title: Error parsing json from POST request using GSON when mapped against a getter/setter
body: <p>When sending a JSON POST request to my RESful API running Jetty, I'm parsing the JSON data received in the request and attempting to map it against my constructor class. The problem arises when the data received isn't in the exact layout of the getter/setter.</p>
  
  <p>It's almost like it's not actually mapping it against the getter/setter, This is what I'm using to parse the JSON from the request when it comes in:</p>
  
  <pre><code>Vehicle v = new Gson().fromJson(req.getReader(), Vehicle.class);
  </code></pre>
  
  <p>I expected the output to parse correctly, since the API should just read each key and map it against the getter and setter so I could access it like</p>
  
  <pre><code>v.getVehicle_id();
  </code></pre>
  
  <p>However when sending JSON data which isn't in the exact layout of the getter/setter. It causes a error as it expects the first value coming in to be "vehicle_id" with a integer, when sometimes it's getting a different value, such as "colour" with a string of "black".</p>
  
  <p>Is there a better way to parse the JSON when it's coming in? I have to use Gson as it's for a University assignment.</p>
  
  <p>This is my Vehicle.class </p>
  
  <pre><code>public class Vehicle {
  
      public Vehicle() {
      }
  
      /*
       * Maps the database into this class so they can be used in the getter/setter, they are private as other classes don't need access to them
       * This is because they go through the getters/setters, which are public.
       */
      private int vehicle_id;
      private String make;
      private String model;
      private int year;
      private int price;
      private String license_number;
      private String colour;
      private int number_doors;
      private String transmission;
      private int mileage;
      private String fuel_type;
      private int engine_size;
      private String body_style;
      private String condition;
      private String notes;
  
      public Vehicle(int vehicle_id, String make, String model, int
              year, int price, String license_number, String colour, int
              number_doors, String transmission, int mileage, String fuel_type,
              int engine_size, String body_style, String condition, String
              notes) {
  
              this.vehicle_id = vehicle_id;
              this.make = make;
              this.model = model;
              this.year = year;
              this.price = price;
              this.license_number = license_number;
              this.colour = colour;
              this.number_doors = number_doors;
              this.transmission = transmission;
              this.mileage = mileage;
              this.fuel_type = fuel_type;
              this.engine_size = engine_size;
              this.body_style = body_style;
              this.condition = condition;
              this.notes = notes;
          }
  
      /*
       * Creates the getter and setters which map to the database so they can be used by the Controller to store and retrieve data when needed.
       */
  
      public int getVehicle_id() {
          return vehicle_id;
      }
  
      public void setVehicle_id(int vehicle_id) {
          this.vehicle_id = vehicle_id;
      }
  
      public String getMake() {
          return make;
      }
  
      public void setMake(String make) {
          this.make = make;
      }
  
      public String getModel() {
          return model;
      }
  
      public void setModel(String model) {
          this.model = model;
      }
  
      public int getYear() {
          return year;
      }
  
      public void setYear(int year) {
          this.year = year;
      }
  
      public int getPrice() {
          return price;
      }
  
      public void setPrice(int price) {
          this.price = price;
      }
  
      public String getLicense_number() {
          return license_number;
      }
  
      public void setLicense_number(String license_number) {
          this.license_number = license_number;
      }
  
      public String getColour() {
          return colour;
      }
  
      public void setColour(String colour) {
          this.colour = colour;
      }
  
      public int getNumber_doors() {
          return number_doors;
      }
  
      public void setNumber_doors(int number_doors) {
          this.number_doors = number_doors;
      }
  
      public String getTransmission() {
          return transmission;
      }
  
      public void setTransmission(String transmission) {
          this.transmission = transmission;
      }
  
      public int getMileage() {
          return mileage;
      }
  
      public void setMileage(int mileage) {
          this.mileage = mileage;
      }
  
      public String getFuel_type() {
          return fuel_type;
      }
  
      public void setFuel_type(String fuel_type) {
          this.fuel_type = fuel_type;
      }
  
      public int getEngine_size() {
          return engine_size;
      }
  
      public void setEngine_size(int engine_size) {
          this.engine_size = engine_size;
      }
  
      public String getBody_style() {
          return body_style;
      }
  
      public void setBody_style(String body_style) {
          this.body_style = body_style;
      }
  
      public String getCondition() {
          return condition;
      }
  
      public void setCondition(String condition) {
          this.condition = condition;
      }
  
      public String getNotes() {
          return notes;
      }
  
      public void setNotes(String notes) {
          this.notes = notes;
      }
  }
  </code></pre>
  
