使用Jackson将许多对象转换为JSON

JsonUnwrapped是要使用的注释，它甚至适用于多层嵌套。例如：

@RunWith(JUnit4.class)public class Sample {    @Test    public void testName() throws Exception {        SampleClass sample = new SampleClass("value1", "value2", new SubClass("value4", "value5", new SubSubClass("value7")));        new ObjectMapper().writevalue(System.out, sample);    }    @JsonAutoDetect(fieldVisibility=Visibility.ANY)    public static class SampleClass {        private String prop1;        private String prop2;        @JsonUnwrapped        private SubClass prop3;        public SampleClass(String prop1, String prop2, SubClass prop3) { this.prop1 = prop1; this.prop2 = prop2; this.prop3 = prop3;        }    }    @JsonAutoDetect(fieldVisibility=Visibility.ANY)    public static class SubClass {        private String prop4;        private String prop5;        @JsonUnwrapped        private SubSubClass prop6;        public SubClass(String prop4, String prop5, SubSubClass prop6) { this.prop4 = prop4; this.prop5 = prop5; this.prop6 = prop6;        }    }    @JsonAutoDetect(fieldVisibility=Visibility.ANY)    public static class SubSubClass{        private String prop7;        public SubSubClass(String prop7) { this.prop7 = prop7;        }    }}

会产生

{"prop1":"value1","prop2":"value2","prop4":"value4","prop5":"value5","prop7":"value7"}