將Java的List構造經由過程GSON庫轉換為JSON的辦法示例

將Java的List構造經由過程GSON庫轉換為JSON的辦法示例。本站提示廣大學習愛好者：（將Java的List構造經由過程GSON庫轉換為JSON的辦法示例）文章只能為提供參考，不一定能成為您想要的結果。以下是將Java的List構造經由過程GSON庫轉換為JSON的辦法示例正文

發明了谷歌的gson，由於之前關於protocolbuf有一些懂得，帶著一些獵奇心，我開端應用了gson。
GitHub主頁：https://github.com/谷歌/gson
經由比擬，gson和其他現有java json類庫最年夜的分歧時gson須要序列化得實體類不須要應用annotation來標識須要序列化得字段，同時gson又可以經由過程應用annotation來靈巧設置裝備擺設須要序列化的字段。
將List或許Map轉換成json異常簡略：    

public String getJsonData(List<?> list) {
  Gson gson = new Gson();
  String jsonstring = gson.toJson(list);
  return jsonstring;
}

上面我們會有具體的例子。

示例
簡略對象轉化和帶泛型的List轉化：

實體類:

public class Student { 
  private int id; 
  private String name; 
  private Date birthDay; 
 
  public int getId() { 
    return id; 
  } 
 
  public void setId(int id) { 
    this.id = id; 
  } 
 
  public String getName() { 
    return name; 
  } 
 
  public void setName(String name) { 
    this.name = name; 
  } 
 
  public Date getBirthDay() { 
    return birthDay; 
  } 
 
  public void setBirthDay(Date birthDay) { 
    this.birthDay = birthDay; 
  } 
 
  @Override 
  public String toString() { 
    return "Student [birthDay=" + birthDay + ", id=" + id + ", name=" 
        + name + "]"; 
  } 
 
} 

測試類:

import java.util.ArrayList; 
import java.util.Date; 
import java.util.List; 
 
import com.谷歌.gson.Gson; 
import com.谷歌.gson.reflect.TypeToken; 
 
public class GsonTest1 { 
 
  public static void main(String[] args) { 
    Gson gson = new Gson(); 
 
    Student student1 = new Student(); 
    student1.setId(1); 
    student1.setName("李坤"); 
    student1.setBirthDay(new Date()); 
 
    // ////////////////////////////////////////////////////////// 
    System.out.println("----------簡略對象之間的轉化-------------"); 
    // 簡略的bean轉為json 
    String s1 = gson.toJson(student1); 
    System.out.println("簡略Bean轉化為Json===" + s1); 
 
    // json轉為簡略Bean 
    Student student = gson.fromJson(s1, Student.class); 
    System.out.println("Json轉為簡略Bean===" + student); 
    // 成果: 
    // 簡略Bean轉化為Json==={"id":1,"name":"李坤","birthDay":"Jun 22, 2012 8:27:52 AM"} 
    // Json轉為簡略Bean===Student [birthDay=Fri Jun 22 08:27:52 CST 2012, id=1, 
    // name=李坤] 
    // ////////////////////////////////////////////////////////// 
 
    Student student2 = new Student(); 
    student2.setId(2); 
    student2.setName("曹貴生"); 
    student2.setBirthDay(new Date()); 
 
    Student student3 = new Student(); 
    student3.setId(3); 
    student3.setName("柳波"); 
    student3.setBirthDay(new Date()); 
 
    List<Student> list = new ArrayList<Student>(); 
    list.add(student1); 
    list.add(student2); 
    list.add(student3); 
 
    System.out.println("----------帶泛型的List之間的轉化-------------"); 
    // 帶泛型的list轉化為json 
    String s2 = gson.toJson(list); 
    System.out.println("帶泛型的list轉化為json==" + s2); 
 
    // json轉為帶泛型的list 
    List<Student> retList = gson.fromJson(s2, 
        new TypeToken<List<Student>>() { 
        }.getType()); 
    for (Student stu : retList) { 
      System.out.println(stu); 
    } 
 
    // 成果: 
    // 帶泛型的list轉化為json==[{"id":1,"name":"李坤","birthDay":"Jun 22, 2012 8:28:52 AM"},{"id":2,"name":"曹貴生","birthDay":"Jun 22, 2012 8:28:52 AM"},{"id":3,"name":"柳波","birthDay":"Jun 22, 2012 8:28:52 AM"}] 
    // Student [birthDay=Fri Jun 22 08:28:52 CST 2012, id=1, name=李坤] 
    // Student [birthDay=Fri Jun 22 08:28:52 CST 2012, id=2, name=曹貴生] 
    // Student [birthDay=Fri Jun 22 08:28:52 CST 2012, id=3, name=柳波] 
 
  } 
} 

履行成果:

----------簡略對象之間的轉化------------- 
簡略Bean轉化為Json==={"id":1,"name":"李坤","birthDay":"Jun 22, 2012 9:10:31 PM"} 
Json轉為簡略Bean===Student [birthDay=Fri Jun 22 21:10:31 CST 2012, id=1, name=李坤] 
----------帶泛型的List之間的轉化------------- 
帶泛型的list轉化為json==[{"id":1,"name":"李坤","birthDay":"Jun 22, 2012 9:10:31 PM"},{"id":2,"name":"曹貴生","birthDay":"Jun 22, 2012 9:10:31 PM"},{"id":3,"name":"柳波","birthDay":"Jun 22, 2012 9:10:31 PM"}] 
Student [birthDay=Fri Jun 22 21:10:31 CST 2012, id=1, name=李坤] 
Student [birthDay=Fri Jun 22 21:10:31 CST 2012, id=2, name=曹貴生] 
Student [birthDay=Fri Jun 22 21:10:31 CST 2012, id=3, name=柳波]