Spring Boot & ES 实战，值得参考！
作者：废物大师兄
cnblogs.com/cjsblog/p/9756978.html
1. 前言
1.1. 集成方式
Spring Boot中集成Elasticsearch有4种方式：
REST Client
Jest
Spring Data
Spring Data Elasticsearch Repositories
本文用后面两种方式来分别连接并操作Elasticsearch
1.2. 环境与配置
服务端：elasticsearch-6.3.2 1台
客户端：elasticsearch 6.4.1
服务端配置文件：elasticsearch.yml
cluster.name: my-application
network.host: 192.168.1.134
http.port: 9200
network.host: 192.168.1.134
http.port: 9200
/etc/security/limits.conf
cheng soft nofile 65536
cheng hard nofile 65536
cheng hard nofile 65536
/etc/sysctl.conf
vm.max_map_count=262144
1.3. 版本
Spring Boot 2.0.5默认的elasticsearch版本很低，这里我们用最新版本6.4.1
如果启动过程中出现
java.lang.NoClassDefFoundError: org/elasticsearch/common/transport/InetSocketTransportAddress
则说明，elasticsearch依赖的jar包版本不一致，统一改成6.4.1即可
另外，Spring Boot 2.0.5依赖的spring-data-elasticsearch版本是3.0.1，需要升级到3.1.0
2. 依赖
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.cjs.example</groupId>
<artifactId>cjs-elasticsearch-example</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>cjs-elasticsearch-example</name>
<description></description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.5.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
<elasticsearch.version>6.4.1</elasticsearch.version>
<spring.data.elasticsearch.version>3.1.0.RELEASE</spring.data.elasticsearch.version>
</properties>
<dependencies>
<dependency>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
<version>${elasticsearch.version}</version>
</dependency>
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>transport</artifactId>
<version>${elasticsearch.version}</version>
</dependency>
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-client</artifactId>
<version>${elasticsearch.version}</version>
</dependency>
<dependency>
<groupId>org.elasticsearch.plugin</groupId>
<artifactId>transport-netty4-client</artifactId>
<version>${elasticsearch.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-elasticsearch</artifactId>
<version>${spring.data.elasticsearch.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-elasticsearch</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.cjs.example</groupId>
<artifactId>cjs-elasticsearch-example</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>cjs-elasticsearch-example</name>
<description></description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.5.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
<elasticsearch.version>6.4.1</elasticsearch.version>
<spring.data.elasticsearch.version>3.1.0.RELEASE</spring.data.elasticsearch.version>
</properties>
<dependencies>
<dependency>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
<version>${elasticsearch.version}</version>
</dependency>
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>transport</artifactId>
<version>${elasticsearch.version}</version>
</dependency>
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-client</artifactId>
<version>${elasticsearch.version}</version>
</dependency>
<dependency>
<groupId>org.elasticsearch.plugin</groupId>
<artifactId>transport-netty4-client</artifactId>
<version>${elasticsearch.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-elasticsearch</artifactId>
<version>${spring.data.elasticsearch.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-elasticsearch</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
3. application.properties
spring.data.elasticsearch.cluster-name=my-application
spring.data.elasticsearch.cluster-nodes=192.168.1.134:9300
spring.data.elasticsearch.cluster-nodes=192.168.1.134:9300
也许，大家会疑惑，配置文件中明明写的端口是9200，为何这里配置文件中连接的时候写的端口是9300呢？
因为，配置9200是通过HTTP连接的端口，9300是TCP连接的端口
4. 操作
4.1. 使用Spring Data Elasticsearch Repositories操作Elasticsearch
首先，定义一个实体类
package com.cjs.example.entity;
import lombok.Data;
import org.springframework.data.annotation.Id;
import org.springframework.data.elasticsearch.annotations.Document;
import java.io.Serializable;
@Data
@Document(indexName = "commodity")
public class Commodity implements Serializable {
@Id
private String skuId;
