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/**
 * MVEL 2.0
 * Copyright (C) 2007  MVFLEX/Valhalla Project and the Codehaus
 * Mike Brock, Dhanji Prasanna, John Graham, Mark Proctor
 * 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.
 */
package org.mvel2;

import org.mvel2.compiler.CompiledAccExpression;
import org.mvel2.compiler.CompiledExpression;
import org.mvel2.compiler.ExecutableStatement;
import org.mvel2.compiler.ExpressionCompiler;
import org.mvel2.integration.Interceptor;
import org.mvel2.integration.VariableResolverFactory;
import org.mvel2.integration.impl.*;
import org.mvel2.optimizers.impl.refl.nodes.GetterAccessor;

import java.io.File;
import java.io.IOException;
import java.io.Serializable;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.HashMap;
import java.util.Map;

import static java.lang.Boolean.getBoolean;
import static java.lang.String.valueOf;
import static org.mvel2.DataConversion.convert;
import static org.mvel2.MVELRuntime.execute;
import static org.mvel2.util.ParseTools.loadFromFile;
import static org.mvel2.util.ParseTools.optimizeTree;

/**
 * The MVEL convienence class is a collection of static methods that provides a set of easy integration points for
 * MVEL.  The vast majority of MVEL's core functionality can be directly accessed through methods in this class.
 */
public class MVEL {
  public static final String NAME = "MVEL (MVFLEX Expression Language)";
  public static final String VERSION = "2.1";
  public static final String VERSION_SUB = "0";
  public static final String CODENAME = "liberty";
  static boolean DEBUG_FILE = getBoolean("mvel2.debug.fileoutput");
  static String ADVANCED_DEBUGGING_FILE = System.getProperty("mvel2.debugging.file") == null ? "mvel_debug.txt" : System.getProperty("mvel2.debugging.file");
  static boolean ADVANCED_DEBUG = getBoolean("mvel2.advanced_debugging");
  static boolean WEAK_CACHE = getBoolean("mvel2.weak_caching");
  static boolean NO_JIT = getBoolean("mvel2.disable.jit");
  public static boolean INVOKED_METHOD_EXCEPTIONS_BUBBLE = getBoolean("mvel2.invoked_meth_exceptions_bubble");
  public static boolean COMPILER_OPT_ALLOW_NAKED_METH_CALL = getBoolean("mvel2.compiler.allow_naked_meth_calls");
  public static boolean COMPILER_OPT_ALLOW_OVERRIDE_ALL_PROPHANDLING = getBoolean("mvel2.compiler.allow_override_all_prophandling");
  public static boolean COMPILER_OPT_ALLOW_RESOLVE_INNERCLASSES_WITH_DOTNOTATION = getBoolean("mvel2.compiler.allow_resolve_inner_classes_with_dotnotation");
  public static boolean COMPILER_OPT_SUPPORT_JAVA_STYLE_CLASS_LITERALS = getBoolean("mvel2.compiler.support_java_style_class_literals");
  public static boolean COMPILER_OPT_ALLOCATE_TYPE_LITERALS_TO_SHARED_SYMBOL_TABLE = getBoolean("mvel2.compiler.allocate_type_literals_to_shared_symbol_table");

  static boolean OPTIMIZER = true;

  static {
    if (System.getProperty("mvel2.optimizer") != null) {
      OPTIMIZER = getBoolean("mvel2.optimizer");
    }
  }

  private MVEL() {
  }

  public static boolean isAdvancedDebugging() {
    return ADVANCED_DEBUG;
  }

  public static String getDebuggingOutputFileName() {
    return ADVANCED_DEBUGGING_FILE;
  }

  public static boolean isFileDebugging() {
    return DEBUG_FILE;
  }

  /**
   * Evaluate an expression and return the value.
   *
   * @param expression A String containing the expression to be evaluated.
   * @return the resultant value
   */
  public static Object eval(String expression) {
    return new MVELInterpretedRuntime(expression, new ImmutableDefaultFactory()).parse();
  }

  /**
   * Evaluate an expression against a context object.  Expressions evaluated against a context object are designed
   * to treat members of that context object as variables in the expression.  For example:
   * 

