Android下的图片压缩及图片和视频的上传

Android开发中上传图片很常见，一般为了节省流量会进行压缩的操作，本篇记录一下压缩和上传的方法。

图片压缩的方法 ：

import java.io.ByteArrayOutputStream;
import java.io.File;

import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Environment;
import android.util.Base64;

public class PictureUtil {

/**
* 把bitmap转换成String
*
* @param filePath
* @return
*/
public static String bitmapToString(String filePath) {

Bitmap bm = getSmallBitmap(filePath);

ByteArrayOutputStream baos = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.JPEG, 40, baos);
byte[] b = baos.toByteArray();

return Base64.encodeToString(b, Base64.DEFAULT);

}

/**
* 根据路径获得图片并压缩返回bitmap用于显示
*
* @param imagesrc
* @return
*/
public static Bitmap getSmallBitmap(String filePath) {
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(filePath, options);

// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, 480, 800);

// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;

return BitmapFactory.decodeFile(filePath, options);
}

/**
* 计算图片的缩放值
*
* @param options
* @param reqWidth
* @param reqHeight
* @return
*/
public static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;

if (height > reqHeight || width > reqWidth) {

// Calculate ratios of height and width to requested height and
// width
final int heightRatio = Math.round((float) height / (float) reqHeight);
final int widthRatio = Math.round((float) width / (float) reqWidth);

// Choose the smallest ratio as inSampleSize value, this will
// guarantee
// a final image with both dimensions larger than or equal to the
// requested height and width.
inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
}

return inSampleSize;
}

}

图片上传的代码：

/**
* 将图片转成String的形式，进行上传
*
* @param json
* @return
* @return String
* @author hsx
* @time 2014-3-21上午10:47:30
*/
public String sendPost(String json) {
try {
HttpURLConnection httpcon = (HttpURLConnection) ((new URL(POST_URL)
.openConnection()));
httpcon.setDoOutput(true);
httpcon.setRequestProperty("Content-Type", "application/json");
httpcon.setRequestProperty("Accept", "application/json");
httpcon.setRequestMethod("POST");
httpcon.connect();

byte[] outputBytes = json.getBytes("UTF-8");
OutputStream os = httpcon.getOutputStream();
os.write(outputBytes);
os.close();

int status = httpcon.getResponseCode();
if (status != 200) {
throw new IOException("Post failed with error code " + status);
}
BufferedReader br = new BufferedReader(new InputStreamReader(httpcon.getInputStream()));
StringBuilder sb = new StringBuilder();
String line;
while ((line = br.readLine()) != null) {
sb.append(line+"\n");
}
br.close();

return sb.toString();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}

图片压缩的方式还有其他的形式，可以参考一下这篇文字：http://104zz.iteye.com/blog/1694762

下载：http://download.csdn.net/detail/jdsjlzx/9496302