Add API's for normalizing MIME's and URI's.

Helps developers create well-behaved intents:
- lower case MIME data type
- strip parameters from MIME content types
- lowercase URI scheme

The new API's are
normalizeAndSetType()
normalizeAndSetData()
normalizeAndSetDataAndType()
Uri.normalize()
normalizeMimeType()

Change-Id: Ib5c907897f39b1f705bcc4c9103ba1e6f316380b

1 files changed, 33 insertions, 0 deletions

diff --git a/core/java/android/net/Uri.java b/core/java/android/net/Uri.java
index 0fb49bc..defe7aa 100644
--- a/core/java/android/net/Uri.java
+++ b/core/java/android/net/Uri.java
@@ -28,6 +28,7 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.RandomAccess;
 import java.util.Set;
 import libcore.net.UriCodec;
@@ -1716,6 +1717,38 @@ public abstract class Uri implements Parcelable, Comparable<Uri> {
         return (!"false".equals(flag) && !"0".equals(flag));
     }
 
+    /**
+     * Return a normalized representation of this Uri.
+     *
+     * <p>A normalized Uri has a lowercase scheme component.
+     * This aligns the Uri with Android best practices for
+     * intent filtering.
+     *
+     * <p>For example, "HTTP://www.android.com" becomes
+     * "http://www.android.com"
+     *
+     * <p>All URIs received from outside Android (such as user input,
+     * or external sources like Bluetooth, NFC, or the Internet) should
+     * be normalized before they are used to create an Intent.
+     *
+     * <p class="note">This method does <em>not</em> validate bad URI's,
+     * or 'fix' poorly formatted URI's - so do not use it for input validation.
+     * A Uri will always be returned, even if the Uri is badly formatted to
+     * begin with and a scheme component cannot be found.
+     *
+     * @return normalized Uri (never null)
+     * @see {@link android.content.Intent#setData}
+     * @see {@link #setNormalizedData}
+     */
+    public Uri normalize() {
+        String scheme = getScheme();
+        if (scheme == null) return this;  // give up
+        String lowerScheme = scheme.toLowerCase(Locale.US);
+        if (scheme.equals(lowerScheme)) return this;  // no change
+
+        return buildUpon().scheme(lowerScheme).build();
+    }
+
     /** Identifies a null parcelled Uri. */
     private static final int NULL_TYPE_ID = 0;