   * MVEL.eval("foo == 1", ctx);
   * 
* In this case, the identifier foo would be resolved against the ctx object. So it would have * the equivalent of: ctc.getFoo() == 1 in Java. * * @param expression A String containing the expression to be evaluated. * @param ctx The context object to evaluate against. * @return The resultant value */ public static Object eval(String expression, Object ctx) { return new MVELInterpretedRuntime(expression, ctx, new ImmutableDefaultFactory()).parse(); } /** * Evaluate an expression with externally injected variables via a {@link VariableResolverFactory}. A factory * provides the means by which MVEL can resolve external variables. MVEL contains a straight-forward implementation * for wrapping Maps: {@link MapVariableResolverFactory}, which is used implicitly when calling overloaded methods * in this class that use Maps. *

* An example: *


   * Map varsMap = new HashMap();
   * varsMap.put("x", 5);
   * varsMap.put("y", 2);
   * 

* VariableResolverFactory factory = new MapVariableResolverFactory(varsMap); *

* Integer i = (Integer) MVEL.eval("x * y", factory); *

* assert i == 10; *

* * @param expression A String containing the expression to be evaluated. * @param resolverFactory The instance of the VariableResolverFactory to be used. * @return The resultant value. */ public static Object eval(String expression, VariableResolverFactory resolverFactory) { return new MVELInterpretedRuntime(expression, resolverFactory).parse(); } /** * Evaluates an expression against a context object and injected variables from a {@link VariableResolverFactory}. * This method of execution will prefer to find variables from the factory and then from the context. * * @param expression A string containing the expression to be evaluated * @param ctx The context object to evaluate against. * @param resolverFactory The instance of the VariableResolverFactory to be used. * @return The resultant value * @see #eval(String, org.mvel2.integration.VariableResolverFactory) */ public static Object eval(String expression, Object ctx, VariableResolverFactory resolverFactory) { return new MVELInterpretedRuntime(expression, ctx, resolverFactory).parse(); } /** * Evaluates an expression against externally injected variables. This is a wrapper convenience method which * wraps the provided Map of vars in a {@link MapVariableResolverFactory} * * @param expression A string containing the expression to be evaluated. * @param vars A map of vars to be injected * @return The resultant value * @see #eval(String, org.mvel2.integration.VariableResolverFactory) */ public static Object eval(String expression, Map vars) { CachingMapVariableResolverFactory factory = new CachingMapVariableResolverFactory(vars); try { return new MVELInterpretedRuntime(expression, null, factory).parse(); } finally { factory.externalize(); } } /** * Evaluates an expression against a context object and externally injected variables. This is a wrapper * convenience method which wraps the provided Map of vars in a {@link MapVariableResolverFactory} * * @param expression A string containing the expression to be evaluated. * @param ctx The context object to evaluate against. * @param vars A map of vars to be injected * @return The resultant value * @see #eval(String, VariableResolverFactory) */ public static Object eval(String expression, Object ctx, Map vars) { CachingMapVariableResolverFactory factory = new CachingMapVariableResolverFactory(vars); try { return new MVELInterpretedRuntime(expression, ctx, factory).parse(); } finally { factory.externalize(); } } /** * Evaluates an expression and, if necessary, coerces the resultant value to the specified type. Example: *

