java.lang.Package.getPackages()方法实例-优快云博客

java.lang.Package.getPackages()方法实例

java.lang.Package.getPackages() 方法获取所有目前已知调用方的ClassLoader实例的软件包。这些包对应于通过加载或名称至ClassLoader实例访问的类。如果调用者的ClassLoader实例是引导类加载器的实例，这可能是null，在一些实现来表示，对应于由引导类加载器实例加载的类仅包将被返回。

声明

以下是java.lang.Package.getPackages()方法的声明

public static Package[] getPackages()

参数

返回值

此方法返回已知调用方的ClassLoader实例程序包的新数组。如果没有已知的，返回0长度数组。

异常

例子

下面的例子显示lang.Object.getPackages()方法的使用。

package com.yiibai;

public class PackageDemo {

   public static void main(String[] args) {

      // get all the packages
      Package[] pack = Package.getPackages();

      // print all packages, one by one
      for (int i = 0; i < pack.length; i++) {
         System.out.println("" + pack[i]);
      }
   }
}

让我们来编译和运行上面的程序，这将产生以下结果：

package sun.util, Java Platform API Specification, version 1.6
package java.util, Java Platform API Specification, version 1.6
package java.net, Java Platform API Specification, version 1.6
package sun.reflect.misc, Java Platform API Specification, version 1.6
package sun.security.provider, Java Platform API Specification, version 1.6
package sun.net.www.protocol.jar, Java Platform API Specification, version 1.6
package sun.security.action, Java Platform API Specification, version 1.6
package java.nio.charset, Java Platform API Specification, version 1.6
package sun.io, Java Platform API Specification, version 1.6
package java.io, Java Platform API Specification, version 1.6
package sun.nio, Java Platform API Specification, version 1.6
package sun.net.www, Java Platform API Specification, version 1.6
package java.lang.ref, Java Platform API Specification, version 1.6
package java.lang, Java Platform API Specification, version 1.6
package sun.misc, Java Platform API Specification, version 1.6
package sun.net.www.protocol.file, Java Platform API Specification, version 1.6
package java.util.concurrent, Java Platform API Specification, version 1.6
package java.util.concurrent.atomic, Java Platform API Specification, version 1.6
package com.yiibai
package java.nio.charset.spi, Java Platform API Specification, version 1.6
package java.nio, Java Platform API Specification, version 1.6
package java.util.concurrent.locks, Java Platform API Specification, version 1.6
package sun.reflect, Java Platform API Specification, version 1.6
package java.security, Java Platform API Specification, version 1.6
package java.lang.reflect, Java Platform API Specification, version 1.6
package sun.nio.cs, Java Platform API Specification, version 1.6
package sun.security.util, Java Platform API Specification, version 1.6
package java.security.cert, Java Platform API Specification, version 1.6
package sun.jkernel, Java Platform API Specification, version 1.6
package sun.net.util, Java Platform API Specification, version 1.6