前言
有时候正则表达式不只是匹配一下什么数字/邮箱/身份证/日期等等,还需要匹配某一段文字,并按照既定格式提取其中的某些值.
场景一:提取SAML2报文
SAML2报文内容如下,从中提取对应的attribute name和value.
<saml:AttributeStatement> <saml:Attribute Name="mail"> <saml:AttributeValue xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="xs:string">zhengkai.blog.csdn.net</saml:AttributeValue> </saml:Attribute> <saml:Attribute Name="cn"> <saml:AttributeValue xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="xs:string">amAdmin</saml:AttributeValue> </saml:Attribute> </saml:AttributeStatement>
show time
public static void main(String[] args) { String content = ""; content = "<saml:AttributeStatement>"; content = " <saml:Attribute Name=\"mail\">"; content = " <saml:AttributeValue xmlns:xs=\"http://www.w3.org/2001/XMLSchema\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xsi:type=\"xs:string\">zhengkai.blog.csdn.net</saml:AttributeValue>"; content = " </saml:Attribute>"; content = " <saml:Attribute Name=\"cn\">"; content = " <saml:AttributeValue xmlns:xs=\"http://www.w3.org/2001/XMLSchema\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xsi:type=\"xs:string\">amAdmin</saml:AttributeValue>"; content = " </saml:Attribute>"; content = "</saml:AttributeStatement>"; String pattern = "\\<saml\\:Attribute Name=\\\"(?<scope>.*?)\\\"\\>[\\s\\S]*?\\<saml\\:AttributeValue[\\s\\S]*?\\>(?<value>.*?)\\<\\/saml\\:AttributeValue\\>[\\s\\S]*?\\<\\/saml\\:Attribute\\>"; Pattern r = Pattern.compile(pattern); Matcher matcher = r.matcher(saml2attributeString); while (matcher.find()){ String attributeName = matcher.group("scope"); String attributeValue = matcher.group("value"); System.out.println("attributeName->" attributeName ",attributeValue->" attributeValue ); } }
控制台输出
$ attributeName->mail,attributeValue->zhengkai.blog.csdn.net
$ vattributeName->cn,attributeValue->amAdmin
解析
\\<saml\\:Attribute Name=\\\"(?<scope>.*?)\\\"\\>[\\s\\S]*?\\<saml\\:AttributeValue[\\s\\S]*?\\>(?<value>.*?)\\<\\/saml\\:AttributeValue\\>[\\s\\S]*?\\<\\/saml\\:Attribute\\>
- (?<scope>.*?)是用于标识scope的方式,表示夹在中间的字符串都叫scope,可以通过matcher.group("scope")提取。
- 所有非正则的符号都需要转义,所以你会看到很多\\<或者换\\"之类的\\
- [\\s\\S]*? 是用来匹配任意字符,表示在前后有界定的情况下(例如夹在<xxx></xxx>中间的字符串),可以忽略那些不规则字符串的匹配。
场景2:提取sql中的表名和字段
来自github网友@ydq 给SpringBootCodeGenerator贡献的正则表达式,非常不错,值得深刻学习.
