mybatis源码解析7---MappedStatement初始化过程

 1 public <T> void addMapper(Class<T> type) {
 2         if (type.isInterface()) {
 3           if (hasMapper(type)) {
 4             throw new BindingException("Type " + type + " is already known to the MapperRegistry.");
 5           }
 6           boolean loadCompleted = false;
 7           try {
 8             knownMappers.put(type, new MapperProxyFactory<T>(type));//加载指定的mapper接口
 9             MapperAnnotationBuilder parser = new MapperAnnotationBuilder(config, type);//?
10             parser.parse();
11             loadCompleted = true;
12           } finally {
13             if (!loadCompleted) {
14               knownMappers.remove(type);
15             }
16           }
17         }
18       }

 1  public MapperAnnotationBuilder(Configuration configuration, Class<?> type) {
 2     String resource = type.getName().replace('.', '/') + ".java (best guess)";
 3     this.assistant = new MapperBuilderAssistant(configuration, resource);
 4     this.configuration = configuration;
 5     this.type = type;
 6 
 7     sqlAnnotationTypes.add(Select.class);
 8     sqlAnnotationTypes.add(Insert.class);
 9     sqlAnnotationTypes.add(Update.class);
10     sqlAnnotationTypes.add(Delete.class);
11 
12     sqlProviderAnnotationTypes.add(SelectProvider.class);
13     sqlProviderAnnotationTypes.add(InsertProvider.class);
14     sqlProviderAnnotationTypes.add(UpdateProvider.class);
15     sqlProviderAnnotationTypes.add(DeleteProvider.class);
16   }

1     private final Set<Class<? extends Annotation>> sqlAnnotationTypes = new HashSet<Class<? extends Annotation>>();//sql语句上的注解
2     private final Set<Class<? extends Annotation>> sqlProviderAnnotationTypes = new HashSet<Class<? extends Annotation>>();//指定类指定方法上的sql语句注解
3 
4     private Configuration configuration;//全局配置对象
5     private MapperBuilderAssistant assistant;//Mapper构建助手类,组装解析出来的配置,生成Cache、ResultMap以及MappedStatement对象
6     private Class<?> type;//解析的目标mapper接口的Class对象

 1 public void parse() {
 2     String resource = type.toString();//mapper接口名,如：interface com.lucky.test.mapper.UserMapper
 3     //Configuration中Set<String> loadedResources 保存着已经加载过的mapper信息
 4     if (!configuration.isResourceLoaded(resource)) {//判断是否已经加载过
 5       loadXmlResource();//加载XML资源
 6       configuration.addLoadedResource(resource);//加载的resource添加到Configuration的loadedResources中
 7       assistant.setCurrentNamespace(type.getName());
 8       parseCache();
 9       parseCacheRef();
10       Method[] methods = type.getMethods();//遍历mapper的所有方法
11       for (Method method : methods) {
12         try {
13           // issue #237
14           if (!method.isBridge()) {
15             parseStatement(method);
16           }
17         } catch (IncompleteElementException e) {
18           configuration.addIncompleteMethod(new MethodResolver(this, method));
19         }
20       }
21     }
22     parsePendingMethods();
23   }

 1 private void loadXmlResource() {
 2     // Spring may not know the real resource name so we check a flag
 3     // to prevent loading again a resource twice
 4     // this flag is set at XMLMapperBuilder#bindMapperForNamespace
 5     if (!configuration.isResourceLoaded("namespace:" + type.getName())) {
 6       String xmlResource = type.getName().replace('.', '/') + ".xml";//通过mapper接口名找到对应的mapper.xml路径
 7       InputStream inputStream = null;
 8       try {
 9         //读取mapper.xml文件流
10         inputStream = Resources.getResourceAsStream(type.getClassLoader(), xmlResource);
11       } catch (IOException e) {
12         // ignore, resource is not required
13       }
14       if (inputStream != null) {
15         //根据mapper.xml文件流创建XMLMapperBuilder对象
16         XMLMapperBuilder xmlParser = new XMLMapperBuilder(inputStream, assistant.getConfiguration(), xmlResource, configuration.getSqlFragments(), type.getName());
17         //执行parse方法
18         xmlParser.parse();
19       }
20     }
21   }

 1   public XMLMapperBuilder(InputStream inputStream, Configuration configuration, String resource, Map<String, XNode> sqlFragments, String namespace) {
 2     this(inputStream, configuration, resource, sqlFragments);//调用下面一个构造方法
 3     this.builderAssistant.setCurrentNamespace(namespace);
 4   }
 5 
 6   public XMLMapperBuilder(InputStream inputStream, Configuration configuration, String resource, Map<String, XNode> sqlFragments) {
 7     this(new XPathParser(inputStream, true, configuration.getVariables(), new XMLMapperEntityResolver()),
 8         configuration, resource, sqlFragments);//调用下面一个构造方法
 9   }
10 
11   private XMLMapperBuilder(XPathParser parser, Configuration configuration, String resource, Map<String, XNode> sqlFragments) {
12     //对自己的属性进行赋值
13     super(configuration);
14     this.builderAssistant = new MapperBuilderAssistant(configuration, resource);//mapper构造者助手
15     this.parser = parser;//XML解析类
16     this.sqlFragments = sqlFragments;//sql片段集合
17     this.resource = resource;//mapper名称
18   }

 1 public void parse() {
 2     if (!configuration.isResourceLoaded(resource)) {
 3       configurationElement(parser.evalNode("/mapper"));//从XML解析类中获取mapper标签的内容
 4       configuration.addLoadedResource(resource);//将加载过的resource添加到Configuration中
 5       bindMapperForNamespace();//绑定mapper到对应mapper的命名空间中
 6     }
 7 
 8     parsePendingResultMaps();
 9     parsePendingChacheRefs();
10     parsePendingStatements();
11   }

 1 private void configurationElement(XNode context) {
 2     try {
 3       String namespace = context.getStringAttribute("namespace");//从xml中获取namespace标签内容
 4       if (namespace == null || namespace.equals("")) {
 5         throw new BuilderException("Mapper's namespace cannot be empty");
 6       }
 7       builderAssistant.setCurrentNamespace(namespace);
 8       cacheRefElement(context.evalNode("cache-ref"));//获取cache-ref标签内容
 9       cacheElement(context.evalNode("cache"));//获取cache标签内容
10       parameterMapElement(context.evalNodes("/mapper/parameterMap"));//获取parameterMap内容
11       resultMapElements(context.evalNodes("/mapper/resultMap"));//获取resultMap内容
12       sqlElement(context.evalNodes("/mapper/sql"));//获取sql标签内容
13       buildStatementFromContext(context.evalNodes("select|insert|update|delete"));//解析获取各种sql语句标签内容
14     } catch (Exception e) {
15       throw new BuilderException("Error parsing Mapper XML. Cause: " + e, e);
16     }
17   }

 1 loadXmlResource();
 2       configuration.addLoadedResource(resource);
 3       assistant.setCurrentNamespace(type.getName());
 4       parseCache();
 5       parseCacheRef();
 6       Method[] methods = type.getMethods();
 7       for (Method method : methods) {
 8         try {
 9           // issue #237
10           if (!method.isBridge()) {
11             parseStatement(method);
12           }
13         } catch (IncompleteElementException e) {
14           configuration.addIncompleteMethod(new MethodResolver(this, method));
15         }
16       }