bundles/org.apache.tomcat/src/javax/el/ExpressionFactory.java - rap/org.apache.tomcat - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You 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.
  */

 package javax.el;

 import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.UnsupportedEncodingException;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.security.AccessController;
 import java.security.PrivilegedAction;
 import java.util.Properties;

 /**
  *
  * @since 2.1
  */
 public abstract class ExpressionFactory {

     private static final boolean IS_SECURITY_ENABLED =
         (System.getSecurityManager() != null);

     private static final String SERVICE_RESOURCE_NAME =
         "META-INF/services/javax.el.ExpressionFactory";

     private static final String PROPERTY_NAME = "javax.el.ExpressionFactory";

     private static final String SEP;
     private static final String PROPERTY_FILE;

     static {
         if (IS_SECURITY_ENABLED) {
             SEP = AccessController.doPrivileged(
                     new PrivilegedAction<String>(){
                         @Override
                         public String run() {
                             return System.getProperty("file.separator");
                         }

                     }
             );
             PROPERTY_FILE = AccessController.doPrivileged(
                     new PrivilegedAction<String>(){
                         @Override
                         public String run() {
                             return System.getProperty("java.home") + SEP +
                                     "lib" + SEP + "el.properties";
                         }

                     }
             );
         } else {
             SEP = System.getProperty("file.separator");
             PROPERTY_FILE = System.getProperty("java.home") + SEP + "lib" +
                     SEP + "el.properties";
         }
     }

     public abstract Object coerceToType(Object obj, Class<?> expectedType)
             throws ELException;

     public abstract ValueExpression createValueExpression(ELContext context,
             String expression, Class<?> expectedType)
             throws NullPointerException, ELException;

     public abstract ValueExpression createValueExpression(Object instance,
             Class<?> expectedType);

     public abstract MethodExpression createMethodExpression(ELContext context,
             String expression, Class<?> expectedReturnType,
             Class<?>[] expectedParamTypes) throws ELException,
             NullPointerException;

     /**
      * Create a new {@link ExpressionFactory}. The class to use is determined by
      * the following search order:
      * <ol>
      * <li>services API (META-INF/services/javax.el.ExpressionFactory)</li>
      * <li>$JRE_HOME/lib/el.properties - key javax.el.ExpressionFactory</li>
      * <li>javax.el.ExpressionFactory</li>
      * <li>Platform default implementation -
      *     org.apache.el.ExpressionFactoryImpl</li>
      * </ol>
      * @return the new ExpressionFactory
      */
     public static ExpressionFactory newInstance() {
         return newInstance(null);
     }

     /**
      * Create a new {@link ExpressionFactory} passing in the provided
      * {@link Properties}. Search order is the same as {@link #newInstance()}.
      *
      * @param properties the properties to be passed to the new instance (may be null)
      * @return the new ExpressionFactory
      */
     public static ExpressionFactory newInstance(Properties properties) {
         String className = null;
         ExpressionFactory result = null;

         ClassLoader tccl = Thread.currentThread().getContextClassLoader();

         // First services API
         className = getClassNameServices(tccl);
         if (className == null) {
             if (IS_SECURITY_ENABLED) {
                 className = AccessController.doPrivileged(
                         new PrivilegedAction<String>() {
                             @Override
                             public String run() {
                                 return getClassNameJreDir();
                             }
                         }
                 );
             } else {
                 // Second el.properties file
                 className = getClassNameJreDir();
             }
         }
         if (className == null) {
             if (IS_SECURITY_ENABLED) {
                 className = AccessController.doPrivileged(
                         new PrivilegedAction<String>() {
                             @Override
                             public String run() {
                                 return getClassNameSysProp();
                             }
                         }
                 );
             } else {
                 // Third system property
                 className = getClassNameSysProp();
             }
         }
         if (className == null) {
             // Fourth - default
             className = "org.apache.el.ExpressionFactoryImpl";
         }

         try {
             Class<?> clazz = null;
             if (tccl == null) {
                 clazz = Class.forName(className);
             } else {
                 clazz = tccl.loadClass(className);
             }
             Constructor<?> constructor = null;
             // Do we need to look for a constructor that will take properties?
             if (properties != null) {
                 try {
                     constructor = clazz.getConstructor(Properties.class);
                 } catch (SecurityException se) {
                     throw new ELException(se);
                 } catch (NoSuchMethodException nsme) {
                     // This can be ignored
                     // This is OK for this constructor not to exist
                 }
             }
             if (constructor == null) {
                 result = (ExpressionFactory) clazz.newInstance();
             } else {
                 result =
                     (ExpressionFactory) constructor.newInstance(properties);
             }

