JP2004252708A - Object value setting method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an object value setting method and program capable of integrally setting values to objects without depending on classes for which values are to be set and the numbers and types of their fields, for application development based on the techniques of Java (R). <P>SOLUTION: The method includes a first step for creating attribute values to be set for each field of an object for which an attribute value is to be set and for storing the attribute values in a storage means, and a second step for implementing a public accessor method set for each object, using a reflection function provided by JavaAPI, and for setting the attribute value of the object stored in the storage means. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and a method for developing an application program using Java, which is an object-oriented programming language (Java and Java-related trademarks and logos are trademarks or registered trademarks of US SUN Microsystems, Inc.). In particular, the present invention relates to a processing method and a processing program for setting information (attribute value) such as input data of a Web screen and DB records to an object.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in the development work of an application program using Java technology, in order to set a value to each object (specifically, a class that is an instance of the object) which is a component of the application program, a value setting target object is set. A method of setting a field value (attribute value) using a set method incorporated in the object corresponding to each of the fields (attributes) is adopted. For example, for a class having the fields “name” and “age”, methods “setName ()” and “setAge ()” are incorporated in the class, and values such as name and age are set by using these methods. ing.
Also, in the Web application system development by JSP (Java Server Pages), by using the extended syntax <jsp: setProperty>, the values are collectively stored in the field where the parameter name of the HTML form and the field name of the value setting object coincide with each other. It is possible to set. Specifically, the field name of the value setting target object is set to the name of the HTML form part, the value setting target object is specified by the <jsp: useBean> tag, and then the property attribute of the <jsp: setProperty> tag is specified. By setting “*” in the field, the value is set to the object.
Here, there is a method disclosed in the following Patent Document 1 as a method for setting the attribute value of an object.
[0003]
[Patent Document 1]
JP 2001-282537 A
The extended syntax of JSP (Java Server Pages) is introduced in the following Non-Patent Document 1.
[0004]
[Non-patent document 1]
JavaServerPagesTMv1.2Syntax Reference / June 2002
[0005]
[Problems to be solved by the invention]
However, when an attribute value is set for each object using the above set method, a procedure for individually executing the set method for each field for setting the attribute value is required. Therefore, the number of classes or the number of fields (attribute items) In the case of developing an application program having many (number), there is a problem that the amount of coding for individually executing the set methods increases, and the load on the developer in the development and test work is large.
In addition, when the attribute value of each object is set using the JSP extension syntax <jsp: setProperty>, there is a problem that an attribute value for a field other than the Java basic type cannot be set. The Java basic type field is the one shown in “TABLE1” of Non-Patent Document 1 described above.
Further, there is a problem that the attribute value for the array field cannot be automatically set. For example, when there is an attribute of “hobby”, there is a problem that a plurality of attribute values such as “watching a movie” and “fishing” cannot be automatically set, and must be set manually.
Furthermore, since a check function for checking whether or not the set attribute values are inconsistent is not considered, there is a problem that inconsistencies in the set attribute values cannot be found.
Furthermore, since the function of converting the type of the attribute value from, for example, a character type to a numeric type is not considered, there is a problem that the type conversion cannot be performed according to the field type.
In summary, the conventional technology requires a large amount of coding for setting an attribute value to an object, and cannot flexibly cope with a need to perform type conversion and attribute value checking. was there.
[0006]
An object of the present invention is to provide an object value setting method and a program that can set an attribute value for an object with a small coding amount.
It is another object of the present invention to provide an object value setting method and a program capable of automatically setting attribute values for fields other than the Java basic type and attribute values for array fields.
It is another object of the present invention to provide an object value setting method and a program capable of performing type conversion and attribute value inconsistency check.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, an object value setting method according to the present invention is provided by a first step of creating an attribute value to be set in each field of an attribute value setting target object and storing the attribute value in a storage unit, and a Java API. Executing a public accessor method set for each object using a reflection function, and setting an attribute value of the object stored in the storage means.
