Android--------使用gson解析json文件

##使用gson解析json文件

**json的格式有兩種：**

**1. {}類型，及數據用{}包含；**

**2. []類型，即數據用[]包含；**



 
 下面用個例子，簡單的介紹gson如何解析json,僅使用~

 先發兩個json 內容 

1、最外層是{}

    {    
        "resp": "ok",
        "result": {
            "date": "2013-4-19 16:55:58",
            "focus": [
                {
                    "summary": "簡介",
                    "title": "標題",
                    "url": "http://www.ceshi.com"
                },
                {
                    "summary": "簡介22",
                    "title": "標題22",
                    "url": "http://www.ceshi22.com"
                }
            ],
            "items": [
                {
                    "id": "11",
                    "name": "名稱",
                    "price": "88.88"
                },
                {
                    "id": "22",
                    "name": "名稱22",
                    "price": "100"
                }
            ]
        }    
    }


2、外層是[]

    [    
        {
            "addr": "北京",
            "age": "22",
            "name": "zeng"
        },
        {
            "addr": "上海",
            "age": "20",
            "name": "zhang"
        },
        {
            "addr": "深圳",
            "age": "25",
            "name": "wang"
        }    
    ]

###**一、使用Gson,解析，關鍵的就是定義好JavaBean類對象**

1、***定義｛｝類型的JavaBean類***

Bean.java

    public class Bean {  //若實現Serializable接口，則不用寫下面的SerializedName("字段名")，但成員變量名稱必須與json中一樣
    //  @SerializedName("resp")  
    //  private String respone;//假如變量命名與解析數據不同，則加上@SerializedName("")  
    private String resp;  
    private Result result;  
    //....下面省略 set ,get  

//resultBean類

Result.java
 

    public class Result {    
        private String date;  
        private List<FocusItem> focus;  
        private List<Item> items;  
    }
FocusItem.java

    public class FocusItem {        
        private String title;  
        private String summary;  
        private String url;  
    }
Item.java

    public class Item {            
        private String name;  
        private int id;  
        private float price; 
    } 

 2、***定義｛｝類型的JavaBean類***

  Info.java

    public class Info {    
        private String name;  
        private int age;  
        private String addr; 
    } 


###**二、解析代碼，一個最外層是{}  一個是[]**


    private void parse() {  
        Gson gson = new Gson();  
        switch (type) { 
        //最外層是{}，封裝為一個對象
        case OBJ:  
            Bean fromJson = gson.fromJson(readContent, Bean.class);  
            System.out.println(fromJson.toString());  
            break;  
        //最外層是[]，封裝為一個數組對象
        case ARR:  
            Type type = new TypeToken<List<Info>>() {}.getType();  
            Object fromJson2 = gson.fromJson(readContent, type);  
            List<Info> list = (List<Info>) fromJson2; 
            break; 
        }
    }