[Core] update drop Database API and remove api in URL

paimon-core/src/main/java/org/apache/paimon/rest/HttpClient.java

@@ -65,17 +65,9 @@ public HttpClient(HttpClientOptions httpClientOptions) {
     @Override
     public <T extends RESTResponse> T get(
             String path, Class<T> responseType, Map<String, String> headers) {
-        try {
-            Request request =
-                    new Request.Builder()
-                            .url(uri + path)
-                            .get()
-                            .headers(Headers.of(headers))
-                            .build();
-            return exec(request, responseType);
-        } catch (Exception e) {
-            throw new RuntimeException(e);
-        }
+        Request request =
+                new Request.Builder().url(uri + path).get().headers(Headers.of(headers)).build();
+        return exec(request, responseType);
     }
 
     @Override
@@ -90,26 +82,16 @@ public <T extends RESTResponse> T post(
                             .headers(Headers.of(headers))
                             .build();
             return exec(request, responseType);
-        } catch (Exception e) {
-            throw new RuntimeException(e);
+        } catch (JsonProcessingException e) {
+            throw new RESTException(e, "build request failed.");
         }
     }
 
     @Override
-    public <T extends RESTResponse> T delete(
-            String path, RESTRequest body, Map<String, String> headers) {
-        try {
-            RequestBody requestBody = buildRequestBody(body);
-            Request request =
-                    new Request.Builder()
-                            .url(uri + path)
-                            .delete(requestBody)
-                            .headers(Headers.of(headers))
-                            .build();
-            return exec(request, null);
-        } catch (Exception e) {
-            throw new RuntimeException(e);
-        }
+    public <T extends RESTResponse> T delete(String path, Map<String, String> headers) {
+        Request request =
+                new Request.Builder().url(uri + path).delete().headers(Headers.of(headers)).build();
+        return exec(request, null);
     }
 
     @Override
@@ -135,6 +117,8 @@ private <T extends RESTResponse> T exec(Request request, Class<T> responseType)
             } else {
                 throw new RESTException("response body is null.");
             }
+        } catch (RESTException e) {
+            throw e;
         } catch (Exception e) {
             throw new RESTException(e, "rest exception");
         }

paimon-core/src/main/java/org/apache/paimon/rest/RESTCatalog.java

@@ -32,7 +32,6 @@
 import org.apache.paimon.rest.exceptions.AlreadyExistsException;
 import org.apache.paimon.rest.exceptions.NoSuchResourceException;
 import org.apache.paimon.rest.requests.CreateDatabaseRequest;
-import org.apache.paimon.rest.requests.DropDatabaseRequest;
 import org.apache.paimon.rest.responses.ConfigResponse;
 import org.apache.paimon.rest.responses.CreateDatabaseResponse;
 import org.apache.paimon.rest.responses.DatabaseName;
@@ -47,6 +46,7 @@
 import org.apache.paimon.shade.jackson2.com.fasterxml.jackson.databind.ObjectMapper;
 
 import java.time.Duration;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -160,11 +160,15 @@ public Database getDatabase(String name) throws DatabaseNotExistException {
     @Override
     public void dropDatabase(String name, boolean ignoreIfNotExists, boolean cascade)
             throws DatabaseNotExistException, DatabaseNotEmptyException {
-        DropDatabaseRequest request = new DropDatabaseRequest(ignoreIfNotExists, cascade);
         try {
-            client.delete(resourcePaths.database(name), request, headers());
+            if (!cascade && !this.listTables(name).isEmpty()) {
+                throw new DatabaseNotEmptyException(name);
+            }
+            client.delete(resourcePaths.database(name), headers());
         } catch (NoSuchResourceException e) {
-            throw new DatabaseNotExistException(name);
+            if (!ignoreIfNotExists) {
+                throw new DatabaseNotExistException(name);
+            }
         }
     }
 
@@ -180,7 +184,7 @@ public Path getTableLocation(Identifier identifier) {
 
     @Override
     public List<String> listTables(String databaseName) throws DatabaseNotExistException {
-        throw new UnsupportedOperationException();
+        return new ArrayList<String>();
     }
 
