Types

本部分讨论如何使用特定数据类型作为选项值。

String

String 是最为简单的类型，因为它不涉及任何转换，因为用户输入的内容始终为字符串。

link:../../../../src/test/java/org/springframework/shell/docs/OptionTypesSnippets.java[role=include]

尽管要求将类型定义为 String 并非严格规定，但始终建议这样做。

link:../../../../src/test/java/org/springframework/shell/docs/OptionTypesSnippets.java[role=include]

Boolean

使用布尔类型涉及更多内容，因为有 boolean 和 Boolean，而后者可以为 null。布尔类型通常用作标志，这意味着可能不需要参数值。

link:../../../../src/test/java/org/springframework/shell/docs/OptionTypesSnippets.java[role=include]
shell:>example
arg1=false arg2=true arg3=false arg4=false arg5=true arg6=false

shell:>example --arg4
arg1=false arg2=true arg3=false arg4=true arg5=true arg6=false

shell:>example --arg4 false
arg1=false arg2=true arg3=false arg4=false arg5=true arg6=false
link:../../../../src/test/java/org/springframework/shell/docs/OptionTypesSnippets.java[role=include]
shell:>example
arg1=false arg2=true arg3=false arg4=null arg5=true arg6=false

shell:>example --arg4
arg1=false arg2=true arg3=false arg4=true arg5=true arg6=false

shell:>example --arg4 false
arg1=false arg2=true arg3=false arg4=false arg5=true arg6=false

Number

数字按原样转换。

link:../../../../src/test/java/org/springframework/shell/docs/OptionTypesSnippets.java[role=include]
link:../../../../src/test/java/org/springframework/shell/docs/OptionTypesSnippets.java[role=include]

Enum

如果给定值与枚举本身完全匹配，则可以转换为枚举。目前，您可以假设不区分大小写进行转换。

link:../../../../src/test/java/org/springframework/shell/docs/OptionTypesSnippets.java[role=include]
link:../../../../src/test/java/org/springframework/shell/docs/OptionTypesSnippets.java[role=include]
link:../../../../src/test/java/org/springframework/shell/docs/OptionTypesSnippets.java[role=include]

Array

数组可以按原样用于字符串和基元类型。

link:../../../../src/test/java/org/springframework/shell/docs/OptionTypesSnippets.java[role=include]
link:../../../../src/test/java/org/springframework/shell/docs/OptionTypesSnippets.java[role=include]