思路：首先将JSON格式的数据转换成JSONObject，然后将JSONObject转换成Java的实体类（其中类属性包括List等类型）
Java实体类：
SearchFilter 类
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 类：
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 //导入的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);//将json格式的字符串转换成JSONObject 对象
5 JSONArray array = jsonobject.getJSONArray("rules"); //如果json格式的字符串里含有数组格式的属性，将其转换成JSONArray，以方便后面转换成对应的实体
6 List<SearchRule> rules = new ArrayList<SearchRule>();
7 for (int i = 0; i < array.size(); i++) {
8 JSONObject object = (JSONObject) array.get(i); //将array中的数据进行逐条转换
9 SearchRule rule = (SearchRule) JSONObject.toBean(object, SearchRule.class); //通过JSONObject.toBean()方法进行对象间的转换
10 rules.add(rule);
11 }
12 String groupOp = jsonobject.getString("groupOp"); //简单的直接获取值
13 searchFilter = new SearchFilter(); //对SearchFilter对象进行组装
14 searchFilter.setGroupOp(groupOp);
15 searchFilter.setRules(rules);
16 } catch (Exception e) {
17 System.out.println("filters=" + filters.toString() + ".json转换成实体类出错");
18 e.printStackTrace();
19 }
20 return searchFilter;
21 }这里只进行了SearchFilter类中list<SearchRule>rule属性的对象转换，因为它是一个SearchRule对象数组，需要单独拿出来进行json转换成对象，如果直接对filter进行 SearchFilter进行实体转换会报错。如果对象中不含有list,array，map等集合，可以像8-9行一样进行对象转换。
测试：
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 }
结果：gop=OR rules.size=2将java对象转换成json格式：
1 //将Object 对象转换成 json
2 public String objectToJson(Object obj) {
3 ObjectMapper mapper = new ObjectMapper();
4 // Convert object to JSON string
5 String jsonStr = null;
6 try {
7 jsonStr = mapper.writeValueAsString(obj);
8 } catch (IOException e) {
9 log.error(obj + "entity 轉換成 json出錯", e);
10 e.printStackTrace();
11 System.out.println("entity 轉換成 json出錯");
12 }
13 return jsonStr;
14 }
将Object 转换成json字符串时，默认使用用是的驼峰方式，如果不想使用驼峰则可以增加红色部分设置，带下划线的也可以原样输出：
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对象转换失败",e);
10 e.printStackTrace();
11 }
12 return json;
13 }结果：
"UpLoadDateTime":"2017-09-25 10:51:41","OrganizationId":"B3EA5A4D-7C60-4C21-AF09-494890467C34" ，"Test_Code":""