fix:oceanbase datasource support special characters

README.md

@@ -41,7 +41,7 @@ DataX目前已经有了比较全面的插件体系，主流的RDBMS数据库、N
 |--------------|---------------------------|:---------:|:---------:|:----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------:|
 | RDBMS 关系型数据库 | MySQL                           |     √      |     √      |                                       [读](https://github.com/alibaba/DataX/blob/master/mysqlreader/doc/mysqlreader.md) 、[写](https://github.com/alibaba/DataX/blob/master/mysqlwriter/doc/mysqlwriter.md)                                       |
 |                    | Oracle                          |     √      |     √      |                                     [读](https://github.com/alibaba/DataX/blob/master/oraclereader/doc/oraclereader.md) 、[写](https://github.com/alibaba/DataX/blob/master/oraclewriter/doc/oraclewriter.md)                                     |
-|                    | OceanBase                       |     √      |     √      | [读](https://open.oceanbase.com/docs/community/oceanbase-database/V3.1.0/use-datax-to-full-migration-data-to-oceanbase) 、[写](https://open.oceanbase.com/docs/community/oceanbase-database/V3.1.0/use-datax-to-full-migration-data-to-oceanbase) |
+|                    | OceanBase                       |     √      |     √      | [读](https://github.com/alibaba/DataX/blob/master/oceanbasev10reader/doc/oceanbasev10reader.md) 、[写](https://github.com/alibaba/DataX/blob/master/oceanbasev10writer/doc/oceanbasev10writer.md) |
 |                    | SQLServer                       |     √      |     √      |                               [读](https://github.com/alibaba/DataX/blob/master/sqlserverreader/doc/sqlserverreader.md) 、[写](https://github.com/alibaba/DataX/blob/master/sqlserverwriter/doc/sqlserverwriter.md)                               |
 |                    | PostgreSQL                      |     √      |     √      |                             [读](https://github.com/alibaba/DataX/blob/master/postgresqlreader/doc/postgresqlreader.md) 、[写](https://github.com/alibaba/DataX/blob/master/postgresqlwriter/doc/postgresqlwriter.md)                             |
 |                    | DRDS                            |     √      |     √      |                                         [读](https://github.com/alibaba/DataX/blob/master/drdsreader/doc/drdsreader.md) 、[写](https://github.com/alibaba/DataX/blob/master/drdswriter/doc/drdswriter.md)                                         |

oceanbasev10reader/doc/oceanbasev10reader.md

@@ -228,4 +228,17 @@ OceanbaseV10Reader插件实现了从Oceanbase V1.0读取数据。在底层实现
 | 4 | 55862 | 17.60 |
 | 5 | 70860 | 22.31 |
 
-# 
+## 5常见问题
+### 
+4.1 oracle模式下报错Invalid fatch size
+```
+Caused by: java.sql.SQLSyntaxErrorException: (conn=2498) invalid fetch size. in Oracle mode, extendOracleResultSetClass is ineffective if useOraclePrepareExecute is set to true or usePieceData is set to true
+	at com.oceanbase.jdbc.internal.util.exceptions.ExceptionFactory.createException(ExceptionFactory.java:110)
+	at com.oceanbase.jdbc.internal.util.exceptions.ExceptionFactory.create(ExceptionFactory.java:211)
+	at com.oceanbase.jdbc.OceanBaseStatement.setFetchSize(OceanBaseStatement.java:1599)
+	at com.alibaba.datax.plugin.reader.oceanbasev10reader.ext.ReaderTask.doRead(ReaderTask.java:270)
+	... 5 more
+```
+该错误常发生更换了高版本的oceanbase-client.jar驱动，高版本的驱动未来提高效率，增加了oracle预处理语句行为。这个机制和setFetchSize冲突。
+#### 解决方案
+在jdbcUrl中配置extendOracleResultSetClass=true可解决这个冲突。

oceanbasev10reader/src/main/java/com/alibaba/datax/plugin/reader/oceanbasev10reader/ext/Constant.java

@@ -8,6 +8,4 @@ public class Constant {
     public static String WEAK_READ_QUERY_SQL_TEMPLATE_WITHOUT_WHERE = "select /*+read_consistency(weak)*/ %s from %s ";
 
     public static String WEAK_READ_QUERY_SQL_TEMPLATE = "select /*+read_consistency(weak)*/ %s from %s where (%s)";
-
-    public static final int ORACLE_DEFAULT_FETCH_SIZE = 1024;
 }

oceanbasev10reader/src/main/java/com/alibaba/datax/plugin/reader/oceanbasev10reader/ext/ReaderTask.java

@@ -30,9 +30,6 @@ import org.slf4j.LoggerFactory;
 import java.sql.*;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Objects;
-
-import static com.alibaba.datax.plugin.reader.oceanbasev10reader.ext.Constant.ORACLE_DEFAULT_FETCH_SIZE;
 
 public class ReaderTask extends CommonRdbmsReader.Task {
     private static final Logger LOG = LoggerFactory.getLogger(ReaderTask.class);
@@ -259,14 +256,7 @@ public class ReaderTask extends CommonRdbmsReader.Task {
                 }
             }
             // 打开流式接口
-            //oceanbase的oracle模式FetchSize同oracle插件的设置，否则会报错。invalid fetch size. in Oracle mode,
+            ps.setFetchSize(context.getFetchSize());
-            // 具体请看com.oceanbase.jdbc.OceanBaseStatement#setFetchSize
-            if (context.getFetchSize()==Integer.MIN_VALUE
-                    && Objects.equals(compatibleMode, ObReaderUtils.OB_COMPATIBLE_MODE_ORACLE)){
-                ps.setFetchSize(ORACLE_DEFAULT_FETCH_SIZE);
-            }else {
-                ps.setFetchSize(context.getFetchSize());
-            }
             rs = ps.executeQuery();
             ResultSetMetaData metaData = rs.getMetaData();
             int columnNumber = metaData.getColumnCount();