diff --git a/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredHubRequest.java b/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredHubRequest.java
index 603d3c4..eb635d8 100644
--- a/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredHubRequest.java
+++ b/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredHubRequest.java
@@ -24,6 +24,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * Fields common to all types of CredHub requests.
@@ -135,18 +136,14 @@ public class CredHubRequest<T> {
 		if (additionalPermissions != null ?
 				additionalPermissions.equals(that.additionalPermissions) : that.additionalPermissions == null) return false;
 		if (details != null ? !details.equals(that.details) : that.details != null) return false;
+		if (mode != null ? !mode.equals(that.mode) : that.mode != null) return false;
 
 		return true;
 	}
 
 	@Override
 	public int hashCode() {
-		int result = (overwrite ? 1 : 0);
-		result = 31 * result + (name != null ? name.hashCode() : 0);
-		result = 31 * result + (credentialType != null ? credentialType.hashCode() : 0);
-		result = 31 * result + (additionalPermissions != null ? additionalPermissions.hashCode() : 0);
-		result = 31 * result + (details != null ? details.hashCode() : 0);
-		return result;
+		return Objects.hash(overwrite, name, credentialType, additionalPermissions, details, mode);
 	}
 
 	/**
diff --git a/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialDetails.java b/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialDetails.java
index 49c8f94..d2c3a94 100644
--- a/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialDetails.java
+++ b/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialDetails.java
@@ -19,6 +19,8 @@ package org.springframework.credhub.support;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
 
+import java.util.Objects;
+
 /**
  * The details of a credential that has been written to CredHub. Clients don't
  * typically instantiate objects of this type, but will receive them in response
@@ -28,18 +30,21 @@ import com.fasterxml.jackson.annotation.JsonTypeInfo;
  * @author Scott Frederick
  */
 public class CredentialDetails<T> extends CredentialSummary {
-	private String id;
+	private final String id;
 	
 	@JsonProperty("type")
-	private CredentialType credentialType;
+	private final CredentialType credentialType;
 
 	@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.EXTERNAL_PROPERTY, property = "type")
-	private T value;
+	private final T value;
 
 	/**
 	 * Create a {@link CredentialDetails}.
 	 */
 	public CredentialDetails() {
+		this.id = null;
+		this.credentialType = null;
+		this.value = null;
 	}
 
 	/**
@@ -107,13 +112,7 @@ public class CredentialDetails<T> extends CredentialSummary {
 
 	@Override
 	public int hashCode() {
-		int result = id != null ? id.hashCode() : 0;
-		result = 31 * result + (name != null ? name.hashCode() : 0);
-		result = 31 * result + (credentialType != null ? credentialType.hashCode() : 0);
-		result = 31 * result + (value != null ? value.hashCode() : 0);
-		result = 31 * result
-				+ (versionCreatedAt != null ? versionCreatedAt.hashCode() : 0);
-		return result;
+		return Objects.hash(id, name, credentialType, value, versionCreatedAt);
 	}
 
 	@Override
diff --git a/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialDetailsData.java b/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialDetailsData.java
index 6f3ba6d..962d605 100644
--- a/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialDetailsData.java
+++ b/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialDetailsData.java
@@ -20,6 +20,7 @@ package org.springframework.credhub.support;
 
 import java.util.Arrays;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * A collection of {@link CredentialDetails}. Clients don't typically instantiate
@@ -29,12 +30,13 @@ import java.util.List;
  * @author Scott Frederick
  */
 public class CredentialDetailsData<T> {
-	private List<CredentialDetails<T>> data;
+	private final List<CredentialDetails<T>> data;
 
 	/**
 	 * Create a {@link CredentialDetailsData}.
 	 */
 	public CredentialDetailsData() {
+		this.data = null;
 	}
 
 	/**
@@ -74,9 +76,7 @@ public class CredentialDetailsData<T> {
 
 	@Override
 	public int hashCode() {
-		int result = super.hashCode();
-		result = 31 * result + (data != null ? data.hashCode() : 0);
-		return result;
+		return Objects.hashCode(data);
 	}
 
 	@Override
diff --git a/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialName.java b/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialName.java
index dbe148c..3abdf87 100644
--- a/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialName.java
+++ b/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialName.java
@@ -17,6 +17,7 @@
 package org.springframework.credhub.support;
 
 import java.util.Arrays;
+import java.util.Objects;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonInclude;
@@ -32,7 +33,7 @@ import org.springframework.util.StringUtils;
  */
 public class CredentialName {
 	@JsonIgnore
-	protected final String[] segments;
+	final String[] segments;
 
 	/**
 	 * Create a name from the provided value. The name must consist of segments
@@ -93,6 +94,6 @@ public class CredentialName {
 
