Android Development uses Exifinterface to get picture properties after a photo _android

This example describes the Android development using Exifinterface to get picture properties after taking pictures. Share to everyone for your reference, specific as follows:

Exifinterface exif = new Exifinterface (File.getpath ());
String widthstr = Exif.getattribute (exifinterface.tag_image_width);
String heightstr = Exif.getattribute (exifinterface.tag_image_length);
......

* * Copyright (C) 2007 the Android Open Source Project * Licensed under the Apache License, Version 2.0 (the "Licen
 Se ");
 * You could not use this file, except in compliance with the License. * Obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * unless required by APPL Icable or agreed to in writing, software * Distributed under the License was distributed on ' as is ' basis, * witho
 UT warranties or CONDITIONS of any KIND, either express OR implied.
 * The License for the specific language governing permissions and * limitations under the License.
* * Package Android.media;
Import java.io.IOException;
Import java.text.ParsePosition;
Import Java.text.SimpleDateFormat;
Import Java.util.Date;
Import Java.util.HashMap;
Import Java.util.Map;
Import Java.util.TimeZone;
 /** * is a class for reading and writing Exif tags in a JPEG file. */public class Exifinterface {//the Exif tag names/** Type is int. */Public StatiC final String tag_orientation = "orientation"; /** Type is String.
  * * public static final String tag_datetime = "DATETIME"; /** Type is String.
  * * public static final String Tag_make = ' make '; /** Type is String.
  * * public static final String Tag_model = "MODEL";
  /** Type is int. */public static final String Tag_flash = "FLASH";
  /** Type is int. */public static final String tag_image_width = "ImageWidth";
  /** Type is int. */public static final String tag_image_length = "Imagelength"; /** String. The Format is "num1/denom1,num2/denom2,num3/denom3".
  * * public static final String tag_gps_latitude = "Gpslatitude"; /** String. The Format is "num1/denom1,num2/denom2,num3/denom3".
  * * public static final String tag_gps_longitude = "Gpslongitude"; /** Type is String.
  * * public static final String tag_gps_latitude_ref = "Gpslatituderef"; /** Type is String.
  * * public static final String tag_gps_longitude_ref = "Gpslongituderef"; /** Type is String. * * PublIC static final String Tag_gps_timestamp = "Gpstimestamp"; /** Type is String.
  * * public static final String Tag_gps_datestamp = "Gpsdatestamp";
  /** Type is int. */public static final String tag_white_balance = "Whitebalance"; /** Type is rational.
  * * public static final String tag_focal_length = "Focallength"; /** Type is String. Name of GPS processing method used for location finding.
  * * public static final String Tag_gps_processing_method = "Gpsprocessingmethod";
  Constants used for the orientation Exif tag.
  public static final int orientation_undefined = 0;
  public static final int orientation_normal = 1; public static final int orientation_flip_horizontal = 2;
  Left right reversed mirror public static final int orientation_rotate_180 = 3; public static final int orientation_flip_vertical = 4; Upside down Mirror public static final int orientation_transpose = 5; Flipped about Top-left <--> bottom-right axis public static final int ORIEntation_rotate_90 = 6; Rotate CW to right it public static final int orientation_transverse = 7; Flipped about Top-right <--> bottom-left axis public static final int orientation_rotate_270 = 8;
  Rotate 270 to right IT//Constants used for white balance public static final int whitebalance_auto = 0;
  public static final int whitebalance_manual = 1;
  private static SimpleDateFormat Sformatter;
    static {system.loadlibrary ("exif");
    Sformatter = new SimpleDateFormat ("Yyyy:MM:dd HH:mm:ss");
  Sformatter.settimezone (Timezone.gettimezone ("UTC"));
  Private String Mfilename;
  Private hashmap<string, string> mattributes;
  Private Boolean mhasthumbnail; Because the underlying implementation (JHEAD) uses static variables,//There can only is one user at a time for the Native functions (and//They cannot keep state in the native code across function calls).
  We//Use Slock to serialize the accesses. private static Object Slock = nEW Object ();
