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表明Jackson支持反序列化“所有受支持类型的数组”，但是我无法确定确切的语法。

对于单个对象，我可以这样做：

// input{    "id" : "junk",    "stuff" : "things"}//JavaMyClass instance = objectMapper.readValue(json, MyClass.class);

现在，对于数组，我想这样做：

//json input[{    "id" : "junk",    "stuff" : "things"},{    "id" : "spam",    "stuff" : "eggs"}]//JavaList
   
     entries = ?
   

有人知道是否有不可思议的命令吗？ 如果没有，那么解决方案是什么？

#1楼

从

List
   
     myObjects = Arrays.asList(mapper.readValue(json, MyClass[].class))
   

这个解决方案似乎对我来说是最好的

#2楼

try {    ObjectMapper mapper = new ObjectMapper();    JsonFactory f = new JsonFactory();    List
   
     lstUser = null;    JsonParser jp = f.createJsonParser(new File("C:\\maven\\user.json"));    TypeReference
    
     
      > tRef = new TypeReference
      
       
        >() {};    lstUser = mapper.readValue(jp, tRef);    for (User user : lstUser) {        System.out.println(user.toString());    }} catch (JsonGenerationException e) {    e.printStackTrace();} catch (JsonMappingException e) {    e.printStackTrace();} catch (IOException e) {    e.printStackTrace();}
       
      
     
    
   

#3楼

对于通用实现：

public static 
   
     List
    
      parseJsonArray(String json,                                         Class
     
       classOnWhichArrayIsDefined)                                          throws IOException, ClassNotFoundException {   ObjectMapper mapper = new ObjectMapper();   Class
      
        arrayClass = (Class
       
        ) Class.forName("[L" + classOnWhichArrayIsDefined.getName() + ";");   T[] objects = mapper.readValue(json, arrayClass);   return Arrays.asList(objects);}
       
      
     
    
   

#4楼

首先创建一个线程安全的ObjectReader实例。

ObjectMapper objectMapper = new ObjectMapper();ObjectReader objectReader = objectMapper.reader().forType(new TypeReference
   
    
     >(){});
    
   

然后使用它：

List
   
     result = objectReader.readValue(inputStream);
   

#5楼

这是一个可以转换json2object或Object2json的实用程序，无论您的pojo（实体T）如何

import java.io.IOException;import java.io.StringWriter;import java.util.List;import com.fasterxml.jackson.core.JsonGenerationException;import com.fasterxml.jackson.core.JsonParseException;import com.fasterxml.jackson.core.type.TypeReference;import com.fasterxml.jackson.databind.DeserializationFeature;import com.fasterxml.jackson.databind.JsonMappingException;import com.fasterxml.jackson.databind.ObjectMapper;import com.fasterxml.jackson.databind.SerializationFeature;/** *  * @author TIAGO.MEDICI *  */public class JsonUtils {    public static boolean isJSONValid(String jsonInString) {        try {            final ObjectMapper mapper = new ObjectMapper();            mapper.readTree(jsonInString);            return true;        } catch (IOException e) {            return false;        }    }    public static String serializeAsJsonString(Object object) throws JsonGenerationException, JsonMappingException, IOException {        ObjectMapper objMapper = new ObjectMapper();        objMapper.enable(SerializationFeature.INDENT_OUTPUT);        objMapper.disable(SerializationFeature.FAIL_ON_EMPTY_BEANS);        StringWriter sw = new StringWriter();        objMapper.writeValue(sw, object);        return sw.toString();    }    public static String serializeAsJsonString(Object object, boolean indent) throws JsonGenerationException, JsonMappingException, IOException {        ObjectMapper objMapper = new ObjectMapper();        if (indent == true) {            objMapper.enable(SerializationFeature.INDENT_OUTPUT);            objMapper.disable(SerializationFeature.FAIL_ON_EMPTY_BEANS);        }        StringWriter stringWriter = new StringWriter();        objMapper.writeValue(stringWriter, object);        return stringWriter.toString();    }    public static 
   
     T jsonStringToObject(String content, Class
    
      clazz) throws JsonParseException, JsonMappingException, IOException {        T obj = null;        ObjectMapper objMapper = new ObjectMapper();        obj = objMapper.readValue(content, clazz);        return obj;    }    @SuppressWarnings("rawtypes")    public static 
     
       T jsonStringToObjectArray(String content) throws JsonParseException, JsonMappingException, IOException {        T obj = null;        ObjectMapper mapper = new ObjectMapper();        obj = mapper.readValue(content, new TypeReference
      
       () {        });        return obj;    }    public static 
       
         T jsonStringToObjectArray(String content, Class
        
          clazz) throws JsonParseException, JsonMappingException, IOException { T obj = null; ObjectMapper mapper = new ObjectMapper(); mapper = new ObjectMapper().configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true); obj = mapper.readValue(content, mapper.getTypeFactory().constructCollectionType(List.class, clazz)); return obj; }
        
       
      
     
    
   

#6楼

首先创建一个映射器：

import com.fasterxml.jackson.databind.ObjectMapper;// in play 2.3ObjectMapper mapper = new ObjectMapper();

作为数组：

MyClass[] myObjects = mapper.readValue(json, MyClass[].class);

作为列表：

List
   
     myObjects = mapper.readValue(jsonInput, new TypeReference
    
     
      >(){});
     
    
   

指定列表类型的另一种方法：

List
   
     myObjects = mapper.readValue(jsonInput, mapper.getTypeFactory().constructCollectionType(List.class, MyClass.class));
   

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