   * Float output = MVEL.eval("5 + 5", Float.class);
   * 
*

* This converts an expression that would otherwise return an Integer to a Float. * * @param expression A string containing the expression to be evaluated. * @param toType The target type that the resultant value will be converted to, if necessary. * @return The resultant value. */ public static T eval(String expression, Class toType) { return convert(new MVELInterpretedRuntime(expression).parse(), toType); } /** * Evaluates an expression against a context object and, if necessary, coerces the resultant value to the specified * type. * * @param expression A string containing the expression to be evaluated. * @param ctx The context object to evaluate against. * @param toType The target type that the resultant value will be converted to, if necessary. * @return The resultant value * @see #eval(String, Class) */ public static T eval(String expression, Object ctx, Class toType) { return convert(new MVELInterpretedRuntime(expression, ctx).parse(), toType); } /** * Evaluates an expression against externally injected variables and, if necessary, coerces the resultant value * to the specified type. * * @param expression A string containing the expression to be evaluated * @param vars The variables to be injected * @param toType The target type that the resultant value will be converted to, if necessary. * @return The resultant value * @see #eval(String, VariableResolverFactory) * @see #eval(String, Class) */ public static T eval(String expression, VariableResolverFactory vars, Class toType) { return convert(new MVELInterpretedRuntime(expression, null, vars).parse(), toType); } /** * Evaluates an expression against externally injected variables. The resultant value is coerced to the specified * type if necessary. This is a wrapper convenience method which wraps the provided Map of vars in a{@link MapVariableResolverFactory} * * @param expression A string containing the expression to be evaluated. * @param vars A map of vars to be injected * @param toType The target type the resultant value will be converted to, if necessary. * @return The resultant value * @see #eval(String, org.mvel2.integration.VariableResolverFactory) */ public static T eval(String expression, Map vars, Class toType) { CachingMapVariableResolverFactory factory = new CachingMapVariableResolverFactory(vars); try { return convert(new MVELInterpretedRuntime(expression, null, factory).parse(), toType); } finally { factory.externalize(); } } /** * Evaluates an expression against a context object and externally injected variables. If necessary, the resultant * value is coerced to the specified type. * * @param expression A string containing the expression to be evaluated. * @param ctx The context object to evaluate against * @param vars The vars to be injected * @param toType The target type that the resultant value will be converted to, if necessary. * @return The resultant value. * @see #eval(String, Object, VariableResolverFactory) * @see #eval(String, Class) */ public static T eval(String expression, Object ctx, VariableResolverFactory vars, Class toType) { return convert(new MVELInterpretedRuntime(expression, ctx, vars).parse(), toType); } /** * Evaluates an expression against a context object and externally injected variables. If necessary, the resultant * value is coerced to the specified type. * * @param expression A string containing the expression to be evaluated. * @param ctx The context object to evaluate against * @param vars A Map of variables to be injected. * @param toType The target type that the resultant value will be converted to, if necessary. * @return The resultant value. * @see #eval(String, Object, VariableResolverFactory) * @see #eval(String, Class) */ public static T eval(String expression, Object ctx, Map vars, Class toType) { CachingMapVariableResolverFactory factory = new CachingMapVariableResolverFactory(vars); try { return convert(new MVELInterpretedRuntime(expression, ctx, factory).parse(), toType); } finally { factory.externalize(); } } /** * Evaluates an expression and returns the resultant value as a String. * * @param expression A string containing the expressino to be evaluated. * @return The resultant value */ public static String evalToString(String expression) { return valueOf(eval(expression)); } /** * Evaluates an expression and returns the resultant value as a String. * * @param expression A string containing the expressino to be evaluated. * @param ctx The context object to evaluate against * @return The resultant value * @see #eval(String, Object) */ public static String evalToString(String expression, Object ctx) { return valueOf(eval(expression, ctx)); } /** * Evaluates an expression and returns the resultant value as a String. * * @param expression A string containing the expressino to be evaluated. * @param vars The variables to be injected * @return The resultant value * @see #eval(String, VariableResolverFactory) */ public static String evalToString(String expression, VariableResolverFactory vars) { return valueOf(eval(expression, vars)); } /** * Evaluates an expression and returns the resultant value as a String. * * @param expression A string containing the expressino to be evaluated. * @param vars A Map of variables to be injected * @return The resultant value * @see #eval(String, Map) */ public static String evalToString(String expression, Map vars) { return valueOf(eval(expression, vars)); } /** * Evaluates an expression and returns the resultant value as a String. * * @param expression A string containing the expressino to be evaluated. * @param ctx The context object to evaluate against. * @param vars The variables to be injected * @return The resultant value * @see #eval(String, Map) */ public static String evalToString(String expression, Object ctx, VariableResolverFactory vars) { return valueOf(eval(expression, ctx, vars)); } /** * Evaluates an expression and returns the resultant value as a String. * * @param expression A string containing the expressino to be evaluated. * @param ctx The context object to evaluate against. * @param vars A Map of variables to be injected * @return The resultant value * @see #eval(String, Map) */ public static String evalToString(String expression, Object ctx, Map vars) { return valueOf(eval(expression, ctx, vars)); } /** * Evaluate an expression and return the value. * * @param expression A char[] containing the expression to be evaluated. * @return The resultant value * @see #eval(String) */ public static Object eval(char[] expression) { return new MVELInterpretedRuntime(expression, new ImmutableDefaultFactory()).parse(); } /** * Evaluate an expression against a context object and return the value * * @param expression A char[] containing the expression to be evaluated. * @param ctx The context object to evaluate against * @return The resultant value * @see #eval(String, Object) */ public static Object eval(char[] expression, Object ctx) { return new MVELInterpretedRuntime(expression, ctx).parse(); } public static T eval(char[] expression, Class type) { return convert(new MVELInterpretedRuntime(expression).parse(), type); } /** * Evaluate an expression against a context object and return the value * * @param expression A char[] containing the expression to be evaluated. * @param ctx The context object to evaluate against * @param vars The variables to be injected * @return The resultant value * @see #eval(String, Object, VariableResolverFactory) */ public static Object eval(char[] expression, Object ctx, VariableResolverFactory vars) { return new MVELInterpretedRuntime(expression, ctx, vars).parse(); } public static Object eval(char[] expression, int start, int offset, Object ctx, VariableResolverFactory vars) { return new MVELInterpretedRuntime(expression, start, offset, ctx, vars).parse(); } public static T eval(char[] expression, int start, int offset, Object ctx, VariableResolverFactory vars, Class toType) { return convert(new MVELInterpretedRuntime(expression, start, offset, ctx, vars).parse(), toType); } /** * Evaluate an expression against a context object and return the value * * @param expression A char[] containing the expression to be evaluated. * @param ctx The context object to evaluate against * @param vars A Map of variables to be injected * @return The resultant value * @see #eval(String, Object, Map) */ public static Object eval(char[] expression, Object ctx, Map vars) { return new MVELInterpretedRuntime(expression, ctx, vars).parse(); } /** * Evaluate an expression with a context object and injected variables and return the value. If necessary convert * the resultant value to the specified type. * * @param expression A char[] containing the expression to be evaluated. * @param ctx The context object to evaluate against * @param vars A Map of variables to be injected * @param toType The target type the resultant value will be converted to, if necessary. * @return The resultant value * @see #eval(String, Object, Map, Class) */ public static T eval(char[] expression, Object ctx, Map vars, Class toType) { return convert(new MVELInterpretedRuntime(expression, ctx, vars).parse(), toType); } /** * Evaluate an expression with a context object and return the value. If necessary convert * the resultant value to the specified type. * * @param expression A char[] containing the expression to be evaluated. * @param ctx The context object to evaluate against * @param toType The target type the resultant value will be converted to, if necessary. * @return The resultant value * @see #eval(String, Object, Class) */ public static T eval(char[] expression, Object ctx, Class toType) { return convert(new MVELInterpretedRuntime(expression, ctx).parse(), toType); } /** * Evaluate an expression with a context object and injected variables and return the value. If necessary convert * the resultant value to the specified type. * * @param expression A char[] containing the expression to be evaluated. * @param ctx The context object to evaluate against * @param vars The variables to be injected * @param toType The target type the resultant value will be converted to, if necessary. * @return The resultant value * @see #eval(String, Object, VariableResolverFactory, Class) */ public static T eval(char[] expression, Object ctx, VariableResolverFactory vars, Class toType) { return convert(new MVELInterpretedRuntime(expression, ctx, vars).parse(), toType); } /** * Evaluate an expression with injected variables and return the value. If necessary convert * the resultant value to the specified type. * * @param expression A char[] containing the expression to be evaluated. * @param vars The variables to be injected * @param toType The target type the resultant value will be converted to, if necessary. * @return The resultant value * @see #eval(String, VariableResolverFactory, Class) */ public static T eval(char[] expression, VariableResolverFactory vars, Class toType) { return convert(new MVELInterpretedRuntime(expression, null, vars).parse(), toType); } /** * Evaluate an expression with injected variables and return the resultant value. If necessary convert * the resultant value to the specified type. * * @param expression A char[] containing the expression to be evaluated. * @param vars The variables to be injected * @param toType The target type the resultant value will be converted to, if necessary. * @return The resultant value * @see #eval(String, Map, Class) */ public static T eval(char[] expression, Map vars, Class toType) { return convert(new MVELInterpretedRuntime(expression, null, vars).parse(), toType); } /** * Evaluate a script from a file and return the resultant value. * * @param file The file to process * @return The resultant value * @throws IOException Exception thrown if there is an IO problem accessing the file. */ public static Object evalFile(File file) throws IOException { return _evalFile(file, null, new CachedMapVariableResolverFactory(new HashMap())); } public static Object evalFile(File file, String encoding) throws IOException { return _evalFile(file, encoding, null, new CachedMapVariableResolverFactory(new HashMap())); } /** * Evaluate a script from a file, against a context object and return the resultant value. * * @param file The file to process * @param ctx The