Do you remember all kinds of complicated mathematical formulas in the school days ？sin、log2、tan And so on. , If I see this, I think it's troublesome ？

adopt MXReflection frame , You can use Java Computing these mathematical operations and functions that we once thought were extremely complex , Just use the fields related to the class .

MXReflection You can read the value from the specified field , And inject the results into the @Expression Comment fields .

<dependency>
 <groupId>com.github.ismail-mekni</groupId>
 <artifactId>mxreflection</artifactId>
 <version>1.0.1</version>
</dependency>

So how to use this framework ?

It's simple , Only two... Are needed java notes .

1、 adopt @Arg value , We can specify the name of the custom parameter to be used in the objective function .

2、@Expression Comment values contain function expressions with arguments .

It's not hard to use this framework , Here are two calculation cases , It's easy to understand how to use this framework through cases ：

Case study 1

public class Example1Test {

 class Example1 {

 @Arg("f1")

 String field1;

 @Arg("f2")

 int field2;

 @Expression("f1 * sin(f2) * log2(f1 + f2) + der(cos(f1), f1) * pi + int(tan(f2), f2, 0, e)")

 double field3;

 }

 @Test

 public void example1Test() {

 Example1 example1 = new Example1();

 example1.field1 = "2.2";

 example1.field2 = 5;

 Calculator<Example1> calculator = MXFactory.createCalculator(Example1.class);

 calculator.calculate(example1);

 System.out.println("Field 3 result: " + example1.field3);

 }

}

Output:

Field 3 result: -34.32819235851987

Case study 2

public class Example2Test {

 public class Example2{

 @Arg("f1")

 private String field1;

 @Arg("f2")

 private Long field2;

 @Expression("f2 - f1")

 @Arg("f3")

 private double field3;

 @Expression("f3 - f2")

 @Arg("f4")

 private double field4;

 @Expression("f1 - f2")

 @Arg("f5")

 private Double field5;

 @Expression("f4-f5")

 @Arg("f6")

 private String field6;

 @Expression("f6-f5")

 @Arg("f7")

 private long field7;

 @Expression("f7+5")

 private Long field8;

 }

 @Test

 public void exampleTest() {

 Example2 example2 = new Example2();

 example2.field1 = "2.2";
 example1.field2 = 5; Calculator<Example2> calculator = MXFactory.createCalculator(Example2.class);

 calculator.calculate(example2);

 System.out.println("Field 3 result: " + example2.field3);

 System.out.println("Field 4 result: " + example2.field4);

 System.out.println("Field 5 result: " + example2.field5);

 System.out.println("Field 6 result: " + example2.field6);

 System.out.println("Field 7 result: " + example2.field7);

 System.out.println("Field 8 result: " + example2.field8);

 }

}

Output:

Field 3 result: 2.8
Field 4 result: -2.2
Field 5 result: -2.8
Field 6 result: 0.6
Field 7 result: 3
Field 8 result: 8

MXReflection Framework support mXparser The math set provided in the math library is as follows ：

• Operators (+, -, *, /, #, !, ^)
• Binary Relations (=, ==, =<, =>, <, >, <>, !=, ~=)
• Boolean Operators (&, &&, /, ~&, ~&&, ~/, |, ||…)
• Bitwise Operators (@~, @&, @^, @|, @<<, @>>)
• Unary Functions (sin, cos, tan, tg, ctan, ctg, cot, sec,…)
• Binary Functions (log, mod, C, Bern, Stirl1, Stirl2, …)
• 3-args Functions (if, chi, CHi, Chi, cHi, pUni, cUni, qUni, pNor, cNor, qNor)
• Variadic Functions (iff, min, max, ConFrac, ConPol, gcd, …)
• Iterated Operators (sum, prod, avg, vari, stdi, mini, maxi)
• Calculus Operators (int, der, der-, der+, dern, diff, difb)
• Math Constants (pi, e, [gam], [phi], [PN], [B*], [F’d], [F’a], …)
• Physical Constants ([c], [G.], [g], [hP], [h-], [lP], [mP], [tP])
• Astronomical Constants ([ly], [au], [pc], [kpc], [Earth-R-eq], …)
• Random Variables ([Uni], [Int], [Int1], [Int2], [Int3], [Int4], …)
• Metric prefixes ([%], [%%], [Y], [sept], [Z], [sext], [E], …)
• Parser Symbols ((, ), ,, ;)
• Units

In parameter analysis ,MXReflection Supports all field data types with digital content as parameters . You can put all of Java The type is the same as... That returns the numerical result toString Implementation used together . Supported result fields java Type a ：

• Double
• double
• Long
• long
• String
• BigInteger

But pay attention to , about long、long and BigInteger,MXReflection Use to parse the final result before injection . It is recommended to make sure that the expression returns an integer type .

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