Gson在Java中的简要使用

最近在把一个数组或字符串转化成对象时，使用了Google的Gson感觉不错，下面我以代码的形式详细举例来介绍

上面的注释部分为输出结果，使用了maven ，这里是Gson的maven依赖 <dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
<version>2.2</version>
</dependency>package gson;import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;import org.junit.Test;import com.google.common.reflect.TypeToken;
import com.google.gson.Gson;public class AllInAllGSON {
Gson gson = new Gson（）;//生成一个json对象
@Test
/**
* [1,2,3,4,5,6,7,8,9,0] ["one","two","three","four","five","six","seven","eight","nine","zero"] [[1,2,3],[3,4,5],[4,5,6]]
* 3 1n3 2n3 3n3 4n3 5n3 6n3 7n3 8n3 9n3 0n4 onen4 twon4 threen4 fourn4 fiven4 sixn4 sevenn4 eightn4 ninen4 zero data 1 data 2 data 3
*data 3 data 4 data 5
data 4 data 5 data 6
*/
public void arrayToJson（）{
int [] n1 = {1,2,3,4,5,6,7,8,9,0};
int[][] data = {{1, 2, 3}, {3, 4, 5}, {4, 5, 6}};
String [] n2 = {"one","two","three","four","five","six","seven","eight","nine","zero"};

String x1 = gson.toJson（n1）;//把数组转化成json
String x2 = gson.toJson（n2）;
String x3 = gson.toJson（data）;
System.out.println（x1+ " "+ x2+" "+x3）;
int [] n3 = gson.fromJson（x1, int[].class）;//把一个json转成数组
String [] n4 = gson.fromJson（x2, String[].class）;
int [][] n5 = gson.fromJson（x3, int[][].class）;
for（int i=0;i<n3.length;i++）{
System.out.print（"n3 "+n3[i]）;
}
for（int i=0;i<n4.length;i++）{
System.out.print（"n4 "+n4[i]）;
}
for（int i=0;i<data.length;i++）{
for（int j=0;j<data[i].length;j++）{
System.out.print（" data "+data[i][j]）;
}
System.out.println（""）;
}
}
@Test
/**
* list ["hi","hello","how"]
* [{"name":"Alice","address":"AppSt","dateOfBirth":"Nov 1, 3900 12:00:00 AM"},{"name":"Bob","address":"Baa St"},{"name":"Carol","address":"Grape St","dateOfBirth":"Jun 21, 3900 12:00:00 AM"},{"name":"Mallory","address":"Mango St"}]
name Alice
name Bob
name Carol
name Mallory
*/
public void listToJson（）{
List<String> list = new ArrayList<String>（）;//把一个list集合转化成json串
list.add（"hi"）;
list.add（"hello"）;
list.add（"how"）;
String str = gson.toJson（list）;
System.out.println（"list "+str）;
Student a = new Student（"Alice", "AppSt", new Date（2000, 10, 1））;
Student b = new Student（"Bob", "Baa St", null）;
Student c = new Student（"Carol", "Grape St", new Date（2000, 5, 21））;
Student d = new Student（"Mallory", "Mango St", null）;
List<Student> student = new ArrayList<Student>（）;
student.add（a）;
student.add（b）;
student.add（c）;
student.add（d）;
String str1 = gson.toJson（student）;
System.out.println（str1）;
Type type = new TypeToken<List<Student>>（）{}.getType（）;//把json串转化成一个student对象
List<Student> stu = gson.fromJson（str1, type）;
for（Student s:stu）{
System.out.println（"name " + s.getName（））;
}
}
@Test
/**
* {"WHITE":"5454#FFFFFF","BLUE":"0000FF","YELLOW":"sd#FFFF00","GREEN":"1008000","BLACK":"000000","RED":"#FeF0000"}
map 5454#FFFFFF
map 0000FF
map sd#FFFF00
map 1008000
map 000000
map #FeF0000
*/
public void mapToJson（）{
Map<String, String> colours = new HashMap<String, String>（）;
colours.put（"BLACK", "000000"）;
colours.put（"RED", "#FeF0000"）;
colours.put（"GREEN", "1008000"）;
colours.put（"BLUE", "0000FF"）;
colours.put（"YELLOW", "sd#FFFF00"）;
colours.put（"WHITE", "5454#FFFFFF"）;
String str = gson.toJson（colours）;
System.out.println（str）;
Type type = new TypeToken<Map<String,String>>（） {}.getType（）;
Map<String,String> map = gson.fromJson（str, type）;
for（String key:map.keySet（））{
System.out.println（"map " + map.get（key））;
}
}
@Test
/**
* {"name":"Bob","address":"Baa St"}
Bob
*/
public void stuClass（）{
Student b = new Student（"Bob", "Baa St", null）;//对一个类的属性进行转成json串
String str = gson.toJson（b）;
System.out.println（str）;
Student stu = gson.fromJson（str, Student.class）;//把json转成java对象
System.out.println（stu.getName（））;
}
}Student类package gson;
import java.util.Date;public class Student {
private String name;
private String address;
private Date dateOfBirth; public Student（） {
} public Student（String name, String address, Date dateOfBirth） {
this.name = name;
this.address = address;
this.dateOfBirth = dateOfBirth;
} public String getName（） {
return name;
} public void setName（String name） {
this.name = name;
} public String getAddress（） {
return address;
} public void setAddress（String address） {
this.address = address;
} public Date getDateOfBirth（） {
return dateOfBirth;
} public void setDateOfBirth（Date dateOfBirth） {
this.dateOfBirth = dateOfBirth;
}
}--------------------------------------分割线 --------------------------------------编写高质量代码改善Java程序的151个建议 PDF高清完整版 http://www.linuxidc.com/Linux/2014-06/103388.htmJava 8简明教程 http://www.linuxidc.com/Linux/2014-03/98754.htmJava对象初始化顺序的简单验证 http://www.linuxidc.com/Linux/2014-02/96220.htmJava对象值传递和对象传递的总结 http://www.linuxidc.com/Linux/2012-12/76692.htmJava对象序列化ObjectOutputStream和ObjectInputStream示例 http://www.linuxidc.com/Linux/2012-08/68360.htm--------------------------------------分割线 --------------------------------------本文永久更新链接地址：http://www.linuxidc.com/Linux/2014-07/104325.htm