问题描述
@SupportedAnnotationTypes("example.Annotation")
public class Processor extends AbstractProcessor {
@Override
public boolean process(Set<? extends TypeElement> annotations,RoundEnvironment roundEnv) {
for (TypeElement annotation : annotations) {
Set<? extends Element> elementsAnnotatedWith = roundEnv.getElementsAnnotatedWith(annotation);
for (Element element : elementsAnnotatedWith) {
TypeElement typeElement = (TypeElement) element;
// Here,typeElement.getQualifiedname() is accessible,but not the code nor file path.
}
}
return false;
}
}
这个注解只能用在类上。我知道目标类未编译，因此无法进行反射访问，但我希望将类代码作为字符串以我自己的方式进行解析，而不是使用此 API。
解决方法
import numpy as np,matplotlib.pyplot as plt
# Solves linear system given by Tridiagonal Matrix
# Helper for calculating cubic splines
#@numba.njit(cache = True,fastmath = True,inline = 'always')
def tri_diag_solve(A,B,C,F):
n = B.size
assert A.ndim == B.ndim == C.ndim == F.ndim == 1 and (
A.size == B.size == C.size == F.size == n
) #,(A.shape,B.shape,C.shape,F.shape)
Bs,Fs = np.zeros_like(B),np.zeros_like(F)
Bs[0],Fs[0] = B[0],F[0]
for i in range(1,n):
Bs[i] = B[i] - A[i] / Bs[i - 1] * C[i - 1]
Fs[i] = F[i] - A[i] / Bs[i - 1] * Fs[i - 1]
x = np.zeros_like(B)
x[-1] = Fs[-1] / Bs[-1]
for i in range(n - 2,-1,-1):
x[i] = (Fs[i] - C[i] * x[i + 1]) / Bs[i]
return x
# Calculate cubic spline params
#@numba.njit(cache = True,inline = 'always')
def calc_spline_params(x,y):
a = y
h = np.diff(x)
c = np.concatenate((np.zeros((1,),dtype = y.dtype),np.append(tri_diag_solve(h[:-1],(h[:-1] + h[1:]) * 2,h[1:],((a[2:] - a[1:-1]) / h[1:] - (a[1:-1] - a[:-2]) / h[:-1]) * 3),0)))
d = np.diff(c) / (3 * h)
b = (a[1:] - a[:-1]) / h + (2 * c[1:] + c[:-1]) / 3 * h
return a[1:],b,c[1:],d
# Spline value calculating function,given params and "x"
#@numba.njit(cache = True,inline = 'always')
def func_spline(x,ix,x0,a,c,d):
dx = x - x0[1:][ix]
return a[ix] + (b[ix] + (c[ix] + d[ix] * dx) * dx) * dx
# Compute piece-wise spline function for "x" out of sorted "x0" points
#@numba.njit([f'f{ii}[:](f{ii}[:],f{ii}[:],f{ii}[:])' for ii in (4,8)],# cache = True,inline = 'always')
def piece_wise_spline(x,d):
xsh = x.shape
x = x.ravel()
ix = np.searchsorted(x0[1 : -1],x)
y = func_spline(x,d)
y = y.reshape(xsh)
return y
def main():
x0 = np.array([4.0,5.638304088577984,6.785456961280076,4.0])
y0 = np.array([0.0,1.147152872702092,2.7854569612800755,4.423761049858059,3.2766081771559668])
t0 = np.arange(len(x0)).astype(np.float64)
plt.plot(x0,y0)
vs = []
for e in (x0,y0):
a,d = calc_spline_params(t0,e)
x = np.linspace(0,t0[-1],100)
vs.append(piece_wise_spline(x,t0,d))
plt.plot(vs[0],vs[1])
plt.show()
if __name__ == '__main__':
main()
的源代码可以这样加载：
TypeElement测试的 private String loadSource(TypeElement typeElement) throws IOException {
final FileObject source = processingEnv.getFiler().getResource(
StandardLocation.SOURCE_PATH,((PackageElement) typeElement.getEnclosingElement()).getQualifiedName(),typeElement.getSimpleName() + ".java");
try (Reader reader = source.openReader(true)) {
final StringBuilder builder = new StringBuilder();
final char[] buf = new char[1024];
int read;
while ((read = reader.read(buf)) != -1) {
builder.append(buf,read);
}
return builder.toString();
}
}
jar 包含一个 Processor 文件，无需指定 META-INF/services/javax.annotation.processing.Processor 选项：
- Maven：好的
- Gradle：需要额外的配置，假设
-process是源目录
src/main/java- 命令行：添加
tasks.withType(JavaCompile) { configure(options) { options.setSourcepath(project.files('src/main/java')) } }选项：
-sourcepath