jstl源代码，转载内容

# The set of evaluator tests ####################################################### # basic literals Expression: ${1} ExpectedType: int Evaluates to: 1 With type: java.lang.Integer Expression: ${-12} ExpectedType: int Evaluates to: -12 With type: java.lang.Integer Expression: ${true} ExpectedType: boolean Evaluates to: true With type: java.lang.Boolean Expression: ${false} ExpectedType: boolean Evaluates to: false With type: java.lang.Boolean Expression: ${null} ExpectedType: class java.lang.String Evaluates to: With type: java.lang.String Expression: ${4.2} ExpectedType: double Evaluates to: 4.2 With type: java.lang.Double Expression: ${-21.3} ExpectedType: float Evaluates to: -21.3 With type: java.lang.Float Expression: ${4.} ExpectedType: float Evaluates to: 4.0 With type: java.lang.Float Expression: ${.21} ExpectedType: float Evaluates to: 0.21 With type: java.lang.Float Expression: ${3e-1} ExpectedType: double Evaluates to: 0.3 With type: java.lang.Double Expression: ${.2222222222} ExpectedType: double Evaluates to: 0.2222222222 With type: java.lang.Double ####################################################### # basic relationals between literals Expression: ${1 < 2} ExpectedType: boolean Evaluates to: true With type: java.lang.Boolean Expression: ${1 > 2} ExpectedType: boolean Evaluates to: false With type: java.lang.Boolean Expression: ${1 >= 2} ExpectedType: boolean Evaluates to: false With type: java.lang.Boolean Expression: ${1 <= 2} ExpectedType: boolean Evaluates to: true With type: java.lang.Boolean Expression: ${1 == 2} ExpectedType: boolean Evaluates to: false With type: java.lang.Boolean Expression: ${1 != 2} ExpectedType: boolean Evaluates to: true With type: java.lang.Boolean Expression: ${3 >= 3} ExpectedType: boolean Evaluates to: true With type: java.lang.Boolean Expression: ${3 <= 3} ExpectedType: boolean Evaluates to: true With type: java.lang.Boolean Expression: ${3 == 3} ExpectedType: boolean Evaluates to: true With type: java.lang.Boolean Expression: ${3 < 3} ExpectedType: boolean Evaluates to: false With type: java.lang.Boolean Expression: ${3 > 3} ExpectedType: boolean Evaluates to: false With type: java.lang.Boolean Expression: ${3 != 3} ExpectedType: boolean Evaluates to: false With type: java.lang.Boolean ####################################################### # relationals between booleans Expression: ${false < true} ExpectedType: class java.lang.Object Evaluates to: javax.servlet.jsp.JspException: An error occurred while evaluating custom action attribute "test" with value "${false < true}": Attempt to apply operator "<" to arguments of type "java.lang.Boolean" and "java.lang.Boolean" With type: javax.servlet.jsp.JspException Expression: ${false > true} ExpectedType: class java.lang.Object Evaluates to: javax.servlet.jsp.JspException: An error occurred while evaluating custom action attribute "test" with value "${false > true}": Attempt to apply operator ">" to arguments of type "java.lang.Boolean" and "java.lang.Boolean" With type: javax.servlet.jsp.JspException Expression: ${true >= true} ExpectedType: class java.lang.Object Evaluates to: true With type: java.lang.Boolean Expression: ${true <= true} ExpectedType: class java.lang.Object Evaluates to: true With type: java.lang.Boolean Expression: ${true == true} ExpectedType: class java.lang.Object Evaluates to: true With type: java.lang.Boolean Expression: ${true != true} ExpectedType: class java.lang.Object Evaluates to: false With type: java.lang.Boolean ####################################################### # looking up objects in scopes # val1a - defined in page scope Expression: ${pageScope.val1a} ExpectedType: class java.lang.String Evaluates to: page-scoped1 With type: java.lang.String Expression: ${requestScope.val1a} ExpectedType: class java.lang.String Evaluates to: With type: java.lang.String Expression: ${sessionScope.val1a} ExpectedType: class java.lang.String Evaluates to: With type: java.lang.String Expression: ${applicationScope.val1a} ExpectedType: class java.lang.String Evaluates to: With type: java.lang.String Expression: ${val1a} ExpectedType: class java.lang.String Evaluates to: page-scoped1 With type: java.lang.String # val1b - defined in request scope Expression: ${pageScope.val1b} ExpectedType: class java.lang.String Evaluates to: With type: java.lang.String Expression: ${requestScope.val1b} ExpectedType: class java.lang.String Evaluates to: request-scoped1 With type: java.lang.String Expression: ${sessionScope.val1b} ExpectedType: class java.lang.String Evaluates to: With type: java.lang.String Expression: ${applicationScope.val1b} ExpectedType: class java.lang.String Evaluates to: With type: java.lang.String Expression: ${val1b} ExpectedType: class java.lang.String Evaluates to: request-scoped1 With type: java.lang.String # val1c - defined in session scope Expression: ${pageScope.val1c} ExpectedType: class java.lang.String Evaluates to: With type: java.lang.String Expression: ${requestScope.val1c} ExpectedType: class java.lang.String Evaluates to: With type: java.lang.String Expression: ${sessionScope.val1c} ExpectedType: class java.lang.String Evaluates to: session-scoped1 With type: java.lang.String Expression: ${applicationScope.val1c} ExpectedType: class java.lang.String Evaluates to: With type: java.lang.String Expression: ${val1c} ExpectedType: class java.lang.String Evaluates to: session-scoped1 With type: java.lang.String # val1d - defined in application scope Expression: ${pageScope.val1d} ExpectedType: class java.lang.String Evaluates to: With type: java.lang.String Expression: ${requestScope.val1d} ExpectedType: class java.lang.String Evaluates to: With type: java.lang.String Expression: ${sessionScope.val1d} ExpectedType: class java.lang.String Evaluates to: With type: java.lang.String Expression: ${applicationScope.val1d} ExpectedType: class java.lang.String Evaluates to: app-scoped1 With type: java.lang.String Expression: ${val1d} ExpectedType: class java.lang.String Evaluates to: app-scoped1 With type: java.lang.String ####################################################### # accessing properties Expression: ${bean1a.int1} ExpectedType: int Evaluates to: 4 With type: java.lang.Integer Expression: ${bean1a.boolean1} ExpectedType: boolean Evaluates to: true With type: java.lang.Boolean Expression: ${bean1a.string1} ExpectedType: class java.lang.String Evaluates to: hello With type: java.lang.String Expression: ${bean1a.bean1.int2} ExpectedType: int Evaluates to: -224 With type: java.lang.Integer Expression: ${bean1a.bean1.bean2.string2} ExpectedType: class java.lang.String Evaluates to: bean3's string With type: java.lang.String ####################################################### # test the entire conversion matrix Expression: ${bean1a.byte1} ExpectedType: byte Evaluates to: 12 With type: java.lang.Byte Expression: ${bean1a.byte1} ExpectedType: char Evaluates to:  With type: java.lang.Character Expression: ${bean1a.byte1} ExpectedType: short Evaluates to: 12 With type: java.lang.Short Expression: ${bean1a.byte1} ExpectedType: int Evaluates to: 12 With type: java.lang.Integer Expression: ${bean1a.byte1} ExpectedType: long Evaluates to: 12 With type: java.lang.Long Expression: ${bean1a.byte1} ExpectedType: float Evaluates to: 12.0 With type: java.lang.Float Expression: ${bean1a.byte1} ExpectedType: double Evaluates to: 12.0 With type: java.lang.Double Expression: ${bean1a.char1} ExpectedType: byte Evaluates to: 98 With type: java.lang.Byte Expression: ${bean1a.char1} ExpectedType: char Evaluates to: b With type: java.lang.Character Expression: ${bean1a.char1} ExpectedType: short Evaluates to: 98 With type: java.lang.Short Expression: ${bean1a.char1} ExpectedType: int Evaluates to: 98 With type: java.lang.Integer Expression: ${bean1a.char1} ExpectedType: long Evaluates to: 98 With type: java.lang.Long Expression: ${bean1a.char1}