 	@Override
 	public int hashCode() {
-		return Arrays.hashCode(segments);
+		return Objects.hashCode(segments);
 	}
 }
diff --git a/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialPath.java b/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialPath.java
index 68aa5bc..41ea4b5 100644
--- a/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialPath.java
+++ b/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialPath.java
@@ -16,6 +16,8 @@
 
 package org.springframework.credhub.support;
 
+import java.util.Objects;
+
 /**
  * The path to a credential that has been written to CredHub. Clients don't typically
  * instantiate objects of this type, but will receive them in response to requests.
@@ -23,12 +25,14 @@ package org.springframework.credhub.support;
  * @author Scott Frederick
  */
 public class CredentialPath {
-	protected String path;
+	private final String path;
 
 	/**
 	 * Create a {@link CredentialPath}. Intended for internal use.
 	 */
-	CredentialPath() {
+	@SuppressWarnings("unused")
+	private CredentialPath() {
+		this.path = null;
 	}
 
 	/**
@@ -65,7 +69,7 @@ public class CredentialPath {
 
 	@Override
 	public int hashCode() {
-		return path != null ? path.hashCode() : 0;
+		return Objects.hashCode(path);
 	}
 
 	@Override
diff --git a/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialPathData.java b/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialPathData.java
index 18e1b15..80fc3b8 100644
--- a/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialPathData.java
+++ b/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialPathData.java
@@ -18,6 +18,7 @@ package org.springframework.credhub.support;
 
 import java.util.Arrays;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * A collection of {@link CredentialPath}s. Clients don't typically instantiate
@@ -26,12 +27,14 @@ import java.util.List;
  * @author Scott Frederick
  */
 public class CredentialPathData {
-	private List<CredentialPath> paths;
+	private final List<CredentialPath> paths;
 
 	/**
 	 * Create a {@link CredentialPathData}.
 	 */
-	CredentialPathData() {
+	@SuppressWarnings("unused")
+	private CredentialPathData() {
+		this.paths = null;
 	}
 
 	/**
@@ -71,9 +74,7 @@ public class CredentialPathData {
 
 	@Override
 	public int hashCode() {
-		int result = super.hashCode();
-		result = 31 * result + (paths != null ? paths.hashCode() : 0);
-		return result;
+		return Objects.hashCode(paths);
 	}
 
 	@Override
diff --git a/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialPermissions.java b/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialPermissions.java
index ea550df..3337cc3 100644
--- a/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialPermissions.java
+++ b/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialPermissions.java
@@ -22,6 +22,7 @@ import org.springframework.credhub.support.permissions.CredentialPermission;
 
 import java.util.Arrays;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * A collection of {@link CredentialPermission}s. Clients don't typically instantiate
@@ -31,13 +32,16 @@ import java.util.List;
  * @author Scott Frederick
  */
 public class CredentialPermissions {
-	private CredentialName credentialName;
-	private List<CredentialPermission> permissions;
+	private final CredentialName credentialName;
+	private final List<CredentialPermission> permissions;
 
 	/**
 	 * Create a {@link CredentialPermissions}.
 	 */
-	public CredentialPermissions() {
+	@SuppressWarnings("unused")
+	private CredentialPermissions() {
+		this.credentialName = null;
+		this.permissions = null;
 	}
 
 	/**
@@ -93,8 +97,6 @@ public class CredentialPermissions {
 
 	@Override
 	public int hashCode() {
-		int result = credentialName != null ? credentialName.hashCode() : 0;
-		result = 31 * result + (permissions != null ? permissions.hashCode() : 0);
-		return result;
+		return Objects.hash(credentialName, permissions);
 	}
 }
diff --git a/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialSummary.java b/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialSummary.java
index f21e2d1..0fda702 100644
--- a/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialSummary.java
+++ b/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialSummary.java
@@ -17,6 +17,7 @@
 package org.springframework.credhub.support;
 
 import java.util.Date;
+import java.util.Objects;
 
 /**
  * A summary of a credential that has been written to CredHub. Clients don't typically
@@ -26,13 +27,15 @@ import java.util.Date;
  * @author Scott Frederick
  */
 public class CredentialSummary {
-	protected CredentialName name;
-	protected Date versionCreatedAt;
+	protected final CredentialName name;
+	protected final Date versionCreatedAt;
 
 	/**
 	 * Create a {@link CredentialSummary}. Intended for internal use.
 	 */
 	CredentialSummary() {
+		this.name = null;
+		this.versionCreatedAt = null;
 	}
 
 	/**
@@ -82,10 +85,7 @@ public class CredentialSummary {
 
 	@Override
 	public int hashCode() {
-		int result = name != null ? name.hashCode() : 0;
-		result = 31 * result
-				+ (versionCreatedAt != null ? versionCreatedAt.hashCode() : 0);
-		return result;
+		return Objects.hash(name, versionCreatedAt);
 	}
 
