如果仅关于旋转，则可以使用给定的矩阵对向量（1,0）进行变换，并计算所得向量与x轴之间的角度，如原始问题的注释中已经提到的那样。
import java.awt.Point;import java.awt.geom.AffineTransform;import java.awt.geom.Point2D;import java.util.Random;public class ExtractRotation{ public static void main(String[] args) { for (int i=0; i<=180; i++) { double angleRad = Math.toRadians(i); AffineTransform at = createRandomTransform(angleRad); double extractedAngleRad = extractAngle(at); System.out.println( "In: "+Math.toDegrees(angleRad)+ " " + "Out "+Math.toDegrees(extractedAngleRad)); } } private static double extractAngle(double m[]) { return extractAngle(new AffineTransform(m)); } private static double extractAngle(AffineTransform at) { Point2D p0 = new Point(); Point2D p1 = new Point(1,0); Point2D pp0 = at.transform(p0, null); Point2D pp1 = at.transform(p1, null); double dx = pp1.getX() - pp0.getX(); double dy = pp1.getY() - pp0.getY(); double angle = Math.atan2(dy, dx); return angle; } private static Random random = new Random(0); private static AffineTransform createRandomTransform(double angleRad) { AffineTransform at = new AffineTransform(); double scale = 1.0; at.translate(randomDouble(), randomDouble()); scale = Math.abs(randomDouble()); at.scale(scale, scale); at.rotate(angleRad); at.translate(randomDouble(), randomDouble()); scale = Math.abs(randomDouble()); at.scale(scale, scale); return at; } private static double randomDouble() { return -5.0 + random.nextDouble() * 10; }}
