RemoteException.getMessage includes SerializableError parameters (#633)

RemoteException.getMessage (unsafe message) includes SerializableError parameters. RemoteException.getLogMessage (safe) is not impacted.

Author: carterkozak

changelog/@unreleased/pr-633.v2.yml

@@ -0,0 +1,5 @@
+type: improvement
+improvement:
+  description: RemoteException.getMessage (unsafe message) includes SerializableError parameters. RemoteException.getLogMessage (safe) is not impacted.
+  links:
+  - https://github.com/palantir/conjure-java-runtime-api/pull/633

errors/src/main/java/com/palantir/conjure/java/api/errors/RemoteException.java

@@ -30,11 +30,13 @@ public final class RemoteException extends RuntimeException implements SafeLogga
     private static final String ERROR_CODE = "errorCode";
     private static final String ERROR_NAME = "errorName";
 
-    private final String message;
     private final String stableMessage;
     private final SerializableError error;
     private final int status;
     private final List<Arg<?>> args;
+    // Lazily evaluated based on the stableMessage, errorInstanceId, and args.
+    @SuppressWarnings("MutableException")
+    private String unsafeMessage;
 
     /** Returns the error thrown by a remote process which caused an RPC call to fail. */
     public SerializableError getError() {
@@ -48,9 +50,8 @@ public int getStatus() {
 
     public RemoteException(SerializableError error, int status) {
         this.stableMessage = error.errorCode().equals(error.errorName())
-                ? String.format("RemoteException: %s", error.errorCode())
-                : String.format("RemoteException: %s (%s)", error.errorCode(), error.errorName());
-        this.message = this.stableMessage + " with instance ID " + error.errorInstanceId();
+                ? "RemoteException: " + error.errorCode()
+                : "RemoteException: " + error.errorCode() + " (" + error.errorName() + ")";
         this.error = error;
         this.status = status;
         this.args = Collections.unmodifiableList(Arrays.asList(
@@ -61,7 +62,31 @@ public RemoteException(SerializableError error, int status) {
 
     @Override
     public String getMessage() {
-        return message;
+        // This field is not used in most environments so the cost of computation may be avoided.
+        String messageValue = unsafeMessage;
+        if (messageValue == null) {
+            messageValue = renderUnsafeMessage();
+            unsafeMessage = messageValue;
+        }
+        return messageValue;
+    }
+
+    private String renderUnsafeMessage() {
+        StringBuilder builder = new StringBuilder()
+                .append(stableMessage)
+                .append(" with instance ID ")
+                .append(error.errorInstanceId());
+        if (!error.parameters().isEmpty()) {
+            builder.append(": {");
+            error.parameters()
+                    .forEach((name, unsafeValue) ->
+                            builder.append(name).append('=').append(unsafeValue).append(", "));
+            // remove the trailing space
+            builder.setLength(builder.length() - 1);
+            // replace the trailing comma with a close curly brace
+            builder.setCharAt(builder.length() - 1, '}');
+        }
+        return builder.toString();
     }
 
     @Override

errors/src/test/java/com/palantir/conjure/java/api/errors/RemoteExceptionTest.java

@@ -47,16 +47,19 @@ public void testJavaSerialization() {
     }
 
     @Test
-    public void testSuperMessage() {
+    public void testUnsafeMessage_differentCodeAndName() {
         SerializableError error = new SerializableError.Builder()
                 .errorCode("errorCode")
                 .errorName("errorName")
                 .errorInstanceId("errorId")
                 .build();
         assertThat(new RemoteException(error, 500).getMessage())
                 .isEqualTo("RemoteException: errorCode (errorName) with instance ID errorId");
+    }
 
-        error = new SerializableError.Builder()
+    @Test
+    public void testUnsafeMessage_sameCodeAndName() {
+        SerializableError error = new SerializableError.Builder()
                 .errorCode("errorCode")
                 .errorName("errorCode")
                 .errorInstanceId("errorId")
@@ -65,6 +68,31 @@ public void testSuperMessage() {
                 .isEqualTo("RemoteException: errorCode with instance ID errorId");
     }
 
+    @Test
+    public void testUnsafeMessage_oneParameter() {
+        SerializableError error = new SerializableError.Builder()
+                .errorCode("errorCode")
+                .errorName("errorName")
+                .errorInstanceId("errorId")
+                .putParameters("foo", "bar")
+                .build();
+        assertThat(new RemoteException(error, 500).getMessage())
+                .isEqualTo("RemoteException: errorCode (errorName) with instance ID errorId: {foo=bar}");
+    }
+
+    @Test
+    public void testUnsafeMessage_multipleParameters() {
+        SerializableError error = new SerializableError.Builder()
+                .errorCode("errorCode")
+                .errorName("errorName")
+                .errorInstanceId("errorId")
+                .putParameters("a", "b")
+                .putParameters("c", "d")
+                .build();
+        assertThat(new RemoteException(error, 500).getMessage())
+                .isEqualTo("RemoteException: errorCode (errorName) with instance ID errorId: {a=b, c=d}");
+    }
+
     @Test
     public void testLogMessageMessage() {
         SerializableError error = new SerializableError.Builder()
@@ -77,7 +105,19 @@ public void testLogMessageMessage() {
     }
 
     @Test
-    public void testArgsIsEmpty() {
+    public void testLogMessageMessageDoesNotIncludeParameters() {
+        SerializableError error = new SerializableError.Builder()
+                .errorCode("errorCode")
+                .errorName("errorName")
+                .errorInstanceId("errorId")
+                .putParameters("param", "value")
+                .build();
+        RemoteException remoteException = new RemoteException(error, 500);
+        assertThat(remoteException.getLogMessage()).isEqualTo("RemoteException: errorCode (errorName)");
+    }
+
+    @Test
+    public void testArgsContainsOnlyErrorInstanceId() {
         RemoteException remoteException = new RemoteException(
                 new SerializableError.Builder()
                         .errorCode("errorCode")