Further, in the second step, the conversion method is executed on the attribute field in which the conversion method for performing the type conversion is set, and the type of the attribute value stored in the storage means is converted and set in the attribute field. The method further comprises the step of:
In the second step, the method further comprises the step of executing the check on an attribute field in which a check method for checking the attribute value is set, and checking the attribute value specified by the check method. It is characterized by.
Further, in the second step, the method further comprises a step of acquiring an attribute value of the same array stored in the storage means for the attribute value for which an array identifier is set, and setting the attribute value as an attribute value of each array. Features.
[0008]
A program for setting an object value in a Java application program according to the present invention is provided by a first processing step of creating an attribute value to be set in each field of an attribute value setting target object and storing the attribute value in a storage unit, and a Java API. A second processing step of executing a public accessor method set for each object by using a reflection function and setting an attribute value of the object stored in the storage unit.
Further, in the second processing step, the conversion method is executed for the attribute field in which the conversion method for performing the type conversion is set, and the type of the attribute value stored in the storage unit is converted to the attribute field. The method further comprises a setting step.
Further, in the second processing step, a processing step of executing the check on an attribute field in which a check method for checking the attribute value is set and checking the attribute value specified by the check method is further included. It is characterized by having.
Further, the second processing step further includes a processing step of acquiring an attribute value of the same array stored in the storage unit with respect to the attribute value for which an array identifier is set, and setting the attribute value as an attribute value of each array. It is characterized by the following.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be specifically described with reference to the drawings.
FIG. 1 is a diagram showing an embodiment of the present invention. As shown in FIG. 1, the system according to the present embodiment receives a setting information data 101 and a value setting target object 102 as inputs, and sets an attribute value (field value) to the value setting target object 102. 103, and a value setting target class 104 which is an instance of the value setting target object 102.
The setting information data 101, the value setting target object 102, the object value setting program 103, and the value setting target class 104 are stored in a storage device (not shown) of the computer.
[0010]
The value setting target class 104 has a get method 105, a set method 106, a conversion method 107, and a check method 108.
The object value setting program 103 is executed by a computer capable of executing a program in Java language, and includes a detailed setting information creating process 109, a field value setting process 110, a field value checking process 111, a detailed setting information 112, a reflection function 113.
[0011]
The detailed setting information creating process 109 is for creating detailed setting information 112 as shown in FIG. 6 described later based on the setting information data 101 as shown in FIG. Used as processing.
The field value setting processing 110 and the field value checking processing 111 function as subroutines of the object value setting program 103.
The reflection function 113 is provided by the Java API, and is used to execute each method of the value setting target class 104. The reflection function 113 is a function for accessing a field published by a Java object or class, changing an attribute of the Java object, or executing a method by calling a method.
[0012]
FIG. 2 shows an example in which the input content 201 of the Web screen is stored in the value setting target object 102.
The object value setting program 103 searches for setting values and setting fields that can be set in the value setting target object 102 from the setting information data 101 and sets them. At this time, when the type of the setting value or data conversion is necessary as in the prefCode field 202, the setting value is converted using the conversion method of the value setting target class. If there is an error in the input content, a check exception 203 is detected.
[0013]
The value setting target object in the example of FIG. 2 is a UserObj whose object name is UserInfo, and its attribute values are name (kanji) = name, name (kana) = name_kana, mail address = email, gender = sex, date of birth. = Birthdate, home information = address, hobby = hobby.
In the present invention, an attribute value is set for a value setting target class which is an instance of the UserObj object. In addition, independent classes “birthdateObj” and “addressObj” are created for the date of birth and home information, and attribute values are set for these classes. The creation of an independent class is merely performed for convenience in order to easily identify the contents of attributes, and has no special meaning.
In the example of FIG. 2, the UserObj class (204), the birthdayObj class (205), and the addressObj class (206) are the attribute value setting target objects, that is, the value setting target class 104 of FIG.
