Java tutorial
/* * Copyright 2010 Proofpoint, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.proofpoint.json; import com.fasterxml.jackson.annotation.JsonProperty; import com.fasterxml.jackson.core.JsonParser; import com.fasterxml.jackson.core.JsonToken; import com.fasterxml.jackson.core.type.TypeReference; import com.fasterxml.jackson.databind.DeserializationContext; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.deser.std.StdScalarDeserializer; import com.fasterxml.jackson.databind.ser.std.ToStringSerializer; import com.google.common.base.Joiner; import com.google.common.base.Objects; import com.google.common.base.Splitter; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableSet; import com.google.common.collect.Maps; import com.google.inject.Binder; import com.google.inject.Guice; import com.google.inject.Injector; import com.google.inject.Module; import org.joda.time.DateTime; import org.joda.time.format.ISODateTimeFormat; import org.testng.annotations.BeforeMethod; import org.testng.annotations.Test; import java.io.IOException; import java.util.List; import java.util.Map; import static com.proofpoint.json.JsonBinder.jsonBinder; import static org.joda.time.DateTimeZone.UTC; import static org.testng.Assert.assertEquals; public class TestJsonModule { public static final Car CAR = new Car().setMake("BMW").setModel("M3").setYear(2011) .setPurchased(new DateTime().withZone(UTC)).setNotes("sweet!").setNameList(superDuper("d*a*i*n")); private ObjectMapper objectMapper; @BeforeMethod public void setUp() throws Exception { Injector injector = Guice.createInjector(new JsonModule(), new Module() { @Override public void configure(Binder binder) { jsonBinder(binder).addSerializerBinding(SuperDuperNameList.class) .toInstance(ToStringSerializer.instance); jsonBinder(binder).addDeserializerBinding(SuperDuperNameList.class) .to(SuperDuperNameListDeserializer.class); } }); objectMapper = injector.getInstance(ObjectMapper.class); } @Test public void testJsonCodecFactoryBinding() throws Exception { Injector injector = Guice.createInjector(new JsonModule()); JsonCodecFactory codecFactory = injector.getInstance(JsonCodecFactory.class); Person.validatePersonJsonCodec(codecFactory.jsonCodec(Person.class)); Person.validatePersonListJsonCodec(codecFactory.listJsonCodec(Person.class)); Person.validatePersonMapJsonCodec(codecFactory.mapJsonCodec(String.class, Person.class)); } @Test public void testSetup() throws Exception { assertEquals(CAR, CAR); String json = objectMapper.writeValueAsString(CAR); Car actual = objectMapper.readValue(json, Car.class); assertEquals(actual, CAR); } @Test public void testFieldDetection() throws Exception { Map<String, Object> actual = objectMapper.readValue(objectMapper.writeValueAsString(CAR), Map.class); // notes is not annotated so should not be included // color is null so should not be included assertEquals(actual.keySet(), ImmutableSet.of("make", "model", "year", "purchased", "nameList")); } @Test public void testDateTimeRendered() throws Exception { Map<String, Object> actual = objectMapper.readValue(objectMapper.writeValueAsString(CAR), Map.class); assertEquals(actual.get("purchased"), ISODateTimeFormat.dateTime().print(CAR.getPurchased())); } @Test public void testGuavaRoundTrip() throws Exception { ImmutableList<Integer> list = ImmutableList.of(3, 5, 8); String json = objectMapper.writeValueAsString(list); ImmutableList<Integer> actual = objectMapper.readValue(json, new TypeReference<ImmutableList<Integer>>() { }); assertEquals(actual, list); } @Test public void testIgnoreUnknownFields() throws Exception { Map<String, Object> data = Maps .newHashMap(objectMapper.readValue(objectMapper.writeValueAsString(CAR), Map.class)); // add an unknown field data.put("unknown", "bogus"); // Jackson should deserialize the object correctly with the extra unknown data assertEquals(objectMapper.readValue(objectMapper.writeValueAsString(data), Car.class), CAR); } public static class Car { // These fields are public to make sure that Jackson is ignoring them public String make; public String model; public int year; public DateTime purchased; // property that will be null to verify that null fields are not rendered public String color; // non-json property to verify that auto-detection is disabled public String notes; // property that requires special serializer and deserializer public SuperDuperNameList nameList; @JsonProperty public String getMake() { return make; } @JsonProperty public Car setMake(String make) { this.make = make; return this; } @JsonProperty public String getModel() { return model; } @JsonProperty public Car setModel(String model) { this.model = model; return this; } @JsonProperty public int getYear() { return year; } @JsonProperty public Car setYear(int year) { this.year = year; return this; } @JsonProperty public DateTime getPurchased() { return purchased; } @JsonProperty public Car setPurchased(DateTime purchased) { this.purchased = purchased; return this; } @JsonProperty public String getColor() { return color; } @JsonProperty public Car setColor(String color) { this.color = color; return this; } @JsonProperty public SuperDuperNameList getNameList() { return nameList; } @JsonProperty public Car setNameList(SuperDuperNameList nameList) { this.nameList = nameList; return this; } // this field should not be written public String getNotes() { return notes; } public Car setNotes(String notes) { this.notes = notes; return this; } @Override public boolean equals(Object o) { if (this == o) { return true; } if (!(o instanceof Car)) { return false; } Car car = (Car) o; if (year != car.year) { return false; } if (color != null ? !color.equals(car.color) : car.color != null) { return false; } if (make != null ? !make.equals(car.make) : car.make != null) { return false; } if (model != null ? !model.equals(car.model) : car.model != null) { return false; } if (nameList != null ? !nameList.equals(car.nameList) : car.nameList != null) { return false; } if (purchased != null ? !purchased.equals(car.purchased) : car.purchased != null) { return false; } return true; } @Override public int hashCode() { int result = make != null ? make.hashCode() : 0; result = 31 * result + (model != null ? model.hashCode() : 0); result = 31 * result + year; result = 31 * result + (purchased != null ? purchased.hashCode() : 0); result = 31 * result + (color != null ? color.hashCode() : 0); result = 31 * result + (nameList != null ? nameList.hashCode() : 0); return result; } @Override public String toString() { return Objects.toStringHelper(this).add("make", make).add("model", model).add("year", year) .add("purchased", purchased).add("color", color).add("notes", notes).add("nameList", nameList) .toString(); } } public static class SuperDuperNameList { private List<String> name; private SuperDuperNameList(String superDuperNameList) { this(superDuperNameList, null); } private SuperDuperNameList(String superDuperNameList, Object stopJacksonFromUsingStringConstructor) { this.name = ImmutableList.copyOf(Splitter.on('*').split(superDuperNameList)); } public List<String> getName() { return name; } @Override public String toString() { return Joiner.on("*").join(name); } @Override public boolean equals(Object o) { if (this == o) { return true; } if (!(o instanceof SuperDuperNameList)) { return false; } SuperDuperNameList that = (SuperDuperNameList) o; if (!name.equals(that.name)) { return false; } return true; } @Override public int hashCode() { return name.hashCode(); } } public final static class SuperDuperNameListDeserializer extends StdScalarDeserializer<SuperDuperNameList> { public SuperDuperNameListDeserializer() { super(SuperDuperNameList.class); } @Override public SuperDuperNameList deserialize(JsonParser jp, DeserializationContext context) throws IOException { JsonToken token = jp.getCurrentToken(); if (token == JsonToken.VALUE_STRING) { return new SuperDuperNameList(jp.getText(), null); } throw context.mappingException(handledType()); } } public static SuperDuperNameList superDuper(String superDuperNameList) { return new SuperDuperNameList(superDuperNameList, null); } }