net.sf.json------json解析
在测试终端支付时，发现net..sf.json.JSONArray;报红，引入了pom，项目里是jar包下载，不想复制移动一个个add to path，想用依赖的办法
但还是报红色，原因是自动下载的包pom中没有指定版本号
<dependency>
<groupId>net.sf.json-lib</groupId>
<artifactId>json-lib</artifactId>
<version>2.4</version>
<classifier>jdk15</classifier>
</dependency>
如果是gradle，引入：
compile 'net.sf.json-lib:json-lib:2.4:jdk15'
搞定，开始解析json
看一下项目中的代码（解析见下）
@SuppressWarnings("all")
public static <T> List<T> json2List(String jsonstr,Class<T> cls){
JSONArray ja = JSONArray.fromObject(jsonstr);
List<T> list = JSONArray.toList(ja, cls);
return list;
}
@SuppressWarnings("all")
public static <T> T json2Obj(String jsonstr,Class<T> cls){
JSONObject jo = JSONObject.fromObject(jsonstr);
T obj = (T)JSONObject.toBean(jo, cls);
return obj;
}
public static String obj2json(Object obj){
return JSONObject.fromObject(obj).toString();
}
public static String array2json(Object obj){
return JSONArray.fromObject(obj).toString();
}
public static <T1,T2> List<T2> convertMap2List(Map<T1,T2> map){
if(map==null) return null;
return new ArrayList<T2>(map.values());
}
首先我们知道
JSON 和 JS 对象互转
要实现从JSON字符串转换为JS对象，使用 JSON.parse() 方法：
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var obj = JSON.parse('{"a": "Hello", "b": "World"}'); //结果是 {a: 'Hello', b: 'World'} |
要实现从JS对象转换为JSON字符串，使用 JSON.stringify() 方法：
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var json = JSON.stringify({a: 'Hello', b: 'World'}); //结果是 '{"a": "Hello", "b": "World"}' |
而今天我们要用的就是一个json的帮助包之一的net.sf.json-，这些包其实都是类似的，帮我们封装了方法，直接使用
其中jSONArray是一个一个加进去的;
JSONObject是一对一对加进去的;
1.JSONObject
可以理解为是这个包里面的json类型是object就是最初始化的封装，并且给你封装了方法
package com.itlwc.test; import net.sf.json.JSONArray; import net.sf.json.JSONObject; public class Test { public static void main(String[] args) { // 创建JSONObject JSONObject jsonObject = new JSONObject(); jsonObject.put("username", "lwc"); jsonObject.put("password", "123"); // 打印:1 System.out.println(jsonObject); // 增加属性,打印:2 jsonObject.element("sex", "男"); System.out.println(jsonObject); // 根据key返回,打印:3 System.out.println(jsonObject.get("sex")); // 判读输出对象的类型 boolean isArray = jsonObject.isArray(); boolean isEmpty = jsonObject.isEmpty(); boolean isNullObject = jsonObject.isNullObject(); // 打印:4 System.out.println("是否数组:" + isArray + " 是否空:" + isEmpty + " 是否空对象:" + isNullObject); // 把JSONArray增加到JSONObject中 JSONArray jsonArray = new JSONArray(); jsonArray.add(0, "lwc"); jsonArray.add(1, "nxj"); // 开始增加 jsonObject.element("student", jsonArray); // 打印:5 System.out.println(jsonObject); } } /* 打印结果 {"username":"lwc","password":"123"} {"username":"lwc","password":"123","sex":"男"} 男 是否为数组:false 是否为空:false 是否为空对象:false {"username":"lwc","password":"123","sex":"男","student":["lwc","nxj"]} */
2.JSONArray（一般是一个一个加JSONObject）
json数组的封装
package com.itlwc.test; import net.sf.json.JSONArray; import net.sf.json.JSONObject; public class Test { public static void main(String[] args) { //创建JSONArray JSONArray jsonArray = new JSONArray(); jsonArray.add(0, "lwc"); jsonArray.add(1, "nxj"); jsonArray.element("mxj"); //打印:1 System.out.println(jsonArray); //根据下标返回,打印:2 System.out.println(jsonArray.get(0)); //根据下标设置新值,打印:3 jsonArray.set(0, "itlwc"); System.out.println(jsonArray); //把JSONObject放入到JSONArray中 JSONObject jsonObject = new JSONObject(); jsonObject.put("username", "lwc"); jsonObject.put("password", "123"); //开始增加,打印:4 jsonArray.add(jsonObject); System.out.println(jsonArray); //遍历,打印:5 for(int i=0;i<jsonArray.size();i++){ System.out.print(jsonArray.get(i)+"\t"); } } } /* 打印结果 ["lwc","nxj","mxj"] lwc ["itlwc","nxj","mxj"] ["itlwc","nxj","mxj",{"username":"lwc","password":"123"}] itlwc nxj mxj {"username":"lwc","password":"123"}
3.JavaBean与json字符串互转
package com.itlwc.test; import net.sf.json.JSONObject; import com.itlwc.entity.Student; public class Test { public static void main(String[] args) { // JavaBean对象转json字符串 Student stu1 = new Student("lwc", "111111"); JSONObject jsonObject = JSONObject.fromObject(stu1); System.out.println(jsonObject); // json字符串转JavaBean String jsondata = "{\"password\":\"111111\",\"username\":\"lwc\"}"; JSONObject jsonObject1 = JSONObject.fromObject(jsondata); Student stu2 = (Student) JSONObject.toBean(jsonObject1, Student.class); System.out.println(stu2); } } /* 打印结果: {"password":"111111","username":"lwc"} 用户: lwc 密码:111111 */
4.List与json字符串互转
