1. IFS函数
IFS 函数可用于判断是否满足一个或多个条件，且返回符合第一个 true 条件的值。 IFS 公式可以取代多个嵌套 IF 语句，并且有多个条件时更方便阅读。
2. 函数用法
IFS(
logical_test1, value_if_true1, logical_test2, value_if_true2, … ,logical_testn, value_if_truen
)
其中各参数的含义如下：
-
logical_test1：必需，计算结果为 true 或 false 的条件；
-
value_if_true1：必需，当 logical_test1 的计算结果为 true 时要返回结果，可以为空；
-
logical_test2…logical_testn：非必需，计算结果为 true 或 false 的条件；
-
value_if_true2…value_if_truen：非必需，当 logical_testn 的计算结果为 true 时要返回结果。 每个 value_if_truen 对应于一个条件 logical_testn，可以为空。
3. 函数示例
IFS(A1,B1,A2,B2,A3,B3…)，表示满足条件 A1 时，返回结果 B1；满足条件 A2 时，返回结果 B2；满足条件 A3 时，返回结果 B3。依次类推。
如，可通过 IFS 函数来计算成绩的等级，设置公式为IFS(成绩<60,"不及格",成绩<=79,"及格",成绩<=89,"良好",成绩>=90,"优秀")
4. 代码实战
首先我们在function包下创建logic包，在logic包下创建IfsFunction类，代码如下：
package com.ql.util.express.self.combat.function.logic;
import com.ql.util.express.ArraySwap;
import com.ql.util.express.InstructionSetContext;
import com.ql.util.express.OperateData;
import com.ql.util.express.instruction.op.OperatorBase;
import com.ql.util.express.self.combat.exception.FormulaException;
/**
* 类描述:IFS公式函数
*
* @author admin
* @version 1.0.0
* @date 2023/11/21 16:59
*/
public class IfsFunction extends OperatorBase {
public IfsFunction(String name) {
this.name = name;
}
@Override
public OperateData executeInner(InstructionSetContext parent, ArraySwap list) throws Exception {
if (list.length < 2) {
throw new FormulaException("\"" + this.aliasName + "\"操作至少要两个操作数");
}
OperateData rst = null;
for (int i=0;i<list.length-1;i+=2) {
Object obj = list.get(i).getObject(parent);
if (obj == null) {
String msg = "\"" + this.aliasName + "\"的判断条件不能为空";
throw new FormulaException(msg);
} else if (!(obj instanceof Boolean)) {
String msg = "\"" + this.aliasName + "\"的判断条件 必须是 Boolean,不能是：";
throw new FormulaException(msg + obj.getClass().getName());
} else {
if ((Boolean)obj) {
rst = list.get(i+1);
break;
}
}
}
return rst;
}
}
把IfsFunction类注册到公式函数入口类中，代码如下：
package com.ql.util.express.self.combat.ext;
import com.ql.util.express.ExpressRunner;
import com.ql.util.express.IExpressResourceLoader;
import com.ql.util.express.parse.NodeTypeManager;
import com.ql.util.express.self.combat.function.logic.AndFunction;
import com.ql.util.express.self.combat.function.logic.IfFunction;
import com.ql.util.express.self.combat.function.logic.IfsFunction;
/**
* 类描述: 仿简道云公式函数实战入口类
*
* @author admin
* @version 1.0.0
* @date 2023/11/21 15:29
*/
public class FormulaRunner extends ExpressRunner {
public FormulaRunner() {
super();
}
public FormulaRunner(boolean isPrecise, boolean isTrace) {
super(isPrecise,isTrace);
}
public FormulaRunner(boolean isPrecise, boolean isStrace, NodeTypeManager nodeTypeManager) {
super(isPrecise,isStrace,nodeTypeManager);
}
