使用DBUnit做单元测试

    DBUnit是一个方便的数据准备工具, 方便于我们做单元测试的时候准备数据, 它的数据准备是基于XML格式的, 如下:

<?xml version='1.0' encoding='UTF-8'?>
<dataset>
  <YourTableName_1 Field_1="1" Field_2="f2" Field_3="f3"/>
  <YourTableName_1 Field_1="2" Field_2="f2_1" Field_3="f3_1"/>
  <YourTableName_2 Field_1="1" Field_2="2"/>
</dataset>

    DBUnit的一个XML数据文件中,可以同时放多个表的数据,并且可以方便的把上面XML中准备的数据插入倒数据库中. 只需要使用下面简单的代码就可以做到:
		protected ReplacementDataSet createDataSet(InputStream is) throws Exception {
			return new ReplacementDataSet(new FlatXmlDataSetBuilder().build(is));
		}
		ReplacementDataSet createDataSet = createDataSet(Thread.currentThread().getContextClassLoader().getResourceAsStream("data.xml"));
		DatabaseOperation.INSERT.execute(iconn, createDataSet);
     注:准备这处XML数据文件时,一定要把同一个表中字段数最多的记录放在前面,因为DBUnit在根据数据XML文件准备表的元数据字段的时候,是以当前表的第一记录为主的。如下面这个XML文件:
<?xml version='1.0' encoding='UTF-8'?>
<dataset>
  <YourTableName_1 Field_1="1" Field_2="f2"/>
  <YourTableName_1 Field_1="2" Field_2="f2_1" Field_3="f3_1"/>
  <YourTableName_2 Field_1="1" Field_2="2"/>
</dataset>

    Table YourTableName_1有三个字段,但是第三个字段Field_3是允许为空的,所以上面的XML是可以这样写的,并且DBUnit在执行插入的时候也不会报错,但是这里会出现一个问题,因为DBUnit在第一次分析到table YourTableName_1时,第一条记录只有两个字段,因而它在记录table YourTableName_1的字段的时候,就只会记录两个到这个表的元数据信息,因而在对在对后面记录进行数据处理的时候,只会取后面记录的两个字段,而第三个字段是不会被插入到数据库中。解决这个问题很简单,把YourTableName_1的第二条记录和第一条记录给换一下位置就好了。 同理,在数据result数据文件的时候,也要遵循这样的规则,否则会得不到想要的结果的。这是经验总结。

    你可能会担心如果是要准备的数据比较多是不是会比较麻烦,如上百条的数据准备,这个可以不用担心,因为使用DBUnit可以方便的从数据库中导出数据到指定的文件中,然后供我们使用,使用以下这个方法就可以导出数据:

	/**
	 * Export data for the table names by the given IDatabaseConnection into the resultFile.<br>
	 * The export data will be DBUnit format.
	 * 
	 * @param conn
	 * @param tableNameList
	 * @param resultFile
	 * @throws SQLException
	 * @throws DatabaseUnitException
	 * @throws FileNotFoundException
	 * @throws IOException
	 */
	public void exportData(IDatabaseConnection iconn, List<String> tableNameList, String resultFile) throws SQLException, DatabaseUnitException, FileNotFoundException, IOException {
		QueryDataSet dataSet = null;
		if (iconn == null) {
			return;
		}
		if (tableNameList == null || tableNameList.size() == 0) {
			return;
		}
		try {
			dataSet = new QueryDataSet(iconn);
			for (String tableName : tableNameList) {
				dataSet.addTable(tableName);
			}
		} finally {
			if (dataSet != null) {
				FlatXmlDataSet.write(dataSet, new FileOutputStream(resultFile));
			}
		}

	}

    DBUnit的另一个非常有用的功能,就是对执行结果进行比较,这样可以直接得到执行结果是否正确。 操作方式是准备一个执行期待结果的XML文件,再准备一条从数据库查询结果的SQL。这里有一个经验非常重要,那就是用于查询的执行结果的SQL文件,最好是加上某个关键字段的ORDER BY语句,否则可能会因为记录的顺序而比较失败,因为DBUnit是把查询出来的结果和准备的结果进行一一对应的比较。当然,既然SQL查询都加上了排序,那我们的结果XML文件,也应该是根据关键字段排好序的结果的,否则也会因为记录的顺序问题而比较失败。

上面的是热身,该来点实际的东西了, 弄个真实的实例来看看,下面是一个用于DBUnit测试的抽象类:

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.TreeMap;

import junit.framework.Assert;

import org.dbunit.Assertion;
import org.dbunit.DatabaseUnitException;
import org.dbunit.IDatabaseTester;
import org.dbunit.JdbcDatabaseTester;
import org.dbunit.database.DatabaseConnection;
import org.dbunit.database.IDatabaseConnection;
import org.dbunit.database.QueryDataSet;
import org.dbunit.dataset.Column;
import org.dbunit.dataset.IDataSet;
import org.dbunit.dataset.ITable;
import org.dbunit.dataset.ReplacementDataSet;
import org.dbunit.dataset.filter.DefaultColumnFilter;
import org.dbunit.dataset.xml.FlatXmlDataSet;
import org.dbunit.dataset.xml.FlatXmlDataSetBuilder;
import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.TestExecutionListeners;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.support.DependencyInjectionTestExecutionListener;
import org.springframework.transaction.annotation.Transactional;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = { "classpath:/spring.xml" })
@TestExecutionListeners({ DependencyInjectionTestExecutionListener.class })
@Transactional
public abstract class BasedTestCase {

	protected static Properties properties = new Properties();
	static {
		try {
			/**
			 * The DatabaseConfig.properties stores the database configuration information. It's like this: <br>
			 * driverClass=oracle.jdbc.OracleDriver<br>
			 * db_inst=jdbc:oracle:thin:@1.1.1.1:1521:schema<br>
			 * db_user=username<br>
			 * db_pwd=password<br>
			 */
			properties.load(Thread.currentThread().getContextClassLoader().getResourceAsStream("DatabaseConfig.properties"));
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	/**
	 * This abstract is used for prepare data before do the real method call.
	 * 
	 * @param iconn
	 * @throws Exception
	 */
	protected abstract void prepareData(IDatabaseConnection iconn) throws Exception;

	/**
	 * Execute one sql
	 * 
	 * @param iconn
	 * @param sql
	 * @throws Exception
	 */
	protected void execSql(IDatabaseConnection iconn, String sql) throws Exception {
		Connection con = iconn.getConnection();
		Statement stmt = con.createStatement();
		try {
			stmt.execute(sql);
		} finally {
			if (stmt != null) {
				stmt.close();
			}
		}
	}

	/**
	 * Get IDatabaseConnection connection
	 * 
	 * @return
	 * @throws Exception
	 */
	protected IDatabaseConnection getIDatabaseConnection() throws Exception {

		String db_inst = "", db_user = "", db_pwd = "", driverClass = "";
		//The default is commit the record
		db_user = properties.getProperty("db_user");
		db_inst = properties.getProperty("db_inst");
		db_pwd = properties.getProperty("db_pwd");
		driverClass = properties.getProperty("driverClass");

		IDatabaseConnection iconn = null;
		IDatabaseTester databaseTester;
		databaseTester = new JdbcDatabaseTester(driverClass, db_inst, db_user, db_pwd);
		iconn = databaseTester.getConnection();
		return iconn;
	}

	/**
	 * This is used to assert the data from table and the expected data set. If all of the them has the same records, then the assert is true.
	 * 
	 * @param tableName
	 * @param sql
	 * @param expectedDataSet
	 * @param iconn
	 * @throws Exception
	 */
	protected void assertDataSet(String tableName, String sql, IDataSet expectedDataSet, IDatabaseConnection iconn) throws Exception {
		printDataAsXml(iconn, tableName, sql);
		QueryDataSet loadedDataSet = new QueryDataSet(iconn);
		loadedDataSet.addTable(tableName, sql);
		ITable table1 = loadedDataSet.getTable(tableName);
		ITable table2 = expectedDataSet.getTable(tableName);
		Assert.assertEquals(table2.getRowCount(), table1.getRowCount());

		DefaultColumnFilter.includedColumnsTable(table1, table2.getTableMetaData().getColumns());
		Assertion.assertEquals(table2, table1);

	}

	/**
	 * Create the data set by input stream which read from the dbunit xml data file.
	 * 
	 * @param is
	 * @return
	 * @throws Exception
	 */
	protected ReplacementDataSet createDataSet(InputStream is) throws Exception {
		return new ReplacementDataSet(new FlatXmlDataSetBuilder().build(is));
	}