         } catch (ClassNotFoundException e) {
             throw new ELException(
                     "Unable to find ExpressionFactory of type: " + className,
                     e);
         } catch (InstantiationException e) {
             throw new ELException(
                     "Unable to create ExpressionFactory of type: " + className,
                     e);
         } catch (IllegalAccessException e) {
             throw new ELException(
                     "Unable to create ExpressionFactory of type: " + className,
                     e);
         } catch (IllegalArgumentException e) {
             throw new ELException(
                     "Unable to create ExpressionFactory of type: " + className,
                     e);
         } catch (InvocationTargetException e) {
             throw new ELException(
                     "Unable to create ExpressionFactory of type: " + className,
                     e);
         }

         return result;
     }

     private static String getClassNameServices(ClassLoader tccl) {
         InputStream is = null;

         if (tccl == null) {
             is = ClassLoader.getSystemResourceAsStream(SERVICE_RESOURCE_NAME);
         } else {
             is = tccl.getResourceAsStream(SERVICE_RESOURCE_NAME);
         }

         if (is != null) {
             String line = null;
             BufferedReader br = null;
             try {
                 br = new BufferedReader(new InputStreamReader(is, "UTF-8"));
                 line = br.readLine();
                 if (line != null && line.trim().length() > 0) {
                     return line.trim();
                 }
             } catch (UnsupportedEncodingException e) {
                 // Should never happen with UTF-8
                 // If it does - ignore & return null
             } catch (IOException e) {
                 throw new ELException("Failed to read " + SERVICE_RESOURCE_NAME,
                         e);
             } finally {
                 try {
                     if (br != null) {
                         br.close();
                     }
                 } catch (IOException ioe) {/*Ignore*/}
                 try {
                     is.close();
                 } catch (IOException ioe) {/*Ignore*/}
             }
         }

         return null;
     }

     private static String getClassNameJreDir() {
         File file = new File(PROPERTY_FILE);
         if (file.canRead()) {
             InputStream is = null;
             try {
                 is = new FileInputStream(file);
                 Properties props = new Properties();
                 props.load(is);
                 String value = props.getProperty(PROPERTY_NAME);
                 if (value != null && value.trim().length() > 0) {
                     return value.trim();
                 }
             } catch (FileNotFoundException e) {
                 // Should not happen - ignore it if it does
             } catch (IOException e) {
                 throw new ELException("Failed to read " + PROPERTY_FILE, e);
             } finally {
                 if (is != null) {
                     try {
                         is.close();
                     } catch (IOException e) {
                         // Ignore
                     }
                 }
             }
         }
         return null;
     }

     private static final String getClassNameSysProp() {
         String value = System.getProperty(PROPERTY_NAME);
         if (value != null && value.trim().length() > 0) {
             return value.trim();
         }
         return null;
     }

 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You 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.
	*/

	package javax.el;

	import java.io.BufferedReader;
	import java.io.File;
	import java.io.FileInputStream;
	import java.io.FileNotFoundException;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.InputStreamReader;
	import java.io.UnsupportedEncodingException;
	import java.lang.reflect.Constructor;
	import java.lang.reflect.InvocationTargetException;
	import java.security.AccessController;
	import java.security.PrivilegedAction;
	import java.util.Properties;

	/**
	*
	* @since 2.1
	*/
	public abstract class ExpressionFactory {

	private static final boolean IS_SECURITY_ENABLED =
	(System.getSecurityManager() != null);

	private static final String SERVICE_RESOURCE_NAME =
	"META-INF/services/javax.el.ExpressionFactory";

	private static final String PROPERTY_NAME = "javax.el.ExpressionFactory";

	private static final String SEP;
	private static final String PROPERTY_FILE;

	static {
	if (IS_SECURITY_ENABLED) {
	SEP = AccessController.doPrivileged(
	new PrivilegedAction<String>(){
	@Override
	public String run() {
	return System.getProperty("file.separator");
	}

	}
	);
	PROPERTY_FILE = AccessController.doPrivileged(
	new PrivilegedAction<String>(){
	@Override
	public String run() {
	return System.getProperty("java.home") + SEP +
	"lib" + SEP + "el.properties";
	}

	}
	);
	} else {
	SEP = System.getProperty("file.separator");
	PROPERTY_FILE = System.getProperty("java.home") + SEP + "lib" +
	SEP + "el.properties";
	}
	}

	public abstract Object coerceToType(Object obj, Class<?> expectedType)
	throws ELException;

	public abstract ValueExpression createValueExpression(ELContext context,
	String expression, Class<?> expectedType)
	throws NullPointerException, ELException;

	public abstract ValueExpression createValueExpression(Object instance,
	Class<?> expectedType);

	public abstract MethodExpression createMethodExpression(ELContext context,
	String expression, Class<?> expectedReturnType,
	Class<?>[] expectedParamTypes) throws ELException,
	NullPointerException;

	/**
	* Create a new {@link ExpressionFactory}. The class to use is determined by
	* the following search order:
	* <ol>
	* <li>services API (META-INF/services/javax.el.ExpressionFactory)</li>
	* <li>$JRE_HOME/lib/el.properties - key javax.el.ExpressionFactory</li>
	* <li>javax.el.ExpressionFactory</li>
	* <li>Platform default implementation -
	* org.apache.el.ExpressionFactoryImpl</li>
	* </ol>
	* @return the new ExpressionFactory
	*/
	public static ExpressionFactory newInstance() {
	return newInstance(null);
	}

