响应对象转json时属性名大小写问题完美解决

梦里梦外; 2022-02-27 01:50 221阅读 0赞

首先：案例是model里的属性名大写，http response时json默认变成小写开头，和model属性不一致。

例子：

model为：
    class User{
        private String NAME;
        private int AGE;
        getter 和 setter...
    }
    
    http 请求后响应的json为：
    {
        "name":"张三",
        "age":20
    }
    
    
    业务需求json为：
    {
        "NAME":"张三",
        "AGE":20
    }

可行的解决方案：

网上搜了好多，大部分都是在属性上添加@JsonProperty("XXX")，但是这里就又出现了个问题，转json后会有两个同名但大小写不一样的属性；? 就又去搜索，说是在getter方法上添加@JsonProperty("XXX")，解决了，但是字段少没问题，咱每个实体model上添加下，如果字段多了呢？实体多了呢？

完美的解决方案：

本人自己推敲的，分享给大家，好用就用，不好用请忽略，当然肯定有其他更好的，有知道的请文末留言告知博主，非常感谢?

**下面上方法代码：**

> 响应json前将对象传入此方法即可

/**
         * 对象转json时属性变大写
         *
         * @param entity
         * @return
         */
        public static Map<String,Object> object2UpperCase(Object entity){
            Map<String,Object> res = Maps.newHashMap();
            if (null==entity){
                return res;
            }
            //将对象的属性转化为大写
            String json = JacksonUtil.bean2Json(entity);
            Map<String,Object> map = JacksonUtil.json2Map(json,String.class,Object.class);
            if (null!=map && !map.isEmpty()){
                for(Map.Entry<String,Object> entry:map.entrySet()){
                    /**
                     * TODO-关键在这里根据业务需要转大小写
                     */
                    res.put(entry.getKey().toUpperCase(),entry.getValue());
                }
            }
            return res;
        }

JacksonUtil.java json转化工具类

package com.ww.common.json;
    
    import com.fasterxml.jackson.annotation.JsonInclude;
    import com.fasterxml.jackson.core.JsonFactory;
    import com.fasterxml.jackson.core.JsonGenerator;
    import com.fasterxml.jackson.core.JsonParseException;
    import com.fasterxml.jackson.core.JsonParser;
    import com.fasterxml.jackson.core.type.TypeReference;
    import com.fasterxml.jackson.databind.*;
    
    import java.io.IOException;
    import java.io.StringReader;
    import java.io.StringWriter;
    import java.util.*;
    import java.util.concurrent.ConcurrentHashMap;
    import java.util.concurrent.ConcurrentMap;
    
    
    /**
     * json转化工具
     * @author Ace Lee
     * 
     */
    public  class JacksonUtil {
    	
    	
    	private static final ObjectMapper MAPPER = new ObjectMapper();
    
    	static {
    		//MAPPER.configure(Feature.ALLOW_UNQUOTED_FIELD_NAMES, false);
    		MAPPER.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES,false);
    		MAPPER.configure(JsonParser.Feature.ALLOW_UNQUOTED_CONTROL_CHARS, true);
    		MAPPER.configure(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES,true);
    	}
    
    
    	private static final JsonFactory JSONFACTORY = new JsonFactory();
    	
    
    	/**
    	 * 把json参数转换成对应Vo
    	 * <B>第二个参数请使用  Class ,比如JacksonUtil.json2Bean("{\"name\":\"0000\",\"age\":456}", Car.class);</B>
    	 * @param json
    	 * @param valueTypeRef
    	 * @return
    	 */
    	public static <T> T json2Bean(String json, TypeReference<T> valueTypeRef) {
    		
    		T rtn =null;
    		try {
    			rtn = 	MAPPER.readValue(json, valueTypeRef);
    		} catch (JsonParseException e) {
    			throw new RuntimeException(e);
    		} catch (JsonMappingException e) {
    			throw new RuntimeException(e);
    		} catch (IOException e) {
    			throw new RuntimeException(e);
    		}
    		return rtn;
    	}
    	public static <T> T json2Bean(String json, Class<T>  cls) {
    	    
    	    T rtn =null;
    	    try {
    	        rtn = 	MAPPER.readValue(json, cls);
    	    } catch (JsonParseException e) {
    	        throw new RuntimeException(e);
    	    } catch (JsonMappingException e) {
    	        throw new RuntimeException(e);
    	    } catch (IOException e) {
    	        throw new RuntimeException(e);
    	    }
    	    return rtn;
    	}
    
    	
    	