     @Override

paimon-core/src/main/java/org/apache/paimon/rest/RESTClient.java

@@ -29,5 +29,5 @@ public interface RESTClient extends Closeable {
     <T extends RESTResponse> T post(
             String path, RESTRequest body, Class<T> responseType, Map<String, String> headers);
 
-    <T extends RESTResponse> T delete(String path, RESTRequest body, Map<String, String> headers);
+    <T extends RESTResponse> T delete(String path, Map<String, String> headers);
 }

paimon-core/src/main/java/org/apache/paimon/rest/ResourcePaths.java

@@ -23,7 +23,7 @@
 /** Resource paths for REST catalog. */
 public class ResourcePaths {
 
-    public static final String V1_CONFIG = "/api/v1/config";
+    public static final String V1_CONFIG = "/v1/config";
     private static final StringJoiner SLASH = new StringJoiner("/");
 
     public static ResourcePaths forCatalogProperties(String prefix) {
@@ -37,10 +37,10 @@ public ResourcePaths(String prefix) {
     }
 
     public String databases() {
-        return SLASH.add("api").add("v1").add(prefix).add("databases").toString();
+        return SLASH.add("v1").add(prefix).add("databases").toString();
     }
 
     public String database(String databaseName) {
-        return SLASH.add("api").add("v1").add(prefix).add("databases").add(databaseName).toString();
+        return SLASH.add("v1").add(prefix).add("databases").add(databaseName).toString();
     }
 }

paimon-core/src/test/java/org/apache/paimon/rest/HttpClientTest.java

@@ -43,6 +43,7 @@
 
 /** Test for {@link HttpClient}. */
 public class HttpClientTest {
+
     private MockWebServer mockWebServer;
     private HttpClient httpClient;
     private ObjectMapper objectMapper = RESTObjectMapper.create();
@@ -113,14 +114,14 @@ public void testPostFail() {
     @Test
     public void testDeleteSuccess() {
         mockHttpCallWithCode(mockResponseDataStr, 200);
-        MockRESTData response = httpClient.delete(MOCK_PATH, mockResponseData, headers);
+        MockRESTData response = httpClient.delete(MOCK_PATH, headers);
         verify(errorHandler, times(0)).accept(any());
     }
 
     @Test
     public void testDeleteFail() {
         mockHttpCallWithCode(mockResponseDataStr, 400);
-        httpClient.delete(MOCK_PATH, mockResponseData, headers);
+        httpClient.delete(MOCK_PATH, headers);
         verify(errorHandler, times(1)).accept(any());
     }
 

paimon-core/src/test/java/org/apache/paimon/rest/MockRESTMessage.java

@@ -19,9 +19,9 @@
 package org.apache.paimon.rest;
 
 import org.apache.paimon.rest.requests.CreateDatabaseRequest;
-import org.apache.paimon.rest.requests.DropDatabaseRequest;
 import org.apache.paimon.rest.responses.CreateDatabaseResponse;
 import org.apache.paimon.rest.responses.DatabaseName;
+import org.apache.paimon.rest.responses.ErrorResponse;
 import org.apache.paimon.rest.responses.GetDatabaseResponse;
 import org.apache.paimon.rest.responses.ListDatabasesResponse;
 
@@ -46,12 +46,6 @@ public static CreateDatabaseRequest createDatabaseRequest(String name) {
         return new CreateDatabaseRequest(name, ignoreIfExists, options);
     }
 
-    public static DropDatabaseRequest dropDatabaseRequest() {
-        boolean ignoreIfNotExists = true;
-        boolean cascade = true;
-        return new DropDatabaseRequest(ignoreIfNotExists, cascade);
-    }
-
     public static CreateDatabaseResponse createDatabaseResponse(String name) {
         Map<String, String> options = new HashMap<>();
         options.put("a", "b");
@@ -71,4 +65,8 @@ public static ListDatabasesResponse listDatabasesResponse(String name) {
         databaseNameList.add(databaseName);
         return new ListDatabasesResponse(databaseNameList);
     }
+
+    public static ErrorResponse noSuchResourceExceptionErrorResponse() {
+        return new ErrorResponse("message", 404, new ArrayList<>());
+    }
 }