/**
* 构建ResultMap对象
*
* @param id
* @param clazz
* @param configuration
* @return
*/
private ResultMap buildResultMap(String id, Class<?> clazz, Configuration configuration) {
// 判断是否已经存在缓存里
if (configuration.hasResultMap(id)) {
return configuration.getResultMap(id);
}
List<ResultMapping> resultMappings = Lists.newArrayList();
Map<String, Field> columns = EntityUtil.getFields(clazz);
for (Map.Entry<String, Field> column : columns.entrySet()) {
Field field = column.getValue();
String fieldName = field.getName();
Class<?> columnTypeClass = resolveResultJavaType(clazz, fieldName, null);
List<ResultFlag> flags = Lists.newArrayList();
if (field.isAnnotationPresent(Id.class)) {
flags.add(ResultFlag.ID);
}
String columnName = column.getKey();
resultMappings.add(
buildResultMapping(configuration, fieldName, columnName, columnTypeClass, flags));
}
// 构建ResultMap
ResultMap.Builder resultMapBuilder =
new ResultMap.Builder(configuration, id, clazz, resultMappings);
ResultMap rm = resultMapBuilder.build();
// 放到缓存中
configuration.addResultMap(rm);
return rm;
}
/**
* 从传递的参数中找Page对象，并返回
*
* @param paramObj
* @return
*/
public Page<?> findPageParameter(Object paramObj) {
Page<?> page = null;
if (paramObj instanceof Page) {
page = (Page<?>) paramObj;
} else if (paramObj instanceof Map) {
Map<?, ?> m = (Map<?, ?>) paramObj;
for (Object o : m.values()) {
if (o instanceof Page) {
page = (Page<?>) o;
break;
}
}
}
if (page != null) {
PAGE_THREAD_LOCAL.set(page);
}
return page;
}
/**
* 根据namespace查找需要的信息，避免每次反射的耗时操作
*
* @param conf
* @param statementId
* @return
* @throws ClassNotFoundException
*/
private MapperMeta getMapperMeta(Configuration conf, final String statementId)
throws ClassNotFoundException {
MapperMeta meta = CACHED.get(statementId);
if (meta == null) {
int pos = statementId.lastIndexOf('.');
String namespace = statementId.substring(0, pos); // mapper类名
String methodName = statementId.substring(pos + 1);
Class<?> mapperClass;
mapperClass = Class.forName(namespace);
synchronized (this) {
meta = CACHED.get(statementId);
if (meta == null) {
meta = buildMapperMeta(conf, namespace, methodName, mapperClass);
CACHED.put(statementId, meta);
}
}
}
return meta;
}
@SuppressWarnings({"rawtypes", "unchecked"})
private void autoMap(Invocation invocation, String name) throws ClassNotFoundException {
final Object[] queryArgs = invocation.getArgs();
final MappedStatement ms = (MappedStatement) queryArgs[0];
final Object parameter = queryArgs[1];
String statementId = ms.getId();
MapperMeta meta = getMapperMeta(ms.getConfiguration(), statementId);
if (meta.isFillEntity()) {
// 将泛型类加入到参数中供CrudTemplate使用
if (parameter != null) {
Map map;
if (parameter instanceof Map) {
map = (HashMap) parameter;
map.put(CrudProvider.CLASS_KEY, meta.getEntity());
} else {
map = new HashMap();
map.put(CrudProvider.PARA_KEY, parameter);
map.put(CrudProvider.CLASS_KEY, meta.getEntity());
}
queryArgs[1] = map;
} else {
queryArgs[1] = meta.getEntity();
}
}
if (meta.isFillResultMap()) {
MetaObject metaMappedStatement = getMetaObject(ms);
metaMappedStatement.setValue("resultMaps", meta.getResultMaps());
}
if (name.equals("query")) {
final RowBounds rowBounds = (RowBounds) queryArgs[2];
if (rowBounds == null || rowBounds == RowBounds.DEFAULT) {
Page p = findPageParameter(queryArgs[1]);
if (p != null) {
queryArgs[2] = new RowBounds(p.getOffset(), p.getLimit());
}
}
}
}