GSON對象deserialisation

Question

你能告訴我怎麼用GSON提取此字符串中定義了兩個不同的對象： http://json.parser.online.fr/

我嘗試使用

gson.fromJson(json, SeedAttribs.class); 

和

gson.fromJson(json, SettingsAttribs.class); 

但都沒有工作。我很驚訝，爲什麼不呢。 我還需要一種方法來取代這個json字符串時，特定的對象如。 SeedAttribs更改。我需要一種方法來重寫它，而SettingsAttribs不會改變。

這怎麼辦？

謝謝你的回答！

Answer 1

確保您的原始JSon字符串包含正確的格式。最好的方法是用GSON序列化你的對象。這裏是代碼：

public static void main(String[] args) 
{ 
    Gson gson = new Gson(); 
    SettingsAttribs st = new SettingsAttribs(); 
    st.setField1("value1"); 
    st.setField2("value2"); 
    // report constructed object 
    System.out.println("st: " + st); 

    // serialize to json 
    String json = gson.toJson(st, SettingsAttribs.class); 
    System.out.println("json: " + json); 

    // deserialize form json 
    SettingsAttribs restoredSettings = gson.fromJson(json, SettingsAttribs.class); 
    System.out.println("restoredSettings: " + restoredSettings); 
} 

它編譯和運行。輸出它產生：

st: SettingsAttribs [field1=value1, field2=value2] 
json: {"field1":"value1","field2":"value2"} 
restoredSettings: SettingsAttribs [field1=value1, field2=value2] 

而且SettingsAttribs類：

public class SettingsAttribs 
    { 
    private String field1; 
    private String field2; 

    public String getField1() 
    { 
     return field1; 
    } 

    public void setField1(String field1) 
    { 
     this.field1 = field1; 
    } 

    public String getField2() 
    { 
     return field2; 
    } 

    public void setField2(String field2) 
    { 
     this.field2 = field2; 
    } 

    @Override 
    public String toString() 
    { 
     return "SettingsAttribs [field1=" + field1 + ", field2=" + field2 + "]"; 
    } 
    }