feat: 属性查询构建。

mybatis-flex-core/src/main/java/com/mybatisflex/core/query/FieldsBuilder.java

@@ -0,0 +1,141 @@
+/*
+ *  Copyright (c) 2022-2023, Mybatis-Flex (fuhai999@gmail.com).
+ *  <p>
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *  <p>
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *  <p>
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package com.mybatisflex.core.query;
+
+import com.mybatisflex.core.field.FieldQuery;
+import com.mybatisflex.core.field.FieldQueryManager;
+import com.mybatisflex.core.field.QueryBuilder;
+import com.mybatisflex.core.paginate.Page;
+import com.mybatisflex.core.util.FieldWrapper;
+import com.mybatisflex.core.util.LambdaGetter;
+import com.mybatisflex.core.util.LambdaUtil;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * 使用 {@code Fields Query} 的方式进行关联查询。
+ *
+ * @author 王帅
+ * @since 2023-08-08
+ */
+public class FieldsBuilder<T> extends AbstractQueryBuilder<T> {
+
+    protected final Map<String, FieldQuery> fieldQueryMap;
+
+    public FieldsBuilder(MapperQueryChain<T> delegate) {
+        super(delegate);
+        this.fieldQueryMap = new HashMap<>();
+    }
+
+    /**
+     * 设置属性对应的 {@code QueryWrapper} 查询。
+     *
+     * @param field   属性
+     * @param builder {@code QueryWrapper} 构建
+     * @param <F>     属性类型
+     * @return 属性查询构建
+     */
+    public <F> FieldsBuilder<T> fieldMapping(LambdaGetter<F> field, QueryBuilder<F> builder) {
+        return fieldMapping(field, false, builder);
+    }
+
+    /**
+     * 设置属性对应的 {@code QueryWrapper} 查询。
+     *
+     * @param field   属性
+     * @param prevent 阻止对嵌套类属性的查询
+     * @param builder {@code QueryWrapper} 构建
+     * @param <F>     属性类型
+     * @return 属性查询构建
+     */
+    public <F> FieldsBuilder<T> fieldMapping(LambdaGetter<F> field, boolean prevent, QueryBuilder<F> builder) {
+        String fieldName = LambdaUtil.getFieldName(field);
+        Class<?> entityClass = LambdaUtil.getImplClass(field);
+        FieldQuery fieldQuery = new FieldQuery();
+        fieldQuery.setPrevent(prevent);
+        fieldQuery.setFieldName(fieldName);
+        fieldQuery.setQueryBuilder(builder);
+        fieldQuery.setEntityClass(entityClass);
+        fieldQuery.setFieldWrapper(FieldWrapper.of(entityClass, fieldName));
+        this.fieldQueryMap.put(entityClass.getName() + '#' + fieldName, fieldQuery);
+        return this;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public T one() {
+        List<T> entities = Collections.singletonList(baseMapper().selectOneByQuery(queryWrapper()));
+        FieldQueryManager.queryFields(baseMapper(), entities, fieldQueryMap);
+        return entities.get(0);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public <R> R oneAs(Class<R> asType) {
+        List<R> entities = Collections.singletonList(baseMapper().selectOneByQueryAs(queryWrapper(), asType));
+        FieldQueryManager.queryFields(baseMapper(), entities, fieldQueryMap);
+        return entities.get(0);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public List<T> list() {
+        List<T> entities = baseMapper().selectListByQuery(queryWrapper());
+        FieldQueryManager.queryFields(baseMapper(), entities, fieldQueryMap);
+        return entities;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public <R> List<R> listAs(Class<R> asType) {
+        List<R> entities = baseMapper().selectListByQueryAs(queryWrapper(), asType);
+        FieldQueryManager.queryFields(baseMapper(), entities, fieldQueryMap);
+        return entities;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public Page<T> page(Page<T> page) {
+        baseMapper().paginate(page, queryWrapper());
+        FieldQueryManager.queryFields(baseMapper(), page.getRecords(), fieldQueryMap);
+        return page;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public <R> Page<R> pageAs(Page<R> page, Class<R> asType) {
+        baseMapper().paginateAs(page, queryWrapper(), asType);
+        FieldQueryManager.queryFields(baseMapper(), page.getRecords(), fieldQueryMap);
+        return page;
+    }
+
+}