    	/**
    	 * 转换vo 为 json
    	 */
    	public static String bean2Json(Object o) {
    	    StringWriter sw = new StringWriter();
    	    JsonGenerator jsonGenerator = null;
    	    
    	    try {
    	        jsonGenerator = JSONFACTORY.createJsonGenerator(sw);
    	        MAPPER.writeValue(jsonGenerator, o);
    	        return sw.toString();
    	        
    	    } catch (Exception e) {
    	        throw new  RuntimeException(e);
    	        //return null;
    	        
    	    } finally {
    	        if (jsonGenerator != null) {
    	            try {
    	                jsonGenerator.close();
    	            } catch (Exception e) {
    	                throw  new RuntimeException(e);
    	            }
    	        }
    	    }
    	}
    	/**
    	 * 转换vo 为 json
    	 */
    	public static String bean2Json(Object o,ObjectMapper mapper) {
    	    StringWriter sw = new StringWriter();
    	    JsonGenerator jsonGenerator = null;
    	    
    	    try {
    	        jsonGenerator = JSONFACTORY.createJsonGenerator(sw);
    	        mapper.writeValue(jsonGenerator, o);
    	        return sw.toString();
    	        
    	    } catch (Exception e) {
    	        throw new  RuntimeException(e);
    	        //return null;
    	        
    	    } finally {
    	        if (jsonGenerator != null) {
    	            try {
    	                jsonGenerator.close();
    	            } catch (Exception e) {
    	                throw  new RuntimeException(e);
    	            }
    	        }
    	    }
    	}
    	/**
    	 * 转换vo 为 json,属性为null不被序列化
    	 */
    	public static String bean2JsonWithoutNull(Object o) {
    		StringWriter sw = new StringWriter();
    		JsonGenerator jsonGenerator = null;
    		ObjectMapper mapper=new ObjectMapper();
    		mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
    		try {
    			jsonGenerator = JSONFACTORY.createJsonGenerator(sw);
                mapper.writeValue(jsonGenerator, o);
    			return sw.toString();
    
    		} catch (Exception e) {
    			throw new  RuntimeException(e);
    			//return null;
    
    		} finally {
    			if (jsonGenerator != null) {
    				try {
    					jsonGenerator.close();
    				} catch (Exception e) {
    					throw  new RuntimeException(e);
    				}
    			}
    		}
    	}
    	
    	
    
    	/**
    	 * 转换Json String 为 HashMap
    	 */
    	@SuppressWarnings("unchecked")
    	public static Map<String, Object> json2Map(String json,
    			boolean collToString) {
    		try {
    			Map<String, Object> map = MAPPER.readValue(json, HashMap.class);
    			if (collToString) {
    				for (Map.Entry<String, Object> entry : map.entrySet()) {
    					if (entry.getValue() instanceof Collection
    							|| entry.getValue() instanceof Map) {
    						entry.setValue(bean2Json(entry.getValue()));
    					}
    				}
    			}
    			return map;
    		} catch (Exception e) {
    			//return null;
    			throw new RuntimeException(e);
    		}
    	}
    	/**
    	 * json String转换为Map
    	 * @author dingyiming@chinasofti.com
    	 * @date 2016年1月5日 下午9:12:06
    	 * @param json
    	 * @param clk - key的类型
    	 * @param clv - value的类型
    	 * @return 
    	 * @description
    	 */
    	public static <K,V> Map<K, V> json2Map(String json,Class<K> clk,Class<V> clv) {
    		try {
    			JavaType javaType = MAPPER.getTypeFactory().constructMapType(Map.class, clk, clv);
    			Map<K, V> map = MAPPER.readValue(json, javaType);
    			return map;
    		} catch (Exception e) {
    			//return null;
    			throw new RuntimeException(e);
    		}
    	}	
    	/**
    	 * json String转换为ConcurrentMap
    	 * @author dingyiming@chinasofti.com
    	 * @date 2016年1月5日 下午9:12:06
    	 * @param json
    	 * @param clk - key的类型
    	 * @param clv - value的类型
    	 * @return 
    	 * @description
    	 */
    	public static <K,V> ConcurrentMap<K, V> json2ConMap(String json,Class<K> clk,Class<V> clv) {
    		try {
    			JavaType javaType = MAPPER.getTypeFactory().constructMapType(ConcurrentHashMap.class, clk, clv);
    			ConcurrentMap<K, V> map = MAPPER.readValue(json, javaType);
    			return map;
    		} catch (Exception e) {
    			//return null;
    			throw new RuntimeException(e);
    		}
    	}
    
    	@SuppressWarnings("serial")
    	public static class jsonParseException extends Exception {
    		public jsonParseException(String message) {
    			super(message);
    		} 
    	}
    
