swagger-codegen自动生成代码工具的介绍与使用

一、Swagger Codegen简介

Swagger Codegen是一个开源的代码生成器，根据Swagger定义的RESTful API可以自动建立服务端和客户端的连接。Swagger Codegen的源码可以在Github上找到。

GitHub: https://github.com/swagger-api/swagger-codegen

二、Swagger Codegen安装

首先机器上需要安装jdk，具体Java, version 7 or higher，然后在这里（https://oss.sonatype.org/content/repositories/releases/io/swagger/）找到需要的Swagger Codegen版本来安装，不过官方是推荐最新版本。

只要下载一个cli的jar文件就可以了，例如, swagger-codegen-cli-2.2.1.jar（已共享到QQ群文件：301343109）。也可以直接在命令行里下载，例如

Wget https://oss.sonatype.org/content/repositories/releases/io/swagger/swagger-codegen-cli/2.2.1/swagger-codegen-cli-2.2.1.jar

下载好了，运行

java -jar swagger-codegen-cli-2.2.1.jar

根据返回结果可以看到Swagger Codegen支持的语言有很多: [android, aspnet5, async-scala, cwiki, csharp, cpprest, dart, flash, python-flask, go, groovy, java, jaxrs, jaxrs-cxf, jaxrs-resteasy, jaxrs-spec, inflector, javascript, javascript-closure-angular, jmeter, nancyfx, nodejs-server, objc, perl, php, python, qt5cpp, ruby, scala, scalatra, silex-PHP, sinatra, rails5, slim, spring, dynamic-html, html, html2, swagger, swagger-yaml, swift, tizen, typescript-angular2, typescript-angular, typescript-node, typescript-fetch, akka-scala, CsharpDotNet2, clojure, haskell, lumen, go-server]

三、Swagger Codegen的使用

查看Swagger Codegen的帮助信息

java -jar swagger-codegen-cli-2.2.1.jar help generate

查看Swagger Codegen支持的具体某个语言的使用帮助，拿java举例

java -jar swagger-codegen-cli-2.2.1.jar config-help -l java

C:\Users\Administrator\Documents\swagger-coden>java -jar swagger-codegen-cli-2.3..jar help generate
NAME
        swagger-codegen-cli generate - Generate code with chosen lang

SYNOPSIS
        swagger-codegen-cli generate
                [(-a <authorization> | --auth <authorization>)]
                [--additional-properties <additional properties>...]
                [--api-package <api package>] [--artifact-id <artifact id>]
                [--artifact-version <artifact version>]
                [(-c <configuration file> | --config <configuration file>)]
                [-D <system properties>...] [--git-repo-id <git repo id>]
                [--git-user-id <git user id>] [--group-id <group id>]
                [--http-user-agent <http user agent>]
                (-i <spec file> | --input-spec <spec file>)
                [--ignore-file-override <ignore file override location>]
                [--import-mappings <import mappings>...]
                [--instantiation-types <instantiation types>...]
                [--invoker-package <invoker package>]
                (-l <language> | --lang <language>)
                [--language-specific-primitives <language specific primitives>...]
                [--library <library>] [--model-name-prefix <model name prefix>]
                [--model-name-suffix <model name suffix>]
                [--model-package <model package>]
                [(-o <output directory> | --output <output directory>)]
                [--release-note <release note>] [--remove-operation-id-prefix]
                [--reserved-words-mappings <reserved word mappings>...]
                [(-s | --skip-overwrite)]
                [(-t <template directory> | --template-dir <template directory>)]
                [--type-mappings <type mappings>...] [(-v | --verbose)]

OPTIONS
        -a <authorization>, --auth <authorization>
            adds authorization headers when fetching the swagger definitions
            remotely. Pass in a URL-encoded string of name:header with a comma
            separating multiple values

        --additional-properties <additional properties>
            sets additional properties that can be referenced by the mustache
            templates in the format of name=value,name=value. You can also have
            multiple occurrences of this option.

        --api-package <api package>
            package for generated api classes

        --artifact-id <artifact id>
            artifactId in generated pom.xml

        --artifact-version <artifact version>
            artifact version in generated pom.xml

        -c <configuration file>, --config <configuration file>
            Path to json configuration file. File content should be in a json
            format {"optionKey":"optionValue", "optionKey1":"optionValue1"...}
            Supported options can be different for each language. Run
            config-help -l {lang} command for language specific config options.

        -D <system properties>
            sets specified system properties in the format of
            name=value,name=value (or multiple options, each with name=value)

        --git-repo-id <git repo id>
            Git repo ID, e.g. swagger-codegen.

        --git-user-id <git user id>
            Git user ID, e.g. swagger-api.

        --group-id <group id>
            groupId in generated pom.xml

        --http-user-agent <http user agent>
            HTTP user agent, e.g. codegen_csharp_api_client, default to
            'Swagger-Codegen/{packageVersion}}/{language}'

        -i <spec file>, --input-spec <spec file>
            location of the swagger spec, as URL or file (required)

        --ignore-file-override <ignore file override location>
            Specifies an override location for the .swagger-codegen-ignore file.
            Most useful on initial generation.

