JTabbedPanel的美化标签

么现在来说下用法吧，首先附上网上找来的一段代码(其实在csdn里面也有这个代码的资源，不过没说怎么用)，
import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Composite;
import java.awt.FontMetrics;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.LayoutManager;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.geom.Area;
import java.awt.geom.Rectangle2D;
import java.awt.geom.RoundRectangle2D;
import javax.swing.JComponent;
import javax.swing.JTabbedPane;
import javax.swing.plaf.ComponentUI;
import javax.swing.plaf.basic.BasicTabbedPaneUI;
public class SinaTabbedPaneUI extends BasicTabbedPaneUI {
private static final Insets NO_INSETS = new Insets(0, 0, 0, 0);
private ColorSet selectedColorSet;
private ColorSet defaultColorSet;
private ColorSet hoverColorSet;
private boolean contentTopBorderDrawn = true;
private Color lineColor = new Color(158, 158, 158);
private Color dividerColor = new Color(200, 200, 200);
private Insets contentInsets = new Insets(1, 1, 1, 1);
private int lastRollOverTab = -1;
public static ComponentUI createUI(JComponent c) {
  return new SinaTabbedPaneUI();
}
protected LayoutManager createLayoutManager() {
  if (tabPane.getTabLayoutPolicy() == JTabbedPane.SCROLL_TAB_LAYOUT) {
   return super.createLayoutManager();
  } else {
   return new TabbedPaneLayout();
  }
}
// protected void installComponents() {
// super.installComponents();
// int counts = tabPane.getComponents().length;
// for (int i = 0; i < counts; i++) {
// if (tabPane.getComponentAt(i) instanceof JPanel) {
// ((JPanel) tabPane.getComponentAt(i)).setLayout(new FlowLayout(
// 10, 0, FlowLayout.LEFT));
// ((JPanel) tabPane.getComponentAt(i)).updateUI();
// }
// }
//
// }
public SinaTabbedPaneUI() {
  selectedColorSet = new ColorSet();
  selectedColorSet.topGradColor1 =  new Color(255,0,0);//new Color(233, 237, 248);//选中的最上层
  selectedColorSet.topGradColor2 =  new Color(225,225,30);//new Color(158, 199, 240);//选中的第二层
  selectedColorSet.bottomGradColor1 = new Color(225,225,30);//new Color(112, 173, 239);//选中的第三层
  selectedColorSet.bottomGradColor2 = new Color(255,0,0);//new Color(183, 244, 253);//选中的最下层
  defaultColorSet = new ColorSet();
  defaultColorSet.topGradColor1 = new Color(73,50,205);//new Color(253, 253, 253);//未选的最上层
  defaultColorSet.topGradColor2 = new Color(0,255,255);//new Color(237, 237, 237);
  defaultColorSet.bottomGradColor1 = new Color(0,255,255);//new Color(222, 222, 222);
  defaultColorSet.bottomGradColor2 = new Color(73,50,205);//new Color(255, 255, 255);
  hoverColorSet = new ColorSet();
  hoverColorSet.topGradColor1 = new Color(245,245,10);//new Color(244, 244, 244);//鼠标在的时候最上层
  hoverColorSet.topGradColor2 =   new Color(237,18,117);//new Color(223, 223, 223);
  hoverColorSet.bottomGradColor1 = new Color(5,232,255);//new Color(211, 211, 211);
  hoverColorSet.bottomGradColor2 = new Color(19,236,40);//new Color(235, 235, 235);
  maxTabHeight = 21;
  setContentInsets(1);
}
public void setContentTopBorderDrawn(boolean b) {
  contentTopBorderDrawn = b;
}
public void setContentInsets(Insets i) {
  contentInsets = i;
}
public void setContentInsets(int i) {
  contentInsets = new Insets(i, i, i, i);
}
// 返回当前运行的用于显示选项卡的选项卡数
public int getTabRunCount(JTabbedPane pane) {
  return 1;
}
protected void installDefaults() {
  super.installDefaults();
  RollOverListener l = new RollOverListener();
  tabPane.addMouseListener(l);
  tabPane.addMouseMotionListener(l);
  tabAreaInsets = NO_INSETS; // tab色insets边框
  tabInsets = new Insets(0, 0, 50, 50);
}
protected boolean scrollableTabLayoutEnabled() {
  return false;
}
protected Insets getContentBorderInsets(int tabPlacement) {
  return contentInsets;
}
// protected Insets getTabAreaInsets(int tabPlacement) {
//
// return contentInsets;
// }
protected int calculateTabHeight(int tabPlacement, int tabIndex,
   int fontHeight) {
  return 21;
}
protected int calculateTabWidth(int tabPlacement, int tabIndex,
   FontMetrics metrics) {
  int w = super.calculateTabWidth(tabPlacement, tabIndex, metrics);
  int wid = metrics.charWidth('M');
  w += wid * 2;
  return w;
}
protected int calculateMaxTabHeight(int tabPlacement) {
  return 20;
}
protected void paintTabArea(Graphics g, int tabPlacement, int selectedIndex) {
  Graphics2D g2d = (Graphics2D) g;
  // g2d.setPaint(new GradientPaint(0, 0, defaultColorSet.topGradColor1,
  // 0,
  // 10, defaultColorSet.topGradColor2));
  // g2d.fillRect(0, 0, tabPane.getWidth(), 10);
  //
  // g2d.setPaint(new GradientPaint(0, 10,
  // defaultColorSet.bottomGradColor1,
  // 0, 21, defaultColorSet.bottomGradColor2));
  // g2d.fillRect(0, 10, tabPane.getWidth(), 11);
  super.paintTabArea(g, tabPlacement, selectedIndex);
  if (contentTopBorderDrawn) {
   g2d.setColor(lineColor);
   g2d.drawLine(0, 20, tabPane.getWidth() - 1, 20);
  }
}
protected void paintTabBackground(Graphics g, int tabPlacement,
   int tabIndex, int x, int y, int w, int h, boolean isSelected) {
  Graphics2D g2d = (Graphics2D) g;
  ColorSet colorSet;
      