private String name;
private String category;
private Integer price;
private String brand;
private Integer stock;
}
import lombok.Data;
import org.springframework.data.annotation.Id;
import org.springframework.data.elasticsearch.annotations.Document;
import java.io.Serializable;
@Data
@Document(indexName = "commodity")
public class Commodity implements Serializable {
@Id
private String skuId;
private String name;
private String category;
private Integer price;
private String brand;
private Integer stock;
}
这里定义了Commodity实例，表示商品。在Elasticsearch 6.X 版本中，不建议使用type，而且在7.X版本中将会彻底废弃type，所以此处我只指定了indexName，没有指定type。
这里，一个Commodity代表一个商品，同时代表一条索引记录。
类比关系型数据库的话，Index相当于表，Document相当于记录，然后，需要自己定义一个接口，并继承ElasticsearchRepository。
package com.cjs.example.dao;
import com.cjs.example.entity.Commodity;
import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;
import org.springframework.stereotype.Repository;
@Repository
public interface CommodityRepository extends ElasticsearchRepository<Commodity, String> {
}
import com.cjs.example.entity.Commodity;
import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;
import org.springframework.stereotype.Repository;
@Repository
public interface CommodityRepository extends ElasticsearchRepository<Commodity, String> {
}
这里的Repository相当于DAO，操作mysql还是elasticsearch都是一样的
接下来，定义service接口
package com.cjs.example.service;
import com.cjs.example.entity.Commodity;
import org.springframework.data.domain.Page;
import java.util.List;
public interface CommodityService {
long count();
Commodity save(Commodity commodity);
void delete(Commodity commodity);
Iterable<Commodity> getAll();
List<Commodity> getByName(String name);
Page<Commodity> pageQuery(Integer pageNo, Integer pageSize, String kw);
}
import com.cjs.example.entity.Commodity;
import org.springframework.data.domain.Page;
import java.util.List;
public interface CommodityService {
long count();
Commodity save(Commodity commodity);
void delete(Commodity commodity);
Iterable<Commodity> getAll();
List<Commodity> getByName(String name);
Page<Commodity> pageQuery(Integer pageNo, Integer pageSize, String kw);
}
实现类
package com.cjs.example.service.impl;
import com.cjs.example.entity.Commodity;
import com.cjs.example.dao.CommodityRepository;
import com.cjs.example.service.CommodityService;
import org.elasticsearch.index.query.MatchQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.elasticsearch.core.query.NativeSearchQueryBuilder;
import org.springframework.data.elasticsearch.core.query.SearchQuery;
import org.springframework.stereotype.Service;
import java.util.ArrayList;
import java.util.List;
@Service
public class CommodityServiceImpl implements CommodityService {
@Autowired
private CommodityRepository commodityRepository;
@Override
public long count() {
return commodityRepository.count();
}
@Override
public Commodity save(Commodity commodity) {
return commodityRepository.save(commodity);
}
@Override
public void delete(Commodity commodity) {
commodityRepository.delete(commodity);
// commodityRepository.deleteById(commodity.getSkuId());
}
@Override
public Iterable<Commodity> getAll() {
return commodityRepository.findAll();
}
@Override
public List<Commodity> getByName(String name) {
List<Commodity> list = new ArrayList<>();
MatchQueryBuilder matchQueryBuilder = new MatchQueryBuilder("name", name);
Iterable<Commodity> iterable = commodityRepository.search(matchQueryBuilder);
iterable.forEach(e->list.add(e));
return list;
}
@Override
public Page<Commodity> pageQuery(Integer pageNo, Integer pageSize, String kw) {
SearchQuery searchQuery = new NativeSearchQueryBuilder()
.withQuery(QueryBuilders.matchPhraseQuery("name", kw))
.withPageable(PageRequest.of(pageNo, pageSize))
.build();
return commodityRepository.search(searchQuery);
}
}
import com.cjs.example.entity.Commodity;
import com.cjs.example.dao.CommodityRepository;
import com.cjs.example.service.CommodityService;
import org.elasticsearch.index.query.MatchQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.elasticsearch.core.query.NativeSearchQueryBuilder;
