[#3165] fix(client-java): Fix the http client toJson encode without…

… UTF-8 (#3179)

### What changes were proposed in this pull request?

Currently in the java client, the json result is not encoded with
`UTF-8` when requesting the server, which will cause some Chinese
characters to be garbled.It will use `ISO_8859_1` as default. This PR
fixed this.

![image](https://github.com/datastrato/gravitino/assets/26177232/9342dd32-1ded-4670-a3c7-37d9a5673955)

### Why are the changes needed?

Fix: #3165 

### How was this patch tested?

Add some ITs.

---------

Co-authored-by: xiaojiebao <xiaojiebao@xiaomi.com>

catalogs/catalog-hadoop/src/test/java/com/datastrato/gravitino/catalog/hadoop/integration/test/HadoopCatalogIT.java

@@ -197,6 +197,33 @@ public void testCreateFileset() throws IOException {
         Fileset.Type.MANAGED, fileset3.type(), "fileset type should be MANAGED by default");
   }
 
+  @Test
+  public void testCreateFilesetWithChinese() throws IOException {
+    // create fileset
+    String filesetName = "test_create_fileset_with_chinese";
+    String storageLocation = storageLocation(filesetName) + "/中文目录test";
+    Assertions.assertFalse(
+        hdfs.exists(new Path(storageLocation)), "storage location should not exists");
+    Fileset fileset =
+        createFileset(
+            filesetName,
+            "这是中文comment",
+            Fileset.Type.MANAGED,
+            storageLocation,
+            ImmutableMap.of("k1", "v1", "test", "中文测试test", "中文key", "test1"));
+
+    // verify fileset is created
+    assertFilesetExists(filesetName);
+    Assertions.assertNotNull(fileset, "fileset should be created");
+    Assertions.assertEquals("这是中文comment", fileset.comment());
+    Assertions.assertEquals(Fileset.Type.MANAGED, fileset.type());
+    Assertions.assertEquals(storageLocation, fileset.storageLocation());
+    Assertions.assertEquals(3, fileset.properties().size());
+    Assertions.assertEquals("v1", fileset.properties().get("k1"));
+    Assertions.assertEquals("中文测试test", fileset.properties().get("test"));
+    Assertions.assertEquals("test1", fileset.properties().get("中文key"));
+  }
+
   @Test
   public void testExternalFileset() throws IOException {
     // create fileset

clients/client-java/src/main/java/com/datastrato/gravitino/client/HTTPClient.java

@@ -785,7 +785,7 @@ public HTTPClient build() {
 
   private StringEntity toJson(Object requestBody) {
     try {
-      return new StringEntity(mapper.writeValueAsString(requestBody));
+      return new StringEntity(mapper.writeValueAsString(requestBody), StandardCharsets.UTF_8);
     } catch (JsonProcessingException e) {
       throw new RESTException(e, "Failed to write request body: %s", requestBody);
     }

integration-test/src/test/java/com/datastrato/gravitino/integration/test/client/CatalogIT.java

@@ -112,6 +112,27 @@ public void testCreateCatalogWithoutProperties() {
     metalake.dropCatalog(catalogIdent);
   }
 
+  @Test
+  public void testCreateCatalogWithChinese() {
+    String catalogName = GravitinoITUtils.genRandomName("catalogz");
+    NameIdentifier catalogIdent = NameIdentifier.of(metalakeName, catalogName);
+    Assertions.assertFalse(metalake.catalogExists(catalogIdent));
+
+    Map<String, String> properties = Maps.newHashMap();
+    properties.put("metastore.uris", hmsUri);
+    metalake.createCatalog(
+        catalogIdent, Catalog.Type.RELATIONAL, "hive", "这是中文comment", properties);
+    Assertions.assertTrue(metalake.catalogExists(catalogIdent));
+    Catalog catalog = metalake.loadCatalog(catalogIdent);
+    Assertions.assertEquals(catalogName, catalog.name());
+    Assertions.assertEquals(Catalog.Type.RELATIONAL, catalog.type());
+    Assertions.assertEquals("hive", catalog.provider());
+    Assertions.assertEquals("这是中文comment", catalog.comment());
+    Assertions.assertTrue(catalog.properties().containsKey("metastore.uris"));
+
+    metalake.dropCatalog(catalogIdent);
+  }
+
   @Test
   public void testListCatalogsInfo() {
     String relCatalogName = GravitinoITUtils.genRandomName("rel_catalog_");

integration-test/src/test/java/com/datastrato/gravitino/integration/test/client/MetalakeIT.java

@@ -157,6 +157,25 @@ public void testCreateMetalake() {
         });
   }
 
+  @Test
+  public void testCreateMetalakeWithChinese() {
+    client.createMetalake(
+        NameIdentifier.parse(metalakeNameA), "这是中文comment", Collections.emptyMap());
+    GravitinoMetalake metalake = client.loadMetalake(NameIdentifier.of(metalakeNameA));
+    assertEquals(metalakeNameA, metalake.name());
+    assertEquals("这是中文comment", metalake.comment());
+    assertEquals(AuthConstants.ANONYMOUS_USER, metalake.auditInfo().creator());
+
+    // Test metalake name already exists
+    Map<String, String> emptyMap = Collections.emptyMap();
+    NameIdentifier exists = NameIdentifier.parse(metalakeNameA);
+    assertThrows(
+        MetalakeAlreadyExistsException.class,
+        () -> {
+          client.createMetalake(exists, "metalake A comment", emptyMap);
+        });
+  }
+
   @Test
   public void testDropMetalakes() {
     GravitinoMetalake metalakeA =