作者
xiejava1018
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昨天在與對端系統(tǒng)調接口的時候，對端系統(tǒng)對我們傳過去的json串老是處理不了，后來查原因是應為我們傳過去的json串里有json對象數(shù)組，因為我們的json串存在表里的，取出來是作為json字符串放到json數(shù)組里的，所以帶了雙引號，對端認為是字符串，不是json對象所以處理不了。[{'cardName':'bankCard1','cardCode':'888888888','cardValue':99999999},{'cardName':'bankCard2','cardCode':'999999999','cardValue':222222222}] 這種是正確的json對象數(shù)組，['{'cardName':'bankCard1','cardCode':'888888888','cardValue':99999999}','{'cardName':'bankCard2','cardCode':'999999999','cardValue':222222222}']，這種是json字符串數(shù)組。
以下總結一下java轉JSON串的幾種方式：
1、將java對象轉成json串
2、通過JSONObject生成json串
3、通過json字符串生成json串
代碼通過阿里的fastjson包實現(xiàn)。
代碼如下：
1、Person類，包含Crad的List
package com.doit8.test.jsontest.pojo;
import java.util.ArrayList;
import java.util.List;
public class Person {
private String username;
private String email;
private String sex;
private int age;
private List<Card> cardList=new ArrayList<Card>();
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public List<Card> getCardList() {
return cardList;
}
public void setCardList(List<Card> cardList) {
this.cardList = cardList;
}
}2、Card類
package com.doit8.test.jsontest.pojo;
public class Card {
private String cardName;
private String cardCode;
private Integer cardValue;
public String getCardName() {
return cardName;
}
public void setCardName(String cardName) {
this.cardName = cardName;
}
public String getCardCode() {
return cardCode;
}
public void setCardCode(String cardCode) {
this.cardCode = cardCode;
}
public Integer getCardValue() {
return cardValue;
}
public void setCardValue(Integer cardValue) {
this.cardValue = cardValue;
}
}3、JSON處理測試類
package com.doit8.test.jsontest;
import java.util.ArrayList;
import java.util.List;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import com.doit8.test.jsontest.pojo.Card;
import com.doit8.test.jsontest.pojo.Person;
/**
* JSON轉換
*
*/
public class App
{
public static void main( String[] args )
{
//1。通過對象生成JSON串，對象里包含對象數(shù)組轉成JSON串。
Person person=new Person();
person.setUsername('xiejava');
person.setSex('man');
person.setAge(38);
person.setEmail('xiejava@ishareread.com');
Card card1=new Card();
card1.setCardName('bankCard1');
card1.setCardCode('888888888');
card1.setCardValue(99999999);
Card card2=new Card();
card2.setCardName('bankCard1');
card2.setCardCode('999999999');
card2.setCardValue(222222222);
//對象數(shù)組
List<Card> cards=new ArrayList<Card>();
cards.add(card1);
cards.add(card2);
person.setCardList(cards);
String json = JSON.toJSON(person).toString();
System.out.println(json);
//2.通過JSON對象生成JSON串
JSONObject jObject=new JSONObject();
jObject.put('username', 'xiejava');
jObject.put('sex', 'man');
jObject.put('age', 38);
jObject.put('email', 'xiejava@ishareread.com');
//通過JSONArray包裝對象數(shù)組
JSONArray jArray=new JSONArray();
jArray.addAll(cards);
jObject.put('cardList', jArray);
String json2=jObject.toJSONString();
System.out.println(json2);
//3.通過JSON對象生成JSON串
JSONObject jObject2=new JSONObject();
jObject2.put('username', 'xiejava');
jObject2.put('sex', 'man');
jObject2.put('age', 38);
jObject2.put('email', 'xiejava@ishareread.com');
//構造JSON字符串
String cardjsonStr1='{\'cardName\':\'bankCard1\',\'cardCode\':\'888888888\',\'cardValue\':99999999}';
String cardjsonStr2='{\'cardName\':\'bankCard2\',\'cardCode\':\'999999999\',\'cardValue\':222222222}';
JSON.parseObject(cardjsonStr1);
JSONArray jArray2=new JSONArray();
//將JSON字符串轉成JSON對象，加入到JSONArray，[注意一定要用JSON.parseObject()方法轉換成JSON對象，否則還是字符串，轉成JSON串的時候會帶雙引號。]
jArray2.add(JSON.parseObject(cardjsonStr1));
jArray2.add(JSON.parseObject(cardjsonStr2));
jObject2.put('cardList', jArray2);
String json3=jObject2.toJSONString();
System.out.println(json3);
}
}pom.xml中引入fastjson包
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.15</version>
</dependency>運行結果
{'cardList':[{'cardName':'bankCard1','cardCode':'888888888','cardValue':99999999},{'cardName':'bankCard1','cardCode':'999999999','cardValue':222222222}],'sex':'man','age':38,'email':'xiejava@ishareread.com','username':'xiejava'}
{'cardList':[{'cardCode':'888888888','cardName':'bankCard1','cardValue':99999999},{'cardCode':'999999999','cardName':'bankCard1','cardValue':222222222}],'sex':'man','age':38,'email':'xiejava@ishareread.com','username':'xiejava'}
{'cardList':[{'cardName':'bankCard1','cardCode':'888888888','cardValue':99999999},{'cardName':'bankCard2','cardCode':'999999999','cardValue':222222222}],'sex':'man','age':38,'email':'xiejava@ishareread.com','username':'xiejava'}聯(lián)系客服
