Java Context.lookup方法代码示例

import javax.naming.Context; //导入方法依赖的package包/类
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {

    resp.setContentType("text/plain;UTF-8");
    PrintWriter out = resp.getWriter();

    try {
        Context ctx = new InitialContext();
        Object obj = ctx.lookup("java:comp/env/bug50351");
        TesterObject to = (TesterObject) obj;
        out.print(to.getFoo());
    } catch (NamingException ne) {
        ne.printStackTrace(out);
    }
}
 

import javax.naming.Context; //导入方法依赖的package包/类
public Object getInstance() throws InstantiationException
{
    String type = remote ? "remote" : "local";

    try
    {
        Properties props = new Properties();
        props.load(getClass().getResourceAsStream("/jndi.properties"));
        Context jndi = new InitialContext(props);

        return jndi.lookup(bean + beanNamePostfix + "/" + type);
    }
    catch (Exception ex)
    {
        throw new InstantiationException(bean + "/" + type + " not bound:" + ex.getMessage());
    }
}
 

import javax.naming.Context; //导入方法依赖的package包/类
/**
 * 获取连接，使用数据库连接池
 * @param jndi 配置在tomcat的context.xml里面的东西
 * @return 创建的连接对象
 */
public Connection getConnection(String jndi)
{
	try
	{
		log.debug("开始尝试连接数据库！");
		Context context=new InitialContext();
		DataSource dataSource=(DataSource)context.lookup("java:comp/env/"+jndi);
		con=dataSource.getConnection();
		log.debug("连接成功！");
	}
	catch (Exception e)
	{
		log.error("连接数据库失败！", e);
	}
	return con;
}
 

import javax.naming.Context; //导入方法依赖的package包/类
/**
 * Test of returnPooledConnectionToPool method, of class
 * org.apache.geode.internal.datasource.AbstractPoolCache.
 */
@Test
public void testReturnPooledConnectionToPool() throws Exception {
  Context ctx = cache.getJNDIContext();
  GemFireConnPooledDataSource ds =
      (GemFireConnPooledDataSource) ctx.lookup("java:/PooledDataSource");
  GemFireConnectionPoolManager provider =
      (GemFireConnectionPoolManager) ds.getConnectionProvider();
  ConnectionPoolCacheImpl poolCache = (ConnectionPoolCacheImpl) provider.getConnectionPoolCache();
  PooledConnection conn = (PooledConnection) poolCache.getPooledConnectionFromPool();
  if (poolCache.availableCache.containsKey(conn))
    fail("connection not removed from available cache list");
  if (!poolCache.activeCache.containsKey(conn))
    fail("connection not put in active connection list");
  provider.returnConnection(conn);
  if (!poolCache.availableCache.containsKey(conn))
    fail("connection not returned to pool");
  if (poolCache.activeCache.containsKey(conn))
    fail("connection not returned to active list");
}
 

import javax.naming.Context; //导入方法依赖的package包/类
@Test
public void testIndexOnCommitForDestroy() throws Exception {
  AttributesFactory af = new AttributesFactory();
  af.setDataPolicy(DataPolicy.REPLICATE);
  Region region = cache.createRegion("sample", af.create());
  qs.createIndex("foo", IndexType.FUNCTIONAL, "age", "/sample");
  Context ctx = cache.getJNDIContext();
  UserTransaction utx = (UserTransaction) ctx.lookup("java:/UserTransaction");
  Integer x = new Integer(0);
  utx.begin();
  region.create(x, new Person("xyz", 45));
  utx.commit();
  Query q = qs.newQuery("select * from /sample where age < 50");
  assertEquals(1, ((SelectResults) q.execute()).size());
  Person dsample = (Person) CopyHelper.copy(region.get(x));
  dsample.setAge(55);
  utx.begin();
  region.destroy(x);
  utx.commit();
  CacheUtils.log(((Person) region.get(x)));
  assertEquals(0, ((SelectResults) q.execute()).size());
}
 

import javax.naming.Context; //导入方法依赖的package包/类
private void init() {

        if (!isAlwaysLookup()) {
            Context ctx = null;
            try {
                ctx = (props != null) ? new InitialContext(props) : new InitialContext(); 

                datasource = (DataSource) ctx.lookup(url);
            } catch (Exception e) {
                getLog().error(
                        "Error looking up datasource: " + e.getMessage(), e);
            } finally {
                if (ctx != null) {
                    try { ctx.close(); } catch(Exception ignore) {}
                }
            }
        }
    }
 

import javax.naming.Context; //导入方法依赖的package包/类
/**
 * Prepare for the beginning of active use of the public methods of this
 * component and implement the requirements of
 * {@link org.apache.catalina.util.LifecycleBase#startInternal()}.
 *
 * @exception LifecycleException if this component detects a fatal error
 *  that prevents this component from being used
 */
@Override
protected void startInternal() throws LifecycleException {