        --import-mappings <import mappings>
            specifies mappings between a given class and the import that should
            be used for that class in the format of type=import,type=import. You
            can also have multiple occurrences of this option.

        --instantiation-types <instantiation types>
            sets instantiation type mappings in the format of
            type=instantiatedType,type=instantiatedType.For example (in Java):
            array=ArrayList,map=HashMap. In other words array types will get
            instantiated as ArrayList in generated code. You can also have
            multiple occurrences of this option.

        --invoker-package <invoker package>
            root package for generated code

        -l <language>, --lang <language>
            client language to generate (maybe class name in classpath,
            required)

        --language-specific-primitives <language specific primitives>
            specifies additional language specific primitive types in the format
            of type1,type2,type3,type3. For example:
            String,boolean,Boolean,Double. You can also have multiple
            occurrences of this option.

        --library <library>
            library template (sub-template)

        --model-name-prefix <model name prefix>
            Prefix that will be prepended to all model names. Default is the
            empty string.

        --model-name-suffix <model name suffix>
            Suffix that will be appended to all model names. Default is the
            empty string.

        --model-package <model package>
            package for generated models

        -o <output directory>, --output <output directory>
            where to write the generated files (current dir by default)

        --release-note <release note>
            Release note, default to 'Minor update'.

        --remove-operation-id-prefix
            Remove prefix of operationId, e.g. config_getId => getId

        --reserved-words-mappings <reserved word mappings>
            specifies how a reserved name should be escaped to. Otherwise, the
            default _<name> is used. For example id=identifier. You can also
            have multiple occurrences of this option.

        -s, --skip-overwrite
            specifies if the existing files should be overwritten during the
            generation.

        -t <template directory>, --template-dir <template directory>
            folder containing the template files

        --type-mappings <type mappings>
            sets mappings between swagger spec types and generated code types in
            the format of swaggerType=generatedType,swaggerType=generatedType.
            For example: array=List,map=Map,string=String. You can also have
            multiple occurrences of this option.

        -v, --verbose
            verbose mode

利用Swagger Codegen根据服务生成客户端代码

java -jar swagger-codegen-cli-2.2.1.jar generate -i http://petstore.swagger.io/v2/swagger.json -l java -o samples/client/pestore/java

在上面这段代码里，使用了三个参数，分别是-i和-l和-o。

-i指定swagger描述文件的路径,url地址或路径文件;该参数为必须(http://petstore.swagger.io/v2/swagger.json是官方的一个例子，我们可以改成自己的服务)

-l指定生成客户端代码的语言,该参数为必须

-o指定生成文件的位置(默认当前目录)

除了可以指定上面三个参数，还有一些常用的：

-c json格式的配置文件的路径;文件为json格式,支持的配置项因语言的不同而不同

-a 当获取远程swagger定义时,添加授权头信息;URL-encoded格式化的name,逗号隔开的多个值

--api-package 指定生成的api类的包名

--artifact-id 指定pom.xml的artifactId的值

--artifact-version 指定pom.xml的artifact的版本

--group-id 指定pom.xml的groupId的值

--model-package 指定生成的model类的包名

-s 指定该参数表示不覆盖已经存在的文件

-t 指定模版文件所在目录

生成好的客户端代码

生成的这些文件里，src文件下的文件和pom.xml文件是对我们最有用的。把它们导入到我们习惯用的java编辑器里，这里以eclipse为例，下面是导入好的客户端的maven工程，和我们平常新建的maven工程一模一样（已共享到QQ群文件：301343109）。

但是自动生成的客户端代码并不能直接使用，需要我们做一些修改，特别是io.swagger.client.api包下的class类，我们需要把void替换成各自的model。

改好后，我们就可以运行客户端test下的测试代码，进行单元测试了。拿PetApiTest类来举例，运行它的addPetTest()方法。

可以看到测试成功。

2019.6.23 更新

我们会发现生成的默认包是io.swagger.client.api/module，而我们可能想要自己的包，怎么办呢？我看网上居然有人说要改源码，以下是那篇文章的内容。

这边我想说swagger也是一个比较成熟的产品了，也这么多人在用了，怎么可能连修改默认的包这个基础的需求都不提供呢，说明这篇文章的作者，根本就没看Swagger Codegen的帮助信息，上面明明已经列出来了，只需要生成代码的时候指定--api-package这个选项就好了。

命令我贴出来

java -jar swagger-codegen-cli-2.3..jar generate -i http://xxxx:8807/static/swagger.json -l java -o C:\Users\Administrator\Documents\xx-java-gen --api-package com.xxxx.client  --invoker-package com.xxxx.client.invoker --model-package com.xxxx.client.model

所以我们在学习和工作的时候，一定要灵活，多动脑。