Question

我正在编写一个接收Json String的程序，将其转换为Java对象并将其打印到屏幕上。非常简单的东西，但我的问题是让程序读取Json字符串。

下面是类，以及创建Json String的测试类，并调用NameList.java类，它根据Json字符串中的对象数创建Name对象列表。

继承错误：无法识别的字段＆＃34;名称＆＃34; （Class sample.NameList），未在[来源：java.io.StringReader@1a407d53;标记为可忽略; line：1，column：12]（通过引用链：sample.NameList [＆＃34; Name＆＃34;]）

我在线检查了多个来源，很多人建议只使用列表文件中的注释来修复它。其他人说要更改Xxx的名称。的getXxx＆＃39;到JSON文件中的根名称。我尝试了两种选择，似乎没有任何选择。任何帮助将非常感激，感谢

       public class UserTest {

    public static void main(String[] args) throws JSONException{


        String jsonStr = "{"
                + "\"Names\":[{\"field\":\"John\","
                + "\"value\":\"3\"},{"
                + "\"field\":\"Ali\","
                + "\"value\":4 }]}";


        ObjectMapper mapper = new ObjectMapper();
        try {
            System.out.println("before obj creation");

            SelectList testObject = mapper.readValue(jsonStr, NameList.class); 
            System.out.println("Created the class");
            System.out.print(testObject);
        } catch (Exception e) {
            System.out.println("caught the error");
            e.printStackTrace();
        } 
    }

}



    public class Name {
        private String field;
        private String value;

        //getters and setters
@Override
    public String toString() {
        return "Name{" +
                "field='" + field + '\'' +
                ", value='" + value + '\'' +
                '}';
    }

       }



     public class SelectList {
    @JsonProperty("Select")
            private List<Name> name;

            /**
             * @return the selected statements
             */
            public List<Name> getName() {
                return name;
            }

            /**
             * @param the names to set
             */
            public void setName(List<Name> names) {
                this.name = names;
            }

    }

Answer 1

您的代码和json中存在一些问题

#define inline

已编辑：已添加maven依赖项

     public class NameList {                                                                          
        @JsonProperty("Names")                   
        private List<Name> name;//field name should be same as json field or use annnotation                 

        /**                                      
         * @return the selected statements       
         */                                      
        public List<Name> getName() {            
            return name;                         
        }                                        

        /**                                      
         * @param  names to set                  
         */                                      
        public void setName(List<Name> names) {  
            this.name = names;                   
        }                                        

    }                                                                                   


    public class Name {
        private String field;
        private String value;

        public String getField() {
            return field;
        }

        public void setField(String field) {
            this.field = field;
        }

        public String getValue() {
            return value;
        }

        public void setValue(String value) {
            this.value = value;
        }

        @Override
        public String toString() {
            return "Name{" +
                    "field='" + field + '\'' +
                    ", value='" + value + '\'' +
                    '}';
        }
    }


    public class NameListTest {

        @Test
        public void test1() { // values should be in quotes if they are string literal
            String jsonStr = "{"
                    + "\"Names\":[{\"field\":\"John\","
                    + "\"value\":\"3\"},{"
                    + "\"field\":\"Ali\","
                    + "\"value\":4 }]}";
            ObjectMapper mapper = new ObjectMapper();
            try {
                NameList testObject = mapper.readValue(jsonStr, NameList.class);
                System.out.print(testObject);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

如何让java读取包含多个对象的JSON String？

1 个答案: