Java Extreme Programming Cookbook

Testing JDBC Code

Problem

You want to use mock objects to test JDBC code.

Solution

Use mock implementations of JDBC interfaces like Connection, PreparedStatement, and ResultSet.

Discussion

Although you could create your own implementations of the JDBC interfaces, the Mock Objects framework from http://www.mockobjects.com makes your work easier. This framework provides mock implementations of the key JDBC interfaces so you don’t have to manually stub out every method of interfaces like java.sql.ResultSet. Your tests extend from and use these mock implementations.

Warning

These examples work with Version 0.4rc1 of the Mock Objects framework. You will almost certainly have to alter the code when newer versions of Mock Objects are available.

Example 6-9 shows a test for the getAccount( ) method shown in the previous recipe.

Example 6-9. Testing the getAccount( ) method

public void testGetAccount( ) throws Exception { class MyMockResultSet extends MockResultSetJdk14 { public Object getObject(int columnIndex) throws SQLException { return null; } public Object getObject(String columnName) throws SQLException { if ("acctType".equals(columnName)) { return "CH"; } if ("balance".equals(columnName)) { return new Double(100.0); } return null; } public boolean next( ) throws SQLException { super.myNextCalls.inc( ); return true; } public int getRow( ) throws SQLException { return 1; } } MockResultSet mockRs = new MyMockResultSet( ); mockRs.setExpectedCloseCalls(1); mockRs.setExpectedNextCalls(1); MockPreparedStatement ...