關于fastjson的常見API詳解
簡介
首先,介紹一下fastjson。fastjson是由alibaba開源的一套json處理器。與其他json處理器(如Gson,Jackson等)和其他的Java對象序列化反序列化方式相比,有比較明顯的性能優(yōu)勢。
maven 添加配置:
< !-- 阿里fastjson包JSON轉(zhuǎn)換–> < dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.47</version> < /dependency>
常見API
1. 將對象序列化成json字符串
String com.alibaba.fastjson.JSON.toJSONString(Object object)
效果
{ "l_factory": [{ "fcName": "淘寶", "l_worker": [{ "age": 26, "name": "李飛", "sex": "男" }, { "age": 0 }, { "age": 0 }, { "age": 0 }] }, { "fcName": "拼多多", "l_worker": [] }], "pjName": "接口自動化", "waibao": true }
2. 將json字符串反序列化成對象 Project
com.alibaba.fastjson.JSON.parseObject(String text, Class clazz)
System.out.println("parseObject 將json字符串反序列化成對象------" + "waibao="+ testFastJson.getJsonValueObj(json, "waibao", Boolean.class));
效果
waibao=true
3. 將json字符串反序列化成JSON對象 JSONObject
com.alibaba.fastjson.JSON.parseObject(String text)
[{ "l_worker": [{ "sex": "男", "name": "張三", "age": 39 }, { "sex": "男", "name": "李四", "age": 24 }], "fcName": "淘寶" }, { "l_worker": [{ "sex": "女", "name": "王香", "age": 26 }, { "sex": "男", "name": "李飛", "age": 26 }], "fcName": "拼多多" }]
4. 根據(jù)key 得到json中的json數(shù)組 JSONArray
com.alibaba.fastjson.JSONObject.getJSONArray(String key)
[{ "sex": "男", "name": "張三", "age": 39 }, { "sex": "男", "name": "李四", "age": 24 }] [{ "sex": "男", "name": "張三", "age": 39 }, { "sex": "男", "name": "李四", "age": 24 }]
5. 根據(jù)下標拿到json數(shù)組的json對象 JSONObject
com.alibaba.fastjson.JSONArray.getJSONObject(int index)
效果
{ "sex": "男", "name": "張三", "age": 39 }
6.根據(jù)key拿到json的字符串值 String
com.alibaba.fastjson.JSONObject.getString(String key)
api詳細案例
Project
package com.json; import java.util.List; public class Project { String pjName; boolean waibao; public boolean isWaibao() { return waibao; } public void setWaibao(boolean waibao) { this.waibao = waibao; } List<Factory> l_factory; //List<Worker> worker; public String getPjName() { return pjName; } public void setPjName(String pjName) { this.pjName = pjName; } public List<Factory> getL_factory() { return l_factory; } public void setL_factory(List<Factory> l_factory) { this.l_factory = l_factory; } }
Factory
package com.json; import java.util.List; public class Factory { String fcName; List<Worker> l_worker; public String getFcName() { return fcName; } public void setFcName(String fcName) { this.fcName = fcName; } public List<Worker> getL_worker() { return l_worker; } public void setL_worker(List<Worker> l_worker) { this.l_worker = l_worker; } }
Worker
package com.json; public class Worker { String name; String sex; int age; public int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } }
TestFastJson
package com.json; import java.util.ArrayList; import java.util.List; import com.alibaba.fastjson.JSON; import com.alibaba.fastjson.JSONArray; import com.alibaba.fastjson.JSONObject; public class TestFastJson { public static void main(String[] args) { TestFastJson testFastJson = new TestFastJson(); Project project = testFastJson.init(); String json = testFastJson.getJsonString(project); // System.out.println("json="+json); // {"l_factory":[{"fcName":"淘寶","l_worker":[{"age":26,"name":"李飛","sex":"男"},{"age":0},{"age":0},{"age":0}]},{"fcName":"拼多多","l_worker":[]}],"pjName":"接口自動化","waibao":true} // System.out.println("parseObject 將json字符串反序列化成對象------" + "waibao=" // + testFastJson.getJsonValueObj(json, "waibao", Boolean.class)); // waibao=true JSONArray array = (JSONArray) testFastJson.getJsonValueObj(json, "l_factory", JSONArray.class); // System.out.println("array=" + array.toString()); // array=[{"l_worker":[{"sex":"男","name":"張三","age":39},{"sex":"男","name":"李四","age":24}],"fcName":"淘寶"},{"l_worker":[{"sex":"女","name":"王香","age":26},{"sex":"男","name":"李飛","age":26}],"fcName":"拼多多"}] // String jsonArr = testFastJson.getJsonArrayValue(array, 0, "fcName"); // System.out.println("fcname:" + jsonArr); // fcname:淘寶 JSONArray array2 = testFastJson.getJsonArrayValueIsArray(array, 0, "l_worker"); // System.out.println("array2=" + array2.toString()); // array2=[{"sex":"男","name":"張三","age":39},{"sex":"男","name":"李四","age":24}] String json2 = testFastJson.getJsonArrayValue(array2, 0); // System.out.println("json2="+json2); // {"sex":"男","name":"張三","age":39} // System.out.println("name"+testFastJson.getJsonValueObj(json, key, clazz)); /* * 以下輸出 name=張三 sex=男 age=39 jsonArr2=男 * */ System.out.println("name=" + testFastJson.getJsonValueObj(json2, "name", String.class)); System.out.println("sex=" + testFastJson.getJsonValueObj(json2, "sex", String.class)); System.out.println("age=" + testFastJson.getJsonValueObj(json2, "age", Integer.class)); String jsonArr2 = testFastJson.getJsonArrayValue(array2, 0, "sex"); System.out.println("jsonArr2=" + jsonArr2); /* * 接口自動化 淘寶 張三 * */ System.out.println(testFastJson.getJsonValue(json)); System.out.println(testFastJson.getJsonValue(json, "l_factory")); System.out.println(testFastJson.getJsonValue(json, "l_factory", "l_worker")); } public static void main1(String args[]) { TestFastJson tfj = new TestFastJson(); Project prj = tfj.init(); String json = tfj.getJsonString(prj); prj.setPjName("序列化后修改pjname"); System.out.println(prj.getPjName());// 序列化后修改pjname Project po = JSON.parseObject(json, Project.class); System.out.println(po.getPjName());// 接口自動化 } public void tt(Class clazz) { System.out.println(clazz.getSimpleName()); if (clazz.getName().equals("String")) { System.out.println("stringllala"); } } /** * 將對象轉(zhuǎn)化為json * * @param project * @return */ private String getJsonString(Object object) { // TODO Auto-generated method stub String json = JSON.toJSONString(object); return json; } /** * 初始化 * * @return */ private Project init() { Project project = new Project(); Factory f1 = new Factory(); Factory f2 = new Factory(); Worker wk1 = new Worker(); wk1.setName("張三"); wk1.setAge(39); wk1.setSex("男"); Worker wk2 = new Worker(); wk2.setName("李四"); wk2.setAge(24); wk2.setSex("男"); Worker wk3 = new Worker(); wk3.setName("王香"); wk3.setAge(26); wk3.setSex("女"); Worker wk4 = new Worker(); wk4.setName("李飛"); wk4.setAge(26); wk4.setSex("男"); List<Worker> workers1 = new ArrayList<>(); workers1.add(wk1); workers1.add(wk2); List<Worker> workers2 = new ArrayList<>(); workers2.add(wk3); workers2.add(wk4); f1.setFcName("淘寶"); f1.setL_worker(workers1); f2.setFcName("拼多多"); f2.setL_worker(workers2); List<Factory> factorys = new ArrayList<Factory>(); factorys.add(f1); factorys.add(f2); project.setPjName("接口自動化"); project.setWaibao(true); project.setL_factory(factorys); return project; } /** * 根據(jù)key得到json的value * */ public String getJsonValue(String json) { JSONObject jsonObject = JSON.parseObject(json); String value = jsonObject.getString("pjName"); return value; } /** * 根據(jù)對象的類型,自動識別獲取該對象的值 */ public Object getJsonValueObj(String json, String key, Class clazz) { JSONObject jo = JSON.parseObject(json); if (clazz.getSimpleName().equals("String")) { String value = jo.getString(key); return value; } else if (clazz.getSimpleName().equals("Integer")) { Integer value = jo.getInteger(key); return value; } else if (clazz.getSimpleName().equals("Boolean")) { Boolean value = jo.getBoolean(key); return value; } else if (clazz.getSimpleName().equals("JSONArray")) { JSONArray array = jo.getJSONArray(key); return array; } else { return "error, 暫不支持的類型:" + clazz.toString(); } } /** * 根據(jù)key得到json的集合 * */ public JSONArray getJsonArray(String json, String key) { JSONObject jo = JSON.parseObject(json); JSONArray array = jo.getJSONArray(key); return array; } public String getJsonValue(String json, String key) { JSONObject jo = JSON.parseObject(json); JSONArray array = jo.getJSONArray(key); JSONObject jo_fc = array.getJSONObject(0); String value = jo_fc.getString("fcName"); return value; } public String getJsonValue(String json, String key, String keyW) { JSONObject jo = JSON.parseObject(json); JSONArray array = jo.getJSONArray(key); JSONObject jo_fc = array.getJSONObject(0); JSONArray arrayW = jo_fc.getJSONArray(keyW); JSONObject jo_wk = arrayW.getJSONObject(0); String value = jo_wk.getString("name"); int age = jo_wk.getIntValue("age"); return value; } /** * 根據(jù)下標得到json數(shù)組的值 * * @return */ public String getJsonArrayValue(JSONArray array, int index) { JSONObject jo_fc = array.getJSONObject(index); String json = jo_fc.toJSONString(); return json; } /** * 根據(jù)下標得到j'son數(shù)組的值,再根據(jù)key得到該值的value,該值類型是String * * @param array * @param index * @param key * @return */ public String getJsonArrayValue(JSONArray array, int index, String key) { JSONObject jo_fc = array.getJSONObject(index); String value = jo_fc.getString(key); return value; } /** * 根據(jù)下標得到json數(shù)組的值,再根據(jù)key得到該值的value,該值類型是string * * @param array * @return */ public JSONArray getJsonArrayValueIsArray(JSONArray array, int index, String key) { JSONObject jo_fc = array.getJSONObject(index); JSONArray arrayNew = jo_fc.getJSONArray(key); return arrayNew; } }
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