package org.junit.tests.running.core;
   
   import java.io.ByteArrayOutputStream;
   import java.io.FileDescriptor;
   import java.io.PrintStream;
   import java.net.InetAddress;
   import java.security.Permission;
   
   public class MainRunner {
      private static class ExitException extends SecurityException {
          private static final long serialVersionUID = -9104651568237766642L;
  
          private final int status;
  
          public ExitException(int status) {
              super("");
              this.status = status;
          }
  
          public int getStatus() {
              return status;
          }
      }
  
      /**
       * A {@code NoExitSecurityManager} throws a {@link ExitException} exception
       * whenever {@link #checkExit(int)} is called. All other method calls are
       * delegated to the original security manager.
       */
      public class NoExitSecurityManager extends SecurityManager {
          private final SecurityManager originalSecurityManager;
  
          public NoExitSecurityManager(SecurityManager originalSecurityManager) {
              this.originalSecurityManager = originalSecurityManager;
          }
  
          @Override
          public void checkExit(int status) {
              throw new ExitException(status);
          }
  
          @Override
          public boolean getInCheck() {
              return (originalSecurityManager != null) && originalSecurityManager.getInCheck();
          }
  
          @Override
          public Object getSecurityContext() {
              return (originalSecurityManager == null) ? super.getSecurityContext() : originalSecurityManager.getSecurityContext();
          }
  
          @Override
          public void checkPermission(Permission perm) {
              if (originalSecurityManager != null) {
                  originalSecurityManager.checkPermission(perm);
              }
          }
  
          @Override
          public void checkPermission(Permission perm, Object context) {
              if (originalSecurityManager != null) {
                  originalSecurityManager.checkPermission(perm, context);
              }
          }
  
          @Override
          public void checkCreateClassLoader() {
              if (originalSecurityManager != null) {
                  originalSecurityManager.checkCreateClassLoader();
              }
          }
  
          @Override
          public void checkAccess(Thread t) {
              if (originalSecurityManager != null) {
                  originalSecurityManager.checkAccess(t);
              }
          }
  
          @Override
          public void checkAccess(ThreadGroup g) {
              if (originalSecurityManager != null) {
                  originalSecurityManager.checkAccess(g);
              }
          }
  
          @Override
          public void checkExec(String cmd) {
              if (originalSecurityManager != null) {
                  originalSecurityManager.checkExec(cmd);
              }
          }
  
          @Override
          public void checkLink(String lib) {
              if (originalSecurityManager != null) {
                  originalSecurityManager.checkLink(lib);
              }
          }
 
         @Override
         public void checkRead(FileDescriptor fd) {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkRead(fd);
             }
         }
 
         @Override
         public void checkRead(String file) {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkRead(file);
             }
         }
 
         @Override
         public void checkRead(String file, Object context) {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkRead(file, context);
             }
         }
 
         @Override
         public void checkWrite(FileDescriptor fd) {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkWrite(fd);
             }
         }
 
         @Override
         public void checkWrite(String file) {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkWrite(file);
             }
         }
 
         @Override
         public void checkDelete(String file) {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkDelete(file);
             }
         }
 
         @Override
         public void checkConnect(String host, int port) {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkConnect(host, port);
             }
         }
 
         @Override
         public void checkConnect(String host, int port, Object context) {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkConnect(host, port, context);
             }
         }
 
         @Override
         public void checkListen(int port) {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkListen(port);
             }
         }
 
         @Override
         public void checkAccept(String host, int port) {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkAccept(host, port);
             }
         }
 
         @Override
         public void checkMulticast(InetAddress maddr) {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkMulticast(maddr);
             }
         }
 
         @Override
         public void checkMulticast(InetAddress maddr, byte ttl) {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkMulticast(maddr, ttl);
             }
         }
 
         @Override
         public void checkPropertiesAccess() {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkPropertiesAccess();
             }
         }
 
         @Override
         public void checkPropertyAccess(String key) {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkPropertyAccess(key);
             }
         }
 
         @Override
         public boolean checkTopLevelWindow(Object window) {
             return (originalSecurityManager == null) ? super.checkTopLevelWindow(window) : originalSecurityManager.checkTopLevelWindow(window);
         }
 
         @Override
         public void checkPrintJobAccess() {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkPrintJobAccess();
             }
         }
 
         @Override
         public void checkSystemClipboardAccess() {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkSystemClipboardAccess();
             }
         }
 
         @Override
         public void checkAwtEventQueueAccess() {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkAwtEventQueueAccess();
             }
         }
 
         @Override
         public void checkPackageAccess(String pkg) {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkPackageAccess(pkg);
             }
         }
 
         @Override
         public void checkPackageDefinition(String pkg) {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkPackageDefinition(pkg);
             }
         }
 
         @Override
         public void checkSetFactory() {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkSetFactory();
             }
         }
 
         @Override
         public void checkMemberAccess(Class<?> clazz, int which) {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkMemberAccess(clazz, which);
             }
         }
 
         @Override
         public void checkSecurityAccess(String target) {
             if (originalSecurityManager != null) {
                 originalSecurityManager.checkSecurityAccess(target);
             }
         }
 
         @Override
         public ThreadGroup getThreadGroup() {
             return (originalSecurityManager == null) ? super.getThreadGroup() : originalSecurityManager.getThreadGroup();
         }
     }
 
     /**
      * Execute runnable.run(), preventing System.exit(). If System.exit() is called
      * in runnable.run(), the value is returned. If System.exit()
      * is not called, null is returned.
      *
      * @return null if System.exit() is not called, Integer.valueof(status) if not
      */
     public Integer runWithCheckForSystemExit(Runnable runnable) {
         SecurityManager oldSecurityManager = System.getSecurityManager();
         System.setSecurityManager(new NoExitSecurityManager(oldSecurityManager));
         PrintStream oldOut = System.out;
 
         System.setOut(new PrintStream(new ByteArrayOutputStream()));
         try {
             runnable.run();
             System.out.println("System.exit() not called, return null");
             return null;
         } catch (ExitException e) {
             System.out.println("System.exit() called, value=" + e.getStatus());
             return e.getStatus();
         } finally {
             System.setSecurityManager(oldSecurityManager);
             System.setOut(oldOut);
         }
     }
 }