metacode-json-logic
是什么?
Metacode-json-logic 用来构建复杂的规则,将它们序列化为JSON,在前端和后端之间共享
能干什么?
- 通过JSON去表示条件组规则、函数、表达式功能
- 进行计算得出布尔值、数值、日期时间等
- 将语法转换为其他DSL语法(例如SQL)等
语法文档
快速开始
添加依赖
<dependency>
<groupId>tech.wetech.metacode</groupId>
<artifactId>meatacode-json-logic</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
要求Java 17以上版本,低版本不受支持
Examples
返回一个布尔值:
// 创建一个线程安全的新实例
JsonLogic jsonLogic = new JsonLogic();
// 进行逻辑运算
String expression = """
{ "or": [{ ">": [1, 2] }, { "<": [1, 2] }] }
""";
assert jsonLogic.evaluateBoolean(expression, null) == true;
返回一个数字:
// 4+2=6
String expression = """
{"+":[4,2]}
""";
// 进行四则运算
assert jsonLogic.evaluateNumber(expression, null) == 6.0;
使用函数:
// max(1,2)*min(2,3,4)*2*2*2
String expression = """
{ "*": [{ "max": [1, 2] }, { "min": [2, 3, 4] }, 2, 2, 2] }
""";
// 进行四则运算
assert jsonLogic.evaluateNumber(expression, null) == 6.0;
使用变量:
// a=5, b=3
Map<String, String> data = Map.of("a", "5", "b", "3");
// 2+a+b
String expression = """
{"+":[2,{"var":"a"},{"var":"b"}]}
""";
// 进行四则运算
assert jsonLogic.evaluateNumber(expression, data) == 10.0;
返回日期时间:
// TODO
转换为 SQL语法:
String expression = """
{
"and": [
{ ">": [{ "table_field": ["user", "id"] }, 2] },
{ "==": ["jack", { "table_field": ["user", "name"] }] },
{ "<": [{ "table_field": ["user", "age"] }, 21] }
]
}
"""
IndexSqlRenderResult result = jsonLogic.evaluateIndexSql(expression);
assert " ( user.id > ? and ? = user.name and user.age < ? )".equals(result.whereClause());;
assert List.of(2.0, "jack", 21.0).equals(result.args());
转换为 SQL语法(Named Params):
String expression = """
{
"contains": [
{
"table_field": ["xuesheng", "created_by"]
},
[2, 3, 4, 5, 6]
]
}
""";
NamedSqlRenderResult result = jsonLogic.evaluateNamedSql(expression);
assert "xuesheng.created_by in (:xuesheng_created_by_0, :xuesheng_created_by_1, :xuesheng_created_by_2, :xuesheng_created_by_3, :xuesheng_created_by_4) "
.equals(result.whereClause());
assert Map.of("xuesheng_created_by_0",2.0,
"xuesheng_created_by_1",3.0,
"xuesheng_created_by_2",4.0,
"xuesheng_created_by_3",5.0,
"xuesheng_created_by_4",6.0).equals(result.args());
转换为MongoDB语法:
// TODO
更多示例请查看代码测试用例。