Question

java根据url获取网页缩略图

有人用过这个方法吗 Bitmap 是什么包中的类？ 还是java自带的类？ 为什么我找不到。
public static Bitmap loadImageFromUrl(String url, int sc) {
URL m;
InputStream i = null;
BufferedInputStream bis = null;
ByteArrayOutputStream out = null;
byte isBuffer[] = new byte[1024];
if (url == null)
return null;
try {
m = new URL(url);
i = (InputStream) m.getContent();

bis = new BufferedInputStream(i, 1024 * 4);
out = new ByteArrayOutputStream();
int len = 0;
while ((len = bis.read(isBuffer)) != -1) {
out.write(isBuffer, 0, len);
}
out.close();
bis.close();
} catch (MalformedURLException e1) {
e1.printStackTrace();
return null;
} catch (IOException e) {
e.printStackTrace();
}
if (out == null)
return null;
byte[] data = out.toByteArray();
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeByteArray(data, 0, data.length, options);
options.inJustDecodeBounds = false;
int be = (int) (options.outHeight / (float) sc);
if (be <= 0) {
be = 1;
} else if (be > 3) {
be = 3;
}
options.inSampleSize = be;
Bitmap bmp = null;
try {
bmp = BitmapFactory.decodeByteArray(data, 0, data.length, options); // 返回缩略图
} catch (OutOfMemoryError e) {
// TODO: handle exception
System.gc();
bmp = null;
}
return bmp;
}

Answer 1

代码如下:

public static Bitmap 
loadImageFromUrl(String url, int sc) {
        URL m;
        InputStream 
i = null;
        BufferedInputStream bis = null;
        ByteArrayOutputStream out = null;
        byte isBuffer[] = new 
byte[1024];
        if (url == null)
            return null;
        try {
            m = new URL(url);
            i = (InputStream) 
m.getContent();

            bis = new BufferedInputStream(i, 1024 * 4);
            out = 
new ByteArrayOutputStream();
            int len = 0;
            while 
((len = bis.read(isBuffer)) != -1) {
                out.write(isBuffer, 0, 
len);
            }
            out.close();
            bis.close();
        } catch (MalformedURLException e1) {
            e1.printStackTrace();
            return null;
        } catch 
(IOException e) {
            e.printStackTrace();
        }
        if 
(out == null)
            return null;
        byte[] data = 
out.toByteArray();
        BitmapFactory.Options options = new 
BitmapFactory.Options();
        options.inJustDecodeBounds = 
true;
        BitmapFactory.decodeByteArray(data, 0, data.length, 
options);
        options.inJustDecodeBounds = false;
        int be = 
(int) (options.outHeight / (float) sc);
        if (be <= 0) 
{
            be = 1;
        } else if (be > 3) {
            be = 
3;
        }
        options.inSampleSize = be;
        Bitmap bmp = 
null;
        try {
            bmp = BitmapFactory.decodeByteArray(data, 
0, data.length, options); // 返回缩略图
        } catch (OutOfMemoryError e) 
{
            // TODO: handle exception
            System.gc();
            bmp = null;
        }
        return 
bmp;
    }

Answer 2

Bitmap是Android的类，可以通过读写流转为BufferedImage

Answer 3

那是安卓的bitmap

追问

java 没有bitmap类？

追答

java只有Image和BufferedImage你把bitmap改成BufferedImage,自己再做压缩，就可以获取略缩图了啊

Answer 4

找缩略图？ 我只知道在URL在WEB里找根路径