摘要：系列集成的的解析与加载如何根据接口生成其实现类的返回结果集结果的组装序本文主要解答一个问题，即如果没有，而且属性不是的，的自动组装是否可以赋值成功的问题。备注本文的代码引用来自的版本的源码
mybatis系列
SpringBoot集成mybatis
mybatis的statement的解析与加载
mybatis如何根据mapper接口生成其实现类
mybatis的mapper返回map结果集
mybatis结果的组装
序本文主要解答一个问题，即如果bean没有setter，而且属性不是public的，mybatis的自动组装是否可以赋值成功的问题。
查询调用过程DefaultSqlSession.selectList -->SimpleExecutor.doQuery --> SimpleStatementHandler.query --> DefaultResultSetHandler.handleResultSets --> BeanWrapper.setBeanProperty --> MetaClass.getSetInvoker --> Reflector.getSetInvoker
关键方法 SimpleStatementHandler.querypublicDefaultResultSetHandler.handleResultSetsList query(Statement statement, ResultHandler resultHandler) throws SQLException { String sql = boundSql.getSql(); statement.execute(sql); return resultSetHandler. handleResultSets(statement); }
@Override public ListDefaultResultSetHandler.handleResultSets
private void handleResultSet(ResultSetWrapper rsw, ResultMap resultMap, ListDefaultResultSetHandler.handleRowValues
private void handleRowValues(ResultSetWrapper rsw, ResultMap resultMap, ResultHandler resultHandler, RowBounds rowBounds, ResultMapping parentMapping) throws SQLException {
if (resultMap.hasNestedResultMaps()) {
ensureNoRowBounds();
checkResultHandler();
handleRowValuesForNestedResultMap(rsw, resultMap, resultHandler, rowBounds, parentMapping);
} else {
handleRowValuesForSimpleResultMap(rsw, resultMap, resultHandler, rowBounds, parentMapping);
}
}
DefaultResultSetHandler.handleRowValuesForSimpleResultMap
private void handleRowValuesForSimpleResultMap(ResultSetWrapper rsw, ResultMap resultMap, ResultHandler resultHandler, RowBounds rowBounds, ResultMapping parentMapping)
throws SQLException {
DefaultResultContext
DefaultResultSetHandler.getRowValue
private Object getRowValue(ResultSetWrapper rsw, ResultMap resultMap) throws SQLException {
final ResultLoaderMap lazyLoader = new ResultLoaderMap();
Object resultObject = createResultObject(rsw, resultMap, lazyLoader, null);
if (resultObject != null && !typeHandlerRegistry.hasTypeHandler(resultMap.getType())) {
final MetaObject metaObject = configuration.newMetaObject(resultObject);
boolean foundValues = !resultMap.getConstructorResultMappings().isEmpty();
if (shouldApplyAutomaticMappings(resultMap, false)) {
foundValues = applyAutomaticMappings(rsw, resultMap, metaObject, null) || foundValues;
}
foundValues = applyPropertyMappings(rsw, resultMap, metaObject, lazyLoader, null) || foundValues;
foundValues = lazyLoader.size() > 0 || foundValues;
resultObject = foundValues ? resultObject : null;
return resultObject;
}
return resultObject;
}
DefaultResultSetHandler.applyPropertyMappings
private boolean applyPropertyMappings(ResultSetWrapper rsw, ResultMap resultMap, MetaObject metaObject, ResultLoaderMap lazyLoader, String columnPrefix)
throws SQLException {
final List mappedColumnNames = rsw.getMappedColumnNames(resultMap, columnPrefix);
boolean foundValues = false;
final List propertyMappings = resultMap.getPropertyResultMappings();
for (ResultMapping propertyMapping : propertyMappings) {
String column = prependPrefix(propertyMapping.getColumn(), columnPrefix);
if (propertyMapping.getNestedResultMapId() != null) {
// the user added a column attribute to a nested result map, ignore it
column = null;
}
if (propertyMapping.isCompositeResult()
|| (column != null && mappedColumnNames.contains(column.toUpperCase(Locale.ENGLISH)))
|| propertyMapping.getResultSet() != null) {
Object value = getPropertyMappingValue(rsw.getResultSet(), metaObject, propertyMapping, lazyLoader, columnPrefix);
// issue #541 make property optional
final String property = propertyMapping.getProperty();
// issue #377, call setter on nulls
if (value != DEFERED
&& property != null
&& (value != null || (configuration.isCallSettersOnNulls() && !metaObject.getSetterType(property).isPrimitive()))) {
metaObject.setValue(property, value);
}
if (value != null || value == DEFERED) {
foundValues = true;
}
}
}
return foundValues;
}
MetaObject.setValue
public void setValue(String name, Object value) {
PropertyTokenizer prop = new PropertyTokenizer(name);
if (prop.hasNext()) {
MetaObject metaValue = metaObjectForProperty(prop.getIndexedName());
if (metaValue == SystemMetaObject.NULL_META_OBJECT) {
if (value == null && prop.getChildren() != null) {
// don"t instantiate child path if value is null
return;
} else {
metaValue = objectWrapper.instantiatePropertyValue(name, prop, objectFactory);
}
}
metaValue.setValue(prop.getChildren(), value);
} else {
objectWrapper.set(prop, value);
}
}
BeanWrapper.set
@Override
public void set(PropertyTokenizer prop, Object value) {
if (prop.getIndex() != null) {
Object collection = resolveCollection(prop, object);
setCollectionValue(prop, collection, value);
} else {
setBeanProperty(prop, object, value);
}
}
BeanWrapper.setBeanProperty
private void setBeanProperty(PropertyTokenizer prop, Object object, Object value) {
try {
Invoker method = metaClass.getSetInvoker(prop.getName());
Object[] params = {value};
try {
method.invoke(object, params);
} catch (Throwable t) {
throw ExceptionUtil.unwrapThrowable(t);
}
} catch (Throwable t) {
throw new ReflectionException("Could not set property "" + prop.getName() + "" of "" + object.getClass() + "" with value "" + value + "" Cause: " + t.toString(), t);
}
}
MetaClass.getSetInovker
public Invoker getSetInvoker(String name) {
return reflector.getSetInvoker(name);
}
Reflector.getSetInvoker
public Invoker getSetInvoker(String propertyName) {
Invoker method = setMethods.get(propertyName);
if (method == null) {
throw new ReflectionException("There is no setter for property named "" + propertyName + "" in "" + type + """);
}
return method;
}
setMethods的修改
有setter的话，走Reflector. resolveSetterConflicts
