如何在 WSO2 中将 JSON 作为字符串发送？

Question

I am trying to send a payload to rabbitMQ from wso2 and it must be a string but when I try to set the payloadJSON y receive this error missing } after property list but is a String I do not understand why, any one how is the right way to convert this JSON to string? this is my script

function main(mc) {
var log = mc.getServiceLog()
var enviroment = "dev";
var jsonPayload = JSON.parse(mc.getProperty('orderToERP'))
var orderToERP = "'"+ JSON.stringify(jsonPayload) + "'";
log.info(orderToERP)//'{"message":"message from terminal"}'
var rabbitBody = {
    properties: {},
    routing_key: "queue." + enviroment,
    exchange: "queue." + enviroment,
    payload:orderToERP,
    payload_encoding: "string"
}
mc.setPayloadJSON(rabbitBody);

}

This is the error that I recive

 [2021-04-28 10:55:04,378]  INFO {CommonScriptMessageContext} - '{"message":"message from 

terminal"}'
[2021-04-28 10:55:04,381] ERROR {ScriptMediator} - {api:OrderConfirm} The script engine returned an error executing the external js script : Value {name ='null', keyValue ='conf:scripts/rabittMPAdapter.js'} function main com.sun.phobos.script.util.ExtendedScriptException: org.mozilla.javascript.WrappedException: Wrapped com.sun.phobos.script.util.ExtendedScriptException: org.mozilla.javascript.EvaluatorException: `missing } after property list` (<Unknown source>#1) in <Unknown source> at line number 1 (<Unknown source>#15) in <Unknown source> at line number 15
    at com.sun.phobos.script.javascript.RhinoScriptEngine.invokeMethod(RhinoScriptEngine.java:259)
    at com.sun.phobos.script.javascript.RhinoScriptEngine.invokeFunction(RhinoScriptEngine.java:216)
    at org.apache.synapse.mediators.bsf.ScriptMediator.mediateWithExternalScript(ScriptMediator.java:344)
    at org.apache.synapse.mediators.bsf.ScriptMediator.invokeScript(ScriptMediator.java:288)
    at org.apache.synapse.mediators.bsf.ScriptMediator.mediate(ScriptMediator.java:258)
    at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:109)
    at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:71)
    at org.apache.synapse.mediators.filters.FilterMediator.mediate(FilterMediator.java:171)
    at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:109)
    at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:71)
    at org.apache.synapse.mediators.base.SequenceMediator.mediate(SequenceMediator.java:158)
    at org.apache.synapse.rest.Resource.process(Resource.java:331)
    at org.apache.synapse.rest.API.process(API.java:448)
    at org.apache.synapse.rest.RESTRequestHandler.apiProcess(RESTRequestHandler.java:120)
    at org.apache.synapse.rest.RESTRequestHandler.dispatchToAPI(RESTRequestHandler.java:98)
    at org.apache.synapse.rest.RESTRequestHandler.process(RESTRequestHandler.java:71)
    at org.apache.synapse.core.axis2.Axis2SynapseEnvironment.injectMessage(Axis2SynapseEnvironment.java:331)
    at org.apache.synapse.core.axis2.SynapseMessageReceiver.receive(SynapseMessageReceiver.java:99)
    at org.apache.axis2.engine.AxisEngine.receive(AxisEngine.java:180)
    at org.apache.synapse.transport.passthru.ServerWorker.processNonEntityEnclosingRESTHandler(ServerWorker.java:367)
    at org.apache.synapse.transport.passthru.ServerWorker.processEntityEnclosingRequest(ServerWorker.java:426)
    at org.apache.synapse.transport.passthru.ServerWorker.run(ServerWorker.java:181)
    at org.apache.axis2.transport.base.threads.NativeWorkerPool$1.run(NativeWorkerPool.java:172)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)
Caused by: org.mozilla.javascript.WrappedException: Wrapped com.sun.phobos.script.util.ExtendedScriptException: org.mozilla.javascript.EvaluatorException: missing } after property list (<Unknown source>#1) in <Unknown source> at line number 1 (<Unknown source>#15)
    at org.mozilla.javascript.Context.throwAsScriptRuntimeEx(Context.java:1754)
    at org.mozilla.javascript.MemberBox.invoke(MemberBox.java:148)
    at org.mozilla.javascript.NativeJavaMethod.call(NativeJavaMethod.java:225)
    at org.mozilla.javascript.optimizer.OptRuntime.call1(OptRuntime.java:32)
    at org.mozilla.javascript.gen._Unknown_source__4574._c_main_1(<Unknown source>:15)
    at org.mozilla.javascript.gen._Unknown_source__4574.call(<Unknown source>)
    at org.mozilla.javascript.ContextFactory.doTopCall(ContextFactory.java:394)