context to evaluate the script against. * @return The resultant value * @throws IOException Exception thrown if there is an IO problem accessing the file. */ public static Object evalFile(File file, Object ctx) throws IOException { return _evalFile(file, ctx, new CachedMapVariableResolverFactory(new HashMap())); } public static Object evalFile(File file, String encoding, Object ctx) throws IOException { return _evalFile(file, encoding, ctx, new CachedMapVariableResolverFactory(new HashMap())); } /** * Evaluate a script from a file with injected variables and return the resultant value. * * @param file The file to process * @param vars Variables to be injected * @return The resultant value * @throws IOException Exception thrown if there is an IO problem accessing the file. */ public static Object evalFile(File file, Map vars) throws IOException { CachingMapVariableResolverFactory factory = new CachingMapVariableResolverFactory(vars); try { return _evalFile(file, null, factory); } finally { factory.externalize(); } } /** * Evaluate a script from a file with injected variables and a context object, then return the resultant value. * * @param file The file to process * @param ctx The context to evaluate the script against. * @param vars Variables to be injected * @return The resultant value * @throws IOException Exception thrown if there is an IO problem accessing the file. */ public static Object evalFile(File file, Object ctx, Map vars) throws IOException { CachingMapVariableResolverFactory factory = new CachingMapVariableResolverFactory(vars); try { return _evalFile(file, ctx, factory); } finally { factory.externalize(); } } public static Object evalFile(File file, String encoding, Object ctx, Map vars) throws IOException { CachingMapVariableResolverFactory factory = new CachingMapVariableResolverFactory(vars); try { return _evalFile(file, encoding, ctx, factory); } finally { factory.externalize(); } } /** * Evaluate a script from a file with injected variables and a context object, then return the resultant value. * * @param file The file to process * @param ctx The context to evaluate the script against. * @param vars Variables to be injected * @return The resultant value * @throws IOException Exception thrown if there is an IO problem accessing the file. */ public static Object evalFile(File file, Object ctx, VariableResolverFactory vars) throws IOException { return _evalFile(file, ctx, vars); } public static Object evalFile(File file, String encoding, Object ctx, VariableResolverFactory vars) throws IOException { return _evalFile(file, encoding, ctx, vars); } private static Object _evalFile(File file, Object ctx, VariableResolverFactory factory) throws IOException { return _evalFile(file, null, ctx, factory); } private static Object _evalFile(File file, String encoding, Object ctx, VariableResolverFactory factory) throws IOException { return eval(loadFromFile(file, encoding), ctx, factory); } /** * Evaluate an expression in Boolean-only mode against a root context object and injected variables. * * @param expression A string containing the expression to be evaluated. * @param ctx The context against which to evaluate the expression * @param vars The variables to be injected * @return The resultant value as a Boolean */ public static Boolean evalToBoolean(String expression, Object ctx, Map vars) { return eval(expression, ctx, vars, Boolean.class); } /** * Evaluate an expression in Boolean-only mode against a root context object. * * @param expression A string containing the expression to be evaluated. * @param ctx The context against which to evaluate the expression * @return The resultant value as a Boolean */ public static Boolean evalToBoolean(String expression, Object ctx) { return eval(expression, ctx, new ImmutableDefaultFactory(), Boolean.class); } /** * Evaluate an expression in Boolean-only mode against a root context object and injected variables. * * @param expression A string containing the expression to be evaluated. * @param ctx The context against which to evaluate the expression * @param vars The variables to be injected * @return The resultant value as a Boolean */ public static Boolean evalToBoolean(String expression, Object ctx, VariableResolverFactory vars) { return eval(expression, ctx, vars, Boolean.class); } /** * Evaluate an expression in Boolean-only with injected variables. * * @param expression A string containing the expression to be evaluated. * @param vars The variables to be injected * @return The resultant value as a Boolean */ public static Boolean evalToBoolean(String expression, VariableResolverFactory vars) { return eval(expression, vars, Boolean.class); } /** * Evaluate an expression in Boolean-only with injected variables. * * @param expression A string containing the expression to be evaluated. * @param vars The variables to be injected * @return The resultant value as a Boolean */ public static Boolean evalToBoolean(String expression, Map vars) { return evalToBoolean(expression, null, vars); } /** * Performs an analysis compileShared, which will populate the ParserContext with type, input and variable information, * but will not produce a payload. * * @param expression - the expression to analyze * @param ctx - the parser context */ public static void analysisCompile(char[] expression, ParserContext ctx) { ExpressionCompiler compiler = new ExpressionCompiler(expression); compiler.setVerifyOnly(true); compiler.compile(ctx); } public static void analysisCompile(String expression, ParserContext ctx) { analysisCompile(expression.toCharArray(), ctx); } public static Class analyze(char[] expression, ParserContext ctx) { ExpressionCompiler compiler = new ExpressionCompiler(expression); compiler.setVerifyOnly(true); compiler.compile(ctx); return compiler.getReturnType(); } public static Class analyze(String expression, ParserContext ctx) { return analyze(expression.toCharArray(), ctx); } /** * Compiles an expression and returns a Serializable object containing the compiled expression. The returned value * can be reused for higher-performance evaluation of the expression. It is used in a straight forward way: *