[0014]
The UserObj class (204) is set with a name (kanji) = name, a name (kana) = name_kana, an email address = email, gender = sex, and a hobby = hobby. Of these, hobby = hobby is an array field, in which hobby contents such as horse racing and mahjong are set.
The secondDateObj class (205) sets attribute values of year, month, and day, and the addressObj class (206) sets postal code (zipcode), prefecture (prefCode), municipalities ( city, an address (houseNo), an apartment building (building), a telephone number (telephone), and a FAX number (fax).
[0015]
The setting information data 101 is a hash table using a field identifier 401 as a key and a field setting value 402 as a value as shown in FIG. 4, and stores value setting information for the value setting object 102.
For example, in the case of the UserObj class (204), the secondDateObj class (205), and the addressObj class (206) in FIG. 2, identifiers such as name, name_kana,..., Hobby_1, hobby_1, and hobby_3 are set as the field identifier 401, and their setting values are “1”. Information such as “Taro Yamada”, “Taro Yamada”,..., “Null” is stored in advance.
[0016]
In the case of a Web application system using JSP or Servlet, as will be described later with reference to FIG. 111, the field identifier 401 (1102, 1104, 1106, and 1108 in FIG. 11) is set in the name of the form component of the Web screen HTML, so that the Web It is easy to obtain the input data on the screen as a hash table in the same format as the setting information data 101.
[0017]
As shown in FIG. 5, the field identifier 401 is composed of a field name of the value setting target class 104, or a field name 501 and an array identifier 505, or a field identifier 401 and a field connector 502. It is used to uniquely specify a value setting target field of the class 104.
The field name 501 is represented by a character string of the field name of the class. The field connector 502 is represented by a dot symbol “.” Connecting the field names. The array connector 503 is represented by an underscore “_”. The sequence identifier 505 is composed of a sequence connector 503 and a sequence number 504, and the sequence number 504 is represented by an integer value of “1” or more.
For example, the attribute “ear” in the “birthdateObj” class (205) is represented by “birthdate.year” in which “birthdate” and “year” are combined with “.”.
Similarly, hobby is represented by “hobby — 1”, and zipcode is represented by “addresses.zipCode”.
[0018]
As shown in FIG. 3, the UserObj class (204), the secondDateObj class (205), and the addressObj class (206) that constitute the value setting target class 104 are private fields, and public accessor methods, conversion methods, and check methods for the fields. Consists of A private field is a field preceded by a "-" symbol. For example, fields such as "-name", "name_kana", and "-zipcode" are used.
The public accessor method includes a set method, a get method, a conversion method, and a check method. Public accessor methods are shown with a “+” sign at the beginning.
[0019]
The get method 105 of each value setting target class is used to acquire the value of each field, and is prepared for all fields. In order to enable the reflection function 113 to detect a method, the method name is "get + field name in upper case". For example, the name is “+ getName ()”.
The set method 106 is used to set a value in each field, and is prepared for all fields. In order to enable detection of the method by the reflection function 113, the method name is “set + field name in upper case”.
[0020]
The conversion method 107 is used to convert and set a field setting value of the setting information data 101 when setting a value in a field, and is provided for an arbitrary field to be converted. In order to enable the reflection function 113 to detect the conversion method 107 and to use the conversion method 107 for general purposes, the method name is “convert + the field name in the first uppercase letter”, and the argument type is the Object type.
The check method 108 is used to check a value set in each class, and a check method 301 for checking an arbitrary field and a check method 302 for checking between fields are arbitrarily prepared. . In order to allow the reflection function 113 to detect the check methods 301 and 302 and to use them for general use, the method name is “check (+ the first uppercase field name)” and the return value is a void type. Check errors are detected by raising an exception in the method.
[0021]
As shown in FIG. 6, the detailed setting information 112 includes a parent field 601 which is a target class for executing the set method 106, a field name 602 corresponding to the parent field 601, and a field specified by the parent field and the field name. This is array data having the set value 603 as one record, and stores all necessary information in such a manner that the value setting to the value set object 102 can be easily performed by using the reflection function 113.
