Java中利用注解和反射简化编程

我就是我 2021-09-29 03:02 302阅读 0赞

**一 点睛**

当调用大量方法，可以使用反射和注解简化编程。

**二 代码**

import java.lang.annotation.Annotation;
    import java.lang.annotation.Documented;
    import java.lang.annotation.ElementType;
    import java.lang.annotation.Retention;
    import java.lang.annotation.RetentionPolicy;
    import java.lang.annotation.Target;
    import java.lang.reflect.Method;
    import java.util.ArrayList;
    
    @Documented
    @Retention(RetentionPolicy.RUNTIME)
    @Target(ElementType.METHOD)
    @interface testAnnoation10 {
        public String name() default "methodname";
    
        public String unit() default "unit";
    }
    
    public class ch11_10 {
        public static void main( String[] args ) throws Exception {
            ch11_10 ch9 = new ch11_10();
            Method method[] = ch9.getClass().getMethods();
            for (Method method2 : method) {
                Annotation annotation = method2.getAnnotation(testAnnoation10.class);
                Class<?> ts[] = method2.getParameterTypes();
                if (method2.getName().indexOf("getData") == -1) continue;
                ArrayList<Object> params = new ArrayList<Object>();
                for (Class<?> class1 : ts) {
                    if (class1.getSimpleName().equals("int")) {
                        params.add(10);
                    }
                    if (class1.getSimpleName().equals("String")) {
                        params.add("100");
                    }
                }
                if (annotation != null) {
                    testAnnoation10 t9 = (testAnnoation10) annotation;
                    System.out.println(t9.name() + " is " + method2.invoke(ch9, params.toArray()) + " " + t9.unit());
                }
            }
        }
    
        @testAnnoation10(name = "SOC", unit = "%")
        public int getData1( int a ) {
            return a;
        }
    
        @testAnnoation10(name = "Electricity", unit = "Ah")
        public String getData2( String b ) {
            return b;
        }
    
        @testAnnoation10(name = "Tempreture", unit = "AF")
        public int getData3( int a, int b ) {
            return a + b;
        }
    }

**三 运行**

Tempreture is 20 AF
    Electricity is 100 Ah
    SOC is 10 %