   * 

* // Compile the expression * Serializable compiled = MVEL.compileExpression("x * 10"); *

* // Create a Map to hold the variables. * Map vars = new HashMap(); *

* // Create a factory to envelop the variable map * VariableResolverFactory factory = new MapVariableResolverFactory(vars); *

* int total = 0; * for (int i = 0; i < 100; i++) { * // Update the 'x' variable. * vars.put("x", i); *

* // Execute the expression against the compiled payload and factory, and add the result to the total variable. * total += (Integer) MVEL.executeExpression(compiled, factory); * } *

* // Total should be 49500 * assert total == 49500; *

*

* The above example demonstrates a compiled expression being reused ina tight, closed, loop. Doing this greatly * improves performance as re-parsing of the expression is not required, and the runtime can dynamically compileShared * the expression to bytecode of necessary. * * @param expression A String contaiing the expression to be compiled. * @return The cacheable compiled payload. */ public static Serializable compileExpression(String expression) { return compileExpression(expression, null, null, null); } /** * Compiles an expression and returns a Serializable object containing the compiled expression. This method * also accept a Map of imports. The Map's keys are String's representing the imported, short-form name of the * Classes or Methods imported. An import of a Method is essentially a static import. This is a substitute for * needing to declare import statements within the actual script. *

*


   * Map imports = new HashMap();
   * imports.put("HashMap", java.util.HashMap.class); // import a class
   * imports.put("time", MVEL.getStaticMethod(System.class, "currentTimeMillis", new Class[0])); // import a static method
   * 

* // Compile the expression * Serializable compiled = MVEL.compileExpression("map = new HashMap(); map.put('time', time()); map.time"); *

* // Execute with a blank Map to allow vars to be declared. * Long val = (Long) MVEL.executeExpression(compiled, new HashMap()); *

* assert val > 0; *

* * @param expression A String contaiing the expression to be compiled. * @param imports A String-Class/String-Method pair Map containing imports for the compiler. * @return The cacheable compiled payload. */ public static Serializable compileExpression(String expression, Map imports) { return compileExpression(expression, imports, null, null); } /** * Compiles an expression and returns a Serializable object containing the compiled expression. This method * accepts a Map of imports and Interceptors. See {@link #compileExpression(String, Map)} for information on * imports. The imports parameter in this method is optional and it is safe to pass a null * value.
{@link org.mvel2.integration.Interceptor Interceptors} are markers within an expression that allow external hooks * to be tied into the expression. *

*


   * // Create a Map to hold the interceptors.
   * Map interceptors = new HashMap();
   * 

* // Create a simple interceptor. * Interceptor logInterceptor = new Interceptor() { * public int doBefore(ASTNode node, VariableResolverFactory factory) { * System.out.println("Interceptor called before!"); * } *

* public int doAfter(Object exitValue, ASTNode node, VariableResolverFactory factory) { * System.out.println("Interceptor called after!"); * } * }; *

* // Add the interceptor to the Map. * interceptors.put("log", logInterceptor); *

* // Create an expression * String expr = "list = [1,2,3,4,5]; @log for (item : list) { System.out.println(item); }; *

* Serializable compiled = MVEL.compileExpression(expr, null, interceptors); *

* // Execute expression with a blank Map to allow vars to be declared. * MVEL.executeExpression(compiled, new HashMap()); *

