package com.zsk.tool.json; import com.alibaba.fastjson.JSONArray; import com.alibaba.fastjson.JSONObject; import com.fasterxml.jackson.annotation.JsonInclude; import com.fasterxml.jackson.core.type.TypeReference; import com.fasterxml.jackson.databind.DeserializationFeature; import com.fasterxml.jackson.databind.JavaType; import com.fasterxml.jackson.databind.JsonNode; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.SerializationFeature; import com.fasterxml.jackson.databind.node.ArrayNode; import com.fasterxml.jackson.databind.node.ObjectNode; import lombok.Data; import sun.reflect.generics.reflectiveObjects.ParameterizedTypeImpl; import java.lang.reflect.Type; public class JsonUtil { /** * 线程安全,可全局使用 */ public static final ObjectMapper OBJECT_MAPPER = new ObjectMapper(); static { //反序列化的时候如果多了其他属性,不抛出异常 OBJECT_MAPPER.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false); //如果是空对象的时候,不抛异常 OBJECT_MAPPER.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false); //属性为null不转换 OBJECT_MAPPER.setSerializationInclusion(JsonInclude.Include.NON_NULL); } @Data static class ResponseData<T> { private int code; private String message; private T data; } static class ResponseData1 extends ResponseData<User> { } @Data static class User { private String name; private Integer age; private Boolean used; } public static void main(String[] args) throws Exception { serialize(); } // 反序列化 public static void deserialize() throws Exception { String json = "{\n" + " \"code\": 1,\n" + " \"message\": \"test message\",\n" + " \"data\": {\n" + " \"name\":\"zhang\",\n" + " \"age\":\"100\",\n" + " \"used\":true,\n" + " \"test\":\"sds\"\n" + " }\n" + "}"; // 泛型反序列化的5种方式 // 方式1 -- 推荐1 TypeReference<ResponseData<User>> type = new TypeReference<ResponseData<User>>() { }; ResponseData<User> res1 = OBJECT_MAPPER.readValue(json, type); // 方式2 -- 推荐2 依次指定主体class,n个泛型class JavaType javaType1 = OBJECT_MAPPER.getTypeFactory().constructParametricType(ResponseData.class, User.class); ResponseData<User> res2 = OBJECT_MAPPER.readValue(json, javaType1); // 方式3 过时 JavaType javaType2 = OBJECT_MAPPER.getTypeFactory().constructParametrizedType(ResponseData.class, ResponseData.class, User.class); ResponseData<User> res3 = OBJECT_MAPPER.readValue(json, javaType2); // 方式4 Type[] types = new Type[1]; types[0] = User.class; final ParameterizedTypeImpl type4 = ParameterizedTypeImpl.make(ResponseData.class, types, ResponseData.class.getDeclaringClass()); TypeReference<ResponseData> typeReference = new TypeReference<ResponseData>() { @Override public Type getType() { return type4; } }; ResponseData<User> res4 = OBJECT_MAPPER.readValue(json, typeReference); // 方式5 新建一个类指定泛型 ResponseData1 res5 = OBJECT_MAPPER.readValue(json, ResponseData1.class); System.out.println("res1:" + res1); System.out.println("res2:" + res2); System.out.println("res3:" + res3); System.out.println("res4:" + res4); System.out.println("res5:" + res5); String data1 = "{\n" + " \"code\": 1,\n" + " \"message\": \"test message\",\n" + " \"data\": [\n" + " {\n" + " \"name\": \"zhang1\",\n" + " \"age\": \"100\",\n" + " \"used\": false,\n" + " \"test\": \"sds\"\n" + " },\n" + " {\n" + " \"name\": \"zhang2\",\n" + " \"age\": \"100\",\n" + " \"used\": false,\n" + " \"test\": \"sds\"\n" + " }\n" + " ]\n" + "}"; JsonNode root = OBJECT_MAPPER.readTree(data1); // get 没有返回null System.out.println(root.get("111")); // path 不会异常,没有返回空字符串 System.out.println(root.path("111").asText().length()); // 方式1 获取数组 JsonNode node = root.path("data"); if (node.isArray()) { for (JsonNode objNode : node) { System.out.println(objNode); } } // 方式2 获取数组 ArrayNode arrayNode = (ArrayNode) (root.get("data")); for (JsonNode jsonNode : arrayNode) { System.out.println(jsonNode); } } // 序列化成字符串 public static void serialize() throws Exception { // ======================= alibaba JSONObject root = new JSONObject(); root.put("code", 1); root.put("message", "test"); JSONArray jsonArray = new JSONArray(); jsonArray.add("test1"); jsonArray.add("test2"); jsonArray.add("test3"); root.put("data", jsonArray); System.out.println(OBJECT_MAPPER.writeValueAsString(root)); // ========================== jackson ObjectNode root1 = OBJECT_MAPPER.createObjectNode(); root1.put("code", 1); root1.put("message", "test"); ArrayNode array1 = OBJECT_MAPPER.createArrayNode(); ObjectNode element1 = OBJECT_MAPPER.createObjectNode(); element1.put("name", "zhang"); element1.put("age", 99); element1.put("used", true); array1.add(element1); root1.set("data", array1); System.out.println(OBJECT_MAPPER.writeValueAsString(root1)); } }
<jackson.version>2.10.3</jackson.version>
<fastson.version>1.2.58</fastson.version>
<!--Jackson--> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-core</artifactId> <version>${jackson.version}</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>${jackson.version}</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-annotations</artifactId> <version>${jackson.version}</version> </dependency> <!-- Jackson end --> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.18.16</version> </dependency>
<dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>${fastson.version}</version> </dependency>