Revisit MockPart constructors

Issue: SPR-15854

spring-test/src/main/java/org/springframework/mock/web/MockPart.java

@@ -27,13 +27,15 @@ import org.springframework.http.HttpHeaders;
 import org.springframework.http.MediaType;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
-import org.springframework.util.FileCopyUtils;
 
 /**
  * Mock implementation of {@code javax.servlet.http.Part}.
  *
  * @author Rossen Stoyanchev
- * @since 5.0
+ * @author Juergen Hoeller
+ * @since 4.3.12
+ * @see MockHttpServletRequest#addPart
+ * @see MockMultipartFile
  */
 public class MockPart implements Part {
 
@@ -55,19 +57,11 @@ public class MockPart implements Part {
 		this(name, null, content);
 	}
 
-	/**
-	 * Constructor for a part with a filename and streamed content.
-	 * @see #getHeaders()
-	 */
-	public MockPart(String name, @Nullable String filename, InputStream content) throws IOException {
-		this(name, filename, FileCopyUtils.copyToByteArray(content));
-	}
-
 	/**
 	 * Constructor for a part with a filename and byte[] content.
 	 * @see #getHeaders()
 	 */
-	private MockPart(String name, @Nullable String filename, @Nullable byte[] content) {
+	public MockPart(String name, @Nullable String filename, @Nullable byte[] content) {
 		Assert.hasLength(name, "Name must not be null");
 		this.name = name;
 		this.filename = filename;
@@ -104,6 +98,16 @@ public class MockPart implements Part {
 		return new ByteArrayInputStream(this.content);
 	}
 
+	@Override
+	public void write(String fileName) throws IOException {
+		throw new UnsupportedOperationException();
+	}
+
+	@Override
+	public void delete() throws IOException {
+		throw new UnsupportedOperationException();
+	}
+
 	@Override
 	@Nullable
 	public String getHeader(String name) {
@@ -122,20 +126,11 @@ public class MockPart implements Part {
 	}
 
 	/**
-	 * Return the {@link HttpHeaders} backing header related accessor methods.
+	 * Return the {@link HttpHeaders} backing header related accessor methods,
+	 * allowing for populating selected header entries.
 	 */
-	public HttpHeaders getHeaders() {
+	public final HttpHeaders getHeaders() {
 		return this.headers;
 	}
 
-	@Override
-	public void write(String fileName) throws IOException {
-		throw new UnsupportedOperationException();
-	}
-
-	@Override
-	public void delete() throws IOException {
-		throw new UnsupportedOperationException();
-	}
-
 }