docs: add java for markdown format (#11373)

docs-cn/14-reference/03-connector/java.mdx

@@ -171,7 +171,7 @@ Connection conn = DriverManager.getConnection(jdbcUrl);
 
 连接开启批量拉取方式：
 
-```
+```java
 String url = "jdbc:TAOS-RS://taosdemo.com:6041/?user=root&password=taosdata";Properties properties = new Properties();
 properties.setProperty(TSDBDriver.PROPERTY_KEY_BATCH_LOAD, "true");
 Connection connection = DriverManager.getConnection(url, properties);