java以http post object方式发送，play framework接收
我尝试用java把object通过http post 方式发送到play framework连接的mysql中，我不太清楚play framework中的 id怎么处理，返回的错误如下
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java送信端

Exception in thread "main" java.io.IOException: Server returned HTTP response code: 500 for URL: http://localhost:9000/Application/show
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
at sqlPost.SqlPost.httpPost(SqlPost.java:37)
at sqlPost.SqlPost.main(SqlPost.java:47)
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play framework端

Internal Server Error (500) for request POST /Application/show

Execution exception (In /app/controllers/Application.java around line 27)
IllegalArgumentException occured : id to load is required for loading

play.exceptions.JavaExecutionException: id to load is required for loading
  at play.mvc.ActionInvoker.invoke(ActionInvoker.java:231)
  at Invocation.HTTP Request(Play!)
Caused by: java.lang.IllegalArgumentException: id to load is required for loadin
g
  at org.hibernate.event.LoadEvent.<init>(LoadEvent.java:89)
  at org.hibernate.event.LoadEvent.<init>(LoadEvent.java:61)
  at org.hibernate.impl.SessionImpl.get(SessionImpl.java:1002)
  at org.hibernate.impl.SessionImpl.get(SessionImpl.java:998)
  at org.hibernate.ejb.AbstractEntityManagerImpl.find(AbstractEntityManage
rImpl.java:614)
  at org.hibernate.ejb.AbstractEntityManagerImpl.find(AbstractEntityManage
rImpl.java:589)
  at play.db.jpa.JPQL.findById(JPQL.java:36)
  at models.AuctionItem.findById(AuctionItem.java)
  at controllers.Application.show(Application.java:27)
  at play.mvc.ActionInvoker.invokeWithContinuation(ActionInvoker.java:548)

  at play.mvc.ActionInvoker.invoke(ActionInvoker.java:502)
  at play.mvc.ActionInvoker.invokeControllerMethod(ActionInvoker.java:478)

  at play.mvc.ActionInvoker.invokeControllerMethod(ActionInvoker.java:473)

  at play.mvc.ActionInvoker.invoke(ActionInvoker.java:161)
  ... 1 more
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java发送端代码
package sqlPost;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.ObjectOutputStream;
import java.io.OutputStreamWriter;
import java.net.URL;
import java.net.URLConnection;

public class SqlPost {
public void httpPost() throws IOException {
// Create Post String
// String data = URLEncoder.encode("myName", "UTF-8") + "="+
// URLEncoder.encode("ttgg", "UTF-8");

AuctionItem item = new AuctionItem();
item.title = "Football";
item.days = 11;
item.startBid = (float) 1;
item.buyNowEnabled = true;
item.buyNowPrice = (float) 20;
item.deliveryCost = (float) 5;
item.description = "this football is a new one";

// Send Data To Page
URL url = new URL("http://localhost:9000/Application/show");
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
// OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
ObjectOutputStream oos = new ObjectOutputStream(conn.getOutputStream());
oos.writeObject(item);
oos.flush();

// Get The Response
BufferedReader rd = new BufferedReader(new InputStreamReader(
conn.getInputStream()));
String line;
while ((line = rd.readLine()) != null) {
System.out.println(line);
// you Can Break The String Down Here
}
}

public static void main(String args[]) throws Exception {