Java JEXL(Java Expression Language)是一個用于表達式求值的簡單、高效的語言。要簡化表達式處理,你可以遵循以下步驟:
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-jexl3</artifactId>
<version>3.2</version>
</dependency>
import org.apache.commons.jexl3.*;
JexlBuilder jexlBuilder = new JexlBuilder();
JexlEngine jexl = jexlBuilder.create();
String expression = "x + y * z";
Expression expr = jexl.createExpression(expression);
JexlContext context = new MapContext();
context.set("x", 10);
context.set("y", 20);
context.set("z", 30);
Number result = (Number) expr.evaluate(context);
System.out.println("Result: " + result);
將以上代碼整合在一起,完整的示例如下:
import org.apache.commons.jexl3.*;
public class JEXLExample {
public static void main(String[] args) {
JexlBuilder jexlBuilder = new JexlBuilder();
JexlEngine jexl = jexlBuilder.create();
String expression = "x + y * z";
Expression expr = jexl.createExpression(expression);
JexlContext context = new MapContext();
context.set("x", 10);
context.set("y", 20);
context.set("z", 30);
Number result = (Number) expr.evaluate(context);
System.out.println("Result: " + result);
}
}
這個示例展示了如何使用Java JEXL簡化表達式處理。你可以根據需要調整表達式和變量值,以滿足不同的計算需求。