	/**
	* Create a new {@link ExpressionFactory} passing in the provided
	* {@link Properties}. Search order is the same as {@link #newInstance()}.
	*
	* @param properties the properties to be passed to the new instance (may be null)
	* @return the new ExpressionFactory
	*/
	public static ExpressionFactory newInstance(Properties properties) {
	String className = null;
	ExpressionFactory result = null;

	ClassLoader tccl = Thread.currentThread().getContextClassLoader();

	// First services API
	className = getClassNameServices(tccl);
	if (className == null) {
	if (IS_SECURITY_ENABLED) {
	className = AccessController.doPrivileged(
	new PrivilegedAction<String>() {
	@Override
	public String run() {
	return getClassNameJreDir();
	}
	}
	);
	} else {
	// Second el.properties file
	className = getClassNameJreDir();
	}
	}
	if (className == null) {
	if (IS_SECURITY_ENABLED) {
	className = AccessController.doPrivileged(
	new PrivilegedAction<String>() {
	@Override
	public String run() {
	return getClassNameSysProp();
	}
	}
	);
	} else {
	// Third system property
	className = getClassNameSysProp();
	}
	}
	if (className == null) {
	// Fourth - default
	className = "org.apache.el.ExpressionFactoryImpl";
	}

	try {
	Class<?> clazz = null;
	if (tccl == null) {
	clazz = Class.forName(className);
	} else {
	clazz = tccl.loadClass(className);
	}
	Constructor<?> constructor = null;
	// Do we need to look for a constructor that will take properties?
	if (properties != null) {
	try {
	constructor = clazz.getConstructor(Properties.class);
	} catch (SecurityException se) {
	throw new ELException(se);
	} catch (NoSuchMethodException nsme) {
	// This can be ignored
	// This is OK for this constructor not to exist
	}
	}
	if (constructor == null) {
	result = (ExpressionFactory) clazz.newInstance();
	} else {
	result =
	(ExpressionFactory) constructor.newInstance(properties);
	}

	} catch (ClassNotFoundException e) {
	throw new ELException(
	"Unable to find ExpressionFactory of type: " + className,
	e);
	} catch (InstantiationException e) {
	throw new ELException(
	"Unable to create ExpressionFactory of type: " + className,
	e);
	} catch (IllegalAccessException e) {
	throw new ELException(
	"Unable to create ExpressionFactory of type: " + className,
	e);
	} catch (IllegalArgumentException e) {
	throw new ELException(
	"Unable to create ExpressionFactory of type: " + className,
	e);
	} catch (InvocationTargetException e) {
	throw new ELException(
	"Unable to create ExpressionFactory of type: " + className,
	e);
	}

	return result;
	}

	private static String getClassNameServices(ClassLoader tccl) {
	InputStream is = null;

	if (tccl == null) {
	is = ClassLoader.getSystemResourceAsStream(SERVICE_RESOURCE_NAME);
	} else {
	is = tccl.getResourceAsStream(SERVICE_RESOURCE_NAME);
	}

	if (is != null) {
	String line = null;
	BufferedReader br = null;
	try {
	br = new BufferedReader(new InputStreamReader(is, "UTF-8"));
	line = br.readLine();
	if (line != null && line.trim().length() > 0) {
	return line.trim();
	}
	} catch (UnsupportedEncodingException e) {
	// Should never happen with UTF-8
	// If it does - ignore & return null
	} catch (IOException e) {
	throw new ELException("Failed to read " + SERVICE_RESOURCE_NAME,
	e);
	} finally {
	try {
	if (br != null) {
	br.close();
	}
	} catch (IOException ioe) {/Ignore/}
	try {
	is.close();
	} catch (IOException ioe) {/Ignore/}
	}
	}

	return null;
	}

	private static String getClassNameJreDir() {
	File file = new File(PROPERTY_FILE);
	if (file.canRead()) {
	InputStream is = null;
	try {
	is = new FileInputStream(file);
	Properties props = new Properties();
	props.load(is);
	String value = props.getProperty(PROPERTY_NAME);
	if (value != null && value.trim().length() > 0) {
	return value.trim();
	}
	} catch (FileNotFoundException e) {
	// Should not happen - ignore it if it does
	} catch (IOException e) {
	throw new ELException("Failed to read " + PROPERTY_FILE, e);
	} finally {
	if (is != null) {
	try {
	is.close();
	} catch (IOException e) {
	// Ignore
	}
	}
	}
	}
	return null;
	}

	private static final String getClassNameSysProp() {
	String value = System.getProperty(PROPERTY_NAME);
	if (value != null && value.trim().length() > 0) {
	return value.trim();
	}
	return null;
	}

	}