Delphi6调用java编写的web services服务端时报异常 ( 积分: 20 )

我在调用java编写的服务端时，会报异常：
project project1.ext raised exception class Exception with message '参数不正确.'
process stopped.use step or run to contnue;

通过web services import导入后生成的单元文件：
Unit Unit_2;
interface
uses Types, XSBuiltIns;
type

HelloWorld = interface(IInvokable)
['{521A5B71-4CB9-4FAA-82AD-0F9CCF423FB9}']
procedure sayHello(const theName: WideString; out result: WideString); stdcall;
end;
implementation
uses InvokeRegistry;
initialization
InvRegistry.RegisterInterface(TypeInfo(HelloWorld), '', 'UTF-8');
end.

调用：
var
a:WideString;
b:HelloWorld;
begin
b.sayHello('ccccc',a);
edit1.text:=a;
end;

我在调用java编写的服务端时，会报异常：
project project1.ext raised exception class Exception with message '参数不正确.'
process stopped.use step or run to contnue;

通过web services import导入后生成的单元文件：
Unit Unit_2;
interface
uses Types, XSBuiltIns;
type

HelloWorld = interface(IInvokable)
['{521A5B71-4CB9-4FAA-82AD-0F9CCF423FB9}']
procedure sayHello(const theName: WideString; out result: WideString); stdcall;
end;
implementation
uses InvokeRegistry;
initialization
InvRegistry.RegisterInterface(TypeInfo(HelloWorld), '', 'UTF-8');
end.

调用：
var
a:WideString;
b:HelloWorld;
begin
b.sayHello('ccccc',a);
edit1.text:=a;
end;

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