CN102566990A - Method and device for performing data manipulation in Java application - Google Patents

Abstract

The invention discloses a method and a device for performing data manipulation in Java application, wherein the method and the device are used for mapping a data table into a source code form and improving the efficiency and the accuracy of object-relational mapping. The method comprises the following steps of: obtaining structure information of at least one table from a database; mapping the structure information of the at least one table into a domain object class file and a data access class file; while receiving a data manipulation instruction, performing data manipulation on the domain object class file based on a function in the data access class file. The method can map the data table into source codes, and can improve the efficiency and the accuracy of the object-relational mapping. And the invention also discloses a device for performing data manipulation in Java application.

Description

A method and device for data manipulation in Java applications

technical field

The invention relates to the field of computers, in particular to a method and device for performing data operations in Java applications.

Background technique

In the Java-based project development process, it is necessary to frequently add, delete, modify, and query operations on the database. When using Java Database Connectivity (JDBC) to connect to the database, developers are faced with primitive collection of data. In the process of business logic development, developers need to obtain the required data from the database according to the structure information of related tables in the database known in advance, which increases the workload of the developers and reduces the development efficiency.

In order to solve this problem, object-relational mapping is required. The so-called object-relational mapping is to map the data in the database into objects, which introduces the Data Access Object (DAO) mode. DAO is a part of object-relational mapping. way of realization. The DAO mode provides an object-oriented interface for the business layer by encapsulating the underlying data, so that business logic developers can focus on coding entities in the business, making the business logic clearer. The DAO mode is the data access class Data Accessor and A combination of domain object classes Domain Object, in which Data Accessor encapsulates the implementation mechanism of data access and separates it from the data usage code. From an external point of view, Data Accessor provides a black-box data access interface, while Domain Object is the various data objects involved in the domain, and provides the closure of the objects in the targeted domain.

Although the separation of business logic and data logic can be achieved through the DAO mode, a better balance can be achieved in terms of complexity and structural clarity. Usually, an object corresponds to a table in the database, and multiple attributes in the object correspond to the table. Multiple fields, in the actual development process of the DAO mode, it is necessary to manually convert the tables in the database into the objects of the DAO mode. If you need to process multiple tables in the database, you need to convert multiple tables into corresponding objects , so that the development efficiency is low, and because the table in the data block is manually converted to the object of the DAO mode, the stability is not high and error-prone.

Contents of the invention

The invention provides a method and device for data operation in Java applications, which are used to map data tables into source codes and improve the efficiency and accuracy of object-relational mapping.

The specific technical scheme that the embodiment of the present invention provides is as follows:

A method for performing data manipulation in a Java application, comprising:

obtaining structural information of at least one table from the database;

Mapping the structural information of the at least one table into a domain object class file and a data access class file;

When receiving the data operation instruction, perform data operation on the domain object class file based on the functions contained in the data access class file.

A device for performing data manipulation in a Java application, comprising:

A first processing unit, configured to obtain structural information of at least one table from the database;

The second processing unit is configured to map the structural information of the at least one table into a domain object class file and a data access class file;

The third processing unit is configured to perform data operations on the domain object class file based on the functions contained in the data access class file when receiving the data operation instruction.

Based on the above technical solution, after the database connection is established, the structural information of the table is obtained from the database, and the structural information of the table is mapped to a domain object class file and a data access class file, so that the structural information of the table in the database can be mapped to a domain object The class file is to convert the structure of the table into the form of source code, map the data operation on the table in the database to a data access class file, and convert the data operation on the table into the form of source code. When receiving the data operation instruction, Based on the functions contained in the database access class file, the data operation is performed on the domain object class file, so that the records in the table can be automatically obtained without manually reading the original data in the database, thereby improving the efficiency and accuracy of object-relational mapping.

Description of drawings

Fig. 1 is the method flowchart that the present invention carries out data operation in Java application;

FIG. 2 is a structural diagram of a device for performing data operations in a Java application according to the present invention.

Detailed ways

In order to improve the efficiency and accuracy of object-relational mapping, embodiments of the present invention provide a method and device for data manipulation in Java applications, which can improve the efficiency and accuracy of object-relational mapping. The method is as follows: obtaining the structural information of at least one table from the database, mapping the structural information of the at least one table into a domain object class file and a data access class file, and when receiving a data operation instruction, based on the data contained in the data access class file Functions perform data operations on domain object class files.

Preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

Referring to shown in accompanying drawing 1, in the embodiment of the present invention, the concrete method flow process that carries out data operation in Java application is as follows:

Step 101: Obtain structural information of at least one table from a database.

In the Java application, the database connection can be performed through the Java database connection method, that is, the database connection is established through the database connection object (Connection object), and after the database connection is established, the overall comprehensive information object of the database is obtained from the database. The overall comprehensive information The object includes structural information of all tables in the database. In the embodiment of the present invention, the structural information of at least one table is obtained from the overall comprehensive information object of the database.

Wherein, the structural information of a table includes at least a field name of a table, a data type of a field, a precision of a field, and whether the field is empty.

In the embodiment of the present invention, when obtaining the structure information of at least one table, first obtain the primary key of the table, and if the primary key does not exist in the table, the process ends. The primary key of the table refers to the unique identification field of the records in the table. The primary key of the table cannot be repeated, nor can it be empty.

Step 102: Map the structural information of at least one table into a domain object class file and a data access class file.

Wherein, when the structural information of at least one table is mapped to a domain object class file, a domain object class is defined for at least one table, and the external interface for obtaining data and setting data is preset in the domain object class, and the structural information of the table is Mapped as private data of the domain object class.

When the structural information of at least one table is mapped to a data access class file, a data access class is defined for the at least one table, and functions contained in the data access class are generated based on the structural information of the at least one table. The functions contained in the data access class include at least the functions of adding data, deleting functions, modifying functions and querying functions.

A table corresponds to a domain object class file and a data access class file, which can be for all or part of the table structure information in the database.

After the domain object class file and the data access class file are generated, the generated domain object class file and data access class file are saved to a specified location, so as to be called directly from the specified location.

Step 103: When receiving the data operation instruction, perform data operation on the domain object class file based on the functions contained in the database access class file.

The process of mapping information of at least one table into domain object files and data access class files in step 102 will be described in detail below.

Wherein, when mapping the structural information of at least one table into a domain object file, firstly, a domain object class is predefined for the at least one table, including naming rules for defining domain object classes, naming rules for private data members of domain object classes, and data types Mapping rules, constructors, and external interfaces for getting data and setting data; and then mapping the structural information of the table to the private data of the domain object class.

Example 1, the naming rules of the domain object class are set as follows: as shown in Table 1, the name of the domain object class is consistent with the name of the corresponding table, and the first letter is capitalized, the following letters are lowercase, and there is an underscore in the name of the table , remove the underscore from the name of the corresponding domain object class, capitalize the first letter after the underscore, and lowercase the following letter.

Table 1

table name The name of the domain object class APP_USER, app_user AppUser

APPUSER, appuser Appuser

Example 2, when mapping the fields contained in the structure information of the table to the private data of the domain object class, the naming rules used are set as follows: Refer to Table 2, the private data name of the domain object class and the field name in the table structure information Consistent, and all letters are lowercase. When there is an underscore in the field name, when converting to the private data name of the domain object class, the underscore will be removed from the corresponding private data name, and the first letter after the underscore is capitalized, and the subsequent letters lower case.

Table 2

Field names in the table The private data name of the domain object USER_NAME, user_name userName USERNAME, username username

Example 3, the data type mapping rule of the domain object class is set as follows: In Java applications, the data type of a certain field of the table can be obtained through the getColumnType function in the overall comprehensive information object, and whether a certain field of the table is known through the isNullable function For null values, the data type mapping rules are determined according to the data type of the field and whether the field is null, as shown in Table 3 for details. When mapping the structure of the table as a private data member of the domain object class, it can be mapped according to the rules in Table 3.

table 3

Example 4, for the table APP_ROLE in the database, use the method in the embodiment of the present invention to map the structure information of the table into a domain object, and the structure information of the table APP_ROLE is shown in Table 4.