*

* The above example demonstrates inserting an interceptor into a piece of code. The @log interceptor * wraps the subsequent statement. In this case, the interceptor is fired before the for loop and * after the for loop finishes. * * @param expression A String containing the expression to be evaluated. * @param imports A String-Class/String-Method pair Map containing imports for the compiler. * @param interceptors A Map of registered interceptors. * @return A cacheable compiled payload. */ public static Serializable compileExpression(String expression, Map imports, Map interceptors) { return compileExpression(expression, imports, interceptors, null); } /** * Compiles an expression, and accepts a {@link ParserContext} instance. The ParserContext object is the * fine-grained configuration object for the MVEL parser and compiler. * * @param expression A string containing the expression to be compiled. * @param ctx The parser context * @return A cacheable compiled payload. */ public static Serializable compileExpression(String expression, ParserContext ctx) { return optimizeTree(new ExpressionCompiler(expression).compile(ctx)); } public static Serializable compileExpression(char[] expression, int start, int offset, ParserContext ctx) { ExpressionCompiler c = new ExpressionCompiler(expression, start, offset); if (ctx != null) c.setPCtx(ctx); return optimizeTree(c._compile()); } public static Serializable compileExpression(String expression, Map imports, Map interceptors, String sourceName) { return compileExpression(expression, new ParserContext(imports, interceptors, sourceName)); } public static Serializable compileExpression(char[] expression, ParserContext ctx) { return optimizeTree(new ExpressionCompiler(expression).compile(ctx)); } /** * Compiles an expression and returns a Serializable object containing the compiled * expression. * * @param expression The expression to be compiled * @param imports Imported classes * @param interceptors Map of named interceptos * @param sourceName The name of the source file being evaluated (optional) * @return The cacheable compiled payload */ public static Serializable compileExpression(char[] expression, Map imports, Map interceptors, String sourceName) { return compileExpression(expression, new ParserContext(imports, interceptors, sourceName)); } public static Serializable compileExpression(char[] expression) { return compileExpression(expression, null, null, null); } public static Serializable compileExpression(char[] expression, Map imports) { return compileExpression(expression, imports, null, null); } public static Serializable compileExpression(char[] expression, Map imports, Map interceptors) { return compileExpression(expression, imports, interceptors, null); } public static Serializable compileGetExpression(String expression) { return new CompiledAccExpression(expression.toCharArray(), Object.class, new ParserContext()); } public static Serializable compileGetExpression(String expression, ParserContext ctx) { return new CompiledAccExpression(expression.toCharArray(), Object.class, ctx); } public static Serializable compileGetExpression(char[] expression) { return new CompiledAccExpression(expression, Object.class, new ParserContext()); } public static Serializable compileGetExpression(char[] expression, ParserContext ctx) { return new CompiledAccExpression(expression, Object.class, ctx); } public static Serializable compileSetExpression(String expression) { return new CompiledAccExpression(expression.toCharArray(), Object.class, new ParserContext()); } public static Serializable compileSetExpression(String expression, ParserContext ctx) { return new CompiledAccExpression(expression.toCharArray(), Object.class, ctx); } public static Serializable compileSetExpression(String expression, Class ingressType, ParserContext ctx) { return new CompiledAccExpression(expression.toCharArray(), ingressType, ctx); } public static Serializable compileSetExpression(char[] expression) { return new CompiledAccExpression(expression, Object.class, new ParserContext()); } public static Serializable compileSetExpression(char[] expression, ParserContext ctx) { return new CompiledAccExpression(expression, Object.class, ctx); } public static Serializable compileSetExpression(char[] expression, int start, int offset, ParserContext ctx) { return new CompiledAccExpression(expression, start, offset, Object.class, ctx); } public static Serializable compileSetExpression(char[] expression, Class ingressType, ParserContext ctx) { return new CompiledAccExpression(expression, ingressType, ctx); } public static void executeSetExpression(Serializable compiledSet, Object ctx, Object value) { ((CompiledAccExpression) compiledSet).setValue(ctx, ctx, new ImmutableDefaultFactory(), value); } public static void executeSetExpression(Serializable compiledSet, Object ctx, VariableResolverFactory vrf, Object value) { ((CompiledAccExpression) compiledSet).setValue(ctx, ctx, vrf, value); } public static Object executeExpression(Object compiledExpression) { return ((ExecutableStatement) compiledExpression).getValue(null, new ImmutableDefaultFactory()); } /** * Executes a compiled expression. * * @param compiledExpression - * @param ctx - * @param vars - * @return - * @see #compileExpression(String) */ @SuppressWarnings({"unchecked"}) public static Object executeExpression(final Object compiledExpression, final Object ctx, final Map vars) { CachingMapVariableResolverFactory factory = vars != null ? new CachingMapVariableResolverFactory(vars) : null; try { return ((ExecutableStatement) compiledExpression).getValue(ctx, factory); } finally { if (factory != null) factory.externalize(); } } public static Object executeExpression(final Object