  Rectangle rect = rects[tabIndex];
  if (isSelected) {
   colorSet = selectedColorSet;
  } else if (getRolloverTab() == tabIndex) {
   colorSet = hoverColorSet;
  } else {
   colorSet = defaultColorSet;
  }
  g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
    RenderingHints.VALUE_ANTIALIAS_ON);
  int width = rect.width;
  int xpos = rect.x;
  int yPos = rect.y;
  if (tabIndex > -1) {
   width--;
   xpos++;
   yPos += 2;
  }
  g2d.setPaint(new GradientPaint(xpos, 0, colorSet.topGradColor1, xpos,
    h / 2, colorSet.topGradColor2));
  g2d.fill(this.getUpArea(xpos, yPos, width, h - 2));
  g2d.setPaint(new GradientPaint(0, h / 2, colorSet.bottomGradColor1, 0,
    h, colorSet.bottomGradColor2));
  g2d.fill(this.getDownArea(xpos, yPos, width, h - 2));
  if (contentTopBorderDrawn) {
   g2d.setColor(lineColor);
   g2d.drawLine(rect.x, 20, rect.x + rect.width - 1, 20);
  }
}
private Shape getArea(int x, int y, int w, int h) {
  RoundRectangle2D rect = new RoundRectangle2D.Float(x, y, w, h, 15, 15);
  Area a = new Area(rect);
  Rectangle2D rec = new Rectangle2D.Float(x, y + h / 2, w, h / 2);
  Area b = new Area(rec);
  a.add(b);
  return a;
}

private Shape getUpArea(int x, int y, int w, int h) {
  Rectangle2D rec = new Rectangle2D.Float(x, y, w, h / 2 + 1);
  Area a = new Area(rec);
  RoundRectangle2D rect = new RoundRectangle2D.Float(x, y, w, h, 15, 15);
  Area b = new Area(rect);
  a.intersect(b);
  return a;
}