For example, for “name” of the field name 602, “userObj” is set as the parent field 601 and “Taro Yamada” is set as the set value 623 thereof.
Next, the object value setting program 103 will be described.
[0022]
FIG. 7 is a flowchart showing the flow of control processing in the object value setting program 103.
First, the detailed setting information creation processing 109 is executed (step 701), and the detailed setting information 112 required in the subsequent processing is created.
Next, one record of the detailed setting information 112 is read (step 702), the field value setting processing 110 is executed (step 703), and a value is set in the field specified by the field identifier 401 of the value setting target object 102. .
Next, it is determined whether or not the processing for all the records has been completed (step 704). If the processing has been completed, the field value check processing 111 is executed (step 705), and the setting value of the value setting object 102 is checked. Do. If processing has not been completed for all records, the next record is read.
If there is a check error (step 706), an exception including the error content is generated (step 707), and the process ends. If there is no check error, the process ends.
[0023]
Next, detailed setting information creation processing (step 701 in FIG. 7), field value setting processing (step 703 in FIG. 7), and field value check processing (step 705 in FIG. 7) will be described with reference to FIGS. I do. In each process, the reflection function 113 is used to acquire and execute the get method, newInstance method, set method, conversion method, and check method of the value setting target object and its field, and to acquire the type of the field.
Although the newInstance method is not shown in the drawing, all the Java classes have the newInstance method.
FIG. 8 is a flowchart showing the flow of control in the detailed setting information creation processing 109.
First, “0” is set to a variable n (step 801). Next, it is checked whether or not processing has been performed on all records of the setting information data 101 (step 802). If processing has been performed on all records, the program ends.
If processing has not been performed for all records, it is checked whether or not the field identifier 401 of the setting information data 101 has n records of connectors (field connectors or array connectors) (step 803). If there is no corresponding record, n is updated by "+1" (step 804), and the process returns to the beginning of the flow.
[0024]
If there is a corresponding record, the connector reads one record of n records (step 805), and obtains a field name from the field identifier 401 by obtaining a character string after the connector and before the array identifier from the field identifier 401 (step 805). Step 806).
Next, it is checked whether or not there is an array identifier in the field identifier of the record (step 807). If there is no array identifier, the field setting value is read from the record as the setting value (step 808).
[0025]
If there is an array identifier such as "hobby_1", an array object is created from the setting information data 101 by combining all the setting values representing the same field, and is read as the setting value (step 809). By this processing, a value can be set for an array type field other than the Java basic type.
Next, the parent field for the set value is obtained by executing the get method of the value set object or its field (step 810). Here, the obtained parent field is checked (step 811). If the parent field is null, the parent field is generated by executing the newInstance method of the parent field class, and the set method of the parent field is executed. Is set (step 812).
Thus, when trying to acquire the same parent field, the parent field generated here is referred to.
[0026]
Next, the parent field, the field name, and the setting value acquired by the processing up to this point are added to the detailed setting information 112 as one record (step 813). Further, it is determined that the record of the setting information data 101 used so far has been processed, and the process returns to the check processing (step 803) for checking whether the field identifier of the setting information data 101 has n connectors (step 803).
[0027]
FIG. 9 is a flowchart showing the flow of control in the field value setting processing 110.
First, the record of the detailed setting information 112 is read (step 901), and a conversion method for the field name of the parent field is obtained (step 902). Here, it is checked whether or not the conversion method has been acquired (step 903). If the conversion method has been acquired, the conversion method is executed using the record set value 603 as an argument (step 904), and the converted value is set to the set value. (Step 905).
[0028]
If the conversion method cannot be obtained, the type of the value setting target field is obtained (step 906), and it is checked whether the field type is the same as the record set value type (step 907). Here, if the types are different, the setting value type is converted to the field type and read as the setting value (step 908).
If the types are the same, the set value 603 of the record is read as it is as a set value (step 909).
This makes it possible to set a value without depending on the field type.
