使用extends关键字，后跟您要扩展的类的名称。
//n o w j a v a . c o m - 时 代 Java 提供 class WoodenStick extends Stick { private static final String material = "WOOD"; private int lie; private int flex; public WoodenStick(int length, boolean isCurved) { super(length, isCurved, material); } public WoodenStick(int length, boolean isCurved, int lie, int flex) { super(length, isCurved, material); this.lie = lie; this.flex = flex; } /** * @return the lie */ public int getLie() { return lie;/*from nowjava.com - 时 代 Java*/ } /** * @param lie * the lie to set */ public void setLie(int lie) { this.lie = lie; } /** * @return the flex */ public int getFlex() { return flex; } /** * @param flex * the flex to set */ public void setFlex(int flex) { this.flex = flex; } } class Stick { private int length; private boolean curved; private String material; public Stick(int length, boolean curved, String material) { this.length = length; this.curved = curved; this.material = material; } /** * @return the length */ public int getLength() { return length; } /** * @param length * the length to set */ public void setLength(int length) { this.length = length; } /** * @return the curved */ public boolean isCurved() { return curved; } /** * @param curved * the curved to set */ public