How to use

setProperties

method

in

java.lang.System

  public Void run() {
    System.setProperties(properties);
    return null;
  }
}

private static void removeJavaProperties(final Properties javaProps) {
 if (javaProps != null) {
  Properties props = System.getProperties();
  for (Iterator iter = javaProps.keySet().iterator(); iter.hasNext();) {
   props.remove(iter.next());
  }
  System.setProperties(props);
 }
}

 Properties p = new Properties(System.getProperties());
p.put("com.mchange.v2.log.MLog", "com.mchange.v2.log.FallbackMLog");
p.put("com.mchange.v2.log.FallbackMLog.DEFAULT_CUTOFF_LEVEL", "OFF"); // Off or any other level
System.setProperties(p);

@Override
public void close() {
 // Clear the extra stuff from System properties
 Properties properties = System.getProperties();
 properties.remove(SECURITY_SYSTEM_PREFIX + SECURITY_PEER_AUTH_INIT);
 properties.remove(SECURITY_SYSTEM_PREFIX + SECURITY_PEER_AUTHENTICATOR);
 Iterator iter = security.keySet().iterator();
 while (iter.hasNext()) {
  properties.remove(SECURITY_SYSTEM_PREFIX + iter.next());
 }
 System.setProperties(properties);
}

 @Override
 public void intercept(IMethodInvocation invocation) throws Throwable {
  Properties original = new Properties();
  original.putAll(System.getProperties());

  try {
   invocation.proceed();
  } finally {
   System.setProperties(original);
  }
 }
}

  public static void teardown() {
    System.setProperties(null);
  }
}

public static void makeSystemPropertiesWriteOnce() {
  Properties properties = System.getProperties();
  if (properties instanceof WriteOnceProperties) {
    return;
  }
  System.setProperties(new WriteOnceProperties(properties));
}

@Signature
public static void setProperties(Properties properties) {
  System.setProperties(properties);
}

public void tearDown() {
  System.setProperties(savedProperties);
}

@Override
public void beforeTestExecution(ExtensionContext ec) throws Exception {
  getStore(ec).put(SYSPROPS_KEY, System.getProperties());
  Properties copy = new Properties();
  copy.putAll(System.getProperties());
  System.setProperties(copy);
}

/**
 * Properties 本质上是一个HashTable，每次读写都会加锁，所以不支持频繁的System.getProperty(name)来检查系统内容变化 因此扩展了一个ListenableProperties,
 * 在其所关心的属性变化时进行通知.
 * 
 * @see ListenableProperties
 */
public static synchronized void registerSystemPropertiesListener(PropertiesListener listener) {
  Properties currentProperties = System.getProperties();
  // 将System的properties实现替换为ListenableProperties
  if (!(currentProperties instanceof ListenableProperties)) {
    ListenableProperties newProperties = new ListenableProperties(currentProperties);
    System.setProperties(newProperties);
    currentProperties = newProperties;
  }
  ((ListenableProperties) currentProperties).register(listener);
}

/**
 * Constructor.
 *
 * @param name Name.
 * @param val Value.
 */
public SystemProperty(String name, String val) {
  this.name = name;
  Properties props = System.getProperties();
  originalValue = (String)props.put(name, val);
  System.setProperties(props);
}

  /** {@inheritDoc} */
  @Override public void close() {
    Properties props = System.getProperties();
    if (originalValue != null)
      props.put(name, originalValue);
    else
      props.remove(name);
    System.setProperties(props);
  }
}

public void setUp() {
  savedProperties = System.getProperties();
  System.setProperties(new Properties(savedProperties));
}

/**
 * Tests that a lookup object for system properties can deal with a full
 * replacement of the system properties object. This test is related to
 * LANG-1055.
 */
@Test
public void testSystemPropertiesLookupReplacedProperties() {
  final Properties oldProperties = System.getProperties();
  final String osName = "os.name";
  final String newOsName = oldProperties.getProperty(osName) + "_changed";
  final StrLookup<String> sysLookup = StrLookup.systemPropertiesLookup();
  final Properties newProps = new Properties();
  newProps.setProperty(osName, newOsName);
  System.setProperties(newProps);
  try {
    assertEquals("Changed properties not detected", newOsName, sysLookup.lookup(osName));
  } finally {
    System.setProperties(oldProperties);
  }
}

@Override protected void after() {
 cleanUp();
 System.setProperties( originalProperties );
 Locale.setDefault( originalLocale );
 Locale.setDefault( Locale.Category.FORMAT, originalFormatLocale );
 LanguageChoice.getInstance().setDefaultLocale( originalLocale );
 TimeZone.setDefault( originalTimezone );
 FileUtils.deleteQuietly( tmpKettleHome.toFile() );
}

@After
public void cleanUp() {
  System.setProperties(original);
  files.cleanUp();
}

@Test(enabled = false)
public void testIgnoreProxyPropertiesByDefault() throws IOException, TimeoutException, InterruptedException {
 // FIXME not threadsafe!
 Properties originalProps = new Properties();
 originalProps.putAll(System.getProperties());
 System.setProperty(ProxyUtils.PROXY_HOST, "localhost");
 System.setProperty(ProxyUtils.PROXY_PORT, String.valueOf(port1));
 System.setProperty(ProxyUtils.PROXY_NONPROXYHOSTS, "localhost");
 AsyncHttpClientConfigHelper.reloadProperties();
 try (AsyncHttpClient client = asyncHttpClient()) {
  String target = "http://localhost:1234/";
  Future<Response> f = client.prepareGet(target).execute();
  try {
   f.get(3, TimeUnit.SECONDS);
   fail("should not be able to connect");
  } catch (ExecutionException e) {
   // ok, no proxy used
  }
 } finally {
  System.setProperties(originalProps);
 }
}

@Test(enabled = false)
public void testWildcardNonProxyHosts() throws IOException, TimeoutException, InterruptedException {
 // FIXME not threadsafe!
 Properties originalProps = new Properties();
 originalProps.putAll(System.getProperties());
 System.setProperty(ProxyUtils.PROXY_HOST, "127.0.0.1");
 System.setProperty(ProxyUtils.PROXY_PORT, String.valueOf(port1));
 System.setProperty(ProxyUtils.PROXY_NONPROXYHOSTS, "127.*");
 AsyncHttpClientConfigHelper.reloadProperties();
 try (AsyncHttpClient client = asyncHttpClient(config().setUseProxyProperties(true))) {
  String nonProxifiedTarget = "http://127.0.0.1:1234/";
  Future<Response> f = client.prepareGet(nonProxifiedTarget).execute();
  try {
   f.get(3, TimeUnit.SECONDS);
   fail("should not be able to connect");
  } catch (ExecutionException e) {
   // ok, no proxy used
  }
 } finally {
  System.setProperties(originalProps);
 }
}

@After
public void after() {
  System.setProperties(original);
  new SystemEnvironment().reset(SystemEnvironment.ENABLE_CONFIG_MERGE_FEATURE);
}