苏州网站建设制作搜索引擎哪个好用
需求背景
需要一个像mybatis plus 一样的基于lambda, 且面向对象的查询mongo数据的插件。在网上找了很久,没有发现有类似功能的插件。于是自己手写了一个,借助mongoTemplate屏蔽了底层查询语句的实现细节。在此基础上,实现了查询的统一封装。
技术难点
基于SerializedLambda对象获取查询的属性,例如下面是获取task的name;
MongoLambdaQuery.lambdaQuery(Task.class).is(Task::getName, taskCriteria.getName())
怎么传参这种Task::getName 函数引用
通过函数式接口SFunction来表示R实际类型:
Children ne(R column, Object val);@FunctionalInterface
public interface SFunction<T, R> extends Function<T, R>, Serializable {
}
然后通过maybeDo来判断搜索参数不为空才进行查询。这里DoSomething又是一个函数式接口,something.doIt()时才会执行具体columnToString操作,得到我们的属性。
protected Children addCondition(boolean condition, R column, SqlKeyword keyWord, Object val, Object... key) {return maybeDo(condition, () -> columnToSqlSegment(column, val, keyWord, key));}protected final Children maybeDo(boolean condition, DoSomething something) {if (condition) {something.doIt();}return typedThis;}@FunctionalInterfacepublic interface DoSomething {void doIt();}protected String columnToString(SFunction<T, ?> column) {return LambdaUtils.getField(column);}
c. 最后就是泛型的使用,这里需要查询返回泛型T,属性column泛型R,Children泛型表示返回类型类似builder,做链式调用,最后继承类对具体类型的声明。
public interface Query<T>
public interface Func<Children, R> extends Serializable
public abstract class AbstractQuery<T, R, Children extends AbstractQuery<T, R, Children>>
implements Func<Children, R>, Query<T>
public abstract class MongoAbstractLambdaQuery<
T, Children extends MongoAbstractLambdaQuery<T, Children>>
extends AbstractQuery<T, SFunction<T, ?>, Children>
public class MongoLambdaQuery<T> extends MongoAbstractLambdaQuery<T, MongoLambdaQuery<T>>
项目地址:
https://github.com/DarMi7/mongo-lambda-query
使用demo
引入maven依赖文件
<dependency>
<groupId>io.github.darmi7</groupId>
<artifactId>mongo-lambda-query</artifactId>
<version>1.1.0</version>
</dependency>
开启插件注解,加上需要扫描mongo实体的包路径
@EnableMongoLambdaQuery
@EnableMongoRepositories(basePackages = "com.darmi.demo.repository.mongo")
public class Application
编写查询代码
@Repositorypublic interface TaskRepository extends MongoRepository<Task, String> {default Page<Task> search(TaskCriteria taskCriteria) {return MongoLambdaQuery.lambdaQuery(Task.class).is(Task::getName, taskCriteria.getName()).is(Task::getType, taskCriteria.getFuzzyName()).reg(Task::getName, taskCriteria.getName()).gt(Task::getPoints, taskCriteria.getPoints()).gt(Task::getCreated, taskCriteria.getBegin()).lt(Task::getCreated, taskCriteria.getEnd()).page(taskCriteria.getPagination());}}