    try {
        Context context = getServer().getGlobalNamingContext();
        database = (UserDatabase) context.lookup(resourceName);
    } catch (Throwable e) {
        ExceptionUtils.handleThrowable(e);
        containerLog.error(sm.getString("userDatabaseRealm.lookup",
                                        resourceName),
                           e);
        database = null;
    }
    if (database == null) {
        throw new LifecycleException
            (sm.getString("userDatabaseRealm.noDatabase", resourceName));
    }

    super.startInternal();
}
 

import javax.naming.Context; //导入方法依赖的package包/类
/**
 * Test of validateConnection method, of class
 * org.apache.geode.internal.datasource.AbstractPoolCache.
 */
@Test
public void testValidateConnection() throws Exception {
  Context ctx = cache.getJNDIContext();
  GemFireConnPooledDataSource ds =
      (GemFireConnPooledDataSource) ctx.lookup("java:/PooledDataSource");
  GemFireConnectionPoolManager provider =
      (GemFireConnectionPoolManager) ds.getConnectionProvider();
  ConnectionPoolCacheImpl poolCache = (ConnectionPoolCacheImpl) provider.getConnectionPoolCache();
  PooledConnection poolConn = (PooledConnection) poolCache.getPooledConnectionFromPool();
  Connection conn = poolConn.getConnection();
  if (!ds.validateConnection(conn))
    fail("validate connection failed");
  conn.close();
  if (ds.validateConnection(conn))
    fail("validate connection failed");
}
 

import javax.naming.Context; //导入方法依赖的package包/类
/**
 * Inject resources in specified method.
 *
 * @param context
 *            jndi context to extract value from
 * @param instance
 *            object to inject into
 * @param method
 *            field target for injection
 * @param name
 *            jndi name value is bound under
 * @param clazz
 *            class annotation is defined in
 * @throws IllegalAccessException
 *             if method is inaccessible
 * @throws javax.naming.NamingException
 *             if value is not accessible in naming context
 * @throws java.lang.reflect.InvocationTargetException
 *             if setter call fails
 */
protected static void lookupMethodResource(Context context, Object instance, Method method, String name,
		Class<?> clazz) throws NamingException, IllegalAccessException, InvocationTargetException {

	if (!Introspection.isValidSetter(method)) {
		throw new IllegalArgumentException(sm.getString("defaultInstanceManager.invalidInjection"));
	}

	Object lookedupResource;
	boolean accessibility;

	String normalizedName = normalize(name);

	if ((normalizedName != null) && (normalizedName.length() > 0)) {
		lookedupResource = context.lookup(normalizedName);
	} else {
		lookedupResource = context.lookup(clazz.getName() + "/" + Introspection.getPropertyName(method));
	}

	synchronized (method) {
		accessibility = method.isAccessible();
		method.setAccessible(true);
		method.invoke(instance, lookedupResource);
		method.setAccessible(accessibility);
	}
}
 

import javax.naming.Context; //导入方法依赖的package包/类
public Connection getConnection() throws SQLException {
    Context ctx = null;
    try {
        Object ds = this.datasource;

        if (ds == null || isAlwaysLookup()) {
            ctx = (props != null) ? new InitialContext(props): new InitialContext(); 

            ds = ctx.lookup(url);
            if (!isAlwaysLookup()) {
                this.datasource = ds;
            }
        }

        if (ds == null) {
            throw new SQLException( "There is no object at the JNDI URL '" + url + "'");
        }

        if (ds instanceof XADataSource) {
            return (((XADataSource) ds).getXAConnection().getConnection());
        } else if (ds instanceof DataSource) { 
            return ((DataSource) ds).getConnection();
        } else {
            throw new SQLException("Object at JNDI URL '" + url + "' is not a DataSource.");
        }
    } catch (Exception e) {
        this.datasource = null;
        throw new SQLException(
                "Could not retrieve datasource via JNDI url '" + url + "' "
                        + e.getClass().getName() + ": " + e.getMessage());
    } finally {
        if (ctx != null) {
            try { ctx.close(); } catch(Exception ignore) {}
        }
    }
}
 

import javax.naming.Context; //导入方法依赖的package包/类
@Test
public void testGetTranxDataSource() throws Exception {
  Context ctx = cache.getJNDIContext();
  GemFireTransactionDataSource ds =
      (GemFireTransactionDataSource) ctx.lookup("java:/XAPooledDataSource");
  // DataSourceFactory dsf = new DataSourceFactory();
  // GemFireTransactionDataSource ds =
  // (GemFireTransactionDataSource)dsf.getTranxDataSource(map);
  Connection conn = ds.getConnection();
  if (conn == null)
    fail(
        "DataSourceFactoryJUnitTest-testGetTranxDataSource() Error in creating the getTranxDataSource");
}
 

import javax.naming.Context; //导入方法依赖的package包/类
protected DirContextNamePair getTargetContext(Name name)
        throws NamingException {

    if (cpe.getResolvedObj() == null)
        throw (NamingException)cpe.fillInStackTrace();

