package org.json.junit; import static org.junit.Assert.assertTrue; import java.util.EnumSet; import java.util.List; import java.util.Map; import org.json.JSONArray; import org.json.JSONObject; import org.junit.Test; import com.jayway.jsonpath.Configuration; import com.jayway.jsonpath.JsonPath; /** * Enums are not explicitly supported in JSON-Java. But because enums act like * classes, all required behavior is already be present in some form. * These tests explore how enum serialization works with JSON-Java. */ public class EnumTest { /** * To serialize an enum by its getters, use the JSONObject Object constructor. * The JSONObject ctor handles enum like any other bean. A JSONobject * is created whose entries are the getter name/value pairs. */ @Test public void jsonObjectFromEnum() { // If there are no getters then the object is empty. MyEnum myEnum = MyEnum.VAL2; JSONObject jsonObject = new JSONObject(myEnum); assertTrue("simple enum has no getters", jsonObject.length() == 0); // enum with a getters should create a non-empty object MyEnumField myEnumField = MyEnumField.VAL2; jsonObject = new JSONObject(myEnumField); // validate JSON content Object doc = Configuration.defaultConfiguration().jsonProvider() .parse(jsonObject.toString()); assertTrue("expecting 2 items in top level object", ((Map)(JsonPath.read(doc, "$"))).size() == 2); assertTrue("expecting val 2", "val 2".equals(jsonObject.query("/value"))); assertTrue("expecting 2", Integer.valueOf(2).equals(jsonObject.query("/intVal"))); /** * class which contains enum instances. Each enum should be stored * in its own JSONObject */ MyEnumClass myEnumClass = new MyEnumClass(); myEnumClass.setMyEnum(MyEnum.VAL1); myEnumClass.setMyEnumField(MyEnumField.VAL3); jsonObject = new JSONObject(myEnumClass); // validate JSON content doc = Configuration.defaultConfiguration().jsonProvider().parse(jsonObject.toString()); assertTrue("expected 2 top level items", ((Map)(JsonPath.read(doc, "$"))).size() == 2); assertTrue("expected 2 myEnumField items", "VAL3".equals((JsonPath.read(doc, "$.myEnumField")))); assertTrue("expected 0 myEnum items", "VAL1".equals((JsonPath.read(doc, "$.myEnum")))); assertTrue("expecting MyEnumField.VAL3", MyEnumField.VAL3.equals(jsonObject.query("/myEnumField"))); assertTrue("expecting MyEnum.VAL1", MyEnum.VAL1.equals(jsonObject.query("/myEnum"))); } /** * To serialize an enum by its set of allowed values, use getNames() * and the the JSONObject Object with names constructor. */ @Test public void jsonObjectFromEnumWithNames() { String [] names; JSONObject jsonObject; MyEnum myEnum = MyEnum.VAL1; names = JSONObject.getNames(myEnum); // The values will be MyEnum fields jsonObject = new JSONObject(myEnum, names); // validate JSON object Object doc = Configuration.defaultConfiguration().jsonProvider().parse(jsonObject.toString()); assertTrue("expected 3 top level items", ((Map)(JsonPath.read(doc, "$"))).size() == 3); assertTrue("expected VAL1", MyEnum.VAL1.equals(jsonObject.query("/VAL1"))); assertTrue("expected VAL2", MyEnum.VAL2.equals(jsonObject.query("/VAL2"))); assertTrue("expected VAL3", MyEnum.VAL3.equals(jsonObject.query("/VAL3"))); MyEnumField myEnumField = MyEnumField.VAL3; names = JSONObject.getNames(myEnumField); // The values will be MyEnmField fields jsonObject = new JSONObject(myEnumField, names); doc = Configuration.defaultConfiguration().jsonProvider().parse(jsonObject.toString()); assertTrue("expected 3 top level items", ((Map)(JsonPath.read(doc, "$"))).size() == 3); assertTrue("expected VAL1", MyEnumField.VAL1.equals(jsonObject.query("/VAL1"))); assertTrue("expected VAL2", MyEnumField.VAL2.equals(jsonObject.query("/VAL2"))); assertTrue("expected VAL3", MyEnumField.VAL3.equals(jsonObject.query("/VAL3"))); } /** * Verify that enums are handled consistently between JSONArray and JSONObject */ @Test public void verifyEnumConsistency(){ JSONObject jo = new JSONObject(); jo.put("value", MyEnumField.VAL2); String expected="{\"value\":\"VAL2\"}"; String actual = jo.toString(); assertTrue("Expected "+expected+" but actual was "+actual, expected.equals(actual)); jo.accumulate("value", MyEnumField.VAL1); expected="{\"value\":[\"VAL2\",\"VAL1\"]}"; actual = jo.toString(); assertTrue("Expected "+expected+" but actual was "+actual, expected.equals(actual)); jo.remove("value"); jo.append("value", MyEnumField.VAL1); expected="{\"value\":[\"VAL1\"]}"; actual = jo.toString(); assertTrue("Expected "+expected+" but actual was "+actual, expected.equals(actual)); jo.put("value", EnumSet.of(MyEnumField.VAL2)); expected="{\"value\":[\"VAL2\"]}"; actual = jo.toString(); assertTrue("Expected "+expected+" but actual was "+actual, expected.equals(actual)); JSONArray ja = new JSONArray(); ja.put(MyEnumField.VAL2); jo.put("value", ja); actual = jo.toString(); assertTrue("Expected "+expected+" but actual was "+actual, expected.equals(actual)); jo.put("value", new MyEnumField[]{MyEnumField.VAL2}); actual = jo.toString(); assertTrue("Expected "+expected+" but actual was "+actual, expected.equals(actual)); } /** * To serialize by assigned value, use the put() methods. The value * will be stored as a enum type. */ @Test public void enumPut() { JSONObject jsonObject = new JSONObject(); MyEnum myEnum = MyEnum.VAL2; jsonObject.put("myEnum", myEnum); MyEnumField myEnumField = MyEnumField.VAL1; jsonObject.putOnce("myEnumField", myEnumField); // validate JSON content Object doc = Configuration.defaultConfiguration().jsonProvider().parse(jsonObject.toString()); assertTrue("expected 2 top level objects", ((Map)(JsonPath.read(doc, "$"))).size() == 2); assertTrue("expected VAL2", MyEnum.VAL2.equals(jsonObject.query("/myEnum"))); assertTrue("expected VAL1", MyEnumField.VAL1.equals(jsonObject.query("/myEnumField"))); JSONArray jsonArray = new JSONArray(); jsonArray.put(myEnum); jsonArray.put(1, myEnumField); // validate JSON content doc = Configuration.defaultConfiguration().jsonProvider().parse(jsonArray.toString()); assertTrue("expected 2 top level objects", ((List)(JsonPath.read(doc, "$"))).size() == 2); assertTrue("expected VAL2", MyEnum.VAL2.equals(jsonArray.query("/0"))); assertTrue("expected VAL1", MyEnumField.VAL1.equals(jsonArray.query("/1"))); /** * Leaving these tests because they exercise get, opt, and remove */ assertTrue("expecting myEnum value", MyEnum.VAL2.equals(jsonArray.get(0))); assertTrue("expecting myEnumField value", MyEnumField.VAL1.equals(jsonArray.opt(1))); assertTrue("expecting myEnumField value", MyEnumField.VAL1.equals(jsonArray.remove(1))); } /** * The default action of valueToString() is to call object.toString(). * For enums, this means the assigned value will be returned as a string. */ @Test public void enumValueToString() { String expectedStr1 = "\"VAL1\""; String expectedStr2 = "\"VAL1\""; MyEnum myEnum = MyEnum.VAL1; MyEnumField myEnumField = MyEnumField.VAL1; MyEnumClass myEnumClass = new MyEnumClass(); String str1 = JSONObject.valueToString(myEnum); assertTrue("actual myEnum: "+str1+" expected: "+expectedStr1, str1.equals(expectedStr1)); String str2 = JSONObject.valueToString(myEnumField); assertTrue("actual myEnumField: "+str2+" expected: "+expectedStr2, str2.equals(expectedStr2)); /** * However, an enum within another class will not be rendered * unless that class overrides default toString() */ String expectedStr3 = "\"org.json.junit.MyEnumClass@"; myEnumClass.setMyEnum(MyEnum.VAL1); myEnumClass.setMyEnumField(MyEnumField.VAL1); String str3 = JSONObject.valueToString(myEnumClass); assertTrue("actual myEnumClass: "+str3+" expected: "+expectedStr3, str3.startsWith(expectedStr3)); } /** * In whatever form the enum was added to the JSONObject or JSONArray, * json[Object|Array].toString should serialize it in a reasonable way. */ @Test public void enumToString() { MyEnum myEnum = MyEnum.VAL2; JSONObject jsonObject = new JSONObject(myEnum); String expectedStr = "{}"; assertTrue("myEnum toString() should be empty", expectedStr.equals(jsonObject.toString())); MyEnumField myEnumField = MyEnumField.VAL2; jsonObject = new JSONObject(myEnumField); // validate JSON content Object doc = Configuration.defaultConfiguration().jsonProvider().parse(jsonObject.toString()); assertTrue("expected 2 top level items", ((Map)(JsonPath.read(doc, "$"))).size() == 2); assertTrue("expected val 2", "val 2".equals(jsonObject.query("/value"))); assertTrue("expected 2", Integer.valueOf(2).equals(jsonObject.query("/intVal"))); MyEnumClass myEnumClass = new MyEnumClass(); myEnumClass.setMyEnum(MyEnum.VAL1); myEnumClass.setMyEnumField(MyEnumField.VAL3); jsonObject = new JSONObject(myEnumClass); // validate JSON content doc = Configuration.defaultConfiguration().jsonProvider().parse(jsonObject.toString()); assertTrue("expected 2 top level items", ((Map)(JsonPath.read(doc, "$"))).size() == 2); assertTrue("expected VAL3", "VAL3".equals((JsonPath.read(doc, "$.myEnumField")))); assertTrue("expected VAL1", "VAL1".equals((JsonPath.read(doc, "$.myEnum")))); String [] names = JSONObject.getNames(myEnum); jsonObject = new JSONObject(myEnum, names); // validate JSON content doc = Configuration.defaultConfiguration().jsonProvider().parse(jsonObject.toString()); assertTrue("expected 3 top level items", ((Map)(JsonPath.read(doc, "$"))).size() == 3); assertTrue("expected VAL1", MyEnum.VAL1.equals(jsonObject.query("/VAL1"))); assertTrue("expected VAL2", MyEnum.VAL2.equals(jsonObject.query("/VAL2"))); assertTrue("expected VAL3", MyEnum.VAL3.equals(jsonObject.query("/VAL3"))); names = JSONObject.getNames(myEnumField); jsonObject = new JSONObject(myEnumField, names); // validate JSON content doc = Configuration.defaultConfiguration().jsonProvider().parse(jsonObject.toString()); assertTrue("expected 3 top level items", ((Map)(JsonPath.read(doc, "$"))).size() == 3); assertTrue("expected VAL1", MyEnumField.VAL1.equals(jsonObject.query("/VAL1"))); assertTrue("expected VAL2", MyEnumField.VAL2.equals(jsonObject.query("/VAL2"))); assertTrue("expected VAL3", MyEnumField.VAL3.equals(jsonObject.query("/VAL3"))); expectedStr = "{\"myEnum\":\"VAL2\", \"myEnumField\":\"VAL2\"}"; jsonObject = new JSONObject(); jsonObject.putOpt("myEnum", myEnum); jsonObject.putOnce("myEnumField", myEnumField); // validate JSON content doc = Configuration.defaultConfiguration().jsonProvider().parse(jsonObject.toString()); assertTrue("expected 2 top level items", ((Map)(JsonPath.read(doc, "$"))).size() == 2); assertTrue("expected VAL2", MyEnum.VAL2.equals(jsonObject.query("/myEnum"))); assertTrue("expected VAL2", MyEnumField.VAL2.equals(jsonObject.query("/myEnumField"))); JSONArray jsonArray = new JSONArray(); jsonArray.put(myEnum); jsonArray.put(1, myEnumField); // validate JSON content doc = Configuration.defaultConfiguration().jsonProvider().parse(jsonArray.toString()); assertTrue("expected 2 top level items", ((List)(JsonPath.read(doc, "$"))).size() == 2); assertTrue("expected VAL2", MyEnum.VAL2.equals(jsonArray.query("/0"))); assertTrue("expected VAL2", MyEnumField.VAL2.equals(jsonArray.query("/1"))); } /** * Wrap should handle enums exactly as a value type like Integer, Boolean, or String. */ @Test public void wrap() { assertTrue("simple enum has no getters", JSONObject.wrap(MyEnum.VAL2) instanceof MyEnum); MyEnumField myEnumField = MyEnumField.VAL2; JSONObject jsonObject = new JSONObject(); jsonObject.put("enum",myEnumField); // validate JSON content Object doc = Configuration.defaultConfiguration().jsonProvider().parse(jsonObject.toString()); assertTrue("expected 1 top level items", ((Map)(JsonPath.read(doc, "$"))).size() == 1); assertTrue("expected VAL2", MyEnumField.VAL2.equals(jsonObject.query("/enum"))); MyEnumClass myEnumClass = new MyEnumClass(); myEnumClass.setMyEnum(MyEnum.VAL1); myEnumClass.setMyEnumField(MyEnumField.VAL3); jsonObject = (JSONObject)JSONObject.wrap(myEnumClass); // validate JSON content doc = Configuration.defaultConfiguration().jsonProvider().parse(jsonObject.toString()); assertTrue("expected 2 top level items", ((Map)(JsonPath.read(doc, "$"))).size() == 2); assertTrue("expected VAL3", "VAL3".equals((JsonPath.read(doc, "$.myEnumField")))); assertTrue("expected VAL1", "VAL1".equals((JsonPath.read(doc, "$.myEnum")))); assertTrue("expecting MyEnumField.VAL3", MyEnumField.VAL3.equals(jsonObject.query("/myEnumField"))); assertTrue("expecting MyEnum.VAL1", MyEnum.VAL1.equals(jsonObject.query("/myEnum"))); } /** * It was determined that some API methods should be added to * support enums:
