import java.awt.Font;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
 
/**
 * 字體工具類, 獲取需要的字體
 */
public class FontUtil {  
    /**
     * 所有字體配置
     */
    private static Map<String, String> fontNameMap = new HashMap<String, String>();
 
    /**
     * 默認字體的大小
     */
    private static final float defaultFontSize = 20f; 
    static {
        //加載配置文件
        Properties properties = new Properties();
        // 使用properties對象加載輸入流, 編碼使用GBK
        try {
            properties.load(new InputStreamReader(FontUtil.class.getClassLoader().getResourceAsStream("font.properties"), "GBK"));
        } catch (IOException e) {
            System.err.println("font.properties 配置文件不存在");
        }
        //獲取key對應的value值
        for (Map.Entry<Object, Object> entry : properties.entrySet()) {
            Object key = entry.getKey();
            Object value = entry.getValue();
            if (key != null && value != null) {
                fontNameMap.put(String.valueOf(key), String.valueOf(value));
            }
        }
    } 
 
    /**
     * 獲取定義的字體
     *
     * @param key 字體的名字
     * @return
     */
    public static Font getConfigFont(String key) {
        return getConfigFont(key, defaultFontSize);
    } 
 
    /**
     * 獲取自定義的字體
     *
     * @param key      字體的名字
     * @param fontSize 字體的大小
     * @return
     */
    public static Font getConfigFont(String key, float fontSize) {
        String fontUrl = fontNameMap.get(key);
        if (fontUrl == null) {
            throw new RuntimeException("名字是:" + key + "的字體配置不存在");
        }
        //默認先看是不是系統(tǒng)字體
        Font font = new Font(fontUrl, Font.PLAIN, (int) fontSize);
        //判斷當前字體存不存在
        if ("Dialog.plain".equals(font.getFontName())) {
            try (
                    InputStream is = new FileInputStream(new File(fontUrl));
            ) {
                Font definedFont = Font.createFont(Font.TRUETYPE_FONT, is);
                //設置字體大小，float型
                definedFont = definedFont.deriveFont(fontSize);
                return definedFont;
            } catch (Exception e) {
                throw new RuntimeException("名字是:" + key + "的字體不存在");
            }
        }
        return font;
    }  
}

import java.awt.*; 
public class Demo { 
    public static void main(String[] args) throws Exception {        
        Font a = FontUtil.getConfigFont("A");
        System.out.println(a.getName() + "~" + a.getSize());
 
        Font b = FontUtil.getConfigFont("B", 100);
        System.out.println(b.getName() + "~" + b.getSize());
 
        Font c = FontUtil.getConfigFont("C");
        System.out.println(c.getFontName()); 
        Font d = FontUtil.getConfigFont("D"); 
    }  
}

public static void setUIFont()
{
 Font f = new Font("宋體",Font.PLAIN,18);
 String   names[]={ "Label", "CheckBox", "PopupMenu","MenuItem", "CheckBoxMenuItem",
   "JRadioButtonMenuItem","ComboBox", "Button", "Tree", "ScrollPane",
   "TabbedPane", "EditorPane", "TitledBorder", "Menu", "TextArea",
   "OptionPane", "MenuBar", "ToolBar", "ToggleButton", "ToolTip",
   "ProgressBar", "TableHeader", "Panel", "List", "ColorChooser",
   "PasswordField","TextField", "Table", "Label", "Viewport",
   "RadioButtonMenuItem","RadioButton", "DesktopPane", "InternalFrame"
 }; 
 for (String item : names) {
   UIManager.put(item+ ".font",f); 
 }
}