    at org.mozilla.javascript.ScriptRuntime.doTopCall(ScriptRuntime.java:3091)
    at org.mozilla.javascript.gen._Unknown_source__4574.call(<Unknown source>)
    at com.sun.phobos.script.javascript.RhinoScriptEngine.invokeMethod(RhinoScriptEngine.java:245)
    ... 25 more
Caused by: com.sun.phobos.script.util.ExtendedScriptException: org.mozilla.javascript.EvaluatorException: missing } after property list (<Unknown source>#1) in <Unknown source> at line number 1
    at com.sun.phobos.script.javascript.RhinoScriptEngine.eval(RhinoScriptEngine.java:184)
    at javax.script.AbstractScriptEngine.eval(AbstractScriptEngine.java:249)
    at org.apache.synapse.mediators.bsf.CommonScriptMessageContext.setPayloadJSON(CommonScriptMessageContext.java:970)
    at sun.reflect.GeneratedMethodAccessor31.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.mozilla.javascript.MemberBox.invoke(MemberBox.java:126)
    ... 33 more
Caused by: org.mozilla.javascript.EvaluatorException: missing } after property list (<Unknown source>#1)
    at org.mozilla.javascript.DefaultErrorReporter.runtimeError(DefaultErrorReporter.java:77)
    at org.mozilla.javascript.DefaultErrorReporter.error(DefaultErrorReporter.java:64)
    at org.mozilla.javascript.Parser.addError(Parser.java:188)
    at org.mozilla.javascript.Parser.addError(Parser.java:166)
    at org.mozilla.javascript.Parser.reportError(Parser.java:223)
    at org.mozilla.javascript.Parser.reportError(Parser.java:217)
    at org.mozilla.javascript.Parser.mustMatchToken(Parser.java:388)
    at org.mozilla.javascript.Parser.mustMatchToken(Parser.java:378)
    at org.mozilla.javascript.Parser.objectLiteral(Parser.java:3246)
    at org.mozilla.javascript.Parser.primaryExpr(Parser.java:2767)
    at org.mozilla.javascript.Parser.memberExpr(Parser.java:2406)
    at org.mozilla.javascript.Parser.unaryExpr(Parser.java:2304)
    at org.mozilla.javascript.Parser.mulExpr(Parser.java:2229)
    at org.mozilla.javascript.Parser.addExpr(Parser.java:2213)
    at org.mozilla.javascript.Parser.shiftExpr(Parser.java:2194)
    at org.mozilla.javascript.Parser.relExpr(Parser.java:2169)
    at org.mozilla.javascript.Parser.eqExpr(Parser.java:2141)
    at org.mozilla.javascript.Parser.bitAndExpr(Parser.java:2130)
    at org.mozilla.javascript.Parser.bitXorExpr(Parser.java:2119)
    at org.mozilla.javascript.Parser.bitOrExpr(Parser.java:2108)
    at org.mozilla.javascript.Parser.andExpr(Parser.java:2097)
    at org.mozilla.javascript.Parser.orExpr(Parser.java:2086)
    at org.mozilla.javascript.Parser.condExpr(Parser.java:2062)
    at org.mozilla.javascript.Parser.assignExpr(Parser.java:2033)
    at org.mozilla.javascript.Parser.expr(Parser.java:2012)
    at org.mozilla.javascript.Parser.parenExpr(Parser.java:2839)
    at org.mozilla.javascript.Parser.primaryExpr(Parser.java:2773)
    at org.mozilla.javascript.Parser.memberExpr(Parser.java:2406)
    at org.mozilla.javascript.Parser.unaryExpr(Parser.java:2304)
    at org.mozilla.javascript.Parser.mulExpr(Parser.java:2229)
    at org.mozilla.javascript.Parser.addExpr(Parser.java:2213)
    at org.mozilla.javascript.Parser.shiftExpr(Parser.java:2194)
    at org.mozilla.javascript.Parser.relExpr(Parser.java:2169)
    at org.mozilla.javascript.Parser.eqExpr(Parser.java:2141)
    at org.mozilla.javascript.Parser.bitAndExpr(Parser.java:2130)
    at org.mozilla.javascript.Parser.bitXorExpr(Parser.java:2119)
    at org.mozilla.javascript.Parser.bitOrExpr(Parser.java:2108)
    at org.mozilla.javascript.Parser.andExpr(Parser.java:2097)
    at org.mozilla.javascript.Parser.orExpr(Parser.java:2086)
    at org.mozilla.javascript.Parser.condExpr(Parser.java:2062)
    at org.mozilla.javascript.Parser.assignExpr(Parser.java:2033)
    at org.mozilla.javascript.Parser.expr(Parser.java:2012)
    at org.mozilla.javascript.Parser.statementHelper(Parser.java:1039)
    at org.mozilla.javascript.Parser.statement(Parser.java:901)
    at org.mozilla.javascript.Parser.parse(Parser.java:540)
    at org.mozilla.javascript.Parser.parse(Parser.java:502)
    at org.mozilla.javascript.Context.compileImpl(Context.java:2350)
    at org.mozilla.javascript.Context.compileReader(Context.java:1296)
    at org.mozilla.javascript.Context.compileReader(Context.java:1268)
    at org.mozilla.javascript.Context.evaluateReader(Context.java:1107)
    at com.sun.phobos.script.javascript.RhinoScriptEngine.eval(RhinoScriptEngine.java:172)
    ... 39 more

