利用jOOR简化Java 反射使用

     原文：    <a href="/misc/goto?guid=4959500886306536866" target="_blank">http://lukaseder.wordpress.com/2011/12/29/a-neater-way-to-use-reflection-in-java/</a>    <br />    <br /> Java的反射机制是Java一个非常强大的工具, 但是和大多数脚本语言相比, 使用起来却是有种"懒婆娘的裹脚布——又臭又长"的感觉.     <br />    <br /> 比如在PHP语言中, 我们可能这样写:    <br />    <br />    <pre class="brush:php; toolbar: true; auto-links: false;">// PHP $method = 'my_method'; $field  = 'my_field';   // Dynamically call a method $object->$method();   // Dynamically access a field $object->$field;</pre>    <br />    <br /> 在JavaScript语言中, 我们会这样写:    <br />    <pre class="brush:javascript; toolbar: true; auto-links: false;">// JavaScript var method   = 'my_method'; var field    = 'my_field';   // Dynamically call a function object[method]();   // Dynamically access a field object[field];</pre>    <br /> 在Java中, 我们会这样写:    <br />    <br />    <pre class="brush:java; toolbar: true; auto-links: false;">String method = "my_method"; String field  = "my_field";   // Dynamically call a method object.getClass().getMethod(method).invoke(object);   // Dynamically access a field object.getClass().getField(field).get(object);</pre>    <br />    <br /> 上面的代码还没有考虑到对各种异常的处理, 比如NullPointerExceptions, InvocationTargetExceptions, IllegalAccessExceptions, IllegalArgumentExceptions, SecurityExceptions. 以及对基本类型的处理. 但是大部分情况下, 这些都是不需要关心的.    <br />    <br /> 为了解决这个问题, 于是有了这个工具: jOOR (Java Object Oriented Reflection).    <br />    <br /> 对于这样的Java代码:    <br />    <pre class="brush:java; toolbar: true; auto-links: false;">// Classic example of reflection usage 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); }</pre>    <br />    <br /> 使用 jOOR的写法:    <br />    <br />    <pre class="brush:java; toolbar: true; auto-links: false;">Employee[] employees = on(department).call("getEmployees").get();   for (Employee employee : employees) {   Street street = on(employee).call("getAddress").call("getStreet").get();   System.out.println(street); }</pre>    <br />    <br /> 在Stack Overflow上相关的问题讨论:    <br />    <br />    <a href="/misc/goto?guid=4959500886402918978" target="_blank">http://stackoverflow.com/questions/4385003/java-reflection-open-source/8672186</a>    <br />    <br /> 另一个例子:    <br />    <br />    <pre class="brush:java; toolbar: true; auto-links: false;">String world = on("java.lang.String")  // Like Class.forName()  .create("Hello World") // Call the most specific matching constructor  .call("substring", 6)  // Call the most specific matching method  .call("toString")      // Call toString()  .get()                 // Get the wrapped object, in this case a String</pre>    <br />    <br /> jOOR相关的信息, 请猛击:    <br />    <a href="/misc/goto?guid=4959500886487536720" target="_blank">http://code.google.com/p/joor/</a>    <br />    <br /> 转自：    <a href="/misc/goto?guid=4959500886568197152" target="_blank">http://macrochen.iteye.com/blog/1347172</a>