[0029]
Next, a set method for the field name of the parent field is obtained (step 910) and executed (step 911). Thus, the value setting processing for the value setting target object for one record in the detailed setting information 112 is completed.
FIG. 10 is a flowchart showing the flow of control in the field value check processing 111.
First, it is determined whether or not the processing has been performed on all the detailed setting information records 112 (step 1001). If the processing on all the detailed setting information records 112 has been completed, the program ends. If the processing of all the detailed setting information records is not completed, one record of the detailed setting information 112 is read (step 1002), and the check method 301 for the field name of the parent field is obtained (step 1003). Here, it is checked whether or not the check method has been acquired (step 1004). If the check method has been acquired, the check method is executed (step 1005).
As a result, a check process can be performed on the value set in the field. If an exception occurs in the check method (step 1006), the program ends as a check error. If no exception has occurred, processing continues.
If the check method cannot be fetched, field check processing is not performed.
[0030]
Next, it is determined whether the parent field check method has been executed (step 1007). If the parent field check method has already been executed, return to the beginning of the flow and start the next record processing. If the parent field check method has not been executed yet, the parent field check method 302 (FIG. 3) is obtained (step 1008). Here, it is checked whether or not the check method has been acquired (step 1009). If the check method has been acquired, the check method is executed (step 1010).
Thereby, it is possible to check between the fields of the parent field. If an exception occurs in the check method (step 1011), the program ends as a check error. If no exception has occurred, or if the check method of the parent field could not be obtained, return to the beginning of the flow and start the next record processing.
[0031]
Next, an example in which the input content of the Web screen is set to a value setting target object (an instance of the UserInfo class in FIG. 3) using the object value setting program 103 will be described with reference to FIGS.
FIG. 11 shows an example of HTML description of a Web screen.
In order to set the value of the text box name (kanji) 1101 in the name field of the value setting target object, “name” is set in the name attribute 1102 of the INPUT tag. Next, in order to set the value of the text box 1101 in the year field of the “birthdate” field of the value setting target object, “birthdate.year” is set in the name attribute 1104 of the INPUT tag. Further, in order to set the value of the text box zip code 1105 in the zipCode field of the address field of the value setting target object, “address.zipCode” is set in the name attribute 1106 of the INPUT tag. Finally, in order to set the values of the hobbies 1 to 3 of the text box hobby 1107 as an array in the hobby field of the value setting target object, “hobby_1” to “hobby_3” are set in the name attribute 1108 of the INPUT tag.
[0032]
FIG. 12 is a class diagram showing an example in which the object value setting program 103 is implemented as a method of the Java class. The object value setting program 103 is implemented as a static method load 1202 of the ValueSetter class 1201, receives Map as setting information data and Object as a value setting target object as arguments, and returns an object for which a value is set as a return value. It has become.
[0033]
FIG. 13 shows an example of creating a conversion method.
A convertPrefCode method 1302 is created as a conversion method for the prefCode field of the Address class 1301 (corresponding to the class 206 in FIG. 3). When the character string type setting value of the setting information data 101 is “Tokyo”, the numerical value “13” , "Hokkaido" is converted to a numerical value "1".
[0034]
FIG. 14 shows an example of creating a check method.
A checkYear method 1402 is created as a check method for the year field of the ByteDate class 1401 (corresponding to the class 205 in FIG. 3), and when the value of the year field is “0” or less, “year is set to a numerical value of 0 or less”. The check exception 1403 is generated.
In addition, a check method 1404 is created as a check method for checking between fields, and when an invalid value such as {month = 2, day = 30} is set, a check such as "The date is invalid" is performed. The processing is such that an exception 1405 is generated.
[0035]
FIG. 15 shows an example of creating a Servlet that executes the object value setting program 103. A HashMap 1501, which is setting information data, is created based on the contents transmitted from the screen of FIG. 11, a value setting target object 1502 is created, and the object value setting program 1503 is executed using these as arguments. When a check error occurs, an exception 1504 is generated.