Thanks in advance

Answer 1

You say

var orderToERP = "'"+ JSON.stringify(jsonPayload) + "'";

But JSON.stringify() already delivers a perfect string. So this is your root cause. You wrap a string where the parser does not expect it.

Do it this way

var orderToERP = JSON.stringify(jsonPayload);

Answer 2

For sending msg in WSO2 to RabbitMQ you should use:

<send>
  <endpoint>
   <address uri="rabbitmq:/AMQPProducerSample?rabbitmq.server.host.name=localhost&amp;rabbitmq.server.port=5672&amp;rabbitmq.queue.name=queue&amp;rabbitmq.queue.route.key=route&amp;rabbitmq.exchange.name=exchange"/>
  </endpoint>
</send>

See the documentation: RabbitMQ use Cases

I dont know why you need to send JSON payload as string, but payloadFactory like below works for me. Make sure, you have configuration in axis2.xml: <messageFormatter contentType="text/plain" class="org.apache.axis2.format.PlainTextFormatter"/> .

<payloadFactory media-type="text">
    <format>'$1'</format>
    <args>
        <arg evaluator="json" expression="json-eval($)" literal="false"/>
    </args>
</payloadFactory>

On send JSON {"message":"message from terminal"} through API, after mediation i got on RabbitMQ:

If that doesn't work. Provide some more information about version of wso2.

Answer 3

One point of clarification:

var rabbitBody = {
    properties: {},
    routing_key: "queue." + enviroment,
    exchange: "queue." + enviroment,
    payload:orderToERP,
    payload_encoding: "string"
}

This is a JavaScript object. It is data in your JavaScript code. It looks a lot like JSON, but it is not JSON. JSON is a string format for transmitting data. To convert a JavaScript object to a JSON string, use JSON.stringify() :

mc.setPayloadJSON(JSON.stringify(rabbitBody));

I think it is important to understand the difference between a JSON string and a JavaScript object. This will help you know what to do in different situations.