The only way to reliably convert json to xml and back again is via the use of type hints in the xml. the default converter does not do this. it
1. drops everything after the first property
2. confuses single element lists with properties when going from xml to json
i have reimplemented the transconversion classes using the json-util library, which converts the json to xml containing type hints as element attributes, to ensure no ambiguity.
in this way we can smart proxy (ie content route and mediate on transport and payload) for ALL json based rest services through WSO2 with no issues
This solves the problem (I think camel does it this way by default).
Here is the pom file and code:
place the jar into /repository/components/lib
you must update the messageformatter and messagebuilder mappings for content type "application/json" in axis2.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<name>wso2 json/xml converter</name>
<groupId>x.y.z</groupId>
<artifactId>wso2converter</artifactId>
<version>1.0.0-SNAPSHOT</version>
<packaging>jar</packaging>
<properties>
<jdk.version>1.6</jdk.version>
</properties>
<build>
<finalName>wso2converter</finalName>
<resources>
<resource>
<filtering>false</filtering>
<directory>src/main/resources</directory>
</resource>
</resources>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>${jdk.version}</source>
<target>${jdk.version}</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-enforcer-plugin</artifactId>
<version>1.0.1</version>
<executions>
<execution>
<id>enforce-jdk</id>
<phase>validate</phase>
<goals>
<goal>display-info</goal>
<goal>enforce</goal>
</goals>
<configuration>
<rules>
<requireJavaVersion>
<version>[${jdk.version},)</version>
</requireJavaVersion>
</rules>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>net.sf.json-lib</groupId>
<artifactId>json-lib</artifactId>
<version>2.3</version>
<classifier>jdk15</classifier>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-io</artifactId>
<version>1.3.2</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.apache.ws.commons.axiom</groupId>
<artifactId>axiom-api</artifactId>
<version>1.2.13</version>
</dependency>
<dependency>
<groupId>org.apache.axis2</groupId>
<artifactId>axis2-kernel</artifactId>
<version>1.6.2</version>
</dependency>
<dependency>
<groupId>xom</groupId>
<artifactId>xom</artifactId>
<version>1.1</version>
</dependency>
<dependency>
<groupId>org.apache.synapse</groupId>
<artifactId>synapse-core</artifactId>
<version>2.1.0</version>
</dependency>
<dependency>
<groupId>com.sun.jersey</groupId>
<artifactId>jersey-json</artifactId>
<version>1.1.5</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.8.2</version>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.13</version>
<!--scope>provided</scope-->
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.4</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
package a.b.wso2;
import java.io.InputStream;
import net.sf.json.JSON;
import net.sf.json.JSONSerializer;
import net.sf.json.xml.XMLSerializer;
import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.util.AXIOMUtil;
import org.apache.axis2.AxisFault;
import org.apache.axis2.builder.Builder;
import org.apache.axis2.context.MessageContext;
import org.apache.commons.io.IOUtils;
import org.apache.log4j.BasicConfigurator;
import org.apache.log4j.Logger;
public class WsoJtoX implements Builder {
Logger logger = Logger.getLogger("a.b.wso2converter");
@Override
public OMElement processDocument(InputStream is, String contentType,
MessageContext messageContext) throws AxisFault {
String jsonData = "";
try {
jsonData = IOUtils.toString(is,"UTF-8");
String output = process(jsonData);
OMElement e = AXIOMUtil.stringToOM(output);
return e;
} catch (Exception e) {
logger.error("error converting json string " + jsonData, e);
if (e instanceof AxisFault) {
throw (AxisFault) e;
}
throw new AxisFault("(B"+counter+") error converting json to xml", e);
}
}
static int counter=0;
