Kotlin开发springboot项目（三）

Kotlin开发springboot项目（三）

在线工具

https://www.sojson.com

IDEA中Kotlin生成可执行文件
1，项目使用Gradle构建
2，在model的build.gradle中添加插件：
apply plugin: 'application'
mainClassName = "net.println.kotlin.HelloKt"     //注意文件名Kt结尾
3，在ide右侧：Gradle->model name->Tasks->distribution->installDist双击即可执行任务
4，构建完毕，在./build/install/{modelName}/bin/下会生成bash脚本和bat脚本

 

 

高阶函数有点和 scale 的类似

forEach,map,flatmap,fold,reduce,filter,takeWhile,let,apply,with,use

 

 

 领域特定语言DSL

专门解决某一特定问题的计算机语言，比如大家耳熟能详的 SQL 和正则表达式。

 

协成Coroutine

 

 

 java与kotlin互操作

 

kotlin编写脚本

创建HelloWorld.kts

import java.io.File
println("HelloWorld")
File(".").list().forEach(::println)

 

kotlin整合springboot

http://blog.720ui.com/2018/springboot2_kotlin_prime/

环境依赖

修改 POM 文件，添加 spring boot 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.kotlin.springboot</groupId>
    <artifactId>sb-demo</artifactId>
    <version>1.0-SNAPSHOT</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.2.RELEASE</version>
        <relativePath/>
    </parent>
    <dependencies>
        <!-- 基础依赖 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</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-jdbc</artifactId>
        </dependency>

        <!-- 数据库配置 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.35</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.0.14</version>
        </dependency>

        <!-- kotlin配置 -->
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-stdlib-jdk8</artifactId>
        </dependency>
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-reflect</artifactId>
        </dependency>
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-stdlib</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
        <plugin>
            <artifactId>kotlin-maven-plugin</artifactId>
            <groupId>org.jetbrains.kotlin</groupId>
            <version>${kotlin.version}</version>
            <executions>
                <execution>
                    <id>compile</id>
                    <goals> <goal>compile</goal> </goals>
                </execution>
                <execution>
                    <id>test-compile</id>
                    <goals> <goal>test-compile</goal> </goals>
                </execution>
            </executions>
            <dependencies>
                <dependency>
                    <groupId>org.jetbrains.kotlin</groupId>
                    <artifactId>kotlin-maven-noarg</artifactId>
                    <version>${kotlin.version}</version>
                </dependency>
                <dependency>
                    <groupId>org.jetbrains.kotlin</groupId>
                    <artifactId>kotlin-maven-allopen</artifactId>
                    <version>${kotlin.version}</version>
                </dependency>
            </dependencies>
        </plugin>
        </plugins>
    </build>
</project>

脚本初始化

先初始化需要用到的 SQL 脚本。

    CREATE DATABASE /*!32312 IF NOT EXISTS*/`springboot_db` /*!40100 DEFAULT CHARACTER SET utf8 */;
    USE `springboot_db`;
    DROP TABLE IF EXISTS `t_author`;
    CREATE TABLE `t_author` (
      `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT '用户ID',
      `real_name` varchar(32) NOT NULL COMMENT '用户名称',
      `nick_name` varchar(32) NOT NULL COMMENT '用户匿名',
      PRIMARY KEY (`id`)
    ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;