";
  private static final String PREFIX = "io.prometheus.exporter.httpServer";
-  private final Integer port;
+  @Nullable private final Integer port;

-  private ExporterHttpServerProperties(Integer port) {
+  private ExporterHttpServerProperties(@Nullable Integer port) {
    this.port = port;
  }

+  @Nullable
  public Integer getPort() {
    return port;
  }
@@ -34,7 +36,7 @@ public static Builder builder() {

  public static class Builder {

-    private Integer port;
+    @Nullable private Integer port;

    private Builder() {}


@@ -2,6 +2,7 @@

 import java.util.HashMap;
 import java.util.Map;
+import javax.annotation.Nullable;

 // TODO: JavaDoc is currently only in OpenTelemetryExporter.Builder. Look there for reference.
 public class ExporterOpenTelemetryProperties {
@@ -21,27 +22,27 @@ public class ExporterOpenTelemetryProperties {
      "resourceAttributes"; // otel.resource.attributes
  private static final String PREFIX = "io.prometheus.exporter.opentelemetry";

-  private final String protocol;
-  private final String endpoint;
+  @Nullable private final String endpoint;
+  @Nullable private final String protocol;
  private final Map<String, String> headers;
-  private final String interval;
-  private final String timeout;
-  private final String serviceName;
-  private final String serviceNamespace;
-  private final String serviceInstanceId;
-  private final String serviceVersion;
+  @Nullable private final String interval;
+  @Nullable private final String timeout;
+  @Nullable private final String serviceName;
+  @Nullable private final String serviceNamespace;
+  @Nullable private final String serviceInstanceId;
+  @Nullable private final String serviceVersion;
  private final Map<String, String> resourceAttributes;

  private ExporterOpenTelemetryProperties(
-      String protocol,
-      String endpoint,
+      @Nullable String protocol,
+      @Nullable String endpoint,
      Map<String, String> headers,
-      String interval,
-      String timeout,
-      String serviceName,
-      String serviceNamespace,
-      String serviceInstanceId,
-      String serviceVersion,
+      @Nullable String interval,
+      @Nullable String timeout,
+      @Nullable String serviceName,
+      @Nullable String serviceNamespace,
+      @Nullable String serviceInstanceId,
+      @Nullable String serviceVersion,
      Map<String, String> resourceAttributes) {
    this.protocol = protocol;
    this.endpoint = endpoint;
@@ -55,10 +56,12 @@ private ExporterOpenTelemetryProperties(
    this.resourceAttributes = resourceAttributes;
  }

+  @Nullable
  public String getProtocol() {
    return protocol;
  }

+  @Nullable
  public String getEndpoint() {
    return endpoint;
  }
@@ -67,26 +70,32 @@ public Map<String, String> getHeaders() {
    return headers;
  }

+  @Nullable
  public String getInterval() {
    return interval;
  }

+  @Nullable
  public String getTimeout() {
    return timeout;
  }

+  @Nullable
  public String getServiceName() {
    return serviceName;
  }

+  @Nullable
  public String getServiceNamespace() {
    return serviceNamespace;
  }

+  @Nullable
  public String getServiceInstanceId() {
    return serviceInstanceId;
  }

+  @Nullable
  public String getServiceVersion() {
    return serviceVersion;
  }
@@ -131,15 +140,15 @@ public static Builder builder() {

  public static class Builder {

-    private String protocol;
-    private String endpoint;
+    @Nullable private String protocol;
+    @Nullable private String endpoint;
    private final Map<String, String> headers = new HashMap<>();
-    private String interval;
-    private String timeout;
-    private String serviceName;
-    private String serviceNamespace;
-    private String serviceInstanceId;
-    private String serviceVersion;
+    @Nullable private String interval;
+    @Nullable private String timeout;
+    @Nullable private String serviceName;
+    @Nullable private String serviceNamespace;
+    @Nullable private String serviceInstanceId;
+    @Nullable private String serviceVersion;
    private final Map<String, String> resourceAttributes = new HashMap<>();

    private Builder() {}

@@ -1,6 +1,7 @@
 package io.prometheus.metrics.config;

 import java.util.Map;
+import javax.annotation.Nullable;

 /** Properties starting with io.prometheus.exporter */
 public class ExporterProperties {
@@ -11,14 +12,14 @@ public class ExporterProperties {
  private static final String EXEMPLARS_ON_ALL_METRIC_TYPES = "exemplarsOnAllMetricTypes";
  private static final String PREFIX = "io.prometheus.exporter";

-  private final Boolean includeCreatedTimestamps;
-  private final Boolean prometheusTimestampsInMs;
-  private final Boolean exemplarsOnAllMetricTypes;
+  @Nullable private final Boolean includeCreatedTimestamps;
+  @Nullable private final Boolean prometheusTimestampsInMs;
+  @Nullable private final Boolean exemplarsOnAllMetricTypes;

  private ExporterProperties(
-      Boolean includeCreatedTimestamps,
-      Boolean prometheusTimestampsInMs,
-      Boolean exemplarsOnAllMetricTypes) {
+      @Nullable Boolean includeCreatedTimestamps,
+      @Nullable Boolean prometheusTimestampsInMs,
+      @Nullable Boolean exemplarsOnAllMetricTypes) {
    this.includeCreatedTimestamps = includeCreatedTimestamps;
    this.prometheusTimestampsInMs = prometheusTimestampsInMs;
    this.exemplarsOnAllMetricTypes = exemplarsOnAllMetricTypes;
@@ -64,8 +65,8 @@ public static Builder builder() {

  public static class Builder {

-    private Boolean includeCreatedTimestamps;
-    private Boolean exemplarsOnAllMetricTypes;
+    @Nullable private Boolean includeCreatedTimestamps;
+    @Nullable private Boolean exemplarsOnAllMetricTypes;
    boolean prometheusTimestampsInMs;

    private Builder() {}