   /** * Reads Exif tags from the specified JPEG file.
    * * Public exifinterface (String filename) throws IOException {mfilename = filename;
  Loadattributes ();
   }/** * Returns The value of the specified tag or {@code null} if there * is no such tag in the JPEG file.
   * @param tag The name of the tag.
  */public string getattribute (string tag) {return mattributes.get (tag); }/** * Returns The integer value of the specified tag. If There is no such tag * in the JPEG file or the value cannot to parsed as Integer, return * <var>defaultvalu
   E</var>.
   * @param tag The name of the tag.
   * @param defaultvalue the value to return if the ' is ' not available.
    */public int getattributeint (string tag, int defaultvalue) {String value = Mattributes.get (tag);
    if (value = = null) return defaultvalue;
    try {return integer.valueof (value); catch (NumberFormatException ex) {return DefauLtvalue; }/** * Returns The Double value of the specified rational tag. If there is no * such tag in the JPEG file or the value cannot to parsed as double, return * <var>defaultvalue
   </var>.
   * @param tag The name of the tag.
   * @param defaultvalue the value to return if the ' is ' not available.
    */Public double getattributedouble (string tag, double defaultvalue) {String value = Mattributes.get (tag);
    if (value = = null) return defaultvalue;
      try {int index = Value.indexof ("/");
      if (index = = 1) return defaultvalue;
      Double denom = double.parsedouble (value.substring (index + 1));
      if (Denom = = 0) return defaultvalue;
      Double num = double.parsedouble (value.substring (0, index));
    return num/denom;
    catch (NumberFormatException ex) {return defaultvalue;
   }/** * Set The value of the specified tag.
   * @param tag The name of the tag. * @param value The value of the tag.
  */public void setattribute (string tag, string value) {Mattributes.put (tag, value);
   }/** * Initialize mattributes with the attributes from the file mfilename.
   * * Mattributes is a HashMap which stores the Exif attributes of the file.
   * The key is the standard tag name and the value is the tag ' s value:e.g. * Model-> Nikon.
   Numeric values are stored as strings.
   * This function is also initialize Mhasthumbnail to indicate whether the * file has a thumbnail inside.  * * private void Loadattributes () throws IOException {//format of string passed from native C code:///ATTRCNT Attr1=valuelen value1attr2=value2len value2 ... "/example://" 4 attrptr imagelength=4 1024model=6-Fooimagewidth
    =4 1280make=3 FOO "mattributes = new hashmap<string, string> ();
    String Attrstr;
    Synchronized (slock) {attrstr = Getattributesnative (mfilename);
    }//Get count int ptr = Attrstr.indexof ('); int count= Integer.parseint (attrstr.substring (0, PTR));
    Skip past the space between item count and the rest of the attributes ++ptr;
      for (int i = 0; i < count; i++) {//extract the attribute name int equalpos = attrstr.indexof (' = ', ptr);
      String attrname = Attrstr.substring (ptr, equalpos);   PTR = Equalpos + 1;
      Skip past =//Extract the attribute value length int lenpos = Attrstr.indexof (", PTR);
      int attrlen = Integer.parseint (Attrstr.substring (PTR, lenpos));    PTR = Lenpos + 1; 
      Skip PAS the space//extract the attribute value String attrValue = attrstr.substring (ptr, ptr + attrlen);
      PTR + = Attrlen;
      if (Attrname.equals ("Hasthumbnail")) {Mhasthumbnail = Attrvalue.equalsignorecase ("true");
      else {mattributes.put (attrname, AttrValue); }}/** * Save the tag data into the JPEG file. This is expensive because it involves * copying "all" JPG data from ONE file to another and deleting the "old" file * and renaming the other. It's best to use {@link #setAttribute (string,string)} * To set all attributes to write and make a single call rather th
   An multiple * calls for each attribute. */public void saveattributes () throws IOException {//format of string passed to native C code://ATTRCNT at Tr1=valuelen value1attr2=value2len value2 ... "/example://" 4 attrptr imagelength=4 1024model=6-fooimagewidth=4
    1280make=3 FOO "StringBuilder sb = new StringBuilder ();
    int size = Mattributes.size ();
    if (Mattributes.containskey ("Hasthumbnail")) {--size;
