8371091: Improve the exception message of NullPointerException thrown by the methods in the default implementation of HttpRequest.Builder

src/java.net.http/share/classes/jdk/internal/net/http/HttpRequestBuilderImpl.java

@@ -203,7 +203,7 @@ public HttpRequest.Builder GET() {
 
     @Override
     public HttpRequest.Builder POST(BodyPublisher body) {
-        return method0("POST", requireNonNull(body));
+        return method0("POST", requireNonNull(body, "BodyPublisher must be non-null"));
     }
 
     @Override
@@ -218,12 +218,12 @@ public HttpRequest.Builder HEAD() {
 
     @Override
     public HttpRequest.Builder PUT(BodyPublisher body) {
-        return method0("PUT", requireNonNull(body));
+        return method0("PUT", requireNonNull(body, "BodyPublisher must be non-null"));
     }
 
     @Override
     public HttpRequest.Builder method(String method, BodyPublisher body) {
-        requireNonNull(method);
+        requireNonNull(method, "HTTP method must be non-null");
         if (method.isEmpty())
             throw newIAE("illegal method <empty string>");
         if (method.equals("CONNECT"))
@@ -234,7 +234,7 @@ public HttpRequest.Builder method(String method, BodyPublisher body) {
                     .replace("\r", "\\r")
                     .replace("\t", "\\t")
                     + "\"");
-        return method0(method, requireNonNull(body));
+        return method0(method, requireNonNull(body, "BodyPublisher must be non-null"));
     }
 
     private HttpRequest.Builder method0(String method, BodyPublisher body) {

test/jdk/java/net/httpclient/RequestBuilderTest.java

@@ -486,4 +486,41 @@ public void testEquals() {
         assertNotEquals(builder.build(), newBuilder(uri).header("x", "Z").build());
         assertNotEquals(builder.build(), newBuilder(uri).header("z", "y").build());
     }
+
+    @Test
+    public void testNullMessages() {
+        HttpRequest.Builder builder = HttpRequest.newBuilder();
+
+        try {
+            builder.method(null, null);
+            fail("builder.method(null, null) should have thrown NullPointerException");
+        } catch (NullPointerException e) {
+            assertTrue(e.getMessage().contains("HTTP method"),
+                "Expected exception message to contain 'HTTP method', but got: " + e.getMessage());
+        }
+
+        try {
+            builder.POST(null);
+            fail("builder.POST(null) should have thrown NullPointerException");
+        } catch (NullPointerException e) {
+            assertTrue(e.getMessage().contains("BodyPublisher"),
+                "Expected exception message to contain 'BodyPublisher', but got: " + e.getMessage());
+        }
+
+        try {
+            builder.PUT(null);
+            fail("builder.PUT(null) should have thrown NullPointerException");
+        } catch (NullPointerException e) {
+            assertTrue(e.getMessage().contains("BodyPublisher"),
+                "Expected exception message to contain 'BodyPublisher', but got: " + e.getMessage());
+        }
+
+        try {
+            builder.method("PATCH", null);
+            fail("builder.method(\"PATCH\", null) should have thrown NullPointerException");
+        } catch (NullPointerException e) {
+            assertTrue(e.getMessage().contains("BodyPublisher"),
+                "Expected exception message to contain 'BodyPublisher', but got: " + e.getMessage());
+        }
+    }
 }