/mssql-jdbc-clob-exception

Primary LanguageJavaMIT LicenseMIT

Clob Exception Test Case for the Microsoft JDBC Driver for SQL Server

  1. Build the JAR with mvn clean compile assembly:single
  2. Create a new database or use an existing one
  3. Create a new table or use an existing one, which contains a NVARCHAR(MAX) column
CREATE TABLE [dbo].[content](
    [id] [bigint] IDENTITY(1,1) NOT NULL,
    [content] [nvarchar](max) NOT NULL,
    CONSTRAINT [PK_content] PRIMARY KEY CLUSTERED ([id] ASC)
);
INSERT INTO [dbo].[content](content) VALUES('hello world');
  1. Run the test with java -jar target/mssql-jdbc-clob-exception-1.0-SNAPSHOT-jar-with-dependencies.jar
    1. --help shows the help
    2. To connect to localhost on port 1933 with user hello, password world and database example containing the table content use the following arguments: -h localhost:1933 -u hello -p world -d example -q "select top 5 [id], [content] from [content]"
  2. The test executes the given query, which processes the [content] column by using java.sql.ResultSet.getClob(int)
  3. The mssql-jdbc driver version 9.2.1.jre8 throws an IOException (Stream Closed) which will be wrapped into a com.microsoft.sqlserver.jdbc.SQLServerException
  4. The exception is then suppressed in the method com.microsoft.sqlserver.jdbc.SQLServerResultSet.fillLOBs.
  5. You should be able to see this behavior in the logs containing a line with SQLServerResultSet:1Filling Lobs before closing: The stream is closed.:
2021-04-08 10:39:39.028 [main] INFO  o.e.ClobExceptionTester - Connecting to localhost:1933
2021-04-08 10:39:39.669 [main] INFO  o.e.ClobExceptionTester - Connection to localhost:1933 established
2021-04-08 10:39:39.669 [main] INFO  o.e.ClobExceptionTester - Executing query select top 5 [id], [content] from [content]
2021-04-08 10:39:39.720 [main] DEBUG c.m.s.j.SQLServerResultSet - SQLServerResultSet:1 created by (SQLServerStatement:1)
2021-04-08 10:39:39.720 [main] DEBUG c.m.s.j.SQLServerResultSet - SQLServerResultSet:1 currentRow:0 numFetchedRows:0 rowCount:-3
2021-04-08 10:39:39.732 [main] DEBUG c.m.s.j.SQLServerResultSet - SQLServerResultSet:1 Getting Column:1
2021-04-08 10:39:39.732 [main] DEBUG c.m.s.j.SQLServerResultSet - SQLServerResultSet:1 Getting Column:2
2021-04-08 10:39:39.732 [main] INFO  o.e.ClobExceptionTester - Row: [1, hello world]
2021-04-08 10:39:39.732 [main] DEBUG c.m.s.j.SQLServerResultSet - SQLServerResultSet:1 currentRow:1 numFetchedRows:1 rowCount:-3
2021-04-08 10:39:39.732 [main] DEBUG c.m.s.j.SQLServerResultSet - SQLServerResultSet:1Filling Lobs before closing: The stream is closed.
2021-04-08 10:39:39.732 [main] INFO  o.e.ClobExceptionTester - Connection to localhost:1933 closed
  1. If you build the project with the mssql-jdbc driver version 6.2.2, the exception is not thrown. To verify this, rebuild the JAR with version 6.2.2 (pom.xml) and execute the test again.