//匹配整个ddl,将ddl分为表名,列sql部分,表注释 private static final Pattern DDL_PATTERN = Pattern.compile("\\s*create\\s table\\s (?<tableName>\\S )[^\\(]*\\((?<columnsSQL>[\\s\\S] )\\)[^\\)] ?(comment\\s*(=|on\\s table)\\s*'(?<tableComment>.*?)'\\s*;?)?$", Pattern.CASE_INSENSITIVE); //匹配列sql部分,分别解析每一列的列名 类型 和列注释 private static final Pattern COL_PATTERN = Pattern.compile("\\s*(?<fieldName>\\S )\\s (?<fieldType>\\w )\\s*(?:\\([\\s\\d,] \\))?((?!comment).)*(comment\\s*'(?<fieldComment>.*?)')?\\s*(,|$)", Pattern.CASE_INSENSITIVE); public static void parse(String sql){ Matcher matcher = DDL_PATTERN.matcher(sql); if (matcher.find()){ String tableName = matcher.group("tableName"); String tableComment = matcher.group("tableComment"); System.out.println(tableName "\t\t" tableComment); System.out.println("=========="); String columnsSQL = matcher.group("columnsSQL"); if (columnsSQL != null && columnsSQL.length() > 0){ Matcher colMatcher = COL_PATTERN.matcher(columnsSQL); while (colMatcher.find()){ String fieldName = colMatcher.group("fieldName"); String fieldType = colMatcher.group("fieldType"); String fieldComment = colMatcher.group("fieldComment"); if (!"key".equalsIgnoreCase(fieldType)){ System.out.println(fieldName "\t\t" fieldType "\t\t" fieldComment); } } } } } public static void main(String[] args){ System.out.println(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>"); parse("CREATE TABLE `userinfo` (\n" " `user_id` int(11) NOT NULL AUTO_INCREMENT COMMENT '用户ID',\n" " `username` varchar(255) NOT NULL COMMENT '用户名',\n" " `addtime` datetime NOT NULL COMMENT '创建时间',\n" " PRIMARY KEY (`user_id`)\n" ") ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='用户信息'"); System.out.println(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>"); parse("CREATE TABLE `USER` (\n" "`ID` varchar(32) PRIMARY KEY COMMENT '主键',\n" "`password` varchar(32) NOT NULL COMMENT '密码',\n" "`username` varchar(32) NOT NULL COMMENT '用户'\n" ") ENGINE=InnoDB DEFAULT CHARSET=utf8;"); System.out.println(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>"); parse("CREATE TABLE `tb_amount` (\n" "`ID` int(10) NOT NULL AUTO_INCREMENT,\n" "`PRODUCT_CODE` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '产品代码',\n" "`GENDER` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL COMMENT '性别(male,female)',\n" "`MIN_INSURED_AGE` int(3) NULL DEFAULT NULL COMMENT '最小投保年龄',\n" "`MAX_INSURED_AGE` int(3) NULL DEFAULT NULL COMMENT '最大投保年龄',\n" "`AMOUNT` double(10, 2) NULL DEFAULT NULL COMMENT '基本保额',\n" "`PREMIUM_RATE` double(10, 2) NULL DEFAULT NULL COMMENT '基本保费',\n" "`YEAR_NUM` int(3) NULL DEFAULT NULL COMMENT '缴费年限',\n" "`PREMIUM_TYPE` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL COMMENT '费率类型',\n" "`INSURANCE_PERIOD` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL COMMENT '保险期间(30年,60年)',\n" "`INSURANCE_PERIOD_TYPE` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL COMMENT '保险期间类型(如定期年0,定期岁1,终身2,以后终身对应值:200)',\n" "`PAY_MODE` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL COMMENT '交费方式',\n" "PRIMARY KEY (`ID`) USING BTREE\n" ") ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;"); }
控制台输出内容:
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
`userinfo` 用户信息
==========
`user_id` int 用户ID
`username` varchar 用户名
`addtime` datetime 创建时间
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
`USER` null
==========
`ID` varchar 主键
`password` varchar 密码
`username` varchar 用户
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
`tb_amount` null
==========
`ID` int null
`PRODUCT_CODE` varchar 产品代码
`GENDER` varchar 性别(male,female)
`MIN_INSURED_AGE` int 最小投保年龄
`MAX_INSURED_AGE` int 最大投保年龄
`AMOUNT` double 基本保额
`PREMIUM_RATE` double 基本保费
`YEAR_NUM` int 缴费年限
`PREMIUM_TYPE` varchar 费率类型
`INSURANCE_PERIOD` varchar 保险期间(30年,60年)
`INSURANCE_PERIOD_TYPE` varchar 保险期间类型(如定期年0,定期岁1,终身2,以后终身对应值:200)
`PAY_MODE` varchar 交费方式
总结
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