    Context ctx = NamingManager.getContext(cpe.getResolvedObj(),
                                           cpe.getAltName(),
                                           cpe.getAltNameCtx(),
                                           env);
    if (ctx == null)
        throw (NamingException)cpe.fillInStackTrace();

    if (ctx instanceof DirContext)
        return new DirContextNamePair((DirContext)ctx, name);

    if (ctx instanceof Resolver) {
        Resolver res = (Resolver)ctx;
        ResolveResult rr = res.resolveToClass(name, DirContext.class);

        // Reached a DirContext; return result.
        DirContext dctx = (DirContext)rr.getResolvedObj();
        return (new DirContextNamePair(dctx, rr.getRemainingName()));
    }

    // Resolve all the way using lookup().  This may allow the operation
    // to succeed if it doesn't require the penultimate context.
    Object ultimate = ctx.lookup(name);
    if (ultimate instanceof DirContext) {
        return (new DirContextNamePair((DirContext)ultimate,
                                      new CompositeName()));
    }

    throw (NamingException)cpe.fillInStackTrace();
}
 

import javax.naming.Context; //导入方法依赖的package包/类
/**
 * Looks up and returns the proxy to remote stateless calculator bean
 *
 * @return
 * @throws NamingException
 */
private static RemoteHello lookupRemoteStatelessHello() throws NamingException {
    final Hashtable<String, Object> jndiProperties = new Hashtable<String, Object>();
    jndiProperties.put(Context.URL_PKG_PREFIXES, "org.jboss.ejb.client.naming");
    final Context context = new InitialContext(jndiProperties);
    try {
        // The app name is the application name of the deployed EJBs. This is typically the ear name
        // without the .ear suffix. However, the application name could be overridden in the application.xml of the
        // EJB deployment on the server.
        // Since we haven't deployed the application as a .ear, the app name for us will be an empty string
        final String appName = "";
        // This is the module name of the deployed EJBs on the server. This is typically the jar name of the
        // EJB deployment, without the .jar suffix, but can be overridden via the ejb-jar.xml
        // In this example, we have deployed the EJBs in a jboss-as-ejb-remote-app.jar, so the module name is
        // jboss-as-ejb-remote-app
        final String moduleName = "ejb-module";
        // AS7 allows each deployment to have an (optional) distinct name. We haven't specified a distinct name for
        // our EJB deployment, so this is an empty string
        final String distinctName = "";
        // The EJB name which by default is the simple class name of the bean implementation class
        final String beanName = HelloBean.class.getSimpleName();
        // the remote view fully qualified class name
        final String viewClassName = RemoteHello.class.getName();
        // let's do the lookup
        String lookupKey = "ejb:" + appName + "/" + moduleName + "/" + distinctName + "/" + beanName + "!" + viewClassName;
        System.out.println("Lookup for remote EJB bean: " + lookupKey);
        return (RemoteHello) context.lookup(lookupKey);
    } finally {
        context.close();
    }

}
 

import javax.naming.Context; //导入方法依赖的package包/类
private static void testWith(String appletProperty) throws NamingException {
    Hashtable<Object, Object> env = new Hashtable<>();
    // Deliberately put java.lang.Object rather than java.applet.Applet
    // if an applet was used we would see a ClassCastException down there
    env.put(appletProperty, new Object());
    // It's ok to instantiate InitialContext with no parameters
    // and be unaware of it right until you try to use it
    Context ctx = new InitialContext(env);
    boolean threw = true;
    try {
        ctx.lookup("whatever");
        threw = false;
    } catch (NoInitialContextException e) {
        String m = e.getMessage();
        if (m == null || m.contains("applet"))
            throw new RuntimeException("The exception message is incorrect", e);
    } catch (Throwable t) {
        throw new RuntimeException(
                "The test was supposed to catch NoInitialContextException" +
                        " here, but caught: " + t.getClass().getName(), t);
    } finally {
        ctx.close();
    }

    if (!threw)
        throw new RuntimeException("The test was supposed to catch NoInitialContextException here");
}
 

import javax.naming.Context; //导入方法依赖的package包/类
@Test
public void testGetSimpleDataSource() throws Exception {
  try {
    Context ctx = cache.getJNDIContext();
    GemFireBasicDataSource ds = (GemFireBasicDataSource) ctx.lookup("java:/SimpleDataSource");
    Connection conn = ds.getConnection();
    if (conn == null)
      fail(
          "DataSourceFactoryTest-testGetSimpleDataSource() Error in creating the GemFireBasicDataSource");
  } catch (Exception e) {
    fail("Exception occured in testGetSimpleDataSource due to " + e);
    e.printStackTrace();
  }
}