public String process(String jsonData) throws AxisFault {
try {
String tran = "__ns__";
jsonData=jsonData.replace("\r", "").trim();
//jsonData=jsonData.replace("\n", "");
String decoded = (jsonData.replaceAll("\"([a-zA-Z0-9_]*)\\:([a-zA-Z0-9]*)\"(\\s*)(:)", "\"$1" + tran + "$2\"$3:"));
counter++;
if (logger.isDebugEnabled()) {
logger.debug("\n>>>>> (B"+counter+") converting json\n " + jsonData + "\n====");
}
XMLSerializer serializer = new XMLSerializer();
JSON json = JSONSerializer.toJSON(decoded);
String xml = serializer.write(json);
//add in the soap stuff
StringBuilder sb = new StringBuilder();
sb.append("<soap:Envelope xmlns:soap=\"http://www.w3.org/2001/12/soap-envelope\" soap:encodingStyle=\"http://www.w3.org/2001/12/soap-encoding\"> <soap:Body>");
sb.append(xml.replace("<?xml version=\"1.0\" encoding=\"UTF-8\"?>", ""));
sb.append("</soap:Body></soap:Envelope>");
if (logger.isDebugEnabled()) {
logger.debug("\n==== (B"+counter+") to xml\n" + sb.toString()+"\n<<<<<");
}
return sb.toString();
} catch (Exception e) {
throw new AxisFault("(B"+counter+") error transforming json to xml", e);
}
}
}
package a.b.wso2;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import net.sf.json.JSON;
import net.sf.json.xml.XMLSerializer;
import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.OMOutputFormat;
import org.apache.axiom.om.util.AXIOMUtil;
import org.apache.axis2.AxisFault;
import org.apache.axis2.Constants;
import org.apache.axis2.context.MessageContext;
import org.apache.axis2.transport.MessageFormatter;
import org.apache.log4j.BasicConfigurator;
import org.apache.log4j.Logger;
public class WsoXtoJ implements MessageFormatter {
Logger logger = Logger.getLogger("a.b.wso2converter");
private static int counter=0;
public String convert(String xData) {
counter++;
if (logger.isDebugEnabled()) {
logger.debug("\n]]]]] (A"+counter+") converting xml\n " + xData + "\n-----");
}
try {
String tran = "__ns__";
XMLSerializer serializer = new XMLSerializer();
OMElement e = AXIOMUtil.stringToOM(xData);
OMElement b = (OMElement) e.getChildrenWithLocalName("Body").next();
b = (OMElement) b.getChildElements().next();
String xfrag = b.toStringWithConsume();
String str = "";
JSON j = serializer.read(xfrag);
str = j.toString();
String nstr = str.replaceAll("\"([a-zA-Z0-9_]+)" + tran + "([a-zA-Z0-9]+)\"(\\s*)(:)", "\"$1:$2\"$3:"); //", "\"$1:$2\"");
if (logger.isDebugEnabled()) {
logger.debug("\n----- (A"+counter+") to json\n" + nstr+"\n[[[[[");
}
return nstr;
} catch (Exception e) {
throw new RuntimeException(e);
}
}
@Override
public String formatSOAPAction(MessageContext msgCtxt, OMOutputFormat format,
String soapActionString) {
return null;
}
@Override
public byte[] getBytes(MessageContext ctx, OMOutputFormat format)
throws AxisFault {
String env="";
try {
OMElement element = ctx.getEnvelope().getBody().getFirstElement();
String payload = this.convert(element.toString());
return payload.getBytes(format.getCharSetEncoding());
} catch (UnsupportedEncodingException e) {
logger.error("(A"+counter+") error converting xml to json "+ctx.getEnvelope().toString());
throw AxisFault.makeFault(e);
}
}
@Override
public String getContentType(MessageContext msgCtxt, OMOutputFormat format,
String soapActionString) {
String contentType = (String) msgCtxt.getProperty(Constants.Configuration.CONTENT_TYPE);
String encoding = format.getCharSetEncoding();
if (contentType == null) {
contentType = (String) msgCtxt.getProperty(Constants.Configuration.MESSAGE_TYPE);
}
if (encoding != null) {
contentType += "; charset=" + encoding;
}
return contentType;
}
@Override
public URL getTargetAddress(MessageContext msgCtxt, OMOutputFormat format,
URL targetURL) throws AxisFault {
return targetURL;
}
@Override
public void writeTo(MessageContext msgCtxt, OMOutputFormat format,
OutputStream out, boolean preserve) throws AxisFault {
try {
out.write(this.getBytes(msgCtxt, format));
out.flush();
} catch (IOException e) {
throw AxisFault.makeFault(e);
}
}
}
