java - 是否有任何开源 Java 反射实用程序或 jar？

Question

是否有用于在 java 中处理反射的任何开源实用程序或 jar？

我正在将方法动态传递给一个类，我想获取返回值。

例如:

class Department {
    String name ;
    Employee[] employees;
    public void setName(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public  Employee[] getEmployes() {
        return employees;

    }
}

我想将所有员工打印到控制台输出，而不是像这样在运行时获取它:

Department dept = new Department();
// add employees..

getEmployeeNames(dept,"getEmployees.getAddress.getStreet");
// So the user says they want employee street, but we don't know that
// until run-tme.

是否有任何关于反射的开源来适应这样的事情？

Answer 1

除了使用 Apache BeanUtils 或直接使用 java.lang.reflect API，正如其他人所建议的，您还可以使用 jOOR ，我创建它是为了减少在 Java 中使用反射的冗长。您的示例可以这样实现:

Employee[] employees = on(department).call("getEmployees").get();

for (Employee employee : employees) {
  Street street = on(employee).call("getAddress").call("getStreet").get();
  System.out.println(street);
}

在 Java 中使用正常反射的相同示例:

try {
  Method m1 = department.getClass().getMethod("getEmployees");
  Employee employees = (Employee[]) m1.invoke(department);

  for (Employee employee : employees) {
    Method m2 = employee.getClass().getMethod("getAddress");
    Address address = (Address) m2.invoke(employee);

    Method m3 = address.getClass().getMethod("getStreet");
    Street street = (Street) m3.invoke(address);

    System.out.println(street);
  }
}

// There are many checked exceptions that you are likely to ignore anyway 
catch (Exception ignore) {

  // ... or maybe just wrap in your preferred runtime exception:
  throw new RuntimeException(e);
}

此外，jOOR 以更方便的方式包装了 java.lang.reflect.Proxy 功能:

interface StringProxy {
  String mySubString(int beginIndex);
}

// You can easily create a proxy of a custom type to a jOOR-wrapped object
String substring = on("java.lang.String")
                    .create("Hello World")
                    .as(StringProxy.class)
                    .mySubString(6);