Table 4

Field Name field data type Whether it can be empty illustrate ID number no Unique identifier (primary key) NAME Varchar2(80) Yes Role Name DESCRIPTION Varchar2(255) Yes role description GUID char(36) Yes GUID CREATEDATE timestamp(6) Yes Creation date MODIFIED DATE timestamp(6) Yes date modified READ ONLY char(1) Yes Is it read-only DISPLAYNAME Varchar2(255) Yes role display name COORDINATORID number Yes The ID of the role coordinator SHUXING2 Number(10) Yes Judgment sign SORTORDER integer Yes queue number

Using the method of the embodiment of the present invention and the rules set in the above-mentioned examples 1-3, the structural information of the above-mentioned table APP_ROLE is mapped to a domain object class, and the domain object class is as follows:

public class AppRole implementsjava.io.Serializable //AppRole is the name of the mapped domain object class { Define the constructor, the code part is omitted

private long id;//Private data mapped according to the structure information of the table

private String name;

Map the structural information of the table to private data, the code is omitted

For each private data, the external interface for obtaining data and setting data is set separately, and the code is omitted.

}

Wherein, when the structural information of at least one table is mapped to a data access class file, a data access class is defined for the above at least one table, the functions contained in the data access class are generated based on the structural information of the at least one table, and the data is automatically generated through the function. Operational Structured Query Language (Structured Query Language, SQL), to achieve data manipulation.

Example 5, the naming rule of the data access class is set to be composed of the name of the corresponding domain object class plus Dao, for the table APP_ROLE in the database, refer to Table 4, adopt the method in the embodiment of the present invention to change the table Structural information is mapped to a data access object, and the data access class object is as follows:

public class AppRoleDao extends BaseDao //The data access class AppRoleDao corresponding to the domain object class AppRole

{

public final static String TABLE_NAME="APP_ROLE"; //APP_ROLE is the name of the table

Define constructors, including constructors without parameters and constructors with database connection objects, the code part is omitted

public AppRole getAppRole(ResultSet rs) throws SQLException//Set specific data for each private data in the domain object and return

{

AppRole obj = new AppRole();

Obj.setId(rs.getLong(″ID″));//Set ID data

Obj.setName(rs.getString("NAME"));//Set the data of NAME

Perform the same operation on each private data, and return the object after the setting is completed, the specific code is omitted

}

Public AppRole getAppRole(long id) throws SQLException//Get the record corresponding to the primary key id in the table through the primary key, and return the domain object corresponding to the primary key to realize data query

{Initialization definition omitted

    sql = "select*from" + TABLE_NAME + "where ID = "+id+""; generate a query SQL statement, and execute the SQL statement to obtain the domain object corresponding to the id and return

}

Public void insert(AppRole obj)throws Exception//Use the AppRole domain object as a parameter to implement the data operation of adding records by inserting

{Initial definition, in order to prevent the field name from having the same name as the keyword in the database, define a string variable P in the initial definition, and save the obtained database field modifiers in P, such as double quotation marks, the specific code is omitted

String sql="insert into"+TABLE_NAME +"("+P+"ID"+P+", "+P+"NAME"+P+", "+P+"DESCRIPTION"+P+", "+P+"GUID"+P+ ″, ″+P+″CREATEDDATE″+P+″, ″+P+″MODIFIEDDATE″+P+″, ″+P+″READONLY″+P+″, ″+P+″DISPLAYNAME″+P+″, ″+P+″COORDINATORID″+P+ ″,″+P+″SHUXING2″+P+″,″+P+″SORTORDER″+P+″)values(?,?,?,?,?,?,?,?,?,?,?)″;// Generate an insert SQL statement, the SQL statement is: insert into table name ("ID", "NAME", "DESCRIPTION", "GUID", "CREATEDDATE", "MODIFIEDDATE", "READONLY", "DISPLAYNAME", "COORDINATORID" ,"SHUXING2","SORTORDER") values(?,?,?,?,?,?,?,?,?,?,?)

The specific data of each private data obtained in turn, and the fields in the SQL statement are assigned in turn to realize the data operation of adding records by inserting

}

public void update(AppRole obj)throws Exception//AppRole domain object is used as a parameter to implement the data operation of updating records

{

Initial definition, in order to prevent the field name from having the same name as the keyword in the database, define a string variable P in the initial definition, and save the obtained database field modifiers in P, such as double quotation marks, the specific code is omitted

