/**
* 多对多级联查询 1.当主对象没有包含任何一个关联对象时，默认查询所有与之关联的对象 2.当主对象中包含了关联对象时（含有其id值），则只查询这些关联的对象
*
* @param <T>
* @throws InvocationTargetException
* @throws IllegalAccessException
* @throws IllegalArgumentException
*/
public void select() throws DAOException {
if (this.fields == null || this.fields.size() == 0) return;
// select %s from {tarTable} where {referencedColumn} in (select {to} from {relTable} where
// {from} = {idVal})
String format = "SELECT %s FROM %s WHERE %s IN (SELECT %s FROM %s WHERE %s = ?) ";
if (idVal == null || "0".equals(idVal) || "".equals(idVal)) return;
for (Field f : fields) {
Method tarGetter = ru.getGetter(f.getName());
if (tarGetter == null) continue;
ManyToMany ann = tarGetter.getAnnotation(ManyToMany.class);
if (ann == null) {
ann = f.getAnnotation(ManyToMany.class);
if (ann == null) continue;
}
JoinTable join = tarGetter.getAnnotation(JoinTable.class);
if (join == null) {
join = f.getAnnotation(JoinTable.class);
if (join == null) continue;
}
JoinColumn[] froms = join.joinColumns();
if (froms == null || froms.length == 0) continue;
JoinColumn[] tos = join.inverseJoinColumns();
if (tos == null || tos.length == 0) continue;
// 多对多关系目标Class
Class<?> tarClass = ann.targetEntity();
if (void.class.isAssignableFrom(tarClass)) {
tarClass = ClassUtil.getGenericType(f);
}
String tarTable = ORMConfigBeanUtil.getTable(tarClass, true);
// 目标类对应的数据库表Id字段
String referencedColumn = tos[0].referencedColumnName();
if (referencedColumn == null || referencedColumn.trim().length() == 0)
referencedColumn = ORMConfigBeanUtil.getIdColumn(tarClass);
// 目标类在第三方关系表中的字段名
String to = tos[0].name();
// 第三方关系表
String relTable = join.name();
// 主类在第三方关系表中的字段名
String from = froms[0].name();
try {
List<?> tarList = null;
tarList = (List<?>) tarGetter.invoke(t);
if (tarList != null && tarList.size() > 0) {
for (int i = 0; i < tarList.size(); i++) {
Object tarObj = tarList.get(i);
ReflectUtil tarRu = new ReflectUtil(tarObj);
String tarIdField = ORMConfigBeanUtil.getIdField(tarClass);
Method tarIdGetter = tarRu.getGetter(tarIdField);
Object tarIdValObj = tarIdGetter.invoke(tarObj);
if (tarIdValObj == null) continue;
String tarIdVal = String.valueOf(tarIdValObj);
// 查询 select %s from {tarTable} where {tarIdColumn} = {tarIdVal}
tarObj =
DAOFactory.getSelectDAO(dsName)
.selectOne(tarClass, new String[] {tarIdField}, new String[] {tarIdVal});
}
} else {
String sql =
String.format(
format,
ORMConfigBeanUtil.getSelectAllColumn(tarClass),
tarTable,
referencedColumn,
to,
relTable,
from);
// 从数据库中取出与当前主对象id关联的所有目标对象，
tarList = DAOFactory.getSelectDAO(dsName).selectBySQL(tarClass, sql, idVal);
}
// 并注入到当前主对象的属性中
Method tarSetter = ru.getSetter(f.getName());
tarSetter.invoke(t, tarList);
} catch (Exception e) {
e.printStackTrace();
throw new DAOException("", e);
}
}
}
/**
* 多对多级联删除 1.如果主对象不存在与数据库，不处理 2.否则，检查当前主对象中的关联对象，如果关联对象为空，则删除所有与主对象有关的关联关系。
* 3.如果当前主对象中含有关联对象，则删除这些关联对象与主对象的关系 4.不会删除主对象
*/
public void delete() throws DAOException {
if (this.fields == null || this.fields.size() == 0) return;
// "delete from {relTable} WHERE {from} = {idVal} ;"
String format = "delete from %s WHERE %s = ? ";
if (idVal == null || "0".equals(idVal) || "".equals(idVal)) return;
else if (DAOFactory.getSelectDAO(dsName).selectOne(t, this.idField) == null) return;
for (Field f : fields) {
Method tarGetter = ru.getGetter(f.getName());
if (tarGetter == null) continue;
ManyToMany ann = tarGetter.getAnnotation(ManyToMany.class);
if (ann == null) {
ann = f.getAnnotation(ManyToMany.class);
if (ann == null) continue;
}
JoinTable join = tarGetter.getAnnotation(JoinTable.class);
if (join == null) {
join = f.getAnnotation(JoinTable.class);
if (join == null) continue;
}
JoinColumn[] froms = join.joinColumns();
if (froms == null || froms.length == 0) continue;
JoinColumn[] tos = join.inverseJoinColumns();
if (tos == null || tos.length == 0) continue;
String relTable = join.name();
String from = froms[0].name();
List<?> tarList = null;
try {
tarList = (List<?>) tarGetter.invoke(t);
} catch (Exception e) {
throw new DAOException(tarGetter + " invoke exception ", e);
}
if (tarList == null || tarList.size() == 0) {
String sql = String.format(format, relTable, from);
// 删除所有关联记录
DAOFactory.getUpdateDAO(dsName).updateBySQLWithArgs(sql, idVal);
} else {
// 删除指定关联的记录
String to = tos[0].name();
Class<?> tarClass = ann.targetEntity();
if (void.class.isAssignableFrom(tarClass)) {
tarClass = ClassUtil.getGenericType(f);
}
// "delete from {relTable} where {from} = {idVal} and to = {toVal}"
String _format = "delete from %s where %s = ? and %s = ?";
for (int i = 0; i < tarList.size(); i++) {
Object tarObj = tarList.get(i);
if (tarObj == null) continue;
ReflectUtil tarRu = new ReflectUtil(tarObj);
String tarIdField = ORMConfigBeanUtil.getIdField(tarClass);
Method tarIdGetter = tarRu.getGetter(tarIdField);
Object toValObj = null;
try {
toValObj = tarIdGetter.invoke(tarObj);
} catch (Exception e) {
throw new DAOException(tarIdGetter + "invoke exception ", e);
}
if (toValObj == null) continue;
String toVal = String.valueOf(toValObj);
if (DAOFactory.getSelectDAO(dsName)
.selectOne(tarClass, new String[] {tarIdField}, new String[] {toVal})
== null) continue;
String _sql = String.format(_format, relTable, from, to);
DAOFactory.getUpdateDAO(dsName).updateBySQLWithArgs(_sql, idVal, toVal);
}
}
}
}