[#109]Apply placeholder check while binding directUrl and type

[chpengzh]

Motivation:

希望能提供基于spring boot environment 的测试服务直连选项.详细参考#109 (comment)

Modification:

另一部分修改在chpengzh/sofa-boot

demo参考 demo

@RestController
@PropertySource("classpath:/reference.properties")
public class DemoController {

    @SofaReference(binding = @SofaReferenceBinding(
        bindingType = "${demo.alice.scheme}",
        directUrl = "${demo.alice.url}"
    ))
    private CalculateService calculator;

    // ...
}

Result:

Fixes #109

[codecov]

Codecov Report

Merging #111 into master will decrease coverage by 0.07%.
The diff coverage is 37.5%.

@@             Coverage Diff              @@
##             master     #111      +/-   ##
============================================
- Coverage     54.85%   54.77%   -0.08%     
- Complexity      393      394       +1     
============================================
  Files            53       53              
  Lines          1741     1747       +6     
  Branches        310      313       +3     
============================================
+ Hits            955      957       +2     
- Misses          606      608       +2     
- Partials        180      182       +2

Impacted Files	Coverage Δ	Complexity Δ
...pc/boot/runtime/converter/RpcBindingConverter.java	43.69% <37.5%> (-0.29%)	24 <2> (+1)

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[JervyShi]

@chpengzh 可以添加一些测试用例在 sofa-boot-starter test 中，例如：

// 1. import DirectService using anotation

    @SofaReference(binding = @SofaReferenceBinding(
        bindingType = "${test.direct.scheme}",
        directUrl = "${test.direct.url}"
    ))
    private DirectService directService;

// 2. try to invoke sayDirect

    directService.sayDirect("hello");

// 3. confirm result is right

    assert  etc.

test.direct.scheme 配置可以放在 application.properties 中验证被替换场景。

[leyou240]

个人意见。其他参数也应该支持placeholder吧。另外service annotation可能也需要支持。所有的配置我们都倾向于写到配置文件中，然后在java中引用

[chpengzh]

征求下意见 @JervyShi， 在此PR里面顺带添加service placeholder的功能， 还是新建一个issue ticket？

[QilongZhang]

@chpengzh @JervyShi 支持注解中的 placeholder 应该是由 SOFABoot 框架支持，在 RPC|Bolt|Dubbo Converter 做转换是不太优雅的实现。另@SofaService 和 @SofaReference 两个注解应该支持每个属性的替代符.

已经在SOFABoot 提了 PR ，可以一起 review

[QilongZhang]

sofastack/sofa-boot#264