不能在Android的调用String.isEmpty（） [英] can't call String.isEmpty() in android

问题描述

在我的Andr​​oid应用程序，我不能使用的 String.isEmpty（）的功能，这是坐落在JDK 1.6。 Android 2.1的lib中没有此功能java.lang.String中类

我试着输入JRE系统库到我的项目，因为它有这个功能，但没有效果。

我该如何解决这个问题，让我的应用程序使用此功能？

解决方案

  

我该如何解决这个问题，让我的应用程序使用此功能？

您不能。

使用 string.length减（）== 0 代替。它是向后兼容所有的方式回到JDK 1.0 ... ...和J2ME为好。

String.equals（）是另一种选择。

---

  

您肯定是没有办法来配置Eclipse来投入code类的明确的图书馆？

如果你希望你的应用程序，以一个的真正的Andr​​oid设备上运行没有。的Java / Android的平台故意让你很难鼓捣核心类库的行为。一开始，你只能做它通过修改Davlik相当于BOOTCLASSPATH或的rt.jar 的文件，并没有这些可以运行的JVM内完成。

那种修修补补具有的危险的潜在破坏Java的其他应用程序。即使假设你不能妥协，恶意调整到（共享）的Java核心类仍然可以潜在地允许一个应用程序的干扰，或从其他应用程序窃取信息（因为下面提到的过程/ UID分离）直接Android应用程序分离

In my android application I can't use String.isEmpty() function which is situated in JDK 1.6. Android 2.1 lib doesn't have this function in java.lang.String class

I tried to input JRE System library to my project, because it has this function, but there was no effects.

How can I solve this problem and allow my application to use this function?

解决方案

How can I solve this problem and allow my application to use this function?

You can't.

Use String.length() == 0 instead. It is backwards compatible all the way back to JDK 1.0 ... and with J2ME as well.

String.equals("") is another alternative.

---

Are you sure that there is no way to configure Eclipse to put into a code classes from definite libraries?

Not if you want your app to run on a real Android device. Java / Android platforms intentionally make it hard for you to tinker with the behaviour of the core class libraries. For a start, you can only do it by modifying the Davlik equivalent of the bootclasspath or rt.jar file, and neither of these can be done within a running JVM.

That kind of tinkering has the risk of potentially breaking Java for other apps. Even assuming that you can't compromise Android app separation directly (because of the process/uid separation mentioned below), malicious tweaks to the (shared) Java core classes could still potentially allow one app to interfere with, or steal information from another app.

这篇关于不能在Android的调用String.isEmpty（）的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！