问题描述
我在将 python 脚本的输出保存到 java 变量时遇到问题。我的代码看起来像...
Python 脚本:
def main(argv):
filepath = argv[1]
...
output = results.get_forecast(14).predicted_mean.to_json()
print(output)
if __name__ == "__main__":
main(sys.argv)
它有效 - 结果打印到控制台 - 一切正常。
我的 Java 代码:
ProcessBuilder pb = new ProcessBuilder("python","-u","path/to/script.py",args_filepath).inheritIO();
try {
Process p = pb.start();
BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
StringBuilder predictionString = new StringBuilder();
String line;
while((line = br.readLine()) != null) {
predictionString.append(line);
}
int exitCode = p.waitFor();
System.out.println("VALUE: " + predictionString.toString());
br.close();
} catch (IOException | InterruptedException e) {
e.printstacktrace();
}
那部分也有效...我的意思是它的工作方式是执行 python 代码,将输出写入控制台,但它不会将输出字符串保存到 predictionString
。
解决方法
使用 redirectErrorStream
方法捕获 output
流。
ProcessBuilder pb = new ProcessBuilder("python","-u","path/to/script.py",args_filepath)
.redirectErrorStream(true);
代替
ProcessBuilder pb = new ProcessBuilder("python",args_filepath).inheritIO();