Question

java里面的图片如何旋转，不使用控件，能不能给段代码

Answer 1

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Transparency;
import java.awt.geom.AffineTransform;
import java.awt.image.AffineTransformOp;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;

public class ImageChange {

public static InputStream rotateImg(BufferedImage image, int degree, Color bgcolor) throws IOException {

int iw = image.getWidth();//原始图象的宽度
int ih = image.getHeight();//原始图象的高度
int w = 0;
int h = 0;
int x = 0;
int y = 0;
degree = degree % 360;
if (degree < 0)
degree = 360 + degree;//将角度转换到0-360度之间
double ang = Math.toRadians(degree);//将角度转为弧度

/**
*确定旋转后的图象的高度和宽度
*/

if (degree == 180 || degree == 0 || degree == 360) {
w = iw;
h = ih;
} else if (degree == 90 || degree == 270) {
w = ih;
h = iw;
} else {
int d = iw + ih;
w = (int) (d * Math.abs(Math.cos(ang)));
h = (int) (d * Math.abs(Math.sin(ang)));
}

x = (w / 2) - (iw / 2);//确定原点坐标
y = (h / 2) - (ih / 2);
BufferedImage rotatedImage = new BufferedImage(w, h, image.getType());
Graphics2D gs = (Graphics2D)rotatedImage.getGraphics();
if(bgcolor==null){
rotatedImage = gs.getDeviceConfiguration().createCompatibleImage(w, h, Transparency.TRANSLUCENT);
}else{
gs.setColor(bgcolor);
gs.fillRect(0, 0, w, h);//以给定颜色绘制旋转后图片的背景
}

AffineTransform at = new AffineTransform();
at.rotate(ang, w / 2, h / 2);//旋转图象
at.translate(x, y);
AffineTransformOp op = new AffineTransformOp(at, AffineTransformOp.TYPE_BICUBIC);
op.filter(image, rotatedImage);
image = rotatedImage;

ByteArrayOutputStream byteOut= new ByteArrayOutputStream();
ImageOutputStream iamgeOut = ImageIO.createImageOutputStream(byteOut);

ImageIO.write(image, "png", iamgeOut);
InputStream inputStream = new ByteArrayInputStream(byteOut.toByteArray());

return inputStream;
}

}