Treat a null Request.Body as a request with no body

CHANGELOG.md

@@ -1,3 +1,10 @@
+### Version 13.17
+
+* `Request` now accepts a `null` `Request.Body` and treats it as "no body", instead of throwing a
+  `NullPointerException` from `body()`, `charset()`, `isBinary()` and `length()`. A request with no
+  body reports a `null` body and charset, is binary, and has length 0. Its `toString()` prints the
+  request line and headers without a body (#1210).
+
 ### Version 13.16
 
 * Path-style expansion repeats the entry name for each collection or array value inside a map,

core/src/main/java/feign/Request.java

@@ -147,7 +147,7 @@ public static Request create(
    * @param httpMethod for the request.
    * @param url for the request.
    * @param headers to include.
-   * @param body of the request, can be {@literal null}
+   * @param body of the request, can be {@literal null}, meaning the request has no body.
    * @return a Request
    */
   public static Request create(
@@ -184,7 +184,7 @@ public static Request create(
     this.httpMethod = checkNotNull(method, "httpMethod of %s", method.name());
     this.url = checkNotNull(url, "url");
     this.headers = checkNotNull(headers, "headers of %s %s", method, url);
-    this.body = body;
+    this.body = body != null ? body : Body.empty();
     this.requestTemplate = requestTemplate;
     protocolVersion = ProtocolVersion.HTTP_1_1;
   }
@@ -308,7 +308,7 @@ public String toString() {
         builder.append(field).append(": ").append(value).append('\n');
       }
     }
-    if (body != null) {
+    if (body() != null) {
       builder.append('\n').append(body.asString());
     }
     return builder.toString();

core/src/test/java/feign/RequestTest.java

@@ -19,6 +19,8 @@
 import static org.assertj.core.api.Assertions.assertThat;
 
 import feign.Request.Body;
+import feign.Request.HttpMethod;
+import java.util.Collections;
 import org.junit.jupiter.api.Test;
 
 public class RequestTest {
@@ -34,4 +36,52 @@ void stringBodyIsEncodedWithUtf8NotThePlatformDefault() {
     assertThat(body.isBinary()).isFalse();
     assertThat(body.asString()).isEqualTo(content);
   }
+
+  @Test
+  void requestWithoutBodyHasNullBodyAndCharsetZeroLengthAndIsBinary() {
+    Request request = createGetRequestWithNullBody();
+
+    assertThat(request.body()).isNull();
+    assertThat(request.charset()).isNull();
+    assertThat(request.isBinary()).isTrue();
+    assertThat(request.length()).isZero();
+  }
+
+  @Test
+  void toStringOfRequestWithoutBodyOmitsBodySection() {
+    Request request = createGetRequestWithNullBody();
+
+    assertThat(request).hasToString("GET http://example.com HTTP/1.1\n");
+  }
+
+  @Test
+  void requestBuiltFromTemplateWithoutBodyOmitsBodyFromToString() {
+    Request request =
+        new RequestTemplate()
+            .method(HttpMethod.GET)
+            .target("http://example.com")
+            .resolve(Collections.emptyMap())
+            .request();
+
+    assertThat(request).hasToString("GET http://example.com HTTP/1.1\n");
+  }
+
+  @Test
+  void binaryBodyWithoutCharsetPrintsBinaryDataInToString() {
+    Request request =
+        new RequestTemplate()
+            .method(HttpMethod.POST)
+            .target("http://example.com")
+            .body(new byte[] {1, 2, 3}, null)
+            .resolve(Collections.emptyMap())
+            .request();
+
+    assertThat(request)
+        .hasToString("POST http://example.com HTTP/1.1\nContent-Length: 3\n\nBinary data");
+  }
+
+  private static Request createGetRequestWithNullBody() {
+    return Request.create(
+        HttpMethod.GET, "http://example.com", Collections.emptyMap(), (Body) null, null);
+  }
 }