彈簧 - 注入幾個不通過構造函數的字段

Question

我有三個類。 CurrencyUtil需要NumberFormatter。 NumberFormatter僅因爲CurrencyUtil需要而被注入CurrencyUtilFactory。

有沒有辦法將NumberFormatter直接注入CurrencyUtil？

謝謝！

CurrencyUtil

public class CurrencyUtil { 
    private final LocalizationHelper localizationHelper; 
    private final NumberFormatter numberFormatter; 

    public CurrencyFormatter(final LocalizationHelper localizationHelper, final NumberFormatter numberFormatter) { 
     this.localizationHelper = localizationHelper; 
     this.numberFormatter = numberFormatter; 
    } 

    public String prettyPrint(final Currency amount) { 

    } 
} 

CurrencyUtilFactory

public class CurrencyUtilFactory { 
    @Autowired 
    private NumberFormatter numberFormatter; 

    public CurrencyUtil create() { 
     ... 
     final LocalizationHelper localizationHelper = ....; 
     return new CurrencyUtil(localizationHelper, numberFormatter)(); 
    } 

} 

的NumberFormatter

@Component 
public class NumberFormatter {} 

PS：道歉爲此彌補了例子:)

Answer 1

能像下面的代碼段爲你工作？通過這種方式，您可以重複使用CurrencyUtil和amount值。

@Component 
public class CurrencyUtil { 

    private final NumberFormatter numberFormatter; 

    @Autowired 
    public CurrencyFormatter(NumberFormatter numberFormatter) { 
     this.numberFormatter = numberFormatter; 
    } 

    public String prettyPrint(Currency amount) { 
     // ... 
    } 
} 

更新（基於調整後的問題）

Spring可以自動裝配，它僅知道豆子。如果你的bean（或者其中的一些）不是用Spring來管理的，你必須自己自動裝載它們（例如像你一樣通過構造函數）。該解決方案是：

@Configuration 
public class AppConfig { 

    @Autowired 
    private NumberFormatter numberFormatter; 

    @Autowired 
    private LocalizationHelper localizationHelper; 

    @Bean 
    public CurrencyUtil curencyUtil() { 
     return new CurrencyUtil(localizationHelper, numberFormatter); 
    } 

    // ... 
} 

或者

@Component 
public class CurrencyUtil { 

    private LocalizationHelper helper; 

    private NumberFormatter numberFormatter; 

    @Autowired 
    public CurrencyFormatter(LocalizationHelper helper, NumberFormatter numberFormatter) { 
     this.helper = helper; 
     this.numberFormatter = numberFormatter; 
    } 

    public String prettyPrint(Currency amount) { 
     // ... 
    } 
}