java uses FastJson to parse Json data

This article mainly introduces Java's use of FastJson to parse Json data. Fastjson is a JSON parser and generator with excellent performance implemented in Java language. Those who are interested can learn about it.

fastjson is a JSON parser and generator with excellent performance implemented in Java language, developed by engineers from Alibaba.

Main Features:

• Fast FAST (faster than any other Java-based parser and generator, including jackson)

• Powerful (supports ordinary JDK classes including any Java Bean Class, Collection, Map, Date or enum)

• Zero dependency (no dependencies on any other class libraries except JDK)

1. Generate Json:

##JavaBean, List, List, List>

##

String jsonString = JSON.toJSONString(obj);

##2. Parse Json:

（1）JavaBean

##

Class class= JSON.parseObject(jsonString, Class.class);

（2）List

List<Class> class=JSON.parseArray((jsonString, Class.class);

（3）List

List<String> listString = JSON.parseArray(jsonString, String.class);

（4）List>

##Copy code

The code is as follows:

List listMap = JSON.parseObject(jsonString, new TypeReference>>(){});

Existing json data like this:

{"totalRecords":2615, 
"result":{"code":"200","status":"success"}, 
"list":[{"unuAbnId":"0bcd930f-014c-1000-e003-5f160a0d0114", 
"entNo":"1c2e4ca8-00fa-1000-e000-74590a76bf0f", 
"regNO":"442000600169663", 
"entName":"x", 
"entType":"9910 ", 
"speCause":"3", 
"abnTime":"Mar 13, 2015 12:00:00 AM", 
"decOrg":"442020", 
"entNameUrl":"<a href=\".. ", 
"auditingFileNo":"15000684990326", 
"abnormalID":"fd74013d-014b-1000-e00a-72970a0d0114"},{...},{...},...], 
"pageNo":1, 
"pageSize":8, 
"url":"main/abnInfoPage", 
"selList":[{"unuAbnId":"0bcd930f-014c-1000-e003-5f0f0a0d0114", 
"entNo":"16da9629-0131-1000-e005-3effc0a803a8", 
"regNO":"442000602187424", 
"entName":"x", 
"entType":"9910 ", 
"speCause":"3", 
"abnTime":"Mar 13, 2015 12:00:00 AM", 
"decOrg":"442020", 
"entNameUrl":"<a href=\"..\">", 
"auditingFileNo":"15000684990319", 
"abnormalID":"fd74013d-014b-1000-e00a-72970a0d0114"},{...},{...},...], 
"topPageNo":1, 
"totalPages":327, 
"previousPageNo":0, 
"nextPageNo":2, 
"bottomPageNo":327 
}

The list contains 2615 pieces of data, and selList contains 8 pieces of data. The goal is to extract the link of entNameUrl in selList (excluding a href=)

Outer layer It is JSONObject, the list and selList inside are JSONArrary, and the inside is JSONObject. The result is also a JSONObject

JSONObject jsonObj = JSON.parseObject(rawText); 
JSONArray result = jsonObj.getJSONArray("selList"); 
List<Link> links= JSON.parseArray(result.toJSONString(),Link.class);

The Link class must have the attribute entNameUrl, as well as setter and getter methods.

Further processing can be done in the setter method

 public void setEntNameUrl(String entNameUrl) { 
   this.entNameUrl =Html.create(entNameUrl).links().get(); 
}

A custom method is used here, and its function is to take out Link in string.

The Link class can contain abnTime, entName, regNO and other attributes and corresponding getter and setter methods, and FastJson can automatically map them.

It can also be processed through the following methods:

JSONObject jsonObj = new JSONObject(rawText); 
JSONArray jsonArray = result .getJSONArray("selList"); 
for (int i = 0; i < jsonArray.length; i++) {   
}

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