json转换成实体类

org.codehaus.jackson.map.JsonMappingException: No suitable constructor found for type [simple type, class com.macxen.speechrecognition.JsonRootBean$Result] : can not instantiate from JSON object (need to add/enable type information?) at [Source: java.io.StringReader@3db5162; line: 1, column: 100] (through reference chain: com.macxen.speechrecognition.JsonRootBean["origin_result"] ->com.macxen.speechrecognition.Origin_result["result"]) 

1.首先导入marven

 
   
   
     org.codehaus.jackson 
    
   
     jackson-mapper-lgpl 
    
   
     1.9.13 
    
   
     test 
    
   

2.jackonMapper

package com.sunian.besjon; import org.codehaus.jackson.map.ObjectMapper; / * @author sunian * @name speechRecognition * @class name：com.sunian.speechrecognition.util * @time 2018/11/7 10:14 * @describe describe */ public class JacksonMapper { private static final ObjectMapper mapper = new ObjectMapper(); private JacksonMapper() { } public static ObjectMapper getInstance() { return mapper; } } 

3.JsonRootBean

package com.macxen.besjon; import java.io.Serializable; import java.util.List; / * @author lainuo * @name speechRecognition * @class name：com.macxen.speechrecognition * @time 2018/11/6 19:30 * @describe 实体类 */ public class JsonRootBean implements Serializable { private String result_type; private String best_result; private List 
  
    results_recognition; private Origin_result origin_result; private int error; public JsonRootBean() { } public void setResult_type(String result_type) { this.result_type = result_type; } public String getResult_type() { return result_type; } public void setBest_result(String best_result) { this.best_result = best_result; } public String getBest_result() { return best_result; } public void setResults_recognition(List 
   
     results_recognition) { this.results_recognition = results_recognition; } public List 
    
      getResults_recognition() { return results_recognition; } public void setOrigin_result(Origin_result origin_result) { this.origin_result = origin_result; } public Origin_result getOrigin_result() { return origin_result; } public void setError(int error) { this.error = error; } public int getError() { return error; } public static class Result implements Serializable { private List 
     
       word; public Result() { } public void setWord(List 
      
        word) { this.word = word; } public List 
       
         getWord() { return word; } } public static class Origin_result implements Serializable { private Result result; private String sn; private int err_no; private long corpus_no; private double voice_energy; public Origin_result() { } public void setResult(Result result) { this.result = result; } public Result getResult() { return result; } public void setSn(String sn) { this.sn = sn; } public String getSn() { return sn; } public void setErr_no(int err_no) { this.err_no = err_no; } public int getErr_no() { return err_no; } public void setCorpus_no(long corpus_no) { this.corpus_no = corpus_no; } public long getCorpus_no() { return corpus_no; } public void setVoice_energy(double voice_energy) { this.voice_energy = voice_energy; } public double getVoice_energy() { return voice_energy; } } } 
        
       
      
     
    
  

4.JsonUtil

package com.sunian.besjon; import org.codehaus.jackson.map.ObjectMapper; / * @author sunian * @name speechRecognition * @class name：com.sunian.speechrecognition.util * @time 2018/11/7 10:15 * @describe describe */ public class JsonUtil { public static String getJsonString(Object object) throws Exception { return JacksonMapper.getInstance().writeValueAsString(object); } public static Object toObject(String jsonString, Class cls) throws Exception { ObjectMapper objectMapper = new ObjectMapper(); return objectMapper.readValue(jsonString, cls); } } 

5.执行测试类

 String json = "{\n" + "\t\"results_recognition\": [\"沧州。\"],\n" + "\t\"origin_result\": {\n" + "\t\t\"corpus_no\": ,\n" + "\t\t\"err_no\": 0,\n" + "\t\t\"result\": {\n" + "\t\t\t\"word\": [\"沧州。\"]\n" + "\t\t},\n" + "\t\t\"sn\": \"fbc63952-92f7-49cd-b044-5204afd7ba01_s-79\",\n" + "\t\t\"voice_energy\": 12175.6875\n" + "\t},\n" + "\t\"error\": 0,\n" + "\t\"best_result\": \"沧州。\",\n" + "\t\"result_type\": \"final_result\"\n" + "}"; @Test public void getJsonRootBean() throws Exception { Object o = JsonUtil.toObject(json, JsonRootBean.class); System.out.println(o); } 

6.将json转换成实体类