Polishing contribution

Closes gh-25647

spring-web/src/main/java/org/springframework/http/ContentDisposition.java

@@ -48,18 +48,6 @@ public final class ContentDisposition {
 	private static final String INVALID_HEADER_FIELD_PARAMETER_FORMAT =
 			"Invalid header field parameter format (as defined in RFC 5987)";
 
-	/**
-	 * The {@literal attachment} content-disposition type.
-	 */
-	private static final String ATTACHMENT = "attachment";
-	/**
-	 * The {@literal form-data} content-disposition type.
-	 */
-	private static final String FORM_DATA = "form-data";
-	/**
-	 * The {@literal inline} content-disposition type.
-	 */
-	private static final String INLINE = "inline";
 
 	@Nullable
 	private final String type;
@@ -105,8 +93,34 @@ public final class ContentDisposition {
 
 
 	/**
-	 * Return the disposition type, like for example {@literal inline}, {@literal attachment},
-	 * {@literal form-data}, or {@code null} if not defined.
+	 * Return whether the {@link #getType() type} is {@literal "attachment"}.
+	 * @since 5.3
+	 */
+	public boolean isAttachment() {
+		return (this.type != null && this.type.equalsIgnoreCase("attachment"));
+	}
+
+	/**
+	 * Return whether the {@link #getType() type} is {@literal "form-data"}.
+	 * @since 5.3
+	 */
+	public boolean isFormData() {
+		return (this.type != null && this.type.equalsIgnoreCase("form-data"));
+	}
+
+	/**
+	 * Return whether the {@link #getType() type} is {@literal "inline"}.
+	 * @since 5.3
+	 */
+	public boolean isInline() {
+		return (this.type != null && this.type.equalsIgnoreCase("inline"));
+	}
+
+	/**
+	 * Return the disposition type.
+	 * @see #isAttachment()
+	 * @see #isFormData()
+	 * @see #isInline()
 	 */
 	@Nullable
 	public String getType() {
@@ -186,30 +200,6 @@ public final class ContentDisposition {
 		return this.readDate;
 	}
 
-	/**
-	 * Return whether the {@link #getType() type} is {@literal attachment}.
-	 * @since 5.3
-	 */
-	public boolean isAttachment() {
-		return ATTACHMENT.equals(this.type);
-	}
-
-	/**
-	 * Return whether the {@link #getType() type} is {@literal form-data}.
-	 * @since 5.3
-	 */
-	public boolean isFormData() {
-		return FORM_DATA.equals(this.type);
-	}
-
-	/**
-	 * Return whether the {@link #getType() type} is {@literal inline}.
-	 * @since 5.3
-	 */
-	public boolean isInline() {
-		return INLINE.equals(this.type);
-	}
-
 	@Override
 	public boolean equals(@Nullable Object other) {
 		if (this == other) {
@@ -290,43 +280,37 @@ public final class ContentDisposition {
 
 
 	/**
-	 * Return a builder for a {@code ContentDisposition}.
-	 * @param type the disposition type like for example {@literal inline},
-	 * {@literal attachment}, or {@literal form-data}
-	 * @return the builder
+	 * Return a builder for a {@code ContentDisposition} of type {@literal "attachment"}.
+	 * @since 5.3
 	 */
-	public static Builder builder(String type) {
-		return new BuilderImpl(type);
+	public static Builder attachment() {
+		return builder("attachment");
 	}
 
 	/**
-	 * Return a builder for a {@code ContentDisposition} with
-	 * the {@link #ATTACHMENT attachment} type.
-	 * @return the builder
+	 * Return a builder for a {@code ContentDisposition} of type {@literal "form-data"}.
 	 * @since 5.3
 	 */
-	public static Builder attachment() {
-		return builder(ATTACHMENT);
+	public static Builder formData() {
+		return builder("form-data");
 	}
 
 	/**
-	 * Return a builder for a {@code ContentDisposition} with
-	 * the {@link #FORM_DATA form-data} type.
-	 * @return the builder
+	 * Return a builder for a {@code ContentDisposition} of type {@literal "inline"}.
 	 * @since 5.3
 	 */
-	public static Builder formData() {
-		return builder(FORM_DATA);
+	public static Builder inline() {
+		return builder("inline");
 	}
 
 	/**
-	 * Return a builder for a {@code ContentDisposition} with
-	 * the {@link #INLINE inline} type.
+	 * Return a builder for a {@code ContentDisposition}.
+	 * @param type the disposition type like for example {@literal inline},
+	 * {@literal attachment}, or {@literal form-data}
 	 * @return the builder
-	 * @since 5.3
 	 */
-	public static Builder inline() {
-		return builder(INLINE);
+	public static Builder builder(String type) {
+		return new BuilderImpl(type);
 	}
 
 	/**

spring-web/src/test/java/org/springframework/http/ContentDispositionTests.java

@@ -25,8 +25,6 @@ import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
-import static org.springframework.http.ContentDisposition.attachment;
-import static org.springframework.http.ContentDisposition.formData;
 