import org.springframework.data.elasticsearch.core.query.SearchQuery;
import org.springframework.stereotype.Service;
import java.util.ArrayList;
import java.util.List;
@Service
public class CommodityServiceImpl implements CommodityService {
@Autowired
private CommodityRepository commodityRepository;
@Override
public long count() {
return commodityRepository.count();
}
@Override
public Commodity save(Commodity commodity) {
return commodityRepository.save(commodity);
}
@Override
public void delete(Commodity commodity) {
commodityRepository.delete(commodity);
// commodityRepository.deleteById(commodity.getSkuId());
}
@Override
public Iterable<Commodity> getAll() {
return commodityRepository.findAll();
}
@Override
public List<Commodity> getByName(String name) {
List<Commodity> list = new ArrayList<>();
MatchQueryBuilder matchQueryBuilder = new MatchQueryBuilder("name", name);
Iterable<Commodity> iterable = commodityRepository.search(matchQueryBuilder);
iterable.forEach(e->list.add(e));
return list;
}
@Override
public Page<Commodity> pageQuery(Integer pageNo, Integer pageSize, String kw) {
SearchQuery searchQuery = new NativeSearchQueryBuilder()
.withQuery(QueryBuilders.matchPhraseQuery("name", kw))
.withPageable(PageRequest.of(pageNo, pageSize))
.build();
return commodityRepository.search(searchQuery);
}
}
在这个Service中演示了增删查改操作，还有分页查询
最后，写一个测试类测试其中的方法
package com.cjs.example;
import com.cjs.example.entity.Commodity;
import com.cjs.example.service.CommodityService;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.domain.Page;
import org.springframework.test.context.junit4.SpringRunner;
import java.util.List;
@RunWith(SpringRunner.class)
@SpringBootTest
public class CjsElasticsearchExampleApplicationTests {
@Autowired
private CommodityService commodityService;
@Test
public void contextLoads() {
System.out.println(commodityService.count());
}
@Test
public void testInsert() {
Commodity commodity = new Commodity();
commodity.setSkuId("1501009001");
commodity.setName("原味切片面包（10片装）");
commodity.setCategory("101");
commodity.setPrice(880);
commodity.setBrand("良品铺子");
commodityService.save(commodity);
commodity = new Commodity();
commodity.setSkuId("1501009002");
commodity.setName("原味切片面包（6片装）");
commodity.setCategory("101");
commodity.setPrice(680);
commodity.setBrand("良品铺子");
commodityService.save(commodity);
commodity = new Commodity();
commodity.setSkuId("1501009004");
commodity.setName("元气吐司850g");
commodity.setCategory("101");
commodity.setPrice(120);
commodity.setBrand("百草味");
commodityService.save(commodity);
}
@Test
public void testDelete() {
Commodity commodity = new Commodity();
commodity.setSkuId("1501009002");
commodityService.delete(commodity);
}
@Test
public void testGetAll() {
Iterable<Commodity> iterable = commodityService.getAll();
iterable.forEach(e->System.out.println(e.toString()));
}
@Test
public void testGetByName() {
List<Commodity> list = commodityService.getByName("面包");
System.out.println(list);
}
@Test
public void testPage() {
Page<Commodity> page = commodityService.pageQuery(0, 10, "切片");
System.out.println(page.getTotalPages());
System.out.println(page.getNumber());
System.out.println(page.getContent());
}
}
import com.cjs.example.entity.Commodity;
import com.cjs.example.service.CommodityService;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.domain.Page;
import org.springframework.test.context.junit4.SpringRunner;
import java.util.List;
@RunWith(SpringRunner.class)
@SpringBootTest
public class CjsElasticsearchExampleApplicationTests {
@Autowired
private CommodityService commodityService;
@Test
public void contextLoads() {
System.out.println(commodityService.count());
}
@Test
public void testInsert() {
Commodity commodity = new Commodity();
commodity.setSkuId("1501009001");
commodity.setName("原味切片面包（10片装）");
commodity.setCategory("101");
commodity.setPrice(880);
commodity.setBrand("良品铺子");
commodityService.save(commodity);
commodity = new Commodity();
commodity.setSkuId("1501009002");
