問題描述

我已經(jīng)開始發(fā)現(xiàn) Mockito 庫，但有一個問題我沒有找到正確的答案.

I've started to discovered Mockito library and there is a question for which I didn't find the proper answer.

如果我的 UserDAO 類中有這樣的方法，可以將用戶保存在數(shù)據(jù)庫中:

If I have for example such method in my UserDAO class that saves user in database:

public class UserDAO{
...
 public void create(User user) {
        Connection connection = null;
        PreparedStatement pstmt = null;
        ResultSet generatedKeys = null;
        try {

            connection = getConnection();
            pstmt = connection.prepareStatement(INSERT_USER,
                    PreparedStatement.RETURN_GENERATED_KEYS);
            int counter = 1;
            pstmt.setString(counter++, user.getFirstName());
            pstmt.setString(counter++, user.getLastName());
            pstmt.setString(counter++, user.getEmail());
            pstmt.setString(counter++, user.getPassword());
            pstmt.setString(counter++, user.getRole());
            pstmt.setString(counter, user.getLang());

            pstmt.execute();
            connection.commit();
            generatedKeys = pstmt.getGeneratedKeys();

            if (generatedKeys.next()) {
                user.setId(generatedKeys.getInt(Fields.GENERATED_KEY));
            }
        } catch (SQLException e) {
            rollback(connection);
            LOG.error("Can not create a user", e);
        } finally {
            close(connection);
            close(pstmt);
            close(generatedKeys);
        }
    }
  ....
}

我應(yīng)該如何測試它?

如果我想測試一個 DAO 類，那么我需要創(chuàng)建一個 DataSource 模擬、Connection 模擬、ResultSet 模擬等嗎?所以不測試數(shù)據(jù)庫本身?

If I want to test for example a DAO class then I need to create a DataSource mock, Connection mock, ResultSet mock etc ? And so not to test the database itself ?

但是如果我還想測試 dao 和 database 的行為呢?

But what if I want to also test the behavior of dao and database ?

您能否提供一些可能有用的代碼示例、鏈接并展示最佳方法?

Would you please produce some code samples, links that could be helpful and show best approaches of doing it ?

推薦答案

這是使用 Mockito 測試您的 UserDAO 的良好開端.此代碼使用了大量的 Mockito 功能，因此您可以了解如何使用它們.如果您有任何問題，請告訴我.

Here is a good start using Mockito to test your UserDAO. This code uses a good amount of the Mockito features, so you can see how to use them. Let me know if you have questions.

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.sql.DataSource;
import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;
import static org.junit.Assert.*;
import org.junit.runner.RunWith;
import static org.mockito.Matchers.anyInt;
import static org.mockito.Matchers.anyString;
import org.mockito.Mock;
import static org.mockito.Mockito.doNothing;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;
import org.mockito.runners.MockitoJUnitRunner;

@RunWith(MockitoJUnitRunner.class)
public class TestUserDAO {

    @Mock
    DataSource mockDataSource;
    @Mock
    Connection mockConn;
    @Mock
    PreparedStatement mockPreparedStmnt;
    @Mock
    ResultSet mockResultSet;
    int userId = 100;

    public TestUserDAO() {
    }

    @BeforeClass
    public static void setUpClass() throws Exception {
    }

    @AfterClass
    public static void tearDownClass() {
    }

    @Before
    public void setUp() throws SQLException {
        when(mockDataSource.getConnection()).thenReturn(mockConn);
        when(mockDataSource.getConnection(anyString(), anyString())).thenReturn(mockConn);
        doNothing().when(mockConn).commit();
        when(mockConn.prepareStatement(anyString(), anyInt())).thenReturn(mockPreparedStmnt);
        doNothing().when(mockPreparedStmnt).setString(anyInt(), anyString());
        when(mockPreparedStmnt.execute()).thenReturn(Boolean.TRUE);
        when(mockPreparedStmnt.getGeneratedKeys()).thenReturn(mockResultSet);
        when(mockResultSet.next()).thenReturn(Boolean.TRUE, Boolean.FALSE);
        when(mockResultSet.getInt(Fields.GENERATED_KEYS)).thenReturn(userId);
    }

    @After
    public void tearDown() {
    }

    @Test
    public void testCreateWithNoExceptions() throws SQLException {

        UserDAO instance = new UserDAO(mockDataSource);
        instance.create(new User());

        //verify and assert
        verify(mockConn, times(1)).prepareStatement(anyString(), anyInt());
        verify(mockPreparedStmnt, times(6)).setString(anyInt(), anyString());
        verify(mockPreparedStmnt, times(1)).execute();
        verify(mockConn, times(1)).commit();
        verify(mockResultSet, times(2)).next();
        verify(mockResultSet, times(1)).getInt(Fields.GENERATED_KEYS);
    }

    @Test(expected = SQLException.class)
    public void testCreateWithPreparedStmntException() throws SQLException {

         //mock
         when(mockConn.prepareStatement(anyString(), anyInt())).thenThrow(new SQLException());


        try {
            UserDAO instance = new UserDAO(mockDataSource);
            instance.create(new User());
        } catch (SQLException se) {
            //verify and assert
            verify(mockConn, times(1)).prepareStatement(anyString(), anyInt());
            verify(mockPreparedStmnt, times(0)).setString(anyInt(), anyString());
            verify(mockPreparedStmnt, times(0)).execute();
            verify(mockConn, times(0)).commit();
            verify(mockResultSet, times(0)).next();
            verify(mockResultSet, times(0)).getInt(Fields.GENERATED_KEYS);
            throw se;
        }

    }
}

這篇關(guān)于如何使用 Mockito 測試 DAO 方法?的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網(wǎng)！