java - 模拟 databaseMetaData.getTables() 方法时 ResultSet 为空
问题描述
我正在尝试为一个检查数据库中是否存在表的类编写单元测试用例。我已经使用了DatabaseMetadata
接口并Resultset
实现了它。现在我正在尝试为此编写一个单元测试用例,但在模拟时
数据库元数据 getTables()
方法,我的结果集为空。谁能告诉我我做错了什么?还有没有更好的方法来检查数据库中的表?
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import javax.sql.DataSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import com.fasterxml.jackson.core.JsonProcessingException;
@Component
public class DataBaseTableScanner {
public DataBaseTableScanner() {
super();
}
private DataSource datasource;
@Autowired
public DataBaseTableScanner(DataSource datasource) {
this.datasource = datasource;
}
public void setDataSource(DataSource datasource) {
this.datasource = datasource;
}
public boolean checkForTableInDataBase(String entityName) throws SQLException {
try(Connection con = datasource.getConnection()){
DatabaseMetaData databaseMetaData = con.getMetaData();
String tableName = entityName.toUpperCase();
String[] types = {"TABLE"};
resultSet = databaseMetaData.getTables(null, null, tableName, types);
boolean tableExistFlag = resultSet.next();
if(tableExistFlag) {
System.out.println("Check Table:: "+ tableName + " :Table exits in Database!!");
}else {
System.out.println("Check Table:: "+ tableName + " :Table does not exits in Database!!");
}
return tableExistFlag;
}
}
}
我的单元测试用例
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;
import static org.mockito.Mockito.when;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.sql.DataSource;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mapstruct.BeforeMapping;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;
import org.mockito.junit.MockitoJUnitRunner;
@RunWith(MockitoJUnitRunner.class)
public class DataBaseTableScannerTest {
@InjectMocks
DataBaseTableScanner dataBaseTableScanner;
@Mock
DataSource datasource;
@Mock
Connection connection;
@Mock
DatabaseMetaData databaseMetaData;
@Mock
ResultSet resultSet;
@Before
public void setUp() throws TenantResolvingException, TenantNotFoundException, SQLException {
dataBaseTableScanner.setDataSource(datasource);
when(datasource.getConnection()).thenReturn(connection);
when(connection.getMetaData()).thenReturn(databaseMetaData);
String tableName = null;
String[] types = null;
// String tableName = "task";
// String[] types = {"TABLE"};
when(databaseMetaData.getTables(null, null, tableName, types)).thenReturn(resultSet);
}
@Test
public void testIsTableExists() throws SQLException {
boolean tbexists = dataBaseTableScanner.checkForTableInDataBase("task");
assertTrue(tbexists);
}
解决方案
您使用参数模拟方法databaseMetaData.getTables(null, null, null, null))
,因为在 setup 方法中:
String tableName = null;
String[] types = null;
但是当你调用checkForTableInDataBase
方法时,它内部会调用getTables
具有不同参数的方法:
String tableName = entityName.toUpperCase();
String[] types = {"TABLE"};
所以你应该重写你 when 方法:
when(databaseMetaData.getTables(null, null, "task".toUpperCase(), {"TABLE"})).thenReturn(resultSet);
当然,它仅在您使用“任务”作为输入参数的情况下才有效dataBaseTableScanner.checkForTableInDataBase()
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