commodity.setName("原味切片面包（6片装）");
commodity.setCategory("101");
commodity.setPrice(680);
commodity.setBrand("良品铺子");
commodityService.save(commodity);
commodity = new Commodity();
commodity.setSkuId("1501009004");
commodity.setName("元气吐司850g");
commodity.setCategory("101");
commodity.setPrice(120);
commodity.setBrand("百草味");
commodityService.save(commodity);
}
@Test
public void testDelete() {
Commodity commodity = new Commodity();
commodity.setSkuId("1501009002");
commodityService.delete(commodity);
}
@Test
public void testGetAll() {
Iterable<Commodity> iterable = commodityService.getAll();
iterable.forEach(e->System.out.println(e.toString()));
}
@Test
public void testGetByName() {
List<Commodity> list = commodityService.getByName("面包");
System.out.println(list);
}
@Test
public void testPage() {
Page<Commodity> page = commodityService.pageQuery(0, 10, "切片");
System.out.println(page.getTotalPages());
System.out.println(page.getNumber());
System.out.println(page.getContent());
}
}
以上，便是使用Elasticsearch Repositories的方式
4.2. 使用ElasticsearchTemplate方式操作Elasticsearch
package com.cjs.example;
import com.cjs.example.entity.Commodity;
import org.elasticsearch.index.query.QueryBuilders;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.elasticsearch.core.ElasticsearchTemplate;
import org.springframework.data.elasticsearch.core.query.*;
import org.springframework.test.context.junit4.SpringRunner;
import java.util.List;
@RunWith(SpringRunner.class)
@SpringBootTest
public class ElasticsearchTemplateTest {
@Autowired
public ElasticsearchTemplate elasticsearchTemplate;
@Test
public void testInsert() {
Commodity commodity = new Commodity();
commodity.setSkuId("1501009005");
commodity.setName("葡萄吐司面包（10片装）");
commodity.setCategory("101");
commodity.setPrice(160);
commodity.setBrand("良品铺子");
IndexQuery indexQuery = new IndexQueryBuilder().withObject(commodity).build();
elasticsearchTemplate.index(indexQuery);
}
@Test
public void testQuery() {
SearchQuery searchQuery = new NativeSearchQueryBuilder()
.withQuery(QueryBuilders.matchQuery("name", "吐司"))
.build();
List<Commodity> list = elasticsearchTemplate.queryForList(searchQuery, Commodity.class);
System.out.println(list);
}
}
import com.cjs.example.entity.Commodity;
import org.elasticsearch.index.query.QueryBuilders;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.elasticsearch.core.ElasticsearchTemplate;
import org.springframework.data.elasticsearch.core.query.*;
import org.springframework.test.context.junit4.SpringRunner;
import java.util.List;
@RunWith(SpringRunner.class)
@SpringBootTest
public class ElasticsearchTemplateTest {
@Autowired
public ElasticsearchTemplate elasticsearchTemplate;
@Test
public void testInsert() {
Commodity commodity = new Commodity();
commodity.setSkuId("1501009005");
commodity.setName("葡萄吐司面包（10片装）");
commodity.setCategory("101");
commodity.setPrice(160);
commodity.setBrand("良品铺子");
IndexQuery indexQuery = new IndexQueryBuilder().withObject(commodity).build();
elasticsearchTemplate.index(indexQuery);
}
@Test
public void testQuery() {
SearchQuery searchQuery = new NativeSearchQueryBuilder()
.withQuery(QueryBuilders.matchQuery("name", "吐司"))
.build();
List<Commodity> list = elasticsearchTemplate.queryForList(searchQuery, Commodity.class);
System.out.println(list);
}
}
ElasticsearchTemplate是自动配置的
5. 演示
6. 工程结构
7. 参考
https://docs.spring.io/spring-data/elasticsearch/docs/3.1.0.RELEASE/reference/html/#repositories.query-methods.details
- END -
关注Java技术栈微信公众号，在后台回复关键字：Java，可以获取一份栈长整理的 Java 最新技术干货。
最近干货分享
点击「阅读原文」加入栈长的战队～
Spring Boot & ES 实战，值得参考！的更多相关文章
- Spring Boot 项目实战（五）集成 Dubbo
一.前言 上篇介绍了 Redis 的集成过程,可用于解决热点数据访问的性能问题.随着业务复杂度的提高,单体应用越来越庞大,就好比一个类的代码行数越来越多,分而治之,切成多个类应该是更好的解决方法,所以 ...
- “Spring Boot+Marklogic实战应用(1)”
版权声明:本文为博主原创文章,遵循 CC 4.0 BY-SA 版权协议.本文链接:http://www.blbk.info Spring Boot+Marklogic应用 摘要: 在前一节的介绍,相信 ...
- Spring Boot GraphQL 实战 02_增删改查和自定义标量
hello,大叫好,我是小黑,又和大家见面啦~ 今天我们来继续学习 Spring Boot GraphQL 实战,我们使用的框架是 https://github.com/graphql-java-ki ...
