How to force a meta-data value to type string?

Question

I specified a meta-data in my manifest.xml like this:

<meta-data android:value="5555555555" android:name="foo"></meta-data>

When accessing the meta data like this:

ActivityInfo ai = act.getPackageManager().getActivityInfo(componentName, PackageManager.GET_META_DATA);
Object value = (Object)ai.metaData.get(key);

this value gets interpreted as int and - more importantly - incorrectly interepreted (1260588259).

Since the type is determined automatically by the build system ( booleans, ints, floats and strings ) i wondered if there is any way to force the datatype to string.

I tried adding a space at the end ( "5555555555 "), but then the value gets interpreted as 5.5555553E9 float! ).

I also tried using getString instead of get, but then null is returned.

Any ideas? TIA.

Answer 1

Putting an escaped space in front of the number seems to work:

<meta-data android:name="foo" android:value="\ 1234567890"/>

The escaped space doesn't appear in the value returned by get().

I have no idea quite how this works, if I'm honest.

If you want something documented and therefore more reliable you can always put your string value as a resource and refer to it:

<meta-data android:name="foo" android:resource="@string/mynumber"/>

Answer 2

I have also such problem. My solution is as follows:

<meta-data android:value="5555555555\0" android:name="foo"></meta-data>

I added at the end of a variable - eskape sequence "\0" (NULL - is often used to define the end of a character string (for example, in the language C).

This work for me.

Best regards.

Answer 3

Instead of a space, try using a piece of punctuation that should have no role in a numeric value, like a colon, and see if that helps.

Answer 4

I recently came across this problem and it is a very frustrating that something like a Facebook application id is interpreted as an integer leading to problems due to overflow (of course). I would have thought/hoped it would be possible to override the implicit typing. For example, instead of:

<meta-data android:name="value" android:value="12345678901234567890" />

it would be nice if we could write:

<meta-data android:name="value" android:type="string" android:value="12345678901234567890" />

In order to compensate for this, I wrote some supporting code that requires manifest attributes to look as follows:

<meta-data android:name="value1" android:value="string/12345678901234567890" />
<meta-data android:name="value2" android:value="integer/12345" />
<meta-data android:name="value3" android:value="boolean/true" />
<meta-data android:name="value4" android:value="float/1.34" />
<meta-data android:name="value5" android:value="float/6" />

Note that this is intended to look similar to the Android @string/@integer syntax except that I have dropped the @, interpreting this as dropping the level of indirection.

As well as solving the original problem of [0-9]+ always interpreted as integers it seems, it also allows for floats to be specified directly despite looking like an integer.

A further advantage of this is that it is possible to extend the set of types arbitrarily. e.g.

<meta-data android:name="myfrac" android:value="fraction/3/7" />