  <p>This is my JSON data</p>
  
  <pre><code>{"colour":"Black","license_number":"DA98 7BK","body_style":"Small","engine_size":"1","number_doors":"Black","transmission":"manual","year":"2009","price":"10000","make":"Ford","vehicle_id":"8","notes":"Old","fuel_type":"Petrol","condition":"Old","mileage":"20000","model":"Ka"}
  </code></pre>
  
  <p>This is the error I get from the server</p>
  
  <blockquote>
    <p>2019-03-28 12:51:41.703:WARN:oejs.HttpChannel:qtp1225358173-9: /vehicledb/api
    com.google.gson.JsonSyntaxException: java.lang.NumberFormatException: For input string: "Black"  </p>
    
    <p>at com.google.gson.internal.bind.TypeAdapters$7.read(TypeAdapters.java:241)<br>
    at com.google.gson.internal.bind.TypeAdapters$7.read(TypeAdapters.java:231)<br>
    at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:93)<br>
    at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:172)<br>
    at com.google.gson.Gson.fromJson(Gson.java:803)<br>
    at com.google.gson.Gson.fromJson(Gson.java:741)<br>
    at servlets.ServletApi.doPut(ServletApi.java:120)<br>
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)<br>
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)<br>
    at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:841)<br>
    at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:535)<br>
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)<br>
    at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)<br>
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)<br>
    at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:190)<br>
    at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1595)<br>
    at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:188)<br>
    at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1253)<br>
    at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:168)<br>
    at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:473)
        at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1564)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:166)
        at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1155)
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
        at org.eclipse.jetty.server.Server.handle(Server.java:564)
        at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:317)
        at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:251)
        at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:279)
        at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:110)
        at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:124)
        at org.eclipse.jetty.util.thread.Invocable.invokePreferred(Invocable.java:128)
        at org.eclipse.jetty.util.thread.Invocable$InvocableExecutor.invoke(Invocable.java:222)
        at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:294)
        at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.produce(EatWhatYouKill.java:126)
        at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:672)
        at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:590)
        at java.lang.Thread.run(Thread.java:748)
    Caused by: 
    java.lang.NumberFormatException: For input string: "Black"
        at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:2043)
        at sun.misc.FloatingDecimal.parseDouble(FloatingDecimal.java:110)
        at java.lang.Double.parseDouble(Double.java:538)
        at com.google.gson.stream.JsonReader.nextInt(JsonReader.java:1178)
        at com.google.gson.internal.bind.TypeAdapters$7.read(TypeAdapters.java:239)
        at com.google.gson.internal.bind.TypeAdapters$7.read(TypeAdapters.java:231)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:93)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:172)
        at com.google.gson.Gson.fromJson(Gson.java:803)
        at com.google.gson.Gson.fromJson(Gson.java:741)
        at servlets.ServletApi.doPut(ServletApi.java:120)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
        at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:841)
        at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:535)
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
        at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:190)
        at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1595)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:188)
        at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1253)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:168)
        at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:473)
        at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1564)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:166)
        at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1155)
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
        at org.eclipse.jetty.server.Server.handle(Server.java:564)
        at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:317)
        at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:251)
        at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:279)
        at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:110)
        at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:124)
        at org.eclipse.jetty.util.thread.Invocable.invokePreferred(Invocable.java:128)
        at org.eclipse.jetty.util.thread.Invocable$InvocableExecutor.invoke(Invocable.java:222)
        at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:294)
        at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.produce(EatWhatYouKill.java:126)
        at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:672)
        at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:590)
        at java.lang.Thread.run(Thread.java:748)```</p>
  </blockquote>