JSON string converted to Java object

1. The JSON string is converted to Java Object 1.1. JSON string converted to Java bean

Json2bean.java

Package Jackson; import java.io.IOException; import Org.codehaus.jackson.map.ObjectMapper; Public class Json2bean { Public static void main (string[] args)throws ioexception{ String Jsonstr = "{\" name\ ": \" Morris\ ", \" age\ ": \" 22\ ", \" sex\ ": \ " male \ "}"; Objectmapper mapper = new objectmapper (); Person person = mapper.readvalue (jsonstr, person. Class); System. out. println (person); } }

1.2. JSON string conversion to Java list collection

Json2list.java

Package Jackson; import java.io.IOException; import Java.util.LinkedHashMap; import java.util.List; import Org.codehaus.jackson.map.ObjectMapper; Public class json2list { Public static void main (string[] args)throws IOException { String jsonstr = "[{\" name\ ": \" bob\ ", \" age\ ": \" 33\ ", \" sex\ ": \ " F "}," + "{\" name\ ": \" Morris\ ", \" age\ ": \" 22\ ", \" sex\ ": \" male \ "}]"; Objectmapper mapper = new objectmapper (); list<linkedhashmap<string, string>> list = mapper.readvalue (jsonstr, list. class ); for (linkedhashmap<string, string> linkedhashmap:list) { for (String Key:linkedHashMap.keySet ()) { System. out. println (key+":"+linkedhashmap.get (key)); } } } }

The results of the operation are as follows:

Name:bob

Age:33

Sex: Female

Name:morris

Age:22

Sex: Male

1.3. JSON string conversion to Java map Collection

Json2map.java

Package Jackson; import java.io.IOException; import Java.util.Map; import Java.util.Set; import Org.codehaus.jackson.map.ObjectMapper; Public class Json2map { Public static void main (string[] args)throws IOException { String Jsonstr = "{\" success\ ": True,\" a\ ": {\" address\ ": \" address2\ ", \" name\ ": \" haha2\ ", \" id\ ": 2,\" email\ ": \" Email2\ "},"+ "\" b\ ": {\" address\ ": \" Address\ ", \" name\ ": \" Haha\ ", \" id\ ": 1,\" email\ ": \" Email\ "}}"; Objectmapper mapper = new objectmapper (); map map = mapper.readvalue (jsonstr, map. Class); Set keySet = Map.keyset (); for (Object Key:keyset) { System. out. println (key+":"+map.get (key)); } } }

The results of the operation are as follows:

Success:true

A:{address=address2, NAME=HAHA2, ID=2,EMAIL=EMAIL2}

B:{address=address, Name=haha, Id=1,email=email}

1.4. JSON string conversions to arrays

Json2array.java

Package Jackson; import java.io.IOException; import Org.codehaus.jackson.map.ObjectMapper; Public class Json2array { Public static void main (string[] args)throws IOException { String jsonstr = "[{\" name\ ": \" bob\ ", \" age\ ": \" 33\ ", \" sex\ ": \ " F "}," + "{\" name\ ": \" Morris\ ", \" age\ ": \" 22\ ", \" sex\ ": \" male \ "}]"; Objectmapper mapper = new objectmapper (); person[] persons = Mapper.readvalue (Jsonstr, person[]. Class); for (Person Person:persons) { System. out. println (person); } } }

The results of the operation are as follows:

person [Name=bob, age=33, sex= women]

person [Name=morris, age=22, sex= male]

JSON string converted to Java object