Java tutorial
//package com.java2s; /* * Copyright (C) 2014 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.lang.reflect.Constructor; import java.security.Provider; import java.security.Security; public class Main { private static void loadProviderIfNecessary(String providerClassName) { if (providerClassName == null) { return; } final Class<?> klass; try { final ClassLoader sysLoader = ClassLoader.getSystemClassLoader(); if (sysLoader != null) { klass = sysLoader.loadClass(providerClassName); } else { klass = Class.forName(providerClassName); } } catch (ClassNotFoundException e) { e.printStackTrace(); System.exit(1); return; } Constructor<?> constructor = null; for (Constructor<?> c : klass.getConstructors()) { if (c.getParameterTypes().length == 0) { constructor = c; break; } } if (constructor == null) { System.err.println("No zero-arg constructor found for " + providerClassName); System.exit(1); return; } final Object o; try { o = constructor.newInstance(); } catch (Exception e) { e.printStackTrace(); System.exit(1); return; } if (!(o instanceof Provider)) { System.err.println("Not a Provider class: " + providerClassName); System.exit(1); } Security.insertProviderAt((Provider) o, 1); } }