Kettle WebService组件无法传参问题解决

た入场券 2022-08-22 14:14 308阅读 0赞

## 1. Kettle WebService组件 ##

kettle WebService转换组件【Web 服务查询】可以用来调用我们发布的webservice。

## 2. WebService组件使用限制 ##

在使用的过程中，发现这个组件存在一些使用上的限制，如下说明：

**(1) 不能调用wsdl和xsd分离的webservice，在点击“加载”按钮会抛异常。**首先Spoon弹出对话框提示错误：

Could not find the schema with the name xxx within the specified wsdl.

详细异常堆栈如下所示：

org.pentaho.di.core.exception.KettleStepException: 
    Could not retrieve WSDL Operator for operation name: sayHello
    
    Could not find the schema with the name {http://jws.com/}sayHello within the specified wsdl.
    
    
        at org.pentaho.di.trans.steps.webservices.wsdl.Wsdl.getOperation(Wsdl.java:216)
        at org.pentaho.di.trans.steps.webservices.wsdl.Wsdl.getOperations(Wsdl.java:236)
        at org.pentaho.di.ui.trans.steps.webservices.WebServiceDialog.loadWebService(WebServiceDialog.java:233)
        at org.pentaho.di.ui.trans.steps.webservices.WebServiceDialog.initTreeTabWebService(WebServiceDialog.java:365)
        at org.pentaho.di.ui.trans.steps.webservices.WebServiceDialog.access$11(WebServiceDialog.java:362)
        at org.pentaho.di.ui.trans.steps.webservices.WebServiceDialog$5.widgetSelected(WebServiceDialog.java:870)
        at org.eclipse.swt.widgets.TypedListener.handleEvent(Unknown Source)
        at org.eclipse.swt.widgets.EventTable.sendEvent(Unknown Source)
        at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
        at org.eclipse.swt.widgets.Display.runDeferredEvents(Unknown Source)
        at org.eclipse.swt.widgets.Display.readAndDispatch(Unknown Source)
        at org.pentaho.di.ui.trans.steps.webservices.WebServiceDialog.open(WebServiceDialog.java:1295)
        at org.pentaho.di.ui.spoon.delegates.SpoonStepsDelegate.editStep(SpoonStepsDelegate.java:124)
        at org.pentaho.di.ui.spoon.Spoon.editStep(Spoon.java:8777)
        at org.pentaho.di.ui.spoon.trans.TransGraph.editStep(TransGraph.java:3027)
        at org.pentaho.di.ui.spoon.trans.TransGraph.mouseDoubleClick(TransGraph.java:744)
        at org.eclipse.swt.widgets.TypedListener.handleEvent(Unknown Source)
        at org.eclipse.swt.widgets.EventTable.sendEvent(Unknown Source)
        at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
        at org.eclipse.swt.widgets.Display.runDeferredEvents(Unknown Source)
        at org.eclipse.swt.widgets.Display.readAndDispatch(Unknown Source)
        at org.pentaho.di.ui.spoon.Spoon.readAndDispatch(Spoon.java:1317)
        at org.pentaho.di.ui.spoon.Spoon.waitForDispose(Spoon.java:7958)
        at org.pentaho.di.ui.spoon.Spoon.start(Spoon.java:9290)
        at org.pentaho.di.ui.spoon.Spoon.main(Spoon.java:654)
    Caused by: org.pentaho.di.core.exception.KettleStepException: 
    Could not find the schema with the name {http://jws.com/}sayHello within the specified wsdl.
    
        at org.pentaho.di.trans.steps.webservices.wsdl.WsdlTypes.findNamedElement(WsdlTypes.java:86)
        at org.pentaho.di.trans.steps.webservices.wsdl.WsdlOpParameterList.resolvePartElement(WsdlOpParameterList.java:220)
        at org.pentaho.di.trans.steps.webservices.wsdl.WsdlOpParameterList.getParameter(WsdlOpParameterList.java:141)
        at org.pentaho.di.trans.steps.webservices.wsdl.WsdlOpParameterList.add(WsdlOpParameterList.java:107)
        at org.pentaho.di.trans.steps.webservices.wsdl.WsdlOperation.loadParameters(WsdlOperation.java:232)
        at org.pentaho.di.trans.steps.webservices.wsdl.WsdlOperation.<init>(WsdlOperation.java:111)
        at org.pentaho.di.trans.steps.webservices.wsdl.Wsdl.getOperation(Wsdl.java:210)
        ... 24 more

