activiti modeler 用户自定义流程图，怎么判断分支条件？

activiti modeler 用户自定义流程图，怎么判断分支条件？

package org.activiti.editor.rest.model;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;

import org.activiti.editor.constants.ModelDataJsonConstants;
import org.activiti.engine.ProcessEngines;
import org.activiti.engine.RepositoryService;
import org.activiti.engine.repository.Model;
import org.apache.batik.transcoder.TranscoderInput;
import org.apache.batik.transcoder.TranscoderOutput;
import org.apache.batik.transcoder.image.PNGTranscoder;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.node.ObjectNode;
import org.restlet.data.Form;
import org.restlet.data.Status;

import org.restlet.resource.Put;
import org.restlet.resource.ServerResource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import sun.misc.BASE64Encoder;

public class ModelSaveRestResource extends ServerResource implements
ModelDataJsonConstants {

protected static final Logger LOGGER = LoggerFactory
.getLogger(ModelSaveRestResource.class);

@Put
public void saveModel(Form modelForm) {
ObjectMapper objectMapper = new ObjectMapper();
String modelId = (String) getRequest().getAttributes().get("modelId");
// System.out.println("json " + modelForm.getFirstValue("json_xml"));

try {



RepositoryService repositoryService = ProcessEngines
.getDefaultProcessEngine().getRepositoryService();
Model model = repositoryService.getModel(modelId);

ObjectNode modelJson = (ObjectNode) objectMapper.readTree(model
.getMetaInfo());

modelJson.put(MODEL_NAME, modelForm.getFirstValue("name"));
modelJson.put(MODEL_DESCRIPTION,
modelForm.getFirstValue("description"));
model.setMetaInfo(modelJson.toString());
model.setName(modelForm.getFirstValue("name"));


byte[] svg_xml=modelForm.getFirstValue("svg_xml").getBytes("UTF-8");


//转成UTF-8 然后使用base64编码
String gbk=new String(modelForm.getFirstValue("json_xml").getBytes("GBK"));
String iso = new String(gbk.getBytes("UTF-8"),"ISO-8859-1");
String utf8=new String(iso.getBytes("ISO-8859-1"),"UTF-8");
byte[]  json_xml=new BASE64Encoder().encode(utf8.getBytes("UTF-8")).getBytes();
repositoryService.addModelEditorSource(model.getId(),json_xml);



InputStream svgStream = new ByteArrayInputStream(svg_xml);
TranscoderInput input = new TranscoderInput(svgStream);

PNGTranscoder transcoder = new PNGTranscoder();
// Setup output
ByteArrayOutputStream outStream = new ByteArrayOutputStream();
TranscoderOutput output = new TranscoderOutput(outStream);

// Do the transformation
transcoder.transcode(input, output);
final byte[] result = outStream.toByteArray();
repositoryService.addModelEditorSourceExtra(model.getId(), result);
outStream.close();

repositoryService.saveModel(model);

} catch (Exception e) {
LOGGER.error("Error saving model", e);
setStatus(Status.SERVER_ERROR_INTERNAL);
}
}
}