json转换求和问题

Question

product=[{id:1111,amount:0.01},{id:2222,amount:0.01}，{id:3333,amount:2.1}] 如何取得所有的id 并以“”分隔形式拼成字符串，同时对所有的amount求和计算

Answer 1

[code="java"]
import java.util.List;

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
import net.sf.json.util.JSONUtils;

public class Account {

private String id;
private Double amount;
public String getId() {
    return id;
}
public void setId(String id) {
    this.id = id;
}
public Double getAmount() {
    return amount;
}
public void setAmount(Double amount) {
    this.amount = amount;
}

public static void main(String[] args) {

    String json = "[{id:1111,amount:0.01},{id:2222,amount:0.01},{id:3333,amount:2.1}]";
    JSONArray jsonArray = JSONArray.fromObject(json);
    List<Account> list = (List<Account>)JSONArray.toCollection(jsonArray,Account.class);
    String ids = "";
    Double amount =0.0;
    for(Account a:list){
        System.out.println(a.getId());
        System.out.println(a.getAmount());
        ids+=a.getId()+",";
        amount+=a.getAmount();
    }
    ids = ids.substring(0,ids.length()-1);
    System.out.println(ids);
    System.out.println(amount);
}

}

[/code]

json-lib-2.2.3.jar,ezmorph-1.0.2.jar下测试有效。