我正在尝试构建一个 Web 服务，该服务接受许多用于构建 Bing 查询 API 路径的变量。出于某种原因，如果我构建 URI，我的流程会识别出新的 URI 已正确分配给有效负载，但是当我将有效负载分配给出站 HTTP 端点时，它会失败。
<flow name="BingQuery" doc:name="BingQuery">
<http:inbound-endpoint exchange-pattern="one-way" host="localhost" port="8082" doc:name="HTTP" />
<set-variable variableName="query" doc:name="Variable" value="#[header:INBOUND:query]"/>
<set-variable variableName="numResults" doc:name="Variable" value="#[header:INBOUND:top]"/>
<set-variable variableName="offsetResults" doc:name="Variable" value="#[header:INBOUND:offset]"/>
<scripting:component doc:name="Groovy">
<scripting:script engine="Groovy">
<scripting:text><![CDATA[def query = message.getInvocationProperty("query")
def numResults = message.getInvocationProperty("numResults")
def offsetResults = message.getInvocationProperty("offsetResults")
def path = "Data.ashx/Bing/Search/v1/Web?Query=" + "$query" + "&WebFileType=%27PDF%27&\$top=" + "$numResults" + "&\$skip=" + "$offsetResults" + "&\$format=Json"
println "$path"
message.setProperty("pathVar","$path")
return null;]]></scripting:text>
</scripting:script>
</scripting:component>
<logger level="INFO" doc:name="Logger" message="#[header:OUTBOUND:pathVar]"/>
<https:outbound-endpoint exchange-pattern="request-response"
host="api.datamarket.azure.com" port="443" path="#[header:OUTBOUND:pathVar]"
user="*****" password="******"
doc:name="Bing" /> ...
我得到的例外是
ERROR 2012-10-25 14:14:26,250 [[poll_directory].BingQuery.stage1.02] org.mule.exception.DefaultMessagingExceptionStrategy:
********************************************************************************
Message : Failed to transform from "json" to "java.util.Map"
Code : MULE_ERROR-65110
--------------------------------------------------------------------------------
Exception stack is:
1. Unexpected character ('T' (code 84)): expected a valid value (number, String, array, object, 'true', 'false' or 'null')
at [Source: java.io.InputStreamReader@73b62d67; line: 1, column: 2] (org.codehaus.jackson.JsonParseException)
org.codehaus.jackson.JsonParser:1291 (null)
2. Failed to transform from "json" to "java.util.Map" (org.mule.api.transformer.TransformerException)
org.mule.module.json.transformers.JsonToObject:136 (http://www.mulesoft.org/docs/site/current3/apidocs/org/mule/api/transformer/TransformerException.html)
--------------------------------------------------------------------------------
Root Exception stack trace:
org.codehaus.jackson.JsonParseException: Unexpected character ('T' (code 84)): expected a valid value (number, String, array, object, 'true', 'false' or 'null')
at [Source: java.io.InputStreamReader@73b62d67; line: 1, column: 2]
at org.codehaus.jackson.JsonParser._constructError(JsonParser.java:1291)
at org.codehaus.jackson.impl.JsonParserMinimalBase._reportError(JsonParserMinimalBase.java:385)
at org.codehaus.jackson.impl.JsonParserMinimalBase._reportUnexpectedChar(JsonParserMinimalBase.java:306)
+ 3 more (set debug level logging or '-Dmule.verbose.exceptions=true' for everything)
********************************************************************************
它不能正常工作肯定有一个简单的原因，我确信这只是因为我还不知道 Mule 中的正确语法。我也知道使用 MEL 和 Groovy 可能有更好的方法来做到这一点，但我对 MEL 还不够熟悉，无法做到这一点。
解决方案
原来 User 属性和 Password 属性的某些字符在发送之前已被编码。在传递给用户和密码属性之前将该密钥放入变量中可以防止这种情况并导致成功。
<?xml version="1.0" encoding="UTF-8"?>
<mule xmlns:scripting="http://www.mulesoft.org/schema/mule/scripting" xmlns="http://www.mulesoft.org/schema/mule/core" xmlns:json="http://www.mulesoft.org/schema/mule/json"
xmlns:vm="http://www.mulesoft.org/schema/mule/vm" xmlns:http="http://www.mulesoft.org/schema/mule/http"
