blocks|key|278686|text|type|unstyled|depth|inlineStyleRanges|entityRanges|data|278687|如何解决此问题并允许我的应用程序使用此函数？|blockquote|278688|278689|278690|你不能这么做。|278691|请改用String.length()+==+0。它一直向后兼容到JDK+1.0+...J2ME也是如此。|offset|length|style|CODE|278692|String.equals("")是另一种选择。|278693|278694|278695|您确定没有办法将Eclipse配置为将特定库中的类放入代码中吗？|278696|278697|278698|如果你想让你的应用程序在真正的Android设备上运行，就不会。Java+/+Android平台故意让您很难修改核心类库的行为。首先，您只能通过修改与bootclasspath或rt.jar文件等效的Davlik来完成此操作，而这两种操作都不能在运行的JVM中完成。|278699|这种修修补补的做法有可能会破坏Java的其他应用程序。即使假设您不能直接妥协Android应用程序分离(因为下面提到的进程/uid分离)，对(共享的)+Java核心类的恶意调整仍然可能允许一个应用程序干扰或窃取另一个应用程序的信息。|278700|entityMap^0|0|0|0|0|0|3|K|0|0|H|0|0|0|0|0|0|2H|6|0|0^^$0|@$1|2|3|-4|4|5|6|11|7|@]|8|@]|9|$]]|$1|A|3|B|4|C|6|12|7|@]|8|@]|9|$]]|$1|D|3|-4|4|5|6|13|7|@]|8|@]|9|$]]|$1|E|3|-4|4|5|6|14|7|@]|8|@]|9|$]]|$1|F|3|G|4|5|6|15|7|@]|8|@]|9|$]]|$1|H|3|I|4|5|6|16|7|@$J|17|K|18|L|M]]|8|@]|9|$]]|$1|N|3|O|4|5|6|19|7|@$J|1A|K|1B|L|M]]|8|@]|9|$]]|$1|P|3|-4|4|5|6|1C|7|@]|8|@]|9|$]]|$1|Q|3|-4|4|5|6|1D|7|@]|8|@]|9|$]]|$1|R|3|S|4|C|6|1E|7|@]|8|@]|9|$]]|$1|T|3|-4|4|5|6|1F|7|@]|8|@]|9|$]]|$1|U|3|-4|4|5|6|1G|7|@]|8|@]|9|$]]|$1|V|3|W|4|5|6|1H|7|@$J|1I|K|1J|L|M]]|8|@]|9|$]]|$1|X|3|Y|4|5|6|1K|7|@]|8|@]|9|$]]|$1|Z|3|-4|4|5|6|1L|7|@]|8|@]|9|$]]]|10|$]]

<blockquote>
 How can I solve this problem and allow my application to use this function?
</blockquote>

You can't. 

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

<code>String.equals("")</code> is another alternative.

<hr>

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

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 <code>rt.jar</code> 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.

blocks|key|280600|text|据我所知，android支持java5，所以没有可以用length()模拟isEmpty()的isEmpty();。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|280601|entityMap^0|R|8|11|9|1B|A|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|O|8|@]|D|@]|E|$]]]|G|$]]

as far as I know android supports java 5 , so there is no <code>isEmpty();</code> you can use <code>length()</code> to simulate <code>isEmpty()</code>

blocks|key|2983664|text|这个方法出现在API9中，所以你不能在Android2.3之前使用它|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2983665|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

this method appeared in API9, so you cant use it before Android2.3

blocks|key|2983672|text|您可以改用android.text.TextUtils.isEmpty()。此方法还会检查字符串是否为null，以及是否从API级别1开始就可用。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|2983673|if+(TextUtils.isEmpty(str))+{
++++Log.d(TAG,+"String+is+empty+or+null!");
}|code-block|syntax|javascript|2983674|entityMap|0|LINK|mutability|MUTABLE|url|http://developer.android.com/reference/android/text/TextUtils.html#isEmpty%2528java.lang.CharSequence%2529^0|5|W|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

You can use <a href="http://developer.android.com/reference/android/text/TextUtils.html#isEmpty%28java.lang.CharSequence%29" rel="noreferrer">android.text.TextUtils.isEmpty()</a> instead. This method also checks to see if the String is null and has been available since API level 1.

<pre><code>if (TextUtils.isEmpty(str)) {
 Log.d(TAG, "String is empty or null!");
}
</code></pre>

blocks|key|275009|text|"".equals(yourString)；也给出了与String.isEmpty()相同的行为；|type|unstyled|depth|inlineStyleRanges|entityRanges|data|275010|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

"".equals(yourString); also gives the same behavior like String.isEmpty();

blocks|key|3197112|text|您必须将android+API升级到级别9，或者使用String.trim().length()==0或String.equals("")，它应该适用于您的android+API级别和JDK版本。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3197113|entityMap^0|Q|P|1G|H|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|M|8|@]|D|@]|E|$]]]|G|$]]

You have to upgrade android API to level 9, or use <code>String.trim().length()==0</code> or <code>String.equals("")</code> instead, it should work for your android API level and your JDK version.

blocks|key|278721|text|您可以使用此TextUtils.isEmpty(str)。这是从API级别1开始提供的，或者您可以创建自己的方法，如下所示|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|278722|public+boolean+isEmpty(CharSequence+str)+{
++++if+(str+==+null+%7C%7C+str.length()+==+0)
++++++++return+true;
++++else
++++++++return+false;
}|code-block|syntax|javascript|278723|entityMap^0|6|M|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

You can use this <code>TextUtils.isEmpty(str)</code>. This is available since API level 1 or You can create you own method like below

<pre><code>public boolean isEmpty(CharSequence str) {
 if (str == null || str.length() == 0)
 return true;
 else
 return false;
}
</code></pre>

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?

can't call String.isEmpty() in android

Android

Eclipse

Java

在我的安卓应用程序中，我不能使用JDK1.6中的String.isEmpty()函数。Android2.1lib在java.lang.String类中没有这个函数我尝试将JRE系统库输入到我的项目中，因为它有这个功能，但是没有效果。如何解决此问题并允许我的应用程序使用此功能？

问无法在安卓中调用String.isEmpty()
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