[Java知识库]Springboot构建RESTFUL风格接口

1.RESTFUL简介

1.REST全称为Representational State Transfer，是一种web软件架构风格，注意它是一种风格而不是一种标准，匹配或者兼容这种架构风格的服务称为REST服务。REST服务简介并且有层次，它通常基于HTTTP,URI,XML以及HTML这些现有的流行的标准。在REST中，资源是由URI来指定，对资源的增删改查操作可以通过HTTP协议提供的GET,POST,DELETE,UPDATE等方法来实现，使用REST可以更高效地利用缓存来提供响应速度，同时REST中的通信会话状态由客户端来维护，这可以让不同的服务器处理一系列请求中的不同请求，进而提高服务器的扩展性。在前后端分离项目中，一个设计良好的web软件架构必然要符合REST风格，在springmvc中，开发者可以通过@RestController注解来开发一个REST服务，springboot对此提供了自动化配置方案，只要添加相关依赖就能快速构建REST服务应用了。

2.快速构建RESTFUL应用

1.pom.xml

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.3</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.yl</groupId>
    <artifactId>restful</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>restful</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>11</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-rest</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </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>

2.application.properties

# 数据库的配置
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8&serverTimeZone=Asia/shanghai

# jpa的配置
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=update
spring.jpa.database-platform=mysql
spring.jpa.database=mysql
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL57Dialect

3.实体类

package com.yl.restful.domain;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import java.io.Serializable;

@Entity(name = "user")
public class User implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;
    private String username;
    private String password;


    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

4.dao

package com.yl.restful.dao;

import com.yl.restful.domain.User;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.repository.query.Param;
import org.springframework.data.rest.core.annotation.RepositoryRestResource;
import org.springframework.data.rest.core.annotation.RestResource;

import java.util.List;

@RepositoryRestResource(path = "human",collectionResourceRel = "us",itemResourceRel = "u")
public interface UserDao extends JpaRepository<User,Integer> {

    @RestResource(path = "getByName")
    List<User> findUserByUsernameIs(@Param("username") String username);
}

5.测试

1）查找id为1的user，实体类名加上s就代表接口，GET请求代表查找数据

2）分页查询数据，不传参数就查所有数据，也可以传参数，或者排序


3）添加数据，请求改为POST，在请求体传参即可，插入数据成功后会返回当前数据

3）修改数据，请求改为PUT，在请求体传参即可，更新数据成功后会返回当前数据

4）删除数据，请求改为DELETE

3.Spring Data Rest各种定制操作

1.根据用户名查找用户

2.在application.properties可以配置rest的一些参数

3.如何自定义接口的名称长度

4.快速构建RESTFUL应用（mongodb）

1.pom.xml

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.3</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.yl</groupId>
    <artifactId>restful_mongodb</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>restful_mongodb</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>11</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-mongodb</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-rest</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </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>

2.application.properties

# mongodb端口号
spring.data.mongodb.port=27017
# 主机
spring.data.mongodb.host=192.168.244.135
spring.data.mongodb.username=admin
spring.data.mongodb.password=123456
# 新建一个数据库test用于保存数据
spring.data.mongodb.database=test
# 认证用户名和密码时使用admin数据库
spring.data.mongodb.authentication-database=admin

3.实体类

package com.yl.restful_mongodb.domain;

import java.io.Serializable;

public class Student implements Serializable {
    private Integer id;
    private String name;
    private Integer age;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Student{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

4.dao

package com.yl.restful_mongodb.dao;

import com.yl.restful_mongodb.domain.Student;
import org.springframework.data.mongodb.repository.MongoRepository;

public interface StudentDao extends MongoRepository<Student,Integer> {
}

5.测试
1）插入数据

2）查找数据

5.快速构建RESTFUL应用（ElasticSearch）

after.