是否有任何开源 Java 反射实用程序或 jars? [英] Are there any open source Java reflection utilities or jars?
问题描述
是否有任何开源实用程序或 jar 来处理 Java 中的反射?
Is there any open source utility or jar for handling reflection in java?
我正在将方法动态地传递给一个类,我想获取返回值.
I am passing methods Dynamically to a class and I would like to fetch the return value.
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:
I would like to print all the employees to the console output but instead getting it at run-time like this:
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.
有没有关于反射的开源来适应这样的事情?
Is there any opensource on reflection to accommodate something like this?
推荐答案
这种事情我看到的时候总是会敲响设计警钟.
This kind of thing always rings design alarm bells when I see it.
话虽如此,我通常认为 JXPath ( http://commons.apache.org/jxpath/users-guide.html ) 是解决这类问题的最合理的解决方案,如果它不能以更工程化的方式解决:
That being said, I usually think that JXPath ( http://commons.apache.org/jxpath/users-guide.html ) is the most reasonable solution for that type of problem if it can't be solved in a more engineered way:
import org.apache.commons.jxpath.JXPathContext;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
/**
*/
public class JXPather {
public static void main(String[] args) {
Department d = new Department();
d.employees.add(new Employee(new Address("wherever a")));
d.employees.add(new Employee(new Address("wherever b")));
d.employees.add(new Employee(new Address("wherever c")));
d.employees.add(new Employee(new Address("wherever def")));
JXPathContext context = JXPathContext.newContext(d);
// access matched xpath objects by iterating over them
for (Iterator iterator = context.iterate("/employees/address/street"); iterator.hasNext();) {
System.out.println(iterator.next());
}
// or directly via standard xpath expressions
System.out.println("street of third employee is: "+context.getValue("/employees[3]/address/street"));
// supports most (or all ?) xpath expressions
for (Iterator iterator = context.iterate("/employees/address/street[string-length(.) > 11]"); iterator.hasNext();) {
System.out.println("street length longer than 11 c'ars:"+iterator.next());
}
}
static public class Department {
List<Employee> employees = new ArrayList<Employee>();
public List<Employee> getEmployees() {
return employees;
}
}
static public class Employee {
Address address;
Employee(Address address) {
this.address = address;
}
public Address getAddress() {
return address;
}
}
static public class Address {
String street;
Address(String street) {
this.street = street;
}
public String getStreet() {
return street;
}
}
}
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