package com.itlwc.test; import java.util.ArrayList; import java.util.List; import net.sf.json.JSONArray; import net.sf.json.JSONObject; import com.itlwc.entity.Student; public class Test { public static void main(String[] args) { // List转json字符串 List list = new ArrayList(); list.add(new Student("lwc", "111111")); list.add(new Student("nxj", "222222")); JSONArray jsonArray = JSONArray.fromObject(list); System.out.println(jsonArray); // json字符串转List List list1 = new ArrayList(); String jsondata = "[{\"password\":\"111111\",\"username\":\"lwc\"},{\"password\":\"222222\",\"username\":\"nxj\"}]"; JSONArray jsonArray1 = JSONArray.fromObject(jsondata); for (int i = 0; i < jsonArray1.size(); i++) { JSONObject jsonObject2 = jsonArray1.getJSONObject(i); Student stu2 = (Student) JSONObject.toBean(jsonObject2, Student.class); list1.add(stu2); } System.out.println(list1); } } /* 打印结果: [{"password":"111111","username":"lwc"},{"password":"222222","username":"nxj"}] [用户: lwc 密码:111111, 用户: nxj 密码:222222]
5.Map与json字符串互转
package com.itlwc.test; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import java.util.Set; import net.sf.json.JSONObject; import com.itlwc.entity.Student; public class Test { public static void main(String[] args) { // Map转json字符串 Map map = new HashMap(); map.put("1", new Student("lwc", "111111")); map.put("2", new Student("nxj", "222222")); JSONObject jsonMap = JSONObject.fromObject(map); System.out.println(jsonMap); // json字符串转Map String jsondata = "{\"2\":{\"password\":\"222222\",\"username\":\"nxj\"},\"1\":{\"password\":\"111111\",\"username\":\"lwc\"}}"; Map map1 = (Map) JSONObject.fromObject(jsondata); Set set = map1.keySet(); Iterator ite = set.iterator(); while (ite.hasNext()) { String key = (String) ite.next(); JSONObject jsonObject = JSONObject.fromObject(map1.get(key)); Student stu = (Student) JSONObject .toBean(jsonObject, Student.class); System.out.println(key + " " + stu); } } } /* 打印结果: {"2":{"password":"222222","username":"nxj"},"1":{"password":"111111","username":"lwc"}} 2 用户: nxj 密码:222222 1 用户: lwc 密码:111111
6.JSONArray与List互转
package com.itlwc.test; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import net.sf.json.JSONArray; import net.sf.json.JsonConfig; import com.itlwc.entity.Student; public class Test { public static void main(String[] args) { //List转型JSONArray List<Student> list = new ArrayList<Student>(); list.add(new Student("lwc", "111111")); list.add(new Student("nxj", "222222")); JSONArray jsonArray = JSONArray.fromObject(list); System.out.println(jsonArray.toString()); //JSONArray转型List List<Student> list2 = JSONArray.toList(jsonArray, new Student(), new JsonConfig()); Iterator<Student> ite = list2.iterator(); while(ite.hasNext()){ Student stu =ite.next(); System.out.println(stu); } } } /* 打印结果 [{"password":"111111","username":"lwc"},{"password":"222222","username":"nxj"}] 用户: lwc 密码:111111 用户: nxj 密码:222222
7.JSONArray与数组互转
package com.itlwc.test; import net.sf.json.JSONArray; public class Test { public static void main(String[] args) { // Java数组转JSONArray boolean[] boolArray = new boolean[] { true, false, true }; JSONArray jsonArray = JSONArray.fromObject(boolArray); System.out.println(jsonArray.toString()); // JSONArray转Java数组 Object obj[] = jsonArray.toArray(); for (Object o : obj) { System.out.print(o + " "); } } } /* 打印结果 : [true,false,true] true false true
8.XML与JSON互转
需要导入xom-1.1.jar
package com.itlwc.test; import net.sf.json.JSON; import net.sf.json.JSONObject; import net.sf.json.xml.XMLSerializer; public class Test { public static void main(String[] args) throws Exception { // XML转JSON String xml = "<root>" + "<name type='type'>zhaipuhong</name>" + "<gender>male</gender>" + "<birthday>" + "<year>1970</year>" + "<month>12</month>" + "<day>17</day>" + "</birthday>" + "</root>"; XMLSerializer xmlSerializer = new XMLSerializer(); JSON json = xmlSerializer.read(xml); System.out.println(json.toString(2)); // JSON转XML String jsondata = "{\"root\":{" + "\"name\":\"zhaipuhong\"," + "\"gender\":\"male\"," + "\"birthday\":{" + "\"year\":\"1970\"," + "\"month\":\"12\"," + "\"day\":\"17\"" + "}" + "}" + "}"; JSONObject jsonObject = JSONObject.fromObject(jsondata); String xmlstr = new XMLSerializer().write(jsonObject); System.out.println(xmlstr); } } /* 打印结果: { "name": "zhaipuhong", "gender": "male", "birthday": { "year": "1970", "month": "12", "day": "17" } } <?xml version="1.0" encoding="UTF-8"?> <o> <root class="object"> <birthday class="object"> <day type="string">17</day> <month type="string">12</month> <year type="string">1970</year> </birthday> <gender type="string">male</gender> <name type="string">zhaipuhong</name> </root> </o> */
