需求背景
在数据规范化的过程中，经常面临多种数据源，字段存在不同的命名风格，那有没有一种方法方便我们对字段名称进行规范化。
用什么做
恰好，Guava提供了这种能力。Guava的CaseFormat类可以做到统一命名风格。话不多说，直接看源码。
在CaseFormat中定义了五个枚举值：
五个枚举值分别对应五种场景的命名格式：
| 枚举常量 | 说明 | 输入 | 输出 |
|---|---|---|---|
| LOWER_CAMEL | 小写驼峰式命名 | aa_bb_cc | aaBbCc |
| UPPER_CAMEL | 大写驼峰式命名 | aa_bb_cc | AaBbCc |
| LOWER_UNDERSCORE | 小写下划线命名 | AaBbCc | aa_bb_cc |
| UPPER_UNDERSCORE | 大写下划线命名 | AaBbCc | AA_BB_CC |
| LOWER_HYPHEN | 小写字符连接命名 | AaBbCc | aa-bb-cc |
话不多说，上代码
import com.google.common.base.CaseFormat;
public class CaseFormatTest1 {
public static void main(String[] args) {
System.out.println("------------------");
String inputStr1 = "aa_bb_cc";
System.out.println(String.format("inputStr1:%s,LOWER_CAMEL:%s", inputStr1, CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.LOWER_CAMEL, inputStr1)));
System.out.println(String.format("inputStr1:%s,UPPER_CAMEL:%s", inputStr1, CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.UPPER_CAMEL, inputStr1)));
System.out.println(String.format("inputStr1:%s,LOWER_UNDERSCORE:%s", inputStr1, CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.LOWER_UNDERSCORE, inputStr1)));
System.out.println(String.format("inputStr1:%s,UPPER_UNDERSCORE:%s", inputStr1, CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.UPPER_UNDERSCORE, inputStr1)));
System.out.println(String.format("inputStr1:%s,LOWER_HYPHEN:%s", inputStr1, CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.LOWER_HYPHEN, inputStr1)));
System.out.println("------------------");
String inputStr2 = "AaBbCc";
System.out.println(String.format("inputStr2:%s,LOWER_CAMEL:%s", inputStr2, CaseFormat.LOWER_CAMEL.to(CaseFormat.LOWER_CAMEL, inputStr2)));
System.out.println(String.format("inputStr2:%s,UPPER_CAMEL:%s", inputStr2, CaseFormat.LOWER_CAMEL.to(CaseFormat.UPPER_CAMEL, inputStr2)));
System.out.println(String.format("inputStr2:%s,LOWER_UNDERSCORE:%s", inputStr2, CaseFormat.LOWER_CAMEL.to(CaseFormat.LOWER_UNDERSCORE, inputStr2)));
System.out.println(String.format("inputStr2:%s,UPPER_UNDERSCORE:%s", inputStr2, CaseFormat.LOWER_CAMEL.to(CaseFormat.UPPER_UNDERSCORE, inputStr2)));
System.out.println(String.format("inputStr2:%s,LOWER_HYPHEN:%s", inputStr2, CaseFormat.LOWER_CAMEL.to(CaseFormat.LOWER_HYPHEN, inputStr2)));
System.out.println("------------------");
String inputStr3 = "aaBbCc";
System.out.println(String.format("inputStr3:%s,LOWER_CAMEL:%s", inputStr3, CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.LOWER_CAMEL, inputStr3)));
System.out.println(String.format("inputStr3:%s,UPPER_CAMEL:%s", inputStr3, CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.UPPER_CAMEL, inputStr3)));
System.out.println(String.format("inputStr3:%s,LOWER_UNDERSCORE:%s", inputStr3, CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.LOWER_UNDERSCORE, inputStr3)));
System.out.println(String.format("inputStr3:%s,UPPER_UNDERSCORE:%s", inputStr3, CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.UPPER_UNDERSCORE, inputStr3)));
System.out.println(String.format("inputStr3:%s,LOWER_HYPHEN:%s", inputStr3, CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.LOWER_HYPHEN, inputStr3)));
}
}
输出:
------------------
inputStr1:aa_bb_cc,LOWER_CAMEL:aaBbCc
inputStr1:aa_bb_cc,UPPER_CAMEL:AaBbCc
inputStr1:aa_bb_cc,LOWER_UNDERSCORE:aa_bb_cc
inputStr1:aa_bb_cc,UPPER_UNDERSCORE:AA_BB_CC
inputStr1:aa_bb_cc,LOWER_HYPHEN:aa-bb-cc
------------------
inputStr2:AaBbCc,LOWER_CAMEL:AaBbCc
inputStr2:AaBbCc,UPPER_CAMEL:AaBbCc
inputStr2:AaBbCc,LOWER_UNDERSCORE:aa_bb_cc
inputStr2:AaBbCc,UPPER_UNDERSCORE:AA_BB_CC
inputStr2:AaBbCc,LOWER_HYPHEN:aa-bb-cc
------------------
inputStr3:aaBbCc,LOWER_CAMEL:aabbcc
inputStr3:aaBbCc,UPPER_CAMEL:Aabbcc
inputStr3:aaBbCc,LOWER_UNDERSCORE:aaBbCc
inputStr3:aaBbCc,UPPER_UNDERSCORE:AABBCC
inputStr3:aaBbCc,LOWER_HYPHEN:aaBbCc
总结
对于强迫症患者，看着统一风格的变量、字段，着实有一种满足感。使用CaseFormat，可极大满足这种癖好。良好的命名规范，其实也是一种数据质量的体现。