Java、JS解析JSON对象、JSON数组

曾经终败给现在 2023-02-10 05:07 24阅读 0赞

# 一：三种JSON格式 #

**基本类型**

{ 
        "student": "张三",
        "age": 18,
        "sex": true
    }

**数组类型**

[
        { 
            "student": "张三",
            "age": 18,
            "sex": true
        },
        { 
            "student": "李四",
            "age": 19,
            "sex": false
        }
    ]

**对象嵌套**

{ 
        "student": "张三丰",
        "school": { 
        "class":"7班",
        "floor": "5层"
    	},
    	"students": [
            { 
                "student": "张三",
                "age": 18,
                "sex": true
            },
            { 
                "student": "李四",
                "age": 19,
                "sex": false
            }
        ]
    }

# 二：利用alibaba.fastjson解析JSONObject、JSONArray #

![在这里插入图片描述][20200520104446871.jpg]

package com.test1;
    import com.alibaba.fastjson.JSON;
    import com.alibaba.fastjson.JSONArray;
    import com.alibaba.fastjson.JSONObject;
    public class TestJsonArray { 
    	public static void main(String[] args) { 
    		// json字符串-简单对象型
    		final String JSON_OBJ_STR = "{\"studentName\":\"lily\",\"studentAge\":12}";
    		// json字符串-数组类型
    		final String JSON_ARRAY_STR = "[{\"studentName\":\"lily\",\"studentAge\":12},{\"studentName\":\"lucy\",\"studentAge\":15}]";
    
    		testJSONStrToJSONArray1(JSON_ARRAY_STR);
    		testJSONStrToJSONObject(JSON_OBJ_STR);
    	}
    
    	/** * json字符串-数组类型与JSONArray之间的转换 */
    	public static void testJSONStrToJSONArray1(String JSON_ARRAY_STR) { 
    
    		JSONArray jsonArray = JSON.parseArray(JSON_ARRAY_STR);
    		// JSONArray jsonArray1 =JSONArray.parseArray(JSON_ARRAY_STR);//因为JSONArray继承了JSON，所以这样也是可以的
    		// 遍历方式1
    		int size = jsonArray.size();
    		for (int i = 0; i < size; i++) { 
    			JSONObject jsonObject = jsonArray.getJSONObject(i);
    			System.out.println(jsonObject.getString("studentName") + ":" + jsonObject.getInteger("studentAge"));
    		}
    
    		// 遍历方式2
    		for (Object obj : jsonArray) { 
    			JSONObject jsonObject = (JSONObject) obj;
    			System.out.println(jsonObject.getString("studentName") + ":" + jsonObject.getInteger("studentAge"));
    		}
    	}
    
    	/** * json字符串-简单对象型与JSONObject之间的转换 */
    	public static void testJSONStrToJSONObject(String JSON_OBJ_STR) { 
    		
    		 JSONObject jsonObject = JSON.parseObject(JSON_OBJ_STR);
    		 //JSONObject jsonObject1 = JSONObject.parseObject(JSON_OBJ_STR); //因为JSONObject继承了JSON，所以这样也是可以的
    		 System.out.println(jsonObject.getString("studentName") + ":" + jsonObject.getInteger("studentAge"));
        }
    }

# 三：利用json.JSONObject解析JSONObject #

package com.test1;
    import org.json.JSONException;
    import org.json.JSONObject;
    public class TestJsonObject { 
    	 public static void main(String[] args) throws JSONException { 
    	        //记得转义
    	        String jsonStr="{\"studentName\":\"zhangsanfeng\",\"age\":18,\"school\":\"武当山大学\"}";
    	        JSONObject jsonObj = new JSONObject(jsonStr);
    	        int age = jsonObj.getInt("age");
    	        String school = jsonObj.optString("school");
    	        String studentName= (String) jsonObj.get("studentName");
    	        System.out.println(age);
    	        System.out.println(school);
    	        System.out.println(studentName);
    	    }
    }

解析如下形式json数组  
![在这里插入图片描述][20201229112519905.png]

JSONObject json = new JSONObject(data);
    			JSONArray rows = json.optJSONArray("IT_QUERY");
    			for (int i = 0; i < rows.length(); i++) { 
    				JSONObject row = rows.optJSONObject(i);
    				//打印出WERKS字段值
    				System.out.println(row.optString("WERKS"));
    			}

# 四：将json数组后台解析分组，比如按照OrderNum #

数据库中数据存储如下：  
![在这里插入图片描述][20200611171906274.jpg_pic_center]  
原始数据类型如下：

[
        { 
            ORDER_NUM=SD2520200522001,
            WERKS_DN=2050,
            POSNR=000010
        },
        { 
            ORDER_NUM=SD2520200610001,
            WERKS_DN=2050,
            POSNR=000010
        },
        { 
            ORDER_NUM=SD2520200610001,
            WERKS_DN=2050,
            POSNR=000010
        }
    ]