public FormulaRunner(boolean isPrecise, boolean isTrace, IExpressResourceLoader iExpressResourceLoader, NodeTypeManager nodeTypeManager) {
super(isPrecise,isTrace,iExpressResourceLoader,nodeTypeManager);
}
@Override
public void addSystemFunctions() {
// ExpressRunner 的内部系统函数
super.addSystemFunctions();
// 扩展公式函数
this.customFunction();
}
/***
* 自定义公式函数
*/
public void customFunction() {
// AND函数
this.addFunction("AND",new AndFunction("AND"));
// IF函数
this.addFunction("IF",new IfFunction("IF"));
// IFS函数
this.addFunction("IFS",new IfsFunction("IFS"));
}
}
创建测试用例：
package com.ql.util.express.self.combat;
import com.ql.util.express.DefaultContext;
import com.ql.util.express.self.combat.ext.FormulaRunner;
import org.junit.Test;
/**
* 类描述: 实战测试类
*
* @author admin
* @version 1.0.0
* @date 2023/11/21 15:45
*/
public class CombatTest {
@Test
public void IFS() throws Exception{
FormulaRunner formulaRunner = new FormulaRunner(true,true);
// 创建上下文
DefaultContext<String, Object> context = new DefaultContext<>();
String express = "IFS(成绩<60,\"不及格\",成绩<=79,\"及格\",成绩<=89,\"良好\",成绩>=90,\"优秀\")";
context.put("成绩",119);
Object object = formulaRunner.execute(express, context, null, true, true);
System.out.println(object);
}
}
运行日志：
[2024-02-06 08:45:45,215] [main] (ExpressParse.java:340) DEBUG com.ql.util.express.parse.ExpressParse - 执行的表达式:IFS(成绩<60,"不及格",成绩<=79,"及格",成绩<=89,"良好",成绩>=90,"优秀")
[2024-02-06 08:45:45,218] [main] (ExpressParse.java:341) DEBUG com.ql.util.express.parse.ExpressParse - 单词分解结果:{IFS},{(},{成绩},{<},{60},{,},{"不及格"},{,},{成绩},{<=},{79},{,},{"及格"},{,},{成绩},{<=},{89},{,},{"良好"},{,},{成绩},{>=},{90},{,},{"优秀"},{)}
[2024-02-06 08:45:45,218] [main] (ExpressParse.java:345) DEBUG com.ql.util.express.parse.ExpressParse - 预处理后结果:{IFS},{(},{成绩},{<},{60},{,},{"不及格"},{,},{成绩},{<=},{79},{,},{"及格"},{,},{成绩},{<=},{89},{,},{"良好"},{,},{成绩},{>=},{90},{,},{"优秀"},{)}
[2024-02-06 08:45:45,221] [main] (ExpressParse.java:370) DEBUG com.ql.util.express.parse.ExpressParse - 单词分析结果:IFS:FUNCTION_NAME,(:(,成绩:ID,<:<,60:CONST_INTEGER,,:,,不及格:CONST_STRING,,:,,成绩:ID,<=:<=,79:CONST_INTEGER,,:,,及格:CONST_STRING,,:,,成绩:ID,<=:<=,89:CONST_INTEGER,,:,,良好:CONST_STRING,,:,,成绩:ID,>=:>=,90:CONST_INTEGER,,:,,优秀:CONST_STRING,):)
[2024-02-06 08:45:45,225] [main] (ExpressParse.java:422) DEBUG com.ql.util.express.parse.ExpressParse - 最后的语法树:
1: STAT_BLOCK:STAT_BLOCK STAT_BLOCK
2: STAT_SEMICOLON:STAT_SEMICOLON STAT_SEMICOLON
3: FUNCTION_CALL:FUNCTION_CALL FUNCTION_CALL
4: IFS:CONST_STRING CONST
4: <:< <
5: 成绩:ID ID
5: 60:CONST_INTEGER CONST
4: 不及格:CONST_STRING CONST
4: <=:<= <=
5: 成绩:ID ID
5: 79:CONST_INTEGER CONST
4: 及格:CONST_STRING CONST
4: <=:<= <=
5: 成绩:ID ID
5: 89:CONST_INTEGER CONST
4: 良好:CONST_STRING CONST
4: >=:>= >=
5: 成绩:ID ID
5: 90:CONST_INTEGER CONST
4: 优秀:CONST_STRING CONST