    	/**
    	 * List 转换成json
    	 * 
    	 * @param list
    	 * @return
    	 */
    	public static String list2Json(List<Map<String, String>> list) {
    		JsonGenerator jsonGenerator = null;
    		StringWriter sw = new StringWriter();
    		try {
    			jsonGenerator = JSONFACTORY.createJsonGenerator(sw);
    			new ObjectMapper().writeValue(jsonGenerator, list);
    			jsonGenerator.flush();
    			return sw.toString();
    		} catch (Exception e) {
    			//return null;
    			throw new  RuntimeException(e);
    		} finally {
    			if (jsonGenerator != null) {
    				try {
    					jsonGenerator.flush();
    					jsonGenerator.close();
    				} catch (Exception e) {
    					//e.printStackTrace();
    					throw new  RuntimeException(e);
    				}
    			}
    		}
    	}
    
    	/**
    	 * json 转List
    	 * 
    	 * @param json
    	 * @return
    	 */
    	@SuppressWarnings("unchecked")
    	public static List<Map<String, String>> json2List(String json) {
    		try {
    			if (json != null && !"".equals(json.trim())) {
    				JsonParser jsonParse = JSONFACTORY
    						.createJsonParser(new StringReader(json));
    
    				ArrayList<Map<String, String>> arrayList = (ArrayList<Map<String, String>>) new ObjectMapper()
    						.readValue(jsonParse, ArrayList.class);
    				return arrayList;
    			} else {
    				return null;
    			}
    		} catch (Exception e) {
    			//return null;
    			throw  new RuntimeException(e);
    			
    		}
    	}
    	
    	
    	// 测试方法
    	public static void main(String[] args) {
    //		User user = new User();
    //		user.setId(1);
    //		user.setUsername("张小三");
    //		user.setAddress("海南");
    //		user.setPhone("010");
    //
    //		User user2 = new User();
    //		user2.setId(2);
    //		user2.setUsername("李小璐");
    //		user2.setAddress("天津");
    //		user2.setPhone("8888888");
    //
    //		List<User> list = new ArrayList<User>();
    //		list.add(user);
    //		list.add(user2);
    //
    //		 String str = bean2Json(user);
    //		 bean2Json(list);
    //		 System.out.println(str);
    //
    //		 String json =
    //		 "{\"address\":\"拾金路\",\"id\":1,\"username\":\"张小宁\",\"phone\":123456789}";
    //		 User u = (User)json2Bean(json,new TypeReference<User>() {
    //        });
    //		 System.out.println(u);
    		String str="{\"naturalPerson\":{\"queryOrangeScoreDetail\":{\"acctLevel\":null,\"behavPref\":null,\"creditHis\":null,\"mobileNo\":null,\"orangeScore\":null,\"repayCap\":null,\"socialRela\":null,\"updatedAt\":null}}}";
    		Map<String, Object> map = JacksonUtil.json2Map(str, String.class, Object.class);
    		System.out.println(map);
    	}
    	
    	
    	static class   User {
    		 
    		 private int id;
    		 private String username;
    		 private String address;
    		 private String phone;
    		 public int getId() {
    		  return id;
    		 }
    		 public void setId(int id) {
    		  this.id = id;
    		 }
    		 public String getUsername() {
    		  return username;
    		 }
    		 public void setUsername(String username) {
    		  this.username = username;
    		 }
    		 public String getAddress() {
    		  return address;
    		 }
    		 public void setAddress(String address) {
    		  this.address = address;
    		 }
    		 public String getPhone() {
    		  return phone;
    		 }
    		 public void setPhone(String phone) {
    		  this.phone = phone;
    		 }
    		 
    		 @Override
    		 public String toString() {
    		  return "id: " + id + " username: " + username + " address: " + address + " phone: " + phone;
    		 }
    		}
    	
    }

**另附上jackson的pom依赖**

> 注意三个版本号必须保持一致

<dependency>
                <groupId>com.fasterxml.jackson.core</groupId>
                <artifactId>jackson-databind</artifactId>
                <version>2.9.3</version>
            </dependency>
            
            <dependency>
                <groupId>com.fasterxml.jackson.core</groupId>
                <artifactId>jackson-core</artifactId>
                <version>2.9.3</version>
            </dependency>
            
            <dependency>
                <groupId>com.fasterxml.jackson.core</groupId>
                <artifactId>jackson-annotations</artifactId>
                <version>2.9.3</version>
            </dependency>

--------------------

有更好的方案，欢迎留言，再次感谢！