java.lang.Package.getPackages() 方法獲取所有目前已知調用方的ClassLoader實例的軟件包。這些包對應於通過加載或名稱至ClassLoader實例訪問的類。如果調用者的ClassLoader實例是引導類加載器的實例，這可能是null，在一些實現來表示，對應於由引導類加載器實例加載的類僅包將被返回。

聲明

以下是java.lang.Package.getPackages()方法的聲明

public static Package[] getPackages()

參數

• NA

返回值

此方法返回已知調用方的ClassLoader實例程序包的新數組。如果冇有已知的，返回0長度數組。

異常

• NA

例子

下麵的例子顯示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]);
      }
   }
}

讓我們來編譯和運行上麵的程序，這將產生以下結果：

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