	/**
	 * Convert the data in the ITable to List
	 * 
	 * @param table
	 * @return
	 * @throws Exception
	 */
	private List<Map<?, ?>> getDataFromTable(ITable table) throws Exception {
		List<Map<?, ?>> ret = new ArrayList<Map<?, ?>>();
		int count_table = table.getRowCount();
		if (count_table > 0) {
			Column[] columns = table.getTableMetaData().getColumns();
			for (int i = 0; i < count_table; i++) {
				Map<String, Object> map = new TreeMap<String, Object>();
				for (Column column : columns) {
					map.put(column.getColumnName().toUpperCase(), table.getValue(i, column.getColumnName()));
				}
				ret.add(map);
			}
		}
		return ret;
	}

	/**
	 * Get data by the SQL and table name, then convert the data in the ITable to List
	 * 
	 * @param iconn
	 * @param tableName
	 * @param sql
	 * @return
	 * @throws Exception
	 */
	protected List<Map<?, ?>> getTableDataFromSql(IDatabaseConnection iconn, String tableName, String sql) throws Exception {
		ITable table = iconn.createQueryTable(tableName, sql);
		return getDataFromTable(table);
	}

	/**
	 * Get data by the SQL and table name, then convert the data in the ITable to List. And the print the data as xml data format.
	 * 
	 * @param iconn
	 * @param tableName
	 * @param sql
	 * @throws Exception
	 */
	protected void printDataAsXml(IDatabaseConnection iconn, String tableName, String sql) throws Exception {
		List<Map<?, ?>> datas = getTableDataFromSql(iconn, tableName, sql);
		StringBuffer sb;
		for (Map<?, ?> data : datas) {
			sb = new StringBuffer();
			sb.append("<" + tableName.toUpperCase() + " ");
			for (Object o : data.keySet()) {
				sb.append(o + "="" + data.get(o) + "" ");
			}
			sb.append("/>");
			System.out.println(sb.toString());
		}
	}

	/**
	 * Export data for the table names by the given Connection into the resultFile.<br>
	 * The export data will be DBUnit format.
	 * 
	 * @param conn
	 * @param tableNameList
	 * @param resultFile
	 * @throws SQLException
	 * @throws DatabaseUnitException
	 * @throws FileNotFoundException
	 * @throws IOException
	 */
	public void exportData(Connection conn, List<String> tableNameList, String resultFile) throws SQLException, DatabaseUnitException, FileNotFoundException, IOException {
		if (conn == null) {
			return;
		}
		IDatabaseConnection iconn = new DatabaseConnection(conn);
		exportData(iconn, tableNameList, resultFile);
	}

	/**
	 * Export data for the table names by the given IDatabaseConnection into the resultFile.<br>
	 * The export data will be DBUnit format.
	 * 
	 * @param conn
	 * @param tableNameList
	 * @param resultFile
	 * @throws SQLException
	 * @throws DatabaseUnitException
	 * @throws FileNotFoundException
	 * @throws IOException
	 */
	public void exportData(IDatabaseConnection iconn, List<String> tableNameList, String resultFile) throws SQLException, DatabaseUnitException, FileNotFoundException, IOException {
		QueryDataSet dataSet = null;
		if (iconn == null) {
			return;
		}
		if (tableNameList == null || tableNameList.size() == 0) {
			return;
		}
		try {
			dataSet = new QueryDataSet(iconn);
			for (String tableName : tableNameList) {
				dataSet.addTable(tableName);
			}
		} finally {
			if (dataSet != null) {
				FlatXmlDataSet.write(dataSet, new FileOutputStream(resultFile));
			}
		}

	}
}

这个抽象类里面有实用插入数据、导出数据及验证数据的实现,也包括了数据库连接的准备,该类里面包含了一个抽象方法prepareData,因为任何使用DBUnit做单元测试的,应该是少不了数据准备这么一个过程,否则就只能够使用数据库中的现成数据,这样的单元测试是不靠谱的,因为数据库中的数据随时可能发生变化,这里的抽象方法prepareData就相当于在提醒写单元测试的人,不要忘了准备单元测试要用的数据。