 /**
  * Unit tests for {@link ContentDisposition}
@@ -42,7 +40,7 @@ class ContentDispositionTests {
 	@SuppressWarnings("deprecation")
 	void parse() {
 		assertThat(parse("form-data; name=\"foo\"; filename=\"foo.txt\"; size=123"))
-				.isEqualTo(formData()
+				.isEqualTo(ContentDisposition.formData()
 						.name("foo")
 						.filename("foo.txt")
 						.size(123L)
@@ -52,7 +50,7 @@ class ContentDispositionTests {
 	@Test
 	void parseFilenameUnquoted() {
 		assertThat(parse("form-data; filename=unquoted"))
-				.isEqualTo(formData()
+				.isEqualTo(ContentDisposition.formData()
 						.filename("unquoted")
 						.build());
 	}
@@ -60,7 +58,7 @@ class ContentDispositionTests {
 	@Test  // SPR-16091
 	void parseFilenameWithSemicolon() {
 		assertThat(parse("attachment; filename=\"filename with ; semicolon.txt\""))
-				.isEqualTo(attachment()
+				.isEqualTo(ContentDisposition.attachment()
 						.filename("filename with ; semicolon.txt")
 						.build());
 	}
@@ -68,7 +66,7 @@ class ContentDispositionTests {
 	@Test
 	void parseEncodedFilename() {
 		assertThat(parse("form-data; name=\"name\"; filename*=UTF-8''%E4%B8%AD%E6%96%87.txt"))
-				.isEqualTo(formData()
+				.isEqualTo(ContentDisposition.formData()
 						.name("name")
 						.filename("中文.txt", StandardCharsets.UTF_8)
 						.build());
@@ -77,7 +75,7 @@ class ContentDispositionTests {
 	@Test // gh-24112
 	void parseEncodedFilenameWithPaddedCharset() {
 		assertThat(parse("attachment; filename*= UTF-8''some-file.zip"))
-				.isEqualTo(attachment()
+				.isEqualTo(ContentDisposition.attachment()
 						.filename("some-file.zip", StandardCharsets.UTF_8)
 						.build());
 	}
@@ -85,7 +83,7 @@ class ContentDispositionTests {
 	@Test
 	void parseEncodedFilenameWithoutCharset() {
 		assertThat(parse("form-data; name=\"name\"; filename*=test.txt"))
-				.isEqualTo(formData()
+				.isEqualTo(ContentDisposition.formData()
 						.name("name")
 						.filename("test.txt")
 						.build());
@@ -112,7 +110,7 @@ class ContentDispositionTests {
 		BiConsumer<String, String> tester = (description, filename) ->
 			assertThat(parse("form-data; name=\"file\"; filename=\"" + filename + "\"; size=123"))
 					.as(description)
-					.isEqualTo(formData().name("file").filename(filename).size(123L).build());
+					.isEqualTo(ContentDisposition.formData().name("file").filename(filename).size(123L).build());
 
 		tester.accept("Escaped quotes should be ignored",
 				"\\\"The Twilight Zone\\\".txt");
@@ -131,7 +129,7 @@ class ContentDispositionTests {
 	@SuppressWarnings("deprecation")
 	void parseWithExtraSemicolons() {
 		assertThat(parse("form-data; name=\"foo\";; ; filename=\"foo.txt\"; size=123"))
-				.isEqualTo(formData()
+				.isEqualTo(ContentDisposition.formData()
 						.name("foo")
 						.filename("foo.txt")
 						.size(123L)
@@ -150,7 +148,7 @@ class ContentDispositionTests {
 						"creation-date=\"" + creationTime.format(formatter) + "\"; " +
 						"modification-date=\"" + modificationTime.format(formatter) + "\"; " +
 						"read-date=\"" + readTime.format(formatter) + "\"")).isEqualTo(
-				attachment()
+				ContentDisposition.attachment()
 						.creationDate(creationTime)
 						.modificationDate(modificationTime)
 						.readDate(readTime)
@@ -167,7 +165,7 @@ class ContentDispositionTests {
 						"creation-date=\"-1\"; " +
 						"modification-date=\"-1\"; " +
 						"read-date=\"" + readTime.format(formatter) + "\"")).isEqualTo(
-				attachment()
+				ContentDisposition.attachment()
 						.readDate(readTime)
 						.build());
 	}
@@ -196,7 +194,7 @@ class ContentDispositionTests {
 	@SuppressWarnings("deprecation")
 	void format() {
 		assertThat(
-				formData()
+				ContentDisposition.formData()
 						.name("foo")
 						.filename("foo.txt")
 						.size(123L)
@@ -207,7 +205,7 @@ class ContentDispositionTests {
 	@Test
 	void formatWithEncodedFilename() {
 		assertThat(
-				formData()
+				ContentDisposition.formData()
 						.name("name")
 						.filename("中文.txt", StandardCharsets.UTF_8)
 						.build().toString())
@@ -217,7 +215,7 @@ class ContentDispositionTests {
 	@Test
 	void formatWithEncodedFilenameUsingUsAscii() {
 		assertThat(
-				formData()
+				ContentDisposition.formData()
 						.name("name")
 						.filename("test.txt", StandardCharsets.US_ASCII)
 						.build()
@@ -230,10 +228,10 @@ class ContentDispositionTests {
 
 		BiConsumer<String, String> tester = (input, output) -> {
 
-			assertThat(formData().filename(input).build().toString())
+			assertThat(ContentDisposition.formData().filename(input).build().toString())
 					.isEqualTo("form-data; filename=\"" + output + "\"");
 
-			assertThat(formData().filename(input, StandardCharsets.US_ASCII).build().toString())
+			assertThat(ContentDisposition.formData().filename(input, StandardCharsets.US_ASCII).build().toString())
 					.isEqualTo("form-data; filename=\"" + output + "\"");
 		};
 
@@ -263,7 +261,7 @@ class ContentDispositionTests {
 	@Test
 	void formatWithEncodedFilenameUsingInvalidCharset() {
 		assertThatIllegalArgumentException().isThrownBy(() ->
-				formData()
+				ContentDisposition.formData()
 						.name("name")
 						.filename("test.txt", StandardCharsets.UTF_16)
 						.build()