主要用于测试学习用jackson包实现json、对象、Map之间的转换。
1、准备测试用的Java类
（1）Link类
Java代码 package test; /** * Description: 联系方式，被user使用 */ public class Link { private String phone; //移动电话 private String address; //地址 private String qq; //QQ public String getPhone() { return phone; } public void setPhone(String phone) { this.phone = phone; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } public String getQq() { return qq; } public void setQq(String qq) { this.qq = qq; } }
（2）User类
Java代码 package test; import java.util.Date; import java.util.List; import java.util.Map; import java.util.Set; /** * Description: 用户，测试模型类 */ public class User { private String id; //标识 private String name; //姓名 private int age; //年龄 private double pay; //工资 private boolean valid; //是否有效 private char one; //一个字符 private Date birthday; //生日 private Link link; //联系方式，自定义 private Map map; //测试用 private List list; //测试用 private Set set; //测试用 public String getId() { return id; } public void setId(String id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public double getPay() { return pay; } public void setPay(double pay) { this.pay = pay; } public boolean isValid() { return valid; } public void setValid(boolean valid) { this.valid = valid; } public char getOne() { return one; } public void setOne(char one) { this.one = one; } public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } public Link getLink() { return link; } public void setLink(Link link) { this.link = link; } public Map getMap() { return map; } public void setMap(Map map) { this.map = map; } public List getList() { return list; } public void setList(List list) { this.list = list; } public Set getSet() { return set; } public void setSet(Set set) { this.set = set; } }
2、测试类，没用Junit，用Main()方法输出。
Java代码 package test; import java.io.IOException; import java.util.ArrayList; import java.util.Date; import java.util.HashMap; import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Set; import org.codehaus.jackson.JsonGenerationException; import org.codehaus.jackson.map.JsonMappingException; import org.codehaus.jackson.map.ObjectMapper; /** * Description: 主要用于测试学习用jackson包实现json、对象、Map之间的转换 * * Date: 2016年6月6日 * Time: 下午3:23:23 */ public class JsonTest { public static void main(String[] args) throws JsonGenerationException, JsonMappingException, IOException { User user=new User(); user.setId("01"); user.setName("张三"); user.setAge(33); user.setPay(6666.88); user.setValid(true); user.setOne('E'); user.setBirthday(new Date(20l*366*24*3600*1000)); //1990年 Link link = new Link(); link.setAddress("河南省济源市"); link.setPhone("13899995555"); link.setQq("123456"); user.setLink(link); Map map=new HashMap(); map.put("aa", "this is aa"); map.put("bb", "this is bb"); map.put("cc", "this is cc"); user.setMap(map); List list=new ArrayList(){}; list.add("普洱"); list.add("大红袍"); user.setList(list); Set set=new HashSet(); set.add("篮球"); set.add("足球"); set.add("乒乓球"); user.setSet(set); ObjectMapper mapper = new ObjectMapper(); //转换器 //测试01：对象--json String json=mapper.writeValueAsString(user); //将对象转换成json System.out.println(json); /* 结果如下： {"id":"01","name":"张三","age":33,"pay":6666.88,"valid":true,"one":"E","birthday":1465185448998, "link":{"phone":"13899995555","address":"河南省济源市","qq":"123456"}, "map":{"aa":"this is aa","bb":"this is bb","cc":"this is cc"}, "list":["普洱","大红袍"], "set":["乒乓球","足球","篮球"]} 注意点：（1） 日期--长整型 （2）List、Set均转成数组 */ //测试02：json--map Map m = mapper.readValue(json, Map.class); //json转换成map System.out.println("pay："+m.get("pay").getClass().getName()); //java.lang.Double System.out.println("valid："+m.get("valid").getClass().getName()); //java.lang.Boolean System.out.println("birthday："+m.get("birthday").getClass().getName()); //java.lang.Long System.out.println("link："+m.get("link").getClass().getName()); //java.util.LinkedHashMap System.out.println("map："+m.get("map").getClass().getName()); //java.util.LinkedHashMap System.out.println("list："+m.get("list").getClass().getName()); //java.util.ArrayList System.out.println("set："+m.get("set").getClass().getName()); //java.util.ArrayList /* 结果如下： pay：java.lang.Double valid：java.lang.Boolean birthday：java.lang.Long link：java.util.LinkedHashMap map：java.util.LinkedHashMap list：java.util.ArrayList set：java.util.ArrayList 注意点：（1） 日期--长整型 （2）map、子对象均转换成了LinkedHashMap （3）List、Set均转成ArrayList */ //测试03：map--json json=mapper.writeValueAsString(m); //map转json System.out.println(json); //与之前格式完全相同，说明经过map转换后，信息没有丢失 //测试04：json--对象 User u=mapper.readValue(json, User.class); //json转java对象。经测，转成对象后，一切恢复正常 System.out.println("pay："+u.getPay()); System.out.println("valid："+u.isValid()); System.out.println("birthday："+u.getBirthday()); System.out.println("link："+u.getLink()); System.out.println("map："+u.getMap()); System.out.println("list："+u.getList()); System.out.println("set："+u.getSet()); //测试05：其他转换 byte[] data=mapper.writeValueAsBytes(u); //对象转成二进制数组 } }
3、输出结果
Other代码 {"id":"01","name":"张三","age":33,"pay":6666.88,"valid":true,"one":"E","birthday":632448000000,"link":{"phone":"13899995555","address":"河南省济源市","qq":"123456"},"map":{"aa":"this is aa","bb":"this is bb","cc":"this is cc"},"list":["普洱","大红袍"],"set":["乒乓球","足球","篮球"]} pay：java.lang.Double valid：java.lang.Boolean birthday：java.lang.Long link：java.util.LinkedHashMap map：java.util.LinkedHashMap list：java.util.ArrayList set：java.util.ArrayList {"id":"01","name":"张三","age":33,"pay":6666.88,"valid":true,"one":"E","birthday":632448000000,"link":{"phone":"13899995555","address":"河南省济源市","qq":"123456"},"map":{"aa":"this is aa","bb":"this is bb","cc":"this is cc"},"list":["普洱","大红袍"],"set":["乒乓球","足球","篮球"]} pay：6666.88 valid：true birthday：Tue Jan 16 08:00:00 CST 1990 link：test.Link@350385f1 map：{aa=this is aa, bb=this is bb, cc=this is cc} list：[普洱, 大红袍] set：[足球, 乒乓球, 篮球]