private Shape getDownArea(int x, int y, int w, int h) {
  Rectangle2D rec = new Rectangle2D.Float(x, y + h / 2, w, h / 2 + 1);
  Area a = new Area(rec);
  RoundRectangle2D rect = new RoundRectangle2D.Float(x, y, w, h, 15, 15);
  // Area b = new Area(rect);
  // a.intersect(b);
  return a;
}
protected void paintTabBorder(Graphics g, int tabPlacement, int tabIndex,
   int x, int y, int w, int h, boolean isSelected) {
  Rectangle rect = getTabBounds(tabIndex, new Rectangle(x, y, w, h));
  // g.setColor(dividerColor);
  Graphics2D g2 = (Graphics2D) g;
  Composite old = g2.getComposite();
  AlphaComposite comp = AlphaComposite.getInstance(
    AlphaComposite.SRC_OVER, 0.0f);
  g2.setComposite(comp);
  g2.setColor(dividerColor);
  g2.drawLine(rect.x + rect.width, 0, rect.x + rect.width, 20);
  g2.setComposite(old);
}
protected void paintContentBorderTopEdge(Graphics g, int tabPlacement,
   int selectedIndex, int x, int y, int w, int h) {
}
protected void paintContentBorderRightEdge(Graphics g, int tabPlacement,
   int selectedIndex, int x, int y, int w, int h) {
  // Do nothing
}
protected void paintContentBorderLeftEdge(Graphics g, int tabPlacement,
   int selectedIndex, int x, int y, int w, int h) {
  // Do nothing
}
protected void paintContentBorderBottomEdge(Graphics g, int tabPlacement,
   int selectedIndex, int x, int y, int w, int h) {
  // Do nothing
}
protected void paintFocusIndicator(Graphics g, int tabPlacement,
   Rectangle[] rects, int tabIndex, Rectangle iconRect,
   Rectangle textRect, boolean isSelected) {
  // Do nothing
}
protected int getTabLabelShiftY(int tabPlacement, int tabIndex,
   boolean isSelected) {
  return 0;
}
private class ColorSet {
  Color topGradColor1;
  Color topGradColor2;
  Color bottomGradColor1;
  Color bottomGradColor2;
}
private class RollOverListener implements MouseMotionListener,
   MouseListener {
  public void mouseDragged(MouseEvent e) {
  }
  public void mouseMoved(MouseEvent e) {
   checkRollOver();
  }
  public void mouseClicked(MouseEvent e) {
  }
  public void mousePressed(MouseEvent e) {
  }
  public void mouseReleased(MouseEvent e) {
  }
  public void mouseEntered(MouseEvent e) {
   checkRollOver();
  }
  public void mouseExited(MouseEvent e) {
   tabPane.repaint();
  }
  private void checkRollOver() {
   int currentRollOver = getRolloverTab();
   if (currentRollOver != lastRollOverTab) {
    lastRollOverTab = currentRollOver;
    Rectangle tabsRect = new Rectangle(0, 0, tabPane.getWidth(), 20);
    tabPane.repaint(tabsRect);
   }
  }
}
public class TabbedPaneLayout extends BasicTabbedPaneUI.TabbedPaneLayout {
  public TabbedPaneLayout() {
   SinaTabbedPaneUI.this.super();
  }
  protected void calculateTabRects(int tabPlacement, int tabCount) {
   super.calculateTabRects(tabPlacement, tabCount);
   for (int i = 0; i < rects.length; i++) {
    rects[i].x = rects[i].x + (5 * i);
   }
  }
  protected void padSelectedTab(int tabPlacement, int selectedIndex) {
   // don't pad only the selected tab, but all the tabs, to space them.
//   for (int i = 0; i < rects.length; i++) {
//    Rectangle selRect = rects[i];
//    Insets padInsets = getSelectedTabPadInsets(tabPlacement);
//    selRect.x += padInsets.left;
//    selRect.width -= (padInsets.left + padInsets.right);
//    selRect.y -= padInsets.top;
//    selRect.height += (padInsets.top + padInsets.bottom);
//   }
  }
//  protected void normalizeTabRuns(int tabPlacement, int tabCount,
//    int start, int max) {
//   if (tabPlacement == TOP || tabPlacement == BOTTOM) {
//    super.normalizeTabRuns(tabPlacement, tabCount, start, max);
//   }
//  }
//
//  // Don't rotate runs!
//  protected void rotateTabRuns(int tabPlacement, int selectedRun) {
//  }
}
}
这就是那段代码了，我稍微改动了几个地方，接着的一段文字是有关这里用到得几个方法的用处

具体颜色没怎么调，贵在神似阿呵呵
下面简要说一下自定义这种Tab的关键点：
1.     每个JComponent几乎都有其UI 委托对象类，当然JTabbedPane也不例外。我们首先继承BasicTabbedPaneUI类，这其中有我们必须要重写的一个方法，具体形式如下：
       public static ComponentUI createUI(JComponent c) {
          return new XXXTabbedPaneUI();
       }
     其中XXXTabbedPaneUI就是自己实现的BasicTabbedPaneUI的子类的名字。
2．下面类出几个改变外观的重要的方法：
a. protectedvoid installDefaults() //可以改变一些BasicTabbedPaneUI中默认的属性。
b.protectedvoid paintTabArea(Graphics g, int tabPlacement, int selectedIndex)  //绘制整个选项卡区域
c. protectedvoid paintTabBackground(Graphics g, int tabPlacement,
           int tabIndex, int x, int y, int w, int h, boolean isSelected)
//绘制某个选项卡的背景色
d. protectedvoid paintContentBorder(Graphics g, int tabPlacement,
           int selectedIndex) //绘制TabbedPane容器的四周边框样式。
e. protectedvoid paintFocusIndicator(Graphics g, int tabPlacement,
           Rectangle[] rects, int tabIndex, Rectangle iconRect,
           Rectangle textRect, boolean isSelected)
//绘制选中某个Tab后，获得焦点的样式。
3.默认状态下每个选择项卡是连续摆放的，那么我们怎么使得他像新浪网页里那样的Tab中间有一定间隙呢，那么我们还定义一个内部类继承BasicTabbedPaneUI的内部类TabbedPaneLayou重写calculateTabRects方法，因为具体的选项卡标签位置是由变量rects所决定的。
根据上面的介绍是不是你也想自己动手实践一下呢？？那还等什么，让我们共同努力让Swing更美丽！！

也许，看到这里你还是一头雾水，写了这个那到底怎么用它呢，其实很简单，在你要用的地方设置就行了，如下
        UserJTab = new JTabbedPane();
        UserJTab.setTabPlacement(JTabbedPane.TOP);
        UserJTab.setBorder(null);
        UserJTab.setUI(new SinaTabbedPaneUI());
这里就用到了，这样刚才的效果就实现了