Esempio n. 1
0
 public static void main(String[] args) {
   String[] arr = new String[3];
   List<String> list = new ArrayList<String>();
   if (list instanceof Collection) System.out.println("" + "true");
   else System.out.println("" + "false");
   System.out.println(arr.getClass());
   System.out.println(list.getClass());
 }
 public static void main(String[] args) {
   List<Frob> list = new ArrayList<Frob>();
   Map<Frob, Fnorkle> map = new HashMap<Frob, Fnorkle>();
   Quark<Fnorkle> quark = new Quark<Fnorkle>();
   Particle<Long, Double> p = new Particle<Long, Double>();
   System.out.println(Arrays.toString(list.getClass().getTypeParameters()));
   System.out.println(Arrays.toString(map.getClass().getTypeParameters()));
   System.out.println(Arrays.toString(quark.getClass().getTypeParameters()));
   System.out.println(Arrays.toString(p.getClass().getTypeParameters()));
 }
Esempio n. 3
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 public void show() {
   System.out.println(cid);
   System.out.println(cname);
   System.out.println(email);
   System.out.println(phone);
   System.out.println(emails);
   System.out.println(phones);
   System.out.println(refs);
   System.out.println(myprops);
   System.out.println(address);
   for (Account acc : accounts) {
     System.out.println(acc);
   }
   System.out.println(emails.getClass().getName());
   System.out.println(phones.getClass().getName());
   System.out.println(myprops.getClass().getName());
 }
Esempio n. 4
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 private <E> Object executeForMany(SqlSession sqlSession, Object[] args) {
   List<E> result;
   Object param = method.convertArgsToSqlCommandParam(args);
   if (method.hasRowBounds()) {
     RowBounds rowBounds = method.extractRowBounds(args);
     result = sqlSession.<E>selectList(command.getName(), param, rowBounds);
   } else {
     result = sqlSession.<E>selectList(command.getName(), param);
   }
   // issue #510 Collections & arrays support
   if (!method.getReturnType().isAssignableFrom(result.getClass())) {
     if (method.getReturnType().isArray()) {
       return convertToArray(result);
     } else {
       return convertToDeclaredCollection(sqlSession.getConfiguration(), result);
     }
   }
   return result;
 }
  /**
   * ArrayList<String>和ArrayList<Integer>很容易认为是不同的类型, 不同的类型在行为方面肯定不同 但输出发现c1==c2为true
   *
   * @param args
   */
  public static void main(String[] args) {
    Class c1 = new ArrayList<String>().getClass();
    Class c2 = new ArrayList<Integer>().getClass();
    System.out.println(c1 == c2); // 输出为true

    List<Frob> list = new ArrayList<Frob>();
    Map<Frob, Fnorkle> map = new HashMap<Frob, Fnorkle>();
    Quark<Fnorkle> quark = new Quark<Fnorkle>();
    Particle<Long, Double> part = new Particle<Long, Double>();
    // Class.getTypeParameters()将返回一个Typeariable对象数组,表示有泛型声明
    // 的类型参数...
    System.out.println(Arrays.toString(list.getClass().getTypeParameters()));
    System.out.println(Arrays.toString(map.getClass().getTypeParameters()));
    System.out.println(Arrays.toString(quark.getClass().getTypeParameters()));
    System.out.println(Arrays.toString(part.getClass().getTypeParameters()));
    /** 输出结果: [E] [K, V] [Q] [POSITION, MOMENTUM] */
    /**
     * 输出结果是一些占位符 说明:在泛型代码内部,无法获得任何有关泛型参数类型的信息。 当你在使用泛型时,任何具体的类型信息都被擦除了,你唯一知道的就是你在使用一个对象。
     * 因此,List<String>和List<Integer>在运行时事实上是相同的类型。这两种形式都被 擦除成它们的原生类型,即List
     */
  }
 @Override
 public String toString() {
   StringBuilder sb = new StringBuilder();
   sb.append("[Bean, list ");
   if (_beans == null) {
     sb.append("NULL");
   } else {
     sb.append('(').append(_beans.size()).append('/');
     sb.append(_beans.getClass().getName()).append(") ");
     boolean type = false;
     for (CtorValueBean bean : _beans) {
       if (!type) {
         sb.append("(").append(bean.getClass().getSimpleName()).append(")");
         type = true;
       }
       sb.append(bean);
       sb.append(' ');
     }
   }
   sb.append(']');
   return sb.toString();
 }