JPype将参数传递给Java

Question

我有一个试图从python访问的java外观类，所以我决定使用JPype。我的facade类只有一个带有四个参数的构造函数(无默认值)

public facade(String a, String b, List<String> c, List<String> d){
    ...
}

在初始化类的新实例时，我似乎不能正确地获取类型。我尝试的所有操作都给出了相同的错误：

File ".../main.py", line 34, in __init__
    facadeinstance = Facade(jpype.JString(s1), jpype.JString(s2),jpype.JArray(jpype.java.lang.String, 1)(s3), jpype.JArray(jpype.java.lang.String, 1)(s4))
File "/usr/local/lib/python2.7/dist-packages/jpype/_jclass.py", line 79, in _javaInit
    self.__javaobject__ = self.__class__.__javaclass__.newClassInstance(*args)
RuntimeError: No matching overloads found. at src/native/common/jp_method.cpp:121

我知道JPype在工作。我尝试了几种包装器的组合，以获得正确形式的数据，但没有成功。

相关代码：

import jpype

s1 = "something"
s2 = "something else"
s3 = ["something in a list"]
s4 = ["Something else in a list"]

jpype.startJVM(jpype.getDefaultJVMPath(), "-Djava.class.path=" + JavaJarDir)
myLib = jpype.JPackage('myLib')
Facade = myLib.Facade # class loads fine, resources printed to stdout
# The error occurs on the next line
FacadeInstance = Facade(jpype.JString(s1), jpype.JString(s2), jpype.JArray(jpype.java.lang.String, 1)(s3), jpype.JArray(jpype.java.lang.String, 1)(s4))
jpype.shutdownJVM()

Answer 1

JArray(JString)与列表不匹配。您必须使用jpype.java.util.ArrayList() (或实现List的任何东西)。

myArray = ["A", "B", "C"]
myList = jpype.java.util.ArrayList()
for s in myArray:
    myList.add(s)

因此，您的代码将如下所示：

import jpype

s1 = "something"
s2 = "something else"
s3 = ["something in a list"]
s4 = ["Something else in a list"]

jpype.startJVM(jpype.getDefaultJVMPath(), "-Djava.class.path=" + JavaJarDir)

# Import Java library and class
myLib = jpype.JPackage('myLib')
Facade = myLib.Facade

# Prepare List<String> arguments
arg3 = jpype.java.util.ArrayList()
for s in s3:
    list3.add(s)
arg4 = jpype.java.util.ArrayList()
for s in s4:
    list4.add(s)

FacadeInstance = Facade(jpype.JString(s1), jpype.JString(s2), arg3, arg4)

jpype.shutdownJVM()