根据上面的思路,准备一个用于测试的Table:

create table YouTableName_1(
       filed_1 int,
       filed_2 varchar2(50),
       filed_3 varchar2(50)
)
用于测试的数据:
<?xml version='1.0' encoding='UTF-8'?>
<dataset>
  <YouTableName_1 Filed_1="1" Filed_2="f2" Filed_3="f3"/>
  <YouTableName_1 Filed_1="2" Filed_2="f2_1" Filed_3="f3_1"/>
</dataset>
用于验证测试结果的数据:
<?xml version='1.0' encoding='UTF-8'?>
<dataset>
  <YouTableName_1 Filed_1="1" Filed_2="a" Filed_3="a1"/>
  <YouTableName_1 Filed_1="2" Filed_2="b" Filed_3="b1"/>
</dataset>
我们这个测试非常简单,就是把Filed_1为1的字段中Filed_2和Filed_3的字段的值分别设为"a"和"a1",把Filed_1为2的字段中Filed_2和Filed_3的字段的值分别设为"b"和"b1",做完测试后,数据库中是不会插入我们的单元测试的数据的。

下面这个类UpdateTest用于更新数据:

import java.sql.Connection;
import java.sql.SQLException;

public class UpdateTest {
	private static boolean commit = true;

	public UpdateTest() {

	}

	private void commit(Connection conn) throws SQLException {
		if (commit) {
			conn.commit();
		}
	}

	public void updateFiled(Connection conn) throws SQLException {
		conn.createStatement().execute("update YouTableName_1 set filed_2='a',filed_3='a1' where filed_1=1");
		conn.createStatement().execute("update YouTableName_1 set filed_2='b',filed_3='b1' where filed_1=2");
		commit(conn);
	}
}
下面这个MyTest类,就是用于单元测试的类:
package com.ubs.cre.tools.datatool.ipl;

import java.io.IOException;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.sql.Connection;
import java.sql.SQLException;

import junit.framework.Assert;

import org.dbunit.database.IDatabaseConnection;
import org.dbunit.dataset.ReplacementDataSet;
import org.dbunit.operation.DatabaseOperation;
import org.junit.Test;

import com.ubs.cre.BasedTestCase;

public class MyTest extends BasedTestCase {
	@Test
	public void testSend() throws IOException, SQLException {
		Connection conn = null;
		Boolean result = Boolean.FALSE;
		IDatabaseConnection iconn = null;
		try {
			//Get DBUnit conneciton
			iconn = getIDatabaseConnection();
			//Get database connection
			conn = iconn.getConnection();
			//Set auto commit false
			conn.setAutoCommit(false);
			//prepare data
			prepareData(iconn);

			//use reflect to set the commit field to false
			Class<UpdateTest> clazz = UpdateTest.class;
			Field commitField = clazz.getDeclaredField("commit");
			commitField.setAccessible(true);
			commitField.setBoolean(clazz, false);

			//call the method updateFiled
			Method method = clazz.getDeclaredMethod("updateFiled", java.sql.Connection.class);
			method.setAccessible(true);
			//Before call the method, the clazz must be get an new install, because the called method "updateFiled" is not static.<br>
			//If the called method is static, it will not need newInstance.
			method.invoke(clazz.newInstance(), conn);

			// get result data set by result xml file
			ReplacementDataSet dataload_result = createDataSet(Thread.currentThread().getContextClassLoader().getResourceAsStream("MyTest_Result.xml"));

			// compare the data which get from database and the expected result file
			assertDataSet("YouTableName_1", "select filed_1,filed_2,filed_3 from YouTableName_1 order by filed_1", dataload_result, iconn);
		} catch (Exception e) {
			e.printStackTrace();
			Assert.assertTrue(result);
		} finally {
			if (conn != null) {
				conn.rollback();
				conn.close();
			}
		}

	}

	protected void prepareData(IDatabaseConnection iconn) throws Exception {
		//Remove the data from table YouTableName_1
		execSql(iconn, "delete from YouTableName_1");
		//INSERT TEST DATA
		ReplacementDataSet createDataSet = createDataSet(Thread.currentThread().getContextClassLoader().getResourceAsStream("MyTest.xml"));
		DatabaseOperation.INSERT.execute(iconn, createDataSet);

	}

}

    好了,示例完了,非常的简单,也非常的清晰,不过美中不足就是和DBUnit的代码耦合度太高了,这过对于我们使用习惯了Spring的人来说,看起来是非常别扭的,后面我会写另外一个与Spring集成的、完全非侵入式的测试实现,等着吧。

    (基于Spring的已经写好了,看这篇文章了:http://blog.csdn.net/fenglibing/article/details/16856363




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原文地址:https://www.cnblogs.com/skiwdhwhssh/p/10340529.html