/**
* 上传图片
* @param base64 图片编码后的字符串
* @return 上传成功后的文件名
*/
public static String upload(String base64) {
String dir = getRequest().getRealPath(UPLOAD_PATH);
File fileLocation = new File(dir);
String fileType = base64.substring(11, 14);
if(!fileLocation.exists()) {
boolean isCreated = fileLocation.mkdir();
if(!isCreated) {
//目标上传目录创建失败,可做其他处理,例如抛出自定义异常等,一般应该不会出现这种情况。
return null;
}
}
if(base64.indexOf("jpeg") != -1) {
//存在jpeg文件的情况
base64 = base64.replaceFirst("jpeg", "jpg");
}
String tempStr = UUID.randomUUID().toString()+System.currentTimeMillis();
String upName = tempStr+"."+fileType;
FileOutputStream out;
String iconBase64 = base64.substring(22);
try {
byte[] buffer = new BASE64Decoder().decodeBuffer(iconBase64);
out = new FileOutputStream(dir+"/"+upName);
out.write(buffer);
out.close();
String upNameXhdpi = tempStr+"-xhdpi."+fileType;
String upNameMhdpi = tempStr+"-mhdpi."+fileType;
FileOutputStream outXhdpi = new FileOutputStream(dir+"/"+upNameXhdpi);
FileOutputStream outMhdpi = new FileOutputStream(dir+"/"+upNameMhdpi);
resizeImage(iconBase64, outXhdpi, xhdpi, fileType);
resizeImage(iconBase64, outMhdpi, mhdpi, fileType);
return PATH+UPLOAD_PATH + "/" +upName;
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return null;
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return null;
}
}
/**
* 改变图片的大小到宽为size，然后高随着宽等比例变化
* @param is 上传的图片的输入流
* @param os 改变了图片的大小后，把图片的流输出到目标OutputStream
* @param size 新图片的宽
* @param format 新图片的格式
* @throws IOException
*/
public static void resizeImage(String is, OutputStream os, int size, String format) throws IOException {
ByteArrayInputStream in = new ByteArrayInputStream(new BASE64Decoder().decodeBuffer(is));
BufferedImage prevImage = ImageIO.read(in);
double width = prevImage.getWidth();
double height = prevImage.getHeight();
double percent = size/width;
int newWidth = (int)(width * percent);
int newHeight = (int)(height * percent);
BufferedImage image = new BufferedImage(newWidth, newHeight, BufferedImage.TYPE_INT_BGR);
Graphics graphics = image.createGraphics();
graphics.drawImage(prevImage, 0, 0, newWidth, newHeight, null);
ImageIO.write(image, format, os);
os.flush();
in.close();
os.close();
}
upload方法中xhdpi和mhdpi是指不同大小的数字，上传上来的base64是包含头的，例如这样的base64字符串
data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAIAAAACACAYAAADDPmHLAAAABGdBTUEAALGPC/xhBQAAACBjSFJNAAB6JgAAgIQAAPoAAACA6AAAdTAAAOpgAAA6mAAAF3CculE8AAAABmJLR0QAAAAAAAD5Q7t/AAAACXBIWXMAAAsSAAALEgHS3X78AAAI4ElEQVR42u2d2W7b2AGGP1KkRFGStdnxmgToFdHkJfICc9lO537ay2IuivYN2r7HtDOZmwJ9gE4fogPwaprFBmzHlmTtC5deKFQVL7HiiDo85PkAw7AsSD91PpGHZ9X4CK7rPgG+Al4AvwR2gAKKJNMHjoHXwL+Bl47j/PeuJ2u3Pfi+4P8C/ArIiT4ixWcRAC+BPzmO8+b6P28I4LruF8C3QEV0csVa6QO/dRznu+UH9eU/XNf9PfAPVOGnkTLwN9d1v1l+cHEGcF3318B33HFZUKSGEPiN4zgv4X1hv7/
