{"id":544,"date":"2021-02-03T17:49:47","date_gmt":"2021-02-03T09:49:47","guid":{"rendered":"https:\/\/www.52dixiaowo.com\/java\/?p=544"},"modified":"2021-09-03T09:47:56","modified_gmt":"2021-09-03T01:47:56","slug":"%e6%b3%9b%e5%9e%8b%e7%9a%84%e6%a6%82%e5%bf%b5-%e4%b8%8e-%e8%af%ad%e6%b3%95","status":"publish","type":"post","link":"https:\/\/www.52dixiaowo.com\/java\/post-544.html","title":{"rendered":"\u6cdb\u578b\u6982\u5ff5 \u4e0e \u8bed\u6cd5"},"content":{"rendered":"\n
1.\u6cdb\u578b\u6982\u5ff5<\/h5>\n\n\n\n

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\u5b98\u65b9\u5e76\u6ca1\u6709\u5bf9\u6cdb\u578b\u51c6\u786e\u7684\u5b9a\u4e49\uff0c\u8fd9\u91cc\u505a\u4e00\u4e2a\u5b9a\u4e49<\/p>\n\n\n\n

\u6cdb\u578b\u7684\u6982\u5ff5\uff1a\u6cdb\u578b\u662f\u9650\u5b9a\u6570\u636e\u7c7b\u578b\u7684\u4e00\u79cd\u624b\u6bb5<\/strong>\u3002<\/p>\n\n\n\n

2.\u6cdb\u578b\u7684\u8bed\u6cd5<\/h4>\n\n\n\n
1\u6cdb\u578b\u7c7b\u7684\u5b9a\u4e49<\/h5>\n\n\n\n

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public class GeneClass<E>{\n  private E name;\n  public E getName(){\n    return name;\n  }\n  public void setName(E name){\n    this.name = name;\n  }\n}<\/code><\/pre>\n\n\n\n
2.\u6cdb\u578b\u65b9\u6cd5\u7684\u5b9a\u4e49<\/h5>\n\n\n\n
\u5728\u8fd4\u56de\u503c\u7c7b\u578b\u524d\uff0c\u5728static \u540e\u7684\u4f4d\u7f6e\uff0c\u52a0\u4e0a<E><\/p>\n\n\n\n
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public <M> void method1(M m){\n  System.out.println(m);\n}\npublic static <S> void method2(S s){\n  System.out.println(s);\n}<\/code><\/pre>\n\n\n\n
3.\u6cdb\u578b\u63a5\u53e3\u7684\u5b9a\u4e49<\/h5>\n\n\n\n
\u5206\u522b\u6709\u63a5\u53e3\u7c7b\u672c\u8eab \u548c \u5b9e\u73b0\u7c7b\u7684\u6cdb\u578b\u5b9a\u4e49<\/p>\n\n\n\n
\/\/\u63a5\u53e3\u7c7b\u672c\u8eab\u7684\u5b9a\u4e49\npublic interface  Iterator<E>{\n  E next();\n}\n\/\/\u5b9e\u73b0\u7c7b\u5728\u5b9e\u73b0\u65f6\u6307\u5b9a\u6cdb\u578b\npublic final class Scanner implements Iterator<String>{\n  public String next(){}\n}\n\n\/\/\u5b9e\u73b0\u7c7b\u672c\u8eab\u5b9a\u4e49\u548c\u4f7f\u7528\u63a5\u53e3\u7684\u6cdb\u578b,\u6b64\u65f6\u5fc5\u987b\u4f7f\u7528\u76f8\u540c\u7684\u5b57\u6bcd\npublic class ArrayList<E> implements List<E>{\n  public boolean add(E e){}\n  public E get(int index){}\n}<\/code><\/pre>\n\n\n\n
4.\u6cdb\u578b\u7684\u901a\u914d\u7b26 “?”<\/h5>\n\n\n\n
\u901a\u914d\u7b26 ? \u4ee3\u8868\u4efb\u610f\u6570\u636e\u7c7b\u578b<\/p>\n\n\n\n
\u65e0\u6cd5\u521b\u5efa\u5bf9\u8c61\u4f7f\u7528\uff0c\u53ea\u53ef\u4ee5\u4f7f\u7528\u65b9\u6cd5\u65f6\u4f20\u9012\u53c2\u6570\u4f7f\u7528<\/p>\n\n\n\n
public static void printArray(ArrayList<?> list){\n  Iterator<?> it = list.iterator();\n  while(it.hasNext()){\n    Object o = it.next();\n    System.out.println(o);\n  }\n}<\/code><\/pre>\n\n\n\n
5.\u6cdb\u578b\u7684\u4e0a\u9650\u548c\u4e0b\u9650\u9650\u5b9a<\/h5>\n\n\n\n
\u4f7f\u7528 ? extends E \uff0c\u8868\u793a E \u662f\u7236\u7c7b\uff0c? \u53ea\u80fd\u662f\u5b50\u7c7b\uff08\u6216\u8005\u5b83\u672c\u8eab)<\/p>\n\n\n\n
\u4f7f\u7528 ? super E \uff0c\u8868\u793a ? \u662f\u7236\u7c7b\uff08\u6216\u8005\u5b83\u672c\u8eab)\uff0c\u65e0\u6cd5\u4f7f\u7528\u5b50\u7c7b<\/p>\n\n\n\n
\/\/\u6cdb\u578b\u7684\u4e0a\u9650?\u5fc5\u987b\u662fNumber\u7c7b\u578b\u6216\u8005Number\u7c7b\u578b\u7684\u5b50\u7c7b\npublic static void getElement1(Collection<? extends Number> coll){}\n\/\/\u6cdb\u578b\u7684\u4e0b\u9650?\u5fc5\u987b\u662fNumber\u7c7b\u578b\u6216\u8005Number\u7c7b\u578b\u7684\u7236\u7c7b\npublic static void getElement2(Collection<? super Number> coll){}<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
1.\u6cdb\u578b\u6982\u5ff5 \u5f53\u5b58\u50a8\u7684\u7c7b\u578b\u6bd4\u8f83\u5927\uff0c\u6bd4\u5982\u662f Object \u7c7b\u578b\u65f6\uff0c\u53ef\u4ee5\u4f7f\u7528\u6cdb\u578b\u5411\u4e0b\u6307\u5b9a \u914d\u5408 Object, \u6cdb… \u7ee7\u7eed\u9605\u8bfb \u6cdb\u578b\u6982\u5ff5 \u4e0e \u8bed\u6cd5<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[14],"tags":[],"_links":{"self":[{"href":"https:\/\/www.52dixiaowo.com\/java\/wp-json\/wp\/v2\/posts\/544"}],"collection":[{"href":"https:\/\/www.52dixiaowo.com\/java\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.52dixiaowo.com\/java\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.52dixiaowo.com\/java\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.52dixiaowo.com\/java\/wp-json\/wp\/v2\/comments?post=544"}],"version-history":[{"count":0,"href":"https:\/\/www.52dixiaowo.com\/java\/wp-json\/wp\/v2\/posts\/544\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.52dixiaowo.com\/java\/wp-json\/wp\/v2\/media?parent=544"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.52dixiaowo.com\/java\/wp-json\/wp\/v2\/categories?post=544"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.52dixiaowo.com\/java\/wp-json\/wp\/v2\/tags?post=544"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}