比如同一个单号，需要处理成如下类型json数据类型

{ 
        "SD2520200611004":[
            { 
                "ORDER_NUM":"SD2520200611004",
                "WERKS_DN":"2050",
                "POSNR":"000010"
            }],
        "SD2520200610001":[
            { 
                "ORDER_NUM":"SD2520200610001",
                "WERKS_DN":"2050",
                "POSNR":"000010"
            },
            { 
                "ORDER_NUM":"SD2520200610001",
                "WERKS_DN":"2050",
                "POSNR":"000010"
            }],
        "SD2520200522001":[
            { 
                "ORDER_NUM":"SD2520200522001",
                "WERKS_DN":"2050",
                "POSNR":"000010"
            }]
    }

java代码如下：

public void run() { 
    		// TODO Auto-generated method stub
    		SD25TaskService sd25TaskService = applicationContext.getBean(SD25TaskService.class);
    		try { 
    			List list = sd25TaskService.getData();//从数据库中查询出数据
    			JSONObject obj = new JSONObject();
    			for (int i = 0; i < list.size(); i++) { 
    				Map<String,Object> map = (Map<String, Object>) list.get(i);//遍历获取字段集合
    				String orderNum = map.get("ORDER_NUM").toString();//按照ORDER_NUM进行区分
    				if(!obj.containsKey(orderNum)) { //如果JSONObject不存在，则存按照<orderNum,List>形式存入JSONObject
    					List<Map<String,Object>> tempList = new ArrayList<>();//创建临时tempList作为list存储json数据
    					tempList.add(map);
    					obj.put(orderNum, tempList);
    				}else { //如果存在，则先取出放入临时list，然后将当前的map存入临时tempList
    					List<Map<String,Object>> tempList = (List<Map<String, Object>>) obj.get(orderNum);
    					tempList.add(map);
    				}
    			}
    			System.out.println(obj);
    			
    		} catch (Exception ex) { 
    			LOG.error("仓管员收货自动过账提交BPM异常！", ex);
    		}
    	}

# 五：JS解析JSON对象 #

利用**eval函数**进行转换

var data= { 
    	"name": "zhangsanfeng",
    	"age": 118,
    	"address": "beijing"
    };
    
    var json = eval('(' + data+ ')');
    console.info(json.name);
    console.info(json.age);
    console.info(json.address);

# 六：解析JSON数组 #

6.1 解析方式1  
拼接json数组，如\{“IT\_ITEM”:\[\{“VBELN”:“0080001496”\}\]\}

var arry = [];
      var jsonArray = { };
      jsonArray.VBELN = "0080001496";
      arry.push(jsonArray);
      
      var inputTables = { };
      inputTables.IT_ITEM = arry;
      console.info(JSON.stringify(inputTables))

json数组格式如下  
var data = “\{“ET\_INFO”:\[\{“VBELN”:“80001496”,“KBETR”:3.00,“POSNR”:“000010”,“ARKTX”:“受话器SDRP0615PJ02-04-056”,“WAERS”:“RMB”,“MEINS”:“PCS”,“LGMNG”:20.000,“WBSTA”:“A”,“MATNR”:“000000001400009338”,“NAME1”:“AMAZON”\}\]\}”;

{ 
    	"ET_INFO": [{ 
    		"VBELN": "8000149",
    		"KBETR": 3.00,
    		"POSNR": "000010",
    		"ARKTX": "受话器SD",
    		"WAERS": "RMB",
    		"MEINS": "PCS",
    		"LGMNG": 20.0,
    		"WBSTA": "A",
    		"MATNR": "00000000140",
    		"NAME1": "AMA"
    	}]
    }

var arrays = $.parseJSON(data.data).ET_INFO;
     for(var i=0 ;i<arrays.length;i++){ 
       var POSNR = arraus[i].POSNR;//交货项目
       var MATNR = arraus[i].MATNR;//物料号
       var ARKTX = arraus[i].ARKTX;//销售订单项目短文本
       var MEINS = arraus[i].MEINS;//基本计量单位
       var LGMNG = arraus[i].LGMNG;//以仓库保管单位级的实际交货数量
       var KBETR = arraus[i].KBETR;//价格
       var WAERS = arraus[i].WAERS;//货币码
       var WBSTA = arraus[i].WBSTA;//货物移动状态
       var NAME1 = arraus[i].NAME1;//名称
     }

6.2 解析方式2

# 七：JSON与Map互相转换 #

package com.gzsolartech.bpmportal.util;
    
    import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.Iterator;
    import java.util.List;
    import java.util.Map;
    import java.util.Set;
    import org.directwebremoting.json.types.JsonObject;
    import org.json.JSONArray;
    import org.json.JSONObject;
    
    public class JsonMapUtil { 
    	public static Map convertJsonObjectToMap(JSONObject json){ 
    		Map returnMap = new HashMap();
    		Iterator<String> iterator = json.keys();
    		while(iterator.hasNext()){ 
    			String key = iterator.next();
    			returnMap.put(key, json.opt(key));
    		}
    		return returnMap;
    	}
    	public static JSONObject convertMapToJsonObject(Map<String,Object> map){ 
    		JSONObject json = new JSONObject();
    		Set<String> set = map.keySet();
    		Iterator<String> iterator = set.iterator();
    		while(iterator.hasNext()){ 
    			String key = iterator.next();
    			json.put(key, map.get(key));
    		}
    		return json;
    	}
    	public static List<Map> convertJsonArrayToMap(JSONArray jsonArr){ 
    		Map returnMap = new HashMap();
    		List<Map> list = new ArrayList<>();
    		for(int i=0;i<jsonArr.length();i++){ 
    			JSONObject json = jsonArr.optJSONObject(i);
    			Map map = convertJsonObjectToMap(json);
    			list.add(map);
    		}
    		return list;
    	}
    	
    }

参考文章  
https://blog.csdn.net/dirft\_din/article/details/108325419  
https://www.yiibai.com/html/json/2013/0906249.html

[20200520104446871.jpg]: https://img-blog.csdnimg.cn/20200520104446871.jpg
[20201229112519905.png]: https://img-blog.csdnimg.cn/20201229112519905.png
[20200611171906274.jpg_pic_center]: https://img-blog.csdnimg.cn/20200611171906274.jpg#pic_center