xmlns:https="http://www.mulesoft.org/schema/mule/https" xmlns:file="http://www.mulesoft.org/schema/mule/file"
xmlns:doc="http://www.mulesoft.org/schema/mule/documentation"
xmlns:spring="http://www.springframework.org/schema/beans" xmlns:core="http://www.mulesoft.org/schema/mule/core"
version="CE-3.3.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="
http://www.mulesoft.org/schema/mule/json http://www.mulesoft.org/schema/mule/json/current/mule-json.xsd
http://www.mulesoft.org/schema/mule/vm http://www.mulesoft.org/schema/mule/vm/current/mule-vm.xsd
http://www.mulesoft.org/schema/mule/http http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd
http://www.mulesoft.org/schema/mule/https http://www.mulesoft.org/schema/mule/https/current/mule-https.xsd
http://www.mulesoft.org/schema/mule/file http://www.mulesoft.org/schema/mule/file/current/mule-file.xsd
http://www.mulesoft.org/schema/mule/scripting http://www.mulesoft.org/schema/mule/scripting/current/mule-scripting.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-current.xsd
http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd ">
<configuration doc:name="Configuration">
<expression-language>
<import class="org.mule.util.StringUtils" />
</expression-language>
</configuration>
<flow name="BingQuery" doc:name="BingQuery">
<http:inbound-endpoint exchange-pattern="one-way" host="localhost" port="8082" doc:name="HTTP" />
<set-variable variableName="query" doc:name="Variable" value="#[header:INBOUND:query]"/>
<set-variable variableName="numResults" doc:name="Variable" value="#[header:INBOUND:top]"/>
<set-variable variableName="offsetResults" doc:name="Variable" value="#[header:INBOUND:offset]"/>
<scripting:component doc:name="Groovy">
<scripting:script engine="Groovy">
<scripting:text><![CDATA[def query = message.getInvocationProperty("query")
def numResults = message.getInvocationProperty("numResults")
def offsetResults = message.getInvocationProperty("offsetResults")
def path = "Data.ashx/Bing/Search/v1/Web?Query=" + "$query" + "&WebFileType=%27PDF%27&\$top=" + "$numResults" + "&\$skip=" + "$offsetResults" + "&\$format=Json"
println "$path"
message.setProperty("pathVar","$path")
message.setProperty("APIIdentifier","*****")
return null;]]></scripting:text>
</scripting:script>
</scripting:component>
<https:outbound-endpoint exchange-pattern="request-response"
host="api.datamarket.azure.com" port="443" path="#[header:OUTBOUND:pathVar]"
user="#[header:OUTBOUND:APIIdentifier]" password="#[header:OUTBOUND:APIIdentifier]"
doc:name="Bing" />
<json:json-to-object-transformer
returnClass="java.util.Map" doc:name="JSON to Object" />
<expression-transformer expression="#[message.payload.d.results]"
doc:name="Expression" />
<collection-splitter doc:name="Collection Splitter" />
<vm:outbound-endpoint exchange-pattern="one-way"
path="fileWriter" doc:name="VM" />
</flow>
<flow name="RestProcessor" doc:name="RestProcessor">
<vm:inbound-endpoint exchange-pattern="one-way"
path="fileWriter" doc:name="VM" />
<set-variable variableName="fileName" value="#[message.payload.ID].pdf"
doc:name="Variable" />
<http:rest-service-component
serviceUrl="#[joinChar=message.payload.Url.contains('?')?'&':'?' ; StringUtils.join(new String[]{message.payload.Url,(String)joinChar,'followRedirects=true'})]"
httpMethod="GET">
<http:error-filter>
<expression-filter expression="#[Integer.valueOf(message.inboundProperties['http.status']) >= 400]"></expression-filter>
</http:error-filter>
</http:rest-service-component>
<file:outbound-endpoint path="/home/administrator/Documents"
outputPattern="#[flowVars.fileName]" responseTimeout="10000"
mimeType="application/pdf" doc:name="File" />
</flow>
</mule>