57 lines
1.7 KiB
Plaintext
57 lines
1.7 KiB
Plaintext
page.title=Saving Data
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page.tags=data storage,files,sql,database,preferences
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trainingnavtop=true
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startpage=true
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@jd:body
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<div id="tb-wrapper">
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<div id="tb">
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<h2>Dependencies and prerequisites</h2>
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<ul>
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<li>Android 1.6 (API Level 4) or higher</li>
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<li>Familiarity with Map key-value collections</li>
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<li>Familiarity with the Java file I/O API</li>
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<li>Familiarity with SQL databases</li>
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</ul>
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<h2>You should also read</h2>
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<ul>
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<li><a href="{@docRoot}guide/topics/data/data-storage.html">Storage Options</a></li>
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</ul>
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</div>
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</div>
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<p>Most Android apps need to save data, even if only to save information about the app state
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during {@link android.app.Activity#onPause onPause()} so the user's progress is not lost. Most
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non-trivial apps also need to save user settings, and some apps must manage large
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amounts of information in files and databases. This class introduces you to the
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principal data storage options in Android, including:</p>
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<ul>
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<li>Saving key-value pairs of simple data types in a shared preferences
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file</li>
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<li>Saving arbitrary files in Android's file system</li>
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<li>Using databases managed by SQLite</li>
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</ul>
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<h2>Lessons</h2>
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<dl>
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<dt><b><a href="shared-preferences.html">Saving Key-Value Sets</a></b></dt>
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<dd>Learn to use a shared preferences file for storing small amounts of information in
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key-value pairs.</dd>
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<dt><b><a href="files.html">Saving Files</a></b></dt>
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<dd>Learn to save a basic file, such as to store long sequences of data that
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are generally read in order.</dd>
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<dt><b><a href="databases.html">Saving Data in SQL Databases</a></b></dt>
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<dd>Learn to use a SQLite database to read and write structured data.</dd>
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</dl>
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