Jaxb Xml到java.awt

Question

我在我的項目中使用JAXB進行XML投標，我仍然是初學者。 現在，我嘗試這個XML文件綁定到類FontStyle

XML文件看起來像這樣

的example.xml

<fontStyle> 
    <font> 
    <family>Arial</family> 
    <style>0</style> 
    <size>12</size> 
    </font> 
    <fontColor> 
    <red>0</red> 
    <green>0</green> 
    <blue>0</blue> 
    </fontColor> 
    <backgroundColor> 
    <red>255</red> 
    <green>255</green> 
    <blue>255</blue> 
    </backgroundColor> 
</fontStyle> 

這是我的FontStyle類：

FontStyle.java

import java.awt.Color; 
import java.awt.Font; 


public class FontStyle { 

    private Font font; 

    private Color fontColor = Color.BLACK; 

    private Color backgroundColor = Color.WHITE; 

    public FontStyle() { 

    } 

    public FontStyle(Font font, Color fontColor, Color backgroundColor) { 
     this.font = font; 
     this.fontColor = fontColor; 
     this.backgroundColor = backgroundColor; 
    } 

    public Font getFont() { 
     return font; 
    } 


    public void setFont(Font font) { 
     this.font = font; 
    } 

    public Color getFontColor() { 
     return fontColor; 
    } 


    public void setFontColor(Color fontColor) { 
     this.fontColor = fontColor; 
    } 


    public Color getBackgroundColor() { 
     return backgroundColor; 
    } 


    public void setBackgroundColor(Color backgroundColor) { 
     this.backgroundColor = backgroundColor; 
    } 


} 

我希望任何人都可以給我一個建議如何處理這個問題。

歡呼

Answer 1

類型的不自然映射到XML表示需要寫一個XmlAdapter實施，Font和Color是這樣的類型。下面的代碼提供了一個如何在您的案例中編寫適配器的例子。

我將適配器類作爲嵌套類放入FontStyle類中，但您可以根據需要將它們創建爲外部類。

import javax.xml.bind.annotation.*; 
import javax.xml.bind.annotation.adapters.XmlAdapter; 
import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter; 
import java.awt.*; 

@XmlRootElement 
@XmlType(propOrder = {"font", "fontColor", "backgroundColor"}) // to keep ordering consistent with "example.xml" 
public class FontStyle { 

    private Font font; 

    private Color fontColor = Color.BLACK; 

    private Color backgroundColor = Color.WHITE; 

    public FontStyle() { 
    } 

    public FontStyle(Font font, Color fontColor, Color backgroundColor) { 
     this.font = font; 
     this.fontColor = fontColor; 
     this.backgroundColor = backgroundColor; 
    } 

    @XmlJavaTypeAdapter(FontAdapter.class) 
    public Font getFont() { 
     return font; 
    } 

    @XmlJavaTypeAdapter(ColorAdapter.class) 
    public Color getFontColor() { 
     return fontColor; 
    } 

    @XmlJavaTypeAdapter(ColorAdapter.class) 
    public Color getBackgroundColor() { 
     return backgroundColor; 
    } 

    public void setFont(Font font) { 
     this.font = font; 
    } 

    public void setFontColor(Color fontColor) { 
     this.fontColor = fontColor; 
    } 

    public void setBackgroundColor(Color backgroundColor) { 
     this.backgroundColor = backgroundColor; 
    } 

    private static class ColorAdapter extends XmlAdapter<ColorAdapter.ColorValueType, Color> { 

     @Override 
     public Color unmarshal(ColorValueType v) throws Exception { 
      return new Color(v.red, v.green, v.blue); 
     } 

     @Override 
     public ColorValueType marshal(Color v) throws Exception { 
      return new ColorValueType(v.getRed(), v.getRed(), v.getBlue()); 
     } 

     @XmlAccessorType(XmlAccessType.FIELD) 
     public static class ColorValueType { 
      private int red; 
      private int green; 
      private int blue; 

      public ColorValueType() { 
      } 

      public ColorValueType(int red, int green, int blue) { 
       this.red = red; 
       this.green = green; 
       this.blue = blue; 
      } 
     } 
    } 

    private static class FontAdapter extends XmlAdapter<FontAdapter.FontValueType, Font> { 

     @Override 
     public Font unmarshal(FontValueType v) throws Exception { 
      return new Font(v.family, v.style, v.size); 
     } 

     @Override 
     public FontValueType marshal(Font v) throws Exception { 
      return new FontValueType(v.getFamily(), v.getStyle(), v.getSize()); 
     } 

     @XmlAccessorType(XmlAccessType.FIELD) 
     public static class FontValueType { 
      private String family; 
      private int style; 
      private int size; 

      public FontValueType() { 
      } 

      public FontValueType(String family, int style, int size) { 
       this.family = family; 
       this.style = style; 
       this.size = size; 
      } 
     } 
    } 
} 

的代碼來解讀的example.xml和測試結果可能是這樣的：

import javax.xml.bind.JAXBContext; 
import javax.xml.bind.JAXBException; 
import javax.xml.bind.Marshaller; 
import javax.xml.bind.Unmarshaller; 
import java.io.File; 

public class App { 
    public static void main(String[] args) throws JAXBException { 
     JAXBContext jaxbContext = JAXBContext.newInstance(FontStyle.class); 

     // unmarshall "example.xml" 
     File exampleFile = new File("example.xml"); 
     Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller(); 
     FontStyle fontStyle = (FontStyle) jaxbUnmarshaller.unmarshal(exampleFile); 

     // marshall back to XML and print the result 
     Marshaller jaxbMarshaller = jaxbContext.createMarshaller(); 
     jaxbMarshaller.setProperty(Marshaller.JAXB_FRAGMENT, Boolean.TRUE); // removes xml declaration line for consistency with "example.xml" file 
     jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true); 
     jaxbMarshaller.marshal(fontStyle, System.out); 
    } 
}