    } sb.append (Size + "");
      For (map.entry<string, string> iter:mAttributes.entrySet ()) {String key = Iter.getkey ();
      if (Key.equals ("Hasthumbnail")) {//This was a fake attribute not saved as a EXIF tag continue;
      } String val = Iter.getvalue ();
      Sb.append (key + "="); Sb.append (Val.leNgth () + "");
    Sb.append (Val);
    String s = sb.tostring ();
      Synchronized (slock) {saveattributesnative (mfilename, s);
    Commitchangesnative (Mfilename);
   }/** * Returns True if the JPEG file has a thumbnail.
  * * Public boolean hasthumbnail () {return mhasthumbnail;
   }/** * Returns the thumbnail inside the JPEG file, or {@code null} If there is no thumbnail. * The returned data is in JPEG format and can decoded using * {@link Android.graphics.bitmapfactory#decodebytearray ( Byte[],int,int)} */public byte[] GetThumbnail () {synchronized (Slock) {return getthumbnailnative (Mfilena
    ME); }/** * Stores the latitude and longitude value in a float array. The latitude, and the second element is the longitude.
   Returns False if the * Exif tags are not available. */public Boolean getlatlong (float output[]) {String latvalue = Mattributes.get (exifinterface.tag_gps_latituDE);
    String latref = Mattributes.get (exifinterface.tag_gps_latitude_ref);
    String lngvalue = Mattributes.get (exifinterface.tag_gps_longitude);
    String lngref = Mattributes.get (exifinterface.tag_gps_longitude_ref); if (latvalue!= null && latref!= null && lngvalue!= null && lngref!= null) {output[0] =
      Convertrationallatlontofloat (Latvalue, latref);
      OUTPUT[1] = convertrationallatlontofloat (Lngvalue, lngref);
    return true;
    else {return false;
   }/** * Returns number of milliseconds since. 1, 1970, midnight.
   * RETURNS-1 If the date information if not available.
    * @hide/public long GetDateTime () {String datetimestring = Mattributes.get (tag_datetime);
    if (datetimestring = = null) return-1;
    Parseposition pos = new parseposition (0);
      try {Date datetime = Sformatter.parse (datetimestring, POS);
      if (datetime = = null) return-1;
 return Datetime.gettime ();   catch (IllegalArgumentException ex) {return-1;
   }/** * Returns number of milliseconds since. 1, 1970, Midnight UTC.
   * RETURNS-1 If the date information if not available.
    * @hide/public long getgpsdatetime () {String date = Mattributes.get (Tag_gps_datestamp);
    String time = Mattributes.get (Tag_gps_timestamp);
    if (date = NULL | | time = NULL) return-1;
    String datetimestring = date + ' + time;
    if (datetimestring = = null) return-1;
    Parseposition pos = new parseposition (0);
      try {Date datetime = Sformatter.parse (datetimestring, POS);
      if (datetime = = null) return-1;
    return Datetime.gettime ();
    catch (IllegalArgumentException ex) {return-1; } private static float Convertrationallatlontofloat (string rationalstring, string ref) {try {Stri
      ng [] parts = Rationalstring.split (",");
      String [] pair;
      Pair = Parts[0].split ("/"); int degrees = (int) (Float.parsefloat (Pair[0].trim ())/Float.parsefloat (Pair[1].trim ()));
      Pair = Parts[1].split ("/");
      int minutes = (int) (Float.parsefloat (Pair[0].trim ())/Float.parsefloat (Pair[1].trim ()));
      Pair = Parts[2].split ("/");
      float seconds = float.parsefloat (Pair[0].trim ())/Float.parsefloat (Pair[1].trim ());
      float result = degrees + (minutes/60f) + (Seconds/(60F * 60F));
      if ((Ref.equals ("S") | | ref.equals ("W"))) {Return-result;
    return result;
      The catch (RuntimeException ex) {//If for whatever reason we can ' t parse the LAT long then return//NULL
    return 0f;
  } Private Native Boolean appendthumbnailnative (string fileName, string thumbnailfilename);
  Private native void Saveattributesnative (string fileName, string compressedattributes);
  Private native String getattributesnative (string fileName); Private native void Commitchangesnative (String FilenaME);
Private native byte[] getthumbnailnative (String fileName);

 }

For more information about Android development interested readers can view the site topics: "Android Development Introduction and Advanced Course" and "Android graphics and image processing skills summary"

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