cdmlib-remote/src/main/java/eu/etaxonomy/cdm/remote/view/JsonView.java

   1 // $Id$
   2 /**
   3 * Copyright (C) 2007 EDIT
   4 * European Distributed Institute of Taxonomy
   5 * http://www.e-taxonomy.eu
   6 *
   7 * The contents of this file are subject to the Mozilla Public License Version 1.1
   8 * See LICENSE.TXT at the top of this package for the full license terms.
   9 */
  10 package eu.etaxonomy.cdm.remote.view;
  11
  12 import java.io.PrintWriter;
  13 import java.util.Collection;
  14 import java.util.Map;
  15 import java.util.regex.Matcher;
  16 import java.util.regex.Pattern;
  17
  18 import javax.servlet.http.HttpServletRequest;
  19 import javax.servlet.http.HttpServletResponse;
  20
  21 import net.sf.json.JSON;
  22 import net.sf.json.JSONArray;
  23 import net.sf.json.JSONObject;
  24 import net.sf.json.JsonConfig;
  25 import net.sf.json.xml.XMLSerializer;
  26
  27 import org.apache.log4j.Logger;
  28 import org.springframework.web.servlet.View;
  29
  30
  31 public class JsonView extends BaseView implements View{
  32
  33     public static final Logger logger = Logger.getLogger(JsonView.class);
  34
  35     private JsonConfig jsonConfig;
  36
  37     public enum Type{
  38         JSON("application/json"),
  39         XML("application/xml");
  40
  41         private String contentType;
  42
  43         Type(String contentType){
  44             this.contentType = contentType;
  45         }
  46
  47         public String getContentType(){
  48             return contentType;
  49         }
  50     }
  51
  52     private Type type = Type.JSON;
  53
  54     private String xsl = null;
  55
  56     public void setXsl(String xsl) {
  57         this.xsl = xsl;
  58     }
  59
  60     public String getXsl() {
  61         return xsl;
  62     }
  63
  64     public Type getType() {
  65         return type;
  66     }
  67
  68     /**
  69      * Default is Type.JSON
  70      * @param type
  71      */
  72     public void setType(Type type) {
  73         this.type = type;
  74     }
  75
  76     public void setJsonConfig(JsonConfig jsonConfig) {
  77         this.jsonConfig = jsonConfig;
  78     }
  79
  80     /*
  81      * (non-Javadoc)
  82      * @see org.springframework.web.servlet.View#getContentType()
  83      */
  84     public String getContentType() {
  85         return type.getContentType();
  86     }
  87
  88     public void render(Object entity, PrintWriter writer, String documentContextPath, String jsonpCallback) throws Exception {
  89
  90         if(jsonConfig == null){
  91             logger.error("The jsonConfig must not be null. It must be set in the applicationContext.");
  92         }
  93
  94         // create JSON Object
  95         boolean isCollectionType = false;
  96         JSON jsonObj;
  97         if (entity == null){
  98           jsonObj = JSONObject.fromObject("{}");
  99         } else if(Collection.class.isAssignableFrom(entity.getClass())){
 100             isCollectionType = true;
 101             jsonObj = JSONArray.fromObject(entity, jsonConfig);
 102         }else if(entity instanceof String){
 103             jsonObj = JSONObject.fromObject("{\"String\":\""+entity.toString().replace("\"", "\\\"")+"\"}");
 104         } else if(entity instanceof Integer){
 105             jsonObj = JSONObject.fromObject("{\"Integer\":"+((Integer)entity).intValue()+"}");
 106         } else if(entity instanceof Boolean){
 107             jsonObj = JSONObject.fromObject("{\"Boolean\":"+((Boolean)entity).toString()+"}");
 108         } else {
 109             jsonObj = JSONObject.fromObject(entity, jsonConfig);
 110         }
 111
 112         if(type.equals(Type.XML)){
 113             XMLSerializer xmlSerializer = new XMLSerializer();
 114             if(isCollectionType){
 115                 xmlSerializer.setArrayName(entity.getClass().getSimpleName());
 116                 Class elementType = Object.class;
 117                 Collection c = (Collection)entity;
 118                 if(c.size() > 0){
 119                     elementType = c.iterator().next().getClass();
 120                 }
 121                 xmlSerializer.setObjectName(elementType.getSimpleName());
 122             } else if(entity != null){
 123                 xmlSerializer.setObjectName(entity.getClass().getSimpleName());
 124             }
 125             String xml = xmlSerializer.write( jsonObj );
 126             if(type.equals(Type.XML) && xsl != null){
 127                 if(documentContextPath == null){
 128                     documentContextPath = "";
 129                 }
 130                 String replace = "\r\n<?xml-stylesheet type=\"text/xsl\" href=\"" + documentContextPath + "/" + xsl + "\"?>\r\n";
 131                 xml = xml.replaceFirst("\r\n", replace);
 132             }
 133             writer.append(xml);
 134         } else {
 135             // assuming json
 136             if(jsonpCallback != null){
 137                 writer.append(jsonpCallback).append("(").append(jsonObj.toString()).append(")");
 138             } else {
 139                 writer.append(jsonObj.toString());
 140             }
 141         }
 142         //TODO resp.setContentType(type);
 143         writer.flush();
 144     }
 145
 146     /*
 147      * (non-Javadoc)
 148      * @see org.springframework.web.servlet.View#render(java.util.Map, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
 149      */
 150     public void render(Map model, HttpServletRequest request, HttpServletResponse response) throws Exception {
 151
 152         // Retrieve data from model
 153         Object entity = getResponseData(model);
 154
 155         // set content type
 156         response.setContentType(type.getContentType());
 157
 158         PrintWriter writer = response.getWriter();
 159
 160         // read jsonp parameter from query string
 161         String[] tokens = request.getQueryString().split("&", 0);
 162         String jsonpParamName = "callback";
 163         String jsonpCallback= null;
 164         for (int i = 0; i < tokens.length; i++) {
 165              if(tokens[i].startsWith(jsonpParamName)){
 166                  jsonpCallback = tokens[i].substring(jsonpParamName.length() + 1);
 167                  break;
 168              }
 169         }
 170
 171         // render
 172         render(entity, writer, request.getContextPath(), jsonpCallback);
 173     }
 174 }