String sql=″update″+TABLE_NAME+″set″+P+″NAME″+P+″=?, ″+P+″DESCRIPTION″+P+″=?, ″+P+″GUID″+P+″=?, ″+P+″ CREATEDDATE″+P+″=?, ″+P+″MODIFIEDDATE″+P+″=?, ″+P+″READONLY″+P+″=?, ″+P+″DISPLAYNAME″+P+″=?, ″+P+″COORDINATORID” +P+"=?, "+P+"SHUXING2"+P+"=?, "+P+"SORTORDER"+P+"=?where"+P+"ID"+P+"=?";//generate update SQL statement

The specific data of each private data is obtained in turn, and the fields in the SQL statement are assigned in turn to realize the data operation of adding records by inserting

}

Public void delete(long id)throws SQLException//Delete the record corresponding to the primary key in the table through the primary key to realize the operation of deleting data

{ Initial definition omitted

sql="delete from"+TABLE_NAME+"where ID="+id+"";

Generate a delete SQL statement, and execute the delete based on the SQL statement, the specific code is abbreviated

}

}

Based on the above method flow, as shown in accompanying drawing 2, an embodiment of the present invention also provides a device for performing data operations in Java applications, which mainly consists of the following processing units,

The first processing unit 201 is configured to obtain structural information of at least one table from the database;

The second processing unit 202 is configured to map the structural information of the above at least one table into a domain object class file and a data access class file;

The third processing unit 203 is configured to perform data operations on the domain object class file based on the functions contained in the data access class file when receiving the data operation instruction.

Based on the above technical solution, in the embodiment of the present invention, after the database connection is established, the structural information of the table is obtained from the database, and the structural information of the table is mapped to a domain object class file and a data access class file, so that the table in the database can be The structural information is mapped to the domain object class file, that is, the structure of the table is converted into the form of source code, the data operation on the table in the database is mapped into a data access class file, and the data operation on the table is converted into the form of source code. When the data operation instruction is received, the data operation is performed on the domain object class file based on the functions contained in the database access class file, so that the records in the table can be automatically obtained without manually reading the original data in the database, thereby improving the object-relational mapping. efficiency and accuracy.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies thereof, the present invention also intends to include these modifications and variations.

Claims (10)

1. A method for performing data manipulation in a Java application, characterized in that, comprising: obtaining structural information of at least one table from the database; Mapping the structural information of the at least one table into a domain object class file and a data access class file; When receiving the data operation instruction, perform data operation on the domain object class file based on the functions contained in the data access class file. 2. The method according to claim 1, wherein obtaining the structural information of at least one table from the database comprises: Obtain the primary key information of the at least one table, if it exists, map the structural information of the at least one table into a domain object class file and a data access class file, and the primary key information is used in the structural information of the at least one table field for unique identification. 3. The method according to claim 1, wherein mapping the structural information of the at least one table into a domain object class file comprises: Define a domain object class for the at least one table, and preset an external interface for obtaining data and setting data in the domain object class; The structural information of the table is mapped to the private data of the domain object class. 4. The method according to claim 1, wherein mapping the structural information of the at least one table into a data access class file comprises: defining a data access class for the at least one table; The functions contained in the data access class are generated based on the structure information of the at least one table. 5. The method according to claim 4, wherein the functions contained in the data access class at least include a data adding function, a deleting function, a modifying function and a querying function. 6. A device for performing data manipulation in a Java application, characterized in that it comprises: A first processing unit, configured to obtain structural information of at least one table from the database; The second processing unit is configured to map the structural information of the at least one table into a domain object class file and a data access class file; The third processing unit is configured to perform data operations on the domain object class file based on the functions contained in the data access class file when receiving the data operation instruction. 7. The device according to claim 6, wherein when the first processing unit acquires the structural information of at least one table from the database, it acquires the primary key information of the at least one table, and if it exists, the The structural information of the at least one table is mapped to a domain object class file and a data access class file, and the primary key information is a field used as a unique identifier in the structural information of the at least one table. 8. The device according to claim 6, wherein the second processing unit maps the structural information of the at least one table into a domain object class file, specifically: Define a domain object class for the at least one table, and preset an external interface for obtaining data and setting data in the domain object class; The structural information of the table is mapped to the private data of the domain object class. 9. The device according to claim 6, wherein the second processing unit maps the structural information of the at least one table into a data access file, specifically: defining a data access class for the at least one table; The functions contained in the data access class are generated based on the structure information of the at least one table. 10. The device according to claim 9, wherein the functions included in the data access class include at least a data addition function, a deletion function, a modification function and a query function.

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