 	@Override
diff --git a/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialSummaryData.java b/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialSummaryData.java
index 6bcbee4..d4f03da 100644
--- a/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialSummaryData.java
+++ b/spring-credhub-core/src/main/java/org/springframework/credhub/support/CredentialSummaryData.java
@@ -18,6 +18,7 @@ package org.springframework.credhub.support;
 
 import java.util.Arrays;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * A collection of {@link CredentialSummary}s. Clients don't typically instantiate
@@ -27,12 +28,14 @@ import java.util.List;
  * @author Scott Frederick
  */
 public class CredentialSummaryData {
-	private List<CredentialSummary> credentials;
+	private final List<CredentialSummary> credentials;
 
 	/**
 	 * Create a {@link CredentialSummaryData}.
 	 */
-	CredentialSummaryData() {
+	@SuppressWarnings("unused")
+	private CredentialSummaryData() {
+		this.credentials = null;
 	}
 
 	/**
@@ -72,9 +75,7 @@ public class CredentialSummaryData {
 
 	@Override
 	public int hashCode() {
-		int result = super.hashCode();
-		result = 31 * result + (credentials != null ? credentials.hashCode() : 0);
-		return result;
+		return Objects.hashCode(credentials);
 	}
 
 	@Override
diff --git a/spring-credhub-core/src/main/java/org/springframework/credhub/support/StringCredential.java b/spring-credhub-core/src/main/java/org/springframework/credhub/support/StringCredential.java
index a770199..5c9691d 100644
--- a/spring-credhub-core/src/main/java/org/springframework/credhub/support/StringCredential.java
+++ b/spring-credhub-core/src/main/java/org/springframework/credhub/support/StringCredential.java
@@ -18,6 +18,8 @@ package org.springframework.credhub.support;
 
 import org.springframework.util.Assert;
 
+import java.util.Objects;
+
 /**
  * A base type for a credential that contains a single string value.
  *
@@ -50,7 +52,7 @@ public class StringCredential {
 
 	@Override
 	public int hashCode() {
-		return value != null ? value.hashCode() : 0;
+		return Objects.hashCode(value);
 	}
 
 	@Override
diff --git a/spring-credhub-core/src/main/java/org/springframework/credhub/support/permissions/Actor.java b/spring-credhub-core/src/main/java/org/springframework/credhub/support/permissions/Actor.java
index a119300..624d47b 100644
--- a/spring-credhub-core/src/main/java/org/springframework/credhub/support/permissions/Actor.java
+++ b/spring-credhub-core/src/main/java/org/springframework/credhub/support/permissions/Actor.java
@@ -22,6 +22,8 @@ import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonValue;
 import org.springframework.util.Assert;
 
+import java.util.Objects;
+
 import static org.springframework.credhub.support.permissions.ActorType.APP;
 import static org.springframework.credhub.support.permissions.ActorType.OAUTH_CLIENT;
 import static org.springframework.credhub.support.permissions.ActorType.USER;
@@ -32,8 +34,8 @@ import static org.springframework.credhub.support.permissions.ActorType.USER;
  * @author Scott Frederick
  */
 public class Actor {
-	private ActorType authType;
-	private String primaryIdentifier;
+	private final ActorType authType;
+	private final String primaryIdentifier;
 
 	/**
 	 * Create a new {@literal Actor}.
@@ -168,8 +170,6 @@ public class Actor {
 
 	@Override
 	public int hashCode() {
-		int result = authType.hashCode();
-		result = 31 * result + primaryIdentifier.hashCode();
-		return result;
+		return Objects.hash(authType, primaryIdentifier);
 	}
 }
diff --git a/spring-credhub-core/src/main/java/org/springframework/credhub/support/permissions/CredentialPermission.java b/spring-credhub-core/src/main/java/org/springframework/credhub/support/permissions/CredentialPermission.java
index a678136..a5aa935 100644
--- a/spring-credhub-core/src/main/java/org/springframework/credhub/support/permissions/CredentialPermission.java
+++ b/spring-credhub-core/src/main/java/org/springframework/credhub/support/permissions/CredentialPermission.java
@@ -26,6 +26,7 @@ import org.springframework.util.Assert;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * Permissions applied to a credential in CredHub. If provided when a
@@ -38,14 +39,15 @@ import java.util.List;
  * @author Scott Frederick
  */
 public class CredentialPermission {
-	private Actor actor;
+	private final Actor actor;
 
 	@JsonProperty
-	private List<Operation> operations;
+	private final List<Operation> operations;
 
 	/**
 	 * Create a {@literal CredentialPermission}.
 	 */
+	@SuppressWarnings("unused")
 	private CredentialPermission() {
 		this.actor = null;
 		this.operations = null;
@@ -129,9 +131,7 @@ public class CredentialPermission {
 
 	@Override
 	public int hashCode() {
-		int result = actor != null ? actor.hashCode() : 0;
-		result = 31 * result + (operations != null ? operations.hashCode() : 0);
-		return result;
+		return Objects.hash(actor, operations);
 	}
 
 	@Override