思路：首先將JSON格式的數(shù)據(jù)轉(zhuǎn)換成JSONObject，然后將JSONObject轉(zhuǎn)換成Java的實(shí)體類（其中類屬性包括List等類型）

Java實(shí)體類：

SearchFilter 類

1 public class SearchFilter {2 private String groupOp;3 4 private List<SearchRule> rules;5 6 public String getGroupOp() {7 return groupOp;8 }9 10 public void setGroupOp(String groupOp) { 11 this.groupOp = groupOp; 12 } 13 14 public List<SearchRule> getRules() { 15 return rules; 16 } 17 18 public void setRules(List<SearchRule> rules) { 19 this.rules = rules; 20 }

SearchRule 類：

1 public class SearchRule {2 private String field;3 private String op;4 private String data;5 public String getField() {6 return field;7 }8 public void setField(String field) {9 this.field = field; 10 } 11 public String getOp() { 12 return op; 13 } 14 public void setOp(String op) { 15 this.op = op; 16 } 17 public String getData() { 18 return data; 19 } 20 public void setData(String data) { 21 this.data = data; 22 } 23 24 25 }

1 //導(dǎo)入的package 2 import com.fasterxml.jackson.databind.ObjectMapper; 3 import net.sf.json.JSONArray; 4 import net.sf.json.JSONObject;

解析JSon格式字符串的方法

1 public SearchFilter jsonToSearchFilter(String filters) {2 SearchFilter searchFilter = null;3 try {4 JSONObject jsonobject = JSONObject.fromObject(filters);//將json格式的字符串轉(zhuǎn)換成JSONObject 對(duì)象5 JSONArray array = jsonobject.getJSONArray("rules"); //如果json格式的字符串里含有數(shù)組格式的屬性，將其轉(zhuǎn)換成JSONArray，以方便后面轉(zhuǎn)換成對(duì)應(yīng)的實(shí)體6 List<SearchRule> rules = new ArrayList<SearchRule>();7 for (int i = 0; i < array.size(); i++) {8 JSONObject object = (JSONObject) array.get(i); //將array中的數(shù)據(jù)進(jìn)行逐條轉(zhuǎn)換9 SearchRule rule = (SearchRule) JSONObject.toBean(object, SearchRule.class); //通過JSONObject.toBean()方法進(jìn)行對(duì)象間的轉(zhuǎn)換 10 rules.add(rule); 11 } 12 String groupOp = jsonobject.getString("groupOp"); //簡(jiǎn)單的直接獲取值 13 searchFilter = new SearchFilter(); //對(duì)SearchFilter對(duì)象進(jìn)行組裝 14 searchFilter.setGroupOp(groupOp); 15 searchFilter.setRules(rules); 16 } catch (Exception e) { 17 System.out.println("filters=" + filters.toString() + ".json轉(zhuǎn)換成實(shí)體類出錯(cuò)"); 18 e.printStackTrace(); 19 } 20 return searchFilter; 21 }

這里只進(jìn)行了SearchFilter類中l(wèi)ist<SearchRule>rule屬性的對(duì)象轉(zhuǎn)換，因?yàn)樗且粋€(gè)SearchRule對(duì)象數(shù)組，需要單獨(dú)拿出來進(jìn)行json轉(zhuǎn)換成對(duì)象，如果直接對(duì)filter進(jìn)行 SearchFilter進(jìn)行實(shí)體轉(zhuǎn)換會(huì)報(bào)錯(cuò)。如果對(duì)象中不含有l(wèi)ist,array，map等集合，可以像8-9行一樣進(jìn)行對(duì)象轉(zhuǎn)換。

測(cè)試：

1 public static void main(String[] args) { 2 UserMgmtController con = new UserMgmtController(); 3 String filters="{\"groupOp\": \"OR\",\"rules\": [{\"field\": \"realname\",\"op\": \"eq\","+ 4 "\"data\": \"1234\"},{\"field\": \"cityCode\",\"op\": \"ne\",\"data\": \"5678\"}]}"; 5 SearchFilter searchFilter =con.jsonToSearchFilter(filters); 6 System.out.println("gop="+searchFilter.getGroupOp()+" rules.size="+searchFilter.getRules().size()); 7 } 結(jié)果：gop=OR rules.size=2

將java對(duì)象轉(zhuǎn)換成json格式：

1 //將Object 對(duì)象轉(zhuǎn)換成 json2 public String objectToJson(Object obj) {3 ObjectMapper mapper = new ObjectMapper();4 // Convert object to JSON string5 String jsonStr = null;6 try {7 jsonStr = mapper.writeValueAsString(obj);8 } catch (IOException e) {9 log.error(obj + "entity 轉(zhuǎn)換成 json出錯(cuò)", e); 10 e.printStackTrace(); 11 System.out.println("entity 轉(zhuǎn)換成 json出錯(cuò)"); 12 } 13 return jsonStr; 14 }

將Object 轉(zhuǎn)換成json字符串時(shí)，默認(rèn)使用用是的駝峰方式，如果不想使用駝峰則可以增加紅色部分設(shè)置，帶下劃線的也可以原樣輸出：

1 public String objectToJson(Object obj){2 ObjectMapper mapper = new ObjectMapper();3 String json =null;4 try {5 PropertyNamingStrategy.PascalCaseStrategy pp = new PropertyNamingStrategy.PascalCaseStrategy(); 6 mapper.setPropertyNamingStrategy(pp);7 json = mapper.writeValueAsString(obj);8 } catch (JsonProcessingException e) {9 log.error("json對(duì)象轉(zhuǎn)換失敗",e); 10 e.printStackTrace(); 11 } 12 return json; 13 }

結(jié)果：

"UpLoadDateTime":"2017-09-25 10:51:41","OrganizationId":"B3EA5A4D-7C60-4C21-AF09-494890467C34" ，"Test_Code":""

來源：https://www.cnblogs.com/smallfa/p/10495508.html

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