[2024-02-06 08:45:45,230] [main] (ExpressRunner.java:730) DEBUG com.ql.util.express.ExpressRunner -
1:LoadAttr:成绩
2:LoadData 60
3:OP : < OPNUMBER[2]
4:LoadData 不及格
5:LoadAttr:成绩
6:LoadData 79
7:OP : <= OPNUMBER[2]
8:LoadData 及格
9:LoadAttr:成绩
10:LoadData 89
11:OP : <= OPNUMBER[2]
12:LoadData 良好
13:LoadAttr:成绩
14:LoadData 90
15:OP : >= OPNUMBER[2]
16:LoadData 优秀
17:OP : IFS OPNUMBER[8]
[2024-02-06 08:45:45,235] [main] (InstructionLoadAttr.java:34) DEBUG com.ql.util.express.instruction.detail.Instruction - LoadAttr:成绩:119
[2024-02-06 08:45:45,236] [main] (InstructionConstData.java:26) DEBUG com.ql.util.express.instruction.detail.Instruction - LoadData 60
[2024-02-06 08:45:45,236] [main] (InstructionOperator.java:46) DEBUG com.ql.util.express.instruction.detail.Instruction - <(成绩:119,60)
[2024-02-06 08:45:45,238] [main] (InstructionConstData.java:26) DEBUG com.ql.util.express.instruction.detail.Instruction - LoadData 不及格
[2024-02-06 08:45:45,239] [main] (InstructionLoadAttr.java:34) DEBUG com.ql.util.express.instruction.detail.Instruction - LoadAttr:成绩:119
[2024-02-06 08:45:45,239] [main] (InstructionConstData.java:26) DEBUG com.ql.util.express.instruction.detail.Instruction - LoadData 79
[2024-02-06 08:45:45,239] [main] (InstructionOperator.java:46) DEBUG com.ql.util.express.instruction.detail.Instruction - <=(成绩:119,79)
[2024-02-06 08:45:45,239] [main] (InstructionConstData.java:26) DEBUG com.ql.util.express.instruction.detail.Instruction - LoadData 及格
[2024-02-06 08:45:45,239] [main] (InstructionLoadAttr.java:34) DEBUG com.ql.util.express.instruction.detail.Instruction - LoadAttr:成绩:119
[2024-02-06 08:45:45,239] [main] (InstructionConstData.java:26) DEBUG com.ql.util.express.instruction.detail.Instruction - LoadData 89
[2024-02-06 08:45:45,240] [main] (InstructionOperator.java:46) DEBUG com.ql.util.express.instruction.detail.Instruction - <=(成绩:119,89)
[2024-02-06 08:45:45,240] [main] (InstructionConstData.java:26) DEBUG com.ql.util.express.instruction.detail.Instruction - LoadData 良好
[2024-02-06 08:45:45,240] [main] (InstructionLoadAttr.java:34) DEBUG com.ql.util.express.instruction.detail.Instruction - LoadAttr:成绩:119
[2024-02-06 08:45:45,240] [main] (InstructionConstData.java:26) DEBUG com.ql.util.express.instruction.detail.Instruction - LoadData 90
[2024-02-06 08:45:45,240] [main] (InstructionOperator.java:46) DEBUG com.ql.util.express.instruction.detail.Instruction - >=(成绩:119,90)
[2024-02-06 08:45:45,240] [main] (InstructionConstData.java:26) DEBUG com.ql.util.express.instruction.detail.Instruction - LoadData 优秀
[2024-02-06 08:45:45,240] [main] (InstructionOperator.java:46) DEBUG com.ql.util.express.instruction.detail.Instruction - IFS(false,不及格,false,及格,false,良好,true,优秀)
优秀
