fix: add fix error message in Error thrown by API

Signed-off-by: zongz <[email protected]>

Author: zong-zhe

java/src/main/java/com/kcl/api/API.java

@@ -5,6 +5,7 @@
 import java.io.InputStream;
 import java.io.UncheckedIOException;
 import java.util.Map;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.StandardCopyOption;
 
@@ -651,15 +652,17 @@ public GetVersion_Result getVersion(GetVersion_Args args) throws Exception {
     private byte[] call(String name, byte[] args) throws Exception {
         byte[] result = callNative(name.getBytes(), args);
         if (result != null && startsWith(result, ERROR_PREFIX)) {
-            throw new java.lang.Error(result.toString().substring(ERROR_PREFIX.length()).trim());
+            String resultString = new String(result, StandardCharsets.UTF_8);
+            throw new Exception(resultString.substring(ERROR_PREFIX.length()).trim());
         }
         return result;
     }
 
     private byte[] callLoadPackageWithCache(byte[] args) throws Exception {
         byte[] result = loadPackageWithCache(args);
         if (result != null && startsWith(result, ERROR_PREFIX)) {
-            throw new java.lang.Error(result.toString().substring(ERROR_PREFIX.length()).trim());
+            String resultString = new String(result, StandardCharsets.UTF_8);
+            throw new Exception(resultString.substring(ERROR_PREFIX.length()).trim());
         }
         return result;
     }

java/src/test/java/com/kcl/ExecProgramTest.java

@@ -19,4 +19,16 @@ public void testExecProgramApi() throws Exception {
         ExecProgram_Result result = apiInstance.execProgram(args);
         Assert.assertEquals(result.getYamlResult(), "app:\n" + "  replicas: 2");
     }
+
+    @Test
+    public void testExecProgramApiInvalid() {
+        try {
+            ExecProgram_Args args = ExecProgram_Args.newBuilder().build();
+
+            API apiInstance = new API();
+            apiInstance.execProgram(args);
+        } catch (Exception e) {
+            Assert.assertEquals(e.getMessage(), "No input KCL files or paths");
+        }
+    }
 }