- Spring Boot GraphQL 实战 03_分页、全局异常处理和异步加载
hello,大家好,我是小黑,又和大家见面啦~ 今天我们来继续学习 Spring Boot GraphQL 实战,我们使用的框架是 https://github.com/graphql-java-ki ...
- spring boot插件开发实战和原理
本文转载自spring boot插件开发实战和原理 实战:编写spring boot插件 为什么要编写boot插件 因为我们在开发的时候需要提供一些共同的功能,所以我们编写个共同的jar包.开发人员在 ...
- 【建议收藏】缺少 Vue3 和 Spring Boot 的实战项目经验？我这儿有啊！
缺少 Vue3 和 Spring Boot 的实战项目经验?缺少学习项目和练手项目?我这儿有啊! 从 2019 年到 2021 年,空闲时间里陆陆续续做了一些开源项目,推荐给大家啊!记得点赞和收藏噢! ...
- Spring Boot 2 实战：利用Redis的Geo功能实现查找附近的位置
1. 前言 老板突然要上线一个需求,获取当前位置方圆一公里的业务代理点.明天上线!当接到这个需求的时候我差点吐血,这时间也太紧张了.赶紧去查相关的技术选型.经过一番折腾,终于在晚上十点完成了这个需求. ...
- Github 上热门的 Spring Boot 项目实战推荐
最近经常被读者问到有没有 Spring Boot 实战项目可以学习,于是,我就去 Github 上找了 10 个我觉得还不错的实战项目.对于这些实战项目,有部分是比较适合 Spring Boot 刚入 ...
- Spring Boot 2 实战：如何自定义 Servlet Filter
1.前言 有些时候我们需要在 Spring Boot Servlet Web 应用中声明一些自定义的 Servlet Filter 来处理一些逻辑.比如简单的权限系统.请求头过滤.防止 XSS 攻击等 ...
随机推荐
- JVM 程序计数器
程序计数器是一块较小的内存空间,它的作用可以看作是当前线程所执行的字节码的行号指示器.在虚拟机的概念模型里字节码解释器工作时就是通过改变这个计数器的值来选取下一条需要执行的字节码指令,分支.循环.跳转 ...
- 转 Java中final、finally、finalize的区别与用法
Java中final.finally.finalize的区别与用法 1.简单区别:final用于声明属性,方法和类,分别表示属性不可交变,方法不可覆盖,类不可继承.finally是异常处理语句结构 ...
- 在父组件中，传值给子组件-vue
1.通过 props <x-test :name="username"></x-test>1)props为字符串数组 props: ['name']2)pr ...
- oracle中用case when查询列表
查询sql语句如下 SELECT * FROM ( SELECT * ,ROW_NUMBER() OVER ( PARTITION BY scene_code ORDER BY (CASE statu ...
- AGC015做题记录
C 树的性质是点-边=1 森林联通块计数都可以这么做所以直接维护前缀和再把边界处理一下就好了 //Love and Freedom. #include<algorithm> #includ ...
- Thymeleaf静态资源引入方式及公共页面代码抽取
静态资源引入 Thymeleaf模板引擎url问题,要用如下的方式写,确保在任何情况下都能访问到 <!-- Bootstrap core CSS --> <link href=&qu ...
- springboot创建拦截器
一.创建一个MyIntercepor实现HandlerInterceptor接口的类 二.创建一个WebMvcConfig实现WebMvcConfigurer的类 ...
- 使用 flex 弹性布局 ，相关教程记录
一.Flex布局是什么? Flex是Flexible Box的缩写,意为"弹性布局",用来为盒状模型提供最大的灵活性. 任何一个容器都可以指定为Flex布局. .box1{ dis ...
- Floyd求解最短路
Floyd算法适用于求解全源最短路.也就是能够求解任意两点间的最短路径并且是适用于含有负权边的图,但是含有负环则不行了!空间复杂度为O(n2).时间复杂度为O(n3).其具体的原理在百度能够找到很多, ...
- 最短路（模板）【CodeChef CLIQUED，洛谷P3371】
自TG滚粗后咕咕咕了这么久,最近重新开始学OI,也会慢慢开始更博了.... 最短路算法经典的就是SPFA(Bellman-Ford),Dijkstra,Floyd: 本期先讲两个经典的单源最短路算法: ...