* JSONObject.getEnum(class, key)
* JSONObject.optEnum(class, key)
* JSONObject.optEnum(class, key, default)
* JSONArray.getEnum(class, index)
* JSONArray.optEnum(class, index)
* JSONArray.optEnum(class, index, default)
*

* Exercise these enum API methods on JSONObject and JSONArray */ @Test public void enumAPI() { MyEnumClass myEnumClass = new MyEnumClass(); myEnumClass.setMyEnum(MyEnum.VAL1); MyEnumField myEnumField = MyEnumField.VAL2; JSONObject jsonObject = new JSONObject(); jsonObject.put("strKey", "value"); jsonObject.put("enumKey", myEnumField); jsonObject.put("enumClassKey", myEnumClass); // get a plain old enum MyEnumField actualEnum = jsonObject.getEnum(MyEnumField.class, "enumKey"); assertTrue("get myEnumField", actualEnum == MyEnumField.VAL2); // try to get the wrong value try { actualEnum = jsonObject.getEnum(MyEnumField.class, "strKey"); assertTrue("should throw an exception for wrong key", false); } catch (Exception ignored) {} // get a class that contains an enum MyEnumClass actualEnumClass = (MyEnumClass)jsonObject.get("enumClassKey"); assertTrue("get enum", actualEnumClass.getMyEnum() == MyEnum.VAL1); // opt a plain old enum actualEnum = jsonObject.optEnum(MyEnumField.class, "enumKey"); assertTrue("opt myEnumField", actualEnum == MyEnumField.VAL2); // opt the wrong value actualEnum = jsonObject.optEnum(MyEnumField.class, "strKey"); assertTrue("opt null", actualEnum == null); // opt a class that contains an enum actualEnumClass = (MyEnumClass)jsonObject.opt("enumClassKey"); assertTrue("get enum", actualEnumClass.getMyEnum() == MyEnum.VAL1); // opt with default a plain old enum actualEnum = jsonObject.optEnum(MyEnumField.class, "enumKey", null); assertTrue("opt myEnumField", actualEnum == MyEnumField.VAL2); // opt with default the wrong value actualEnum = jsonObject.optEnum(MyEnumField.class, "strKey", null); assertTrue("opt null", actualEnum == null); // opt with default an index that does not exist actualEnum = jsonObject.optEnum(MyEnumField.class, "noKey", null); assertTrue("opt null", actualEnum == null); /** * Exercise the proposed enum API methods on JSONArray */ JSONArray jsonArray = new JSONArray(); jsonArray.put("value"); jsonArray.put(myEnumField); jsonArray.put(myEnumClass); // get a plain old enum actualEnum = jsonArray.getEnum(MyEnumField.class, 1); assertTrue("get myEnumField", actualEnum == MyEnumField.VAL2); // try to get the wrong value try { actualEnum = jsonArray.getEnum(MyEnumField.class, 0); assertTrue("should throw an exception for wrong index", false); } catch (Exception ignored) {} // get a class that contains an enum actualEnumClass = (MyEnumClass)jsonArray.get(2); assertTrue("get enum", actualEnumClass.getMyEnum() == MyEnum.VAL1); // opt a plain old enum actualEnum = jsonArray.optEnum(MyEnumField.class, 1); assertTrue("opt myEnumField", actualEnum == MyEnumField.VAL2); // opt the wrong value actualEnum = jsonArray.optEnum(MyEnumField.class, 0); assertTrue("opt null", actualEnum == null); // opt a class that contains an enum actualEnumClass = (MyEnumClass)jsonArray.opt(2); assertTrue("get enum", actualEnumClass.getMyEnum() == MyEnum.VAL1); // opt with default a plain old enum actualEnum = jsonArray.optEnum(MyEnumField.class, 1, null); assertTrue("opt myEnumField", actualEnum == MyEnumField.VAL2); // opt with default the wrong value actualEnum = jsonArray.optEnum(MyEnumField.class, 0, null); assertTrue("opt null", actualEnum == null); // opt with default an index that does not exist actualEnum = jsonArray.optEnum(MyEnumField.class, 3, null); assertTrue("opt null", actualEnum == null); } }