com.sun.el
类 MethodExpressionLiteral

java.lang.Object
  javax.el.Expression
      javax.el.MethodExpression
          com.sun.el.MethodExpressionLiteral

所有已实现的接口：

Externalizable, Serializable

public class MethodExpressionLiteral
extends MethodExpression
implements Externalizable

另请参见：

序列化表格

构造方法摘要

MethodExpressionLiteral()

MethodExpressionLiteral(String expr, Class expectedType, Class[] paramTypes)

方法摘要

boolean	equals(Object obj) Determines whether the specified object is equal to this Expression.
String	getExpressionString() Returns the original String used to create this Expression, unmodified.
MethodInfo	getMethodInfo(ELContext context) Evaluates the expression relative to the provided context, and returns information about the actual referenced method.
int	hashCode() Returns the hash code for this Expression.
Object	invoke(ELContext context, Object[] params) If a String literal is specified as the expression, returns the String literal coerced to the expected return type of the method signature.
boolean	isLiteralText() Returns whether this expression was created from only literal text.
void	readExternal(ObjectInput in)
void	writeExternal(ObjectOutput out)

从类 javax.el.MethodExpression 继承的方法

isParmetersProvided

从类 java.lang.Object 继承的方法

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

构造方法详细信息

MethodExpressionLiteral

public MethodExpressionLiteral()

MethodExpressionLiteral

public MethodExpressionLiteral(String expr,
                               Class expectedType,
                               Class[] paramTypes)

方法详细信息

getMethodInfo

public MethodInfo getMethodInfo(ELContext context)
                         throws ELException

从类 MethodExpression 复制的描述

Evaluates the expression relative to the provided context, and returns information about the actual referenced method.

指定者：

类 MethodExpression 中的 getMethodInfo

参数：

context - The context of this evaluation

返回：

an instance of MethodInfo containing information about the method the expression evaluated to.

抛出：

PropertyNotFoundException - if one of the property resolutions failed because a specified variable or property does not exist or is not readable.

MethodNotFoundException - if no suitable method can be found.

ELException - if an exception was thrown while performing property or variable resolution. The thrown exception must be included as the cause property of this exception, if available.

invoke

public Object invoke(ELContext context,
                     Object[] params)
              throws ELException

从类 MethodExpression 复制的描述

If a String literal is specified as the expression, returns the String literal coerced to the expected return type of the method signature. An ELException is thrown if expectedReturnType is void or if the coercion of the String literal to the expectedReturnType yields an error (see Section "1.18 Type Conversion" of the EL specification). If not a String literal, evaluates the expression relative to the provided context, invokes the method that was found using the supplied parameters, and returns the result of the method invocation. Any parameters passed to this method is ignored if isLiteralText() or isParmetersProvided() is true.

指定者：

类 MethodExpression 中的 invoke

参数：

context - The context of this evaluation.

params - The parameters to pass to the method, or null if no parameters.

返回：

the result of the method invocation (null if the method has a void return type).

抛出：

PropertyNotFoundException - if one of the property resolutions failed because a specified variable or property does not exist or is not readable.

MethodNotFoundException - if no suitable method can be found.

ELException - if a String literal is specified and expectedReturnType of the MethodExpression is void or if the coercion of the String literal to the expectedReturnType yields an error (see Section "1.18 Type Conversion").

getExpressionString

public String getExpressionString()

从类 Expression 复制的描述

Returns the original String used to create this Expression, unmodified.

This is used for debugging purposes but also for the purposes of comparison (e.g. to ensure the expression in a configuration file has not changed).

This method does not provide sufficient information to re-create an expression. Two different expressions can have exactly the same expression string but different function mappings. Serialization should be used to save and restore the state of an Expression.

指定者：

类 Expression 中的 getExpressionString

返回：

The original expression String.

equals

public boolean equals(Object obj)

从类 Expression 复制的描述

Determines whether the specified object is equal to this Expression.

The result is true if and only if the argument is not null, is an Expression object that is the of the same type (ValueExpression or MethodExpression), and has an identical parsed representation.

Note that two expressions can be equal if their expression Strings are different. For example, ${fn1:foo()} and ${fn2:foo()} are equal if their corresponding FunctionMappers mapped fn1:foo and fn2:foo to the same method.

指定者：

类 Expression 中的 equals

参数：

obj - the Object to test for equality.

返回：

true if obj equals this Expression; false otherwise.

另请参见：

Hashtable, Object.equals(java.lang.Object)

hashCode

public int hashCode()

从类 Expression 复制的描述

Returns the hash code for this Expression.

See the note in the Expression.equals(java.lang.Object) method on how two expressions can be equal if their expression Strings are different. Recall that if two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result. Implementations must take special note and implement hashCode correctly.

指定者：

类 Expression 中的 hashCode

返回：

The hash code for this Expression.

另请参见：

Expression.equals(java.lang.Object), Hashtable, Object.hashCode()

isLiteralText

public boolean isLiteralText()

从类 Expression 复制的描述

Returns whether this expression was created from only literal text.

This method must return true if and only if the expression string this expression was created from contained no unescaped EL delimeters (${...} or #{...}).

指定者：

类 Expression 中的 isLiteralText

返回：

true if this expression was created from only literal text; false otherwise.

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
                         ClassNotFoundException

指定者：

接口 Externalizable 中的 readExternal

抛出：

IOException

ClassNotFoundException

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

指定者：

接口 Externalizable 中的 writeExternal

抛出：

IOException