java 杂物间 （一） Mybatis

这里放置的是一些杂物，生人勿入。

Token的一般parse 过程。

@Test
public void shouldDemonstrateGenericTokenReplacement() {
    GenericTokenParser parser = new GenericTokenParser("${", "}", new VariableTokenHandler(new HashMap<String, String>() {
        {
            put("first_name", "James");
            put("initial", "T");
            put("last_name", "Kirk");
            put("var{with}brace", "Hiya");
            put("", "");
        }
    }));

    assertEquals("James T Kirk reporting.", parser.parse("${first_name} ${initial} ${last_name} reporting."));
    assertEquals("Hello captain James T Kirk", parser.parse("Hello captain ${first_name} ${initial} ${last_name}"));
    assertEquals("James T Kirk", parser.parse("${first_name} ${initial} ${last_name}"));
    assertEquals("JamesTKirk", parser.parse("${first_name}${initial}${last_name}"));
    assertEquals("{}JamesTKirk", parser.parse("{}${first_name}${initial}${last_name}"));
    assertEquals("}JamesTKirk", parser.parse("}${first_name}${initial}${last_name}"));

    assertEquals("}James{{T}}Kirk", parser.parse("}${first_name}{{${initial}}}${last_name}"));
    assertEquals("}James}T{Kirk", parser.parse("}${first_name}}${initial}{${last_name}"));
    assertEquals("}James}T{Kirk", parser.parse("}${first_name}}${initial}{${last_name}"));
    assertEquals("}James}T{Kirk{{}}", parser.parse("}${first_name}}${initial}{${last_name}{{}}"));
    assertEquals("}James}T{Kirk{{}}", parser.parse("}${first_name}}${initial}{${last_name}{{}}${}"));

    assertEquals("{$$something}JamesTKirk", parser.parse("{$$something}${first_name}${initial}${last_name}"));
    assertEquals("${", parser.parse("${"));
    assertEquals("${\\}", parser.parse("${\\}"));
    assertEquals("Hiya", parser.parse("${var{with\\}brace}"));
    assertEquals("", parser.parse("${}"));
    assertEquals("}", parser.parse("}"));
    assertEquals("Hello ${ this is a test.", parser.parse("Hello ${ this is a test."));
    assertEquals("Hello } this is a test.", parser.parse("Hello } this is a test."));
    assertEquals("Hello } ${ this is a test.", parser.parse("Hello } ${ this is a test."));
}

XPath 的Parse

  @Test
  public void shouldTestXPathParserMethods() throws Exception {
    String resource = "resources/nodelet_test.xml";
    InputStream inputStream = Resources.getResourceAsStream(resource);
    XPathParser parser = new XPathParser(inputStream, false, null, null);
    assertEquals((Long)1970l, parser.evalLong("/employee/birth_date/year"));
    assertEquals((short) 6, (short) parser.evalShort("/employee/birth_date/month"));
    assertEquals((Integer) 15, parser.evalInteger("/employee/birth_date/day"));
    assertEquals((Float) 5.8f, parser.evalFloat("/employee/height"));
    assertEquals((Double) 5.8d, parser.evalDouble("/employee/height"));
    assertEquals("${id_var}", parser.evalString("/employee/@id"));
    assertEquals(Boolean.TRUE, parser.evalBoolean("/employee/active"));
    assertEquals("<id>${id_var}</id>", parser.evalNode("/employee/@id").toString().trim());
    assertEquals(7, parser.evalNodes("/employee/*").size());
    XNode node = parser.evalNode("/employee/height");
    assertEquals("employee/height", node.getPath());
    assertEquals("employee[${id_var}]_height", node.getValueBasedIdentifier());
  }

Temp File 的一些操作

@Before
  public void setUp() throws Exception {
    tempFile = File.createTempFile("migration", "properties");
    tempFile.canWrite();
    sourceFile = File.createTempFile("test1", "sql");
    destFile = File.createTempFile("test2", "sql");
  }

使用嵌入型数据库derby

<dependency>
  <groupId>org.apache.derby</groupId>
  <artifactId>derby</artifactId>
  <version>10.12.1.1</version>
  <scope>test</scope>
</dependency>

MyBatis中的依赖关系

@BeforeClass
public static void setup() throws Exception {
DataSource dataSource = BaseDataTest.createBlogDataSource();
BaseDataTest.runScript(dataSource, BaseDataTest.BLOG_DDL);
BaseDataTest.runScript(dataSource, BaseDataTest.BLOG_DATA);
TransactionFactory transactionFactory = new JdbcTransactionFactory();
Environment environment = new Environment("Production", transactionFactory, dataSource);
Configuration configuration = new Configuration(environment);
configuration.setLazyLoadingEnabled(true);
configuration.getTypeAliasRegistry().registerAlias(Blog.class);
configuration.getTypeAliasRegistry().registerAlias(Post.class);
configuration.getTypeAliasRegistry().registerAlias(Author.class);
configuration.addMapper(BoundBlogMapper.class);
configuration.addMapper(BoundAuthorMapper.class);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(configuration);
}

sqlSessionFactory ---> Configuration ---> Environment ---> DataSource
                                          Environment ---> TransactionFactory

单个简单参数的查询

<select id="selectBlogWithPostsUsingSubSelect" parameterType="int" resultMap="blogWithPosts">
select * from Blog where id = #{id}
</select>

参数为列表

List<Post> posts = mapper.findPostsInList(new ArrayList<Integer>() {{
        add(1);
        add(3);
        add(5);
      }});

  <select id="findPostsInList" parameterType="list" resultType="org.apache.ibatis.domain.blog.Post">
    select * from post
    where id in (#{list[0]},#{list[1]},#{list[2]})
  </select>

参数为map

 List<Post> findThreeSpecificPosts(@Param("one") int one,
                                RowBounds rowBounds,
                                @Param("two") int two,
                                int three);

  <select id="findThreeSpecificPosts" parameterType="map" resultType="org.apache.ibatis.domain.blog.Post">
    select * from post
    where id in (#{one},#{two},#{2})
  </select>

参数为对象外加枚举

  <insert id="insertAuthor" parameterType="org.apache.ibatis.domain.blog.Author">
    <selectKey keyProperty="id" resultType="int" order="BEFORE">
      select CAST(RANDOM()*1000000 as INTEGER) a from SYSIBM.SYSDUMMY1
    </selectKey>
    insert into Author (id,username,password,email,bio,favourite_section)
    values(
    #{id}, #{username}, #{password}, #{email}, #{bio}, #{favouriteSection:VARCHAR}
    )
  </insert>

like 的用法

  @Test
  public void shouldSelectListOfPostsLike() {
    SqlSession session = sqlSessionFactory.openSession();
    try {
      BoundBlogMapper mapper = session.getMapper(BoundBlogMapper.class);
      List<Post> posts = mapper.selectPostsLike(new RowBounds(1,1),"%a%");
      assertEquals(1, posts.size());
    } finally {
      session.close();
    }
  }

eager 加载以及延迟加载

  @Select({
      "SELECT *",
      "FROM blog"
  })
  @Results({ 
      @Result(property = "author", column = "author_id", one = @One(select = "org.apache.ibatis.binding.BoundAuthorMapper.selectAuthor", fetchType=FetchType.EAGER)), 
      @Result(property = "posts", column = "id", many = @Many(select = "selectPostsById", fetchType=FetchType.EAGER))
  })
  List<Blog> selectBlogsWithAutorAndPostsEagerly();