[0036]
【The invention's effect】
As described above, according to the present invention, an attribute value to be set in each field of an attribute value setting target object is created and stored in the storage unit, and the attribute value is set using the reflection function provided by the Java API. Since the public accessor method of each object is called and executed, and the attribute values are set collectively, there is no need to perform coding for individually calling and executing the set method of each object. In application development using technology, it is possible to reduce the amount of coding related to setting of input data on a screen, record values of a database, record values of file data, etc. to an object, and setting of a value to an object, thereby improving development efficiency.
In addition, since a check method is incorporated in the attribute value setting target object and the attribute value is checked using this check method, inconsistencies in the set attribute values can be easily found.
Further, by incorporating a type conversion method, for example, a numeric attribute value can be converted into a character attribute value and set.
Also, it is possible to set an attribute value to an object including a field other than the Java basic type such as an array type.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of an object value setting program according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating an operation example of an object value setting program.
FIG. 3 is a class diagram showing a configuration of a value setting target class.
FIG. 4 is a diagram showing a configuration of setting information data.
FIG. 5 is a diagram showing a configuration of a field identifier.
FIG. 6 is a diagram showing a configuration of detailed setting information.
FIG. 7 is a flowchart showing an outline of processing of an object value setting program.
FIG. 8 is a flowchart illustrating detailed setting information creation processing.
FIG. 9 is a flowchart illustrating a field value setting process.
FIG. 10 is a flowchart showing a field value check process.
FIG. 11 is a diagram showing an example of creating a screen HTML.
FIG. 12 is a class diagram illustrating an implementation example of an object value setting program.
FIG. 13 is a diagram illustrating an example of a conversion method implementation class.
FIG. 14 is a diagram illustrating an example of a check method implementation class.
FIG. 15 is a diagram illustrating an example of a Servlet using an object value setting program.
[Explanation of symbols]
101: setting information data, 102: value setting object, 103: object value setting program, 104: value setting class, 105: get method, 106: set method, 107: conversion method, 108: check method, 109: details Setting information creation processing, 110: field value setting processing, 111: field value check processing, 112: detailed setting information, 113: reflection function.

Claims (8)

An object value setting method in a Java application program, comprising: a first step of creating an attribute value to be set in each field of an attribute value setting target object and storing the attribute value in a storage unit;
Executing a public accessor method set for each object using a reflection function provided by a Java API, and setting an attribute value of the object stored in the storage means. Object value setting method to be used. Executing the conversion method on the attribute field in which the conversion method for performing the type conversion is set in the second step, converting the type of the attribute value stored in the storage unit and setting the attribute value in the attribute field The object value setting method according to claim 1, further comprising: In the second step, the method further comprises the step of executing the check on an attribute field in which a check method for checking the attribute value is set, and checking the attribute value specified by the check method. 3. The object value setting method according to claim 1, wherein: In the second step, the method further includes a step of acquiring an attribute value of the same array stored in the storage unit for the attribute value for which the array identifier is set, and setting the attribute value as an attribute value of each array. The object value setting method according to claim 1. A program for setting an object value in a Java application program,
A first processing step of creating an attribute value to be set in each field of the attribute value setting object and storing the attribute value in a storage unit;
A second processing step of executing a public accessor method set for each object using a reflection function provided by a Java API, and setting an attribute value of the object stored in the storage unit. Object value setting program. In the second processing step, the conversion method is executed on the attribute field in which the conversion method for performing the type conversion is set, and the type of the attribute value stored in the storage unit is converted and set in the attribute field. The object value setting program according to claim 5, further comprising a processing step. The second processing step further includes a processing step of executing the check on an attribute field in which a check method for checking the attribute value is set, and checking the attribute value specified by the check method. 7. The object value setting program according to claim 5, wherein: In the second processing step, further comprising a processing step of acquiring an attribute value of the same array stored in the storage unit for the attribute value for which an array identifier is set, and setting the attribute value as an attribute value of each array. An object value setting program according to any one of claims 5 to 7, characterized in that:

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