**(2) 调用不同标准发布的webservice可能会出现参数无法传递到实际webservice调用方法的情况。**

在测试的时候发现，采用不同的技术来发布webservice，如CXF、Asix2等，均会出现参数无法传递到实际的webservice调用方法的情况。

## 3. 解决限制 ##

在我们的实际项目中并不会发布wsdl和xsd分离的webservice，因此第1点暂时不在我们的考虑范围之内。

**然而第2点严重影响了webservice组件的使用。由于我们的使用需求，必须要修复这个缺陷。**

通过调试源码发现原因：  
在`WsdlOpParameterList`这个类的`resolvePartElement`方法不能正确解析参数值，因此我们通过改造这个方法来修复这个bug，改造后的`resolvePartElement`方法如下所示：

private List<WsdlOpParameter> resolvePartElement( Part p ) throws KettleStepException {
    
        List<WsdlOpParameter> resolvedParams = new ArrayList<WsdlOpParameter>();
        Element schemaElement = _wsdlTypes.findNamedElement( p.getElementName() );
    
        if ( schemaElement.hasAttribute( WsdlUtils.ELEMENT_TYPE_ATTR ) ) {
    
            String eleName;
    
            String typeValue = schemaElement.getAttribute("type");
            String tns = typeValue.split(":")[0];
            if (!"xsd".equals(tns)) {
              String complexTypeName = typeValue.split(":")[1];
              ComplexType complexType = this._wsdlTypes.getNamedComplexTypes().getComplexType(complexTypeName);
                    for (Iterator<String> localIterator = complexType.getElementNames()
                            .iterator(); localIterator.hasNext();) {
                        eleName = (String) localIterator.next();
                        QName qName = this._wsdlTypes.getTypeQName(typeValue);
                        resolvedParams.add(new WsdlOpParameter(eleName,
                                this._wsdlTypes.findNamedType(qName),
                                this._wsdlTypes));
                    }
            }
            else {
                 // this is a simple type
                resolvedParams.add( new WsdlOpParameter( p.getName(), schemaElement, _wsdlTypes ) );
            }
    
        } else {
          // this is a complex type
          Element complex = DomUtils.getChildElementByName( schemaElement, WsdlUtils.COMPLEX_TYPE_NAME );
          Element sequence = DomUtils.getChildElementByName( complex, WsdlUtils.SEQUENCE_TAG_NAME );
    
          // may occasionally find a <complex/> tag map to empty but this may be a bug in WSM
          //
          if ( sequence == null ) {
            return resolvedParams;
          }
    
          List<Element> seqElements = DomUtils.getChildElementsByName( sequence, WsdlUtils.ELEMENT_NAME );
    
          for ( Element e : seqElements ) {
            WsdlOpParameter op = new WsdlOpParameter( e, _wsdlTypes );
    
            // special case for bare arrays, change the name of the param
            // to the name of the complex type.
            if ( op.isArray() && _parameterStyle == WsdlOperation.SOAPParameterStyle.BARE ) {
              op.setName( schemaElement.getAttribute( WsdlUtils.NAME_ATTR ), _wsdlTypes );
            }
            resolvedParams.add( op );
          }
        }
        return resolvedParams;
      }

修改完后需要重新编译得到**WsdlOpParameterList.class**，并使用这个class文件替换原来的class文件，这个文件所在的位置如下：

kettle安装目录 /lib子目录 **kettle-engine-xxx.jar**

用解压工具打开并实现替换：

替换文件包目录：

**org/pentaho/di/trans/steps/webservices/wsdl**

为了方便大家快速替换，直接提供这个修改后的文件：

[http://pan.baidu.com/s/1kVctSY7][http_pan.baidu.com_s_1kVctSY7]

大家可以在上面的百度云链接地址下载编译好的修改文件，直接替换原来的文件即可。

【温馨提示】

1) 修复后测试CXF和Axis2发布的WebService均能成功传递参数，其他发布方式并没有测试过，如果在使用过程中发现这个修复并不生效，可以与我联系。

2) 对于限制1，暂时不考虑修复，如果你有好的修复方式，也请联系下我，愿意请教请教。

[http_pan.baidu.com_s_1kVctSY7]: http://pan.baidu.com/s/1kVctSY7