compiledExpression, final Object ctx, final VariableResolverFactory resolverFactory) { return ((ExecutableStatement) compiledExpression).getValue(ctx, resolverFactory); } /** * Executes a compiled expression. * * @param compiledExpression - * @param factory - * @return - * @see #compileExpression(String) */ public static Object executeExpression(final Object compiledExpression, final VariableResolverFactory factory) { return ((ExecutableStatement) compiledExpression).getValue(null, factory); } /** * Executes a compiled expression. * * @param compiledExpression - * @param ctx - * @return - * @see #compileExpression(String) */ public static Object executeExpression(final Object compiledExpression, final Object ctx) { return ((ExecutableStatement) compiledExpression).getValue(ctx, new ImmutableDefaultFactory()); } /** * Executes a compiled expression. * * @param compiledExpression - * @param vars - * @return - * @see #compileExpression(String) */ @SuppressWarnings({"unchecked"}) public static Object executeExpression(final Object compiledExpression, final Map vars) { CachingMapVariableResolverFactory factory = new CachingMapVariableResolverFactory(vars); try { return ((ExecutableStatement) compiledExpression).getValue(null, factory); } finally { factory.externalize(); } } /** * Execute a compiled expression and convert the result to a type * * @param compiledExpression - * @param ctx - * @param vars - * @param toType - * @return - */ @SuppressWarnings({"unchecked"}) public static T executeExpression(final Object compiledExpression, final Object ctx, final Map vars, Class toType) { return convert(executeExpression(compiledExpression, ctx, vars), toType); } public static T executeExpression(final Object compiledExpression, final Object ctx, final VariableResolverFactory vars, Class toType) { return convert(executeExpression(compiledExpression, ctx, vars), toType); } /** * Execute a compiled expression and convert the result to a type * * @param compiledExpression - * @param vars - * @param toType - * @return - */ @SuppressWarnings({"unchecked"}) public static T executeExpression(final Object compiledExpression, Map vars, Class toType) { return convert(executeExpression(compiledExpression, vars), toType); } /** * Execute a compiled expression and convert the result to a type. * * @param compiledExpression - * @param ctx - * @param toType - * @return - */ public static T executeExpression(final Object compiledExpression, final Object ctx, Class toType) { return convert(executeExpression(compiledExpression, ctx), toType); } public static void executeExpression(Iterable compiledExpression) { for (CompiledExpression ce : compiledExpression) { ce.getValue(null, null); } } public static void executeExpression(Iterable compiledExpression, Object ctx) { for (CompiledExpression ce : compiledExpression) { ce.getValue(ctx, null); } } public static void executeExpression(Iterable compiledExpression, Map vars) { CachingMapVariableResolverFactory factory = new CachingMapVariableResolverFactory(vars); executeExpression(compiledExpression, null, factory); factory.externalize(); } public static void executeExpression(Iterable compiledExpression, Object ctx, Map vars) { CachingMapVariableResolverFactory factory = new CachingMapVariableResolverFactory(vars); executeExpression(compiledExpression, ctx, factory); factory.externalize(); } public static void executeExpression(Iterable compiledExpression, Object ctx, VariableResolverFactory vars) { for (CompiledExpression ce : compiledExpression) { ce.getValue(ctx, vars); } } public static Object[] executeAllExpression(Serializable[] compiledExpressions, Object ctx, VariableResolverFactory vars) { if (compiledExpressions == null) return GetterAccessor.EMPTY; Object[] o = new Object[compiledExpressions.length]; for (int i = 0; i < compiledExpressions.length; i++) { o[i] = executeExpression(compiledExpressions[i], ctx, vars); } return o; } public static Object executeDebugger(CompiledExpression expression, Object ctx, VariableResolverFactory vars) { if (expression.isImportInjectionRequired()) { return execute(true, expression, ctx, new ClassImportResolverFactory(expression.getParserContext().getParserConfiguration(), vars, false)); } else { return execute(true, expression, ctx, vars); } } public static String parseMacros(String input, Map macros) { return new MacroProcessor(macros).parse(input); } public static String preprocess(char[] input, PreProcessor[] preprocessors) { char[] ex = input; for (PreProcessor proc : preprocessors) { ex = proc.parse(ex); } return new String(ex); } public static String preprocess(String input, PreProcessor[] preprocessors) { return preprocess(input.toCharArray(), preprocessors); } public static Object getProperty(String property, Object ctx) { return PropertyAccessor.get(property, ctx); } public static void setProperty(Object ctx, String property, Object value) { PropertyAccessor.set(ctx, property, value); } /** * A simple utility method to get a static method from a class with no checked exception. With throw a * RuntimeException if the method is not found or is not a static method. * * @param cls The class containing the static method * @param methodName The method name * @param signature The signature of the method * @return An instance of the Method */ public static Method getStaticMethod(Class cls, String methodName, Class[] signature) { try { Method m = cls.getMethod(methodName, signature); if ((m.getModifiers() & Modifier.STATIC) == 0) throw new RuntimeException("method not a static method: " + methodName); return m; } catch (NoSuchMethodException e) { throw new RuntimeException("no such method: " + methodName); } } }





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