JPAEntityMapper

A simple java application for automating Pojo and JPA Entity code generation.

How it works

The Java program aims to speed up the pojo and entity creation process with the help of the JDBC API. By providing appropriate properties file, the program will generate the designated java source code accordingly.
The program currently supports three types (<TYPE>) of bean production

<TYPE>	Description
entity	JPA Entity Class
pojo	Plain Old Java Object
string-only-pojo	Plain Old Java Object, all member fields are set as String type

To run the program,

• Build a jar with your JDBC database driver.
• Prepare a config.properties file
• Run java -jar <YOUR_JAR_FILE> <YOUR_CONFIG_FILE> in your terminal.

Supported properties

Java .properties file is required and should be supplied to the program by users.

Database Connection Configuration

Property	Description	Mandatory
db.connection.url	A database url of the form jdbc:subprotocol:subname	Y
db.connection.user	The database user on whose behalf the connection is being made	Y
db.connection.password	The user's password	N
db.connection.schema	Target schema in database	N

Remarks: To prevent No suitable driver found error, please pack the database driver jar with the compiled source code if you are going to create a portable jar.

Output File Path Configuration

Property	Description	Mandatory
output.root	Absolute path of the root directory of the output file. Default path is your current working directory	N

Bean Properties Configuration

Properties	Description
bean.package.<TYPE>.X	Package name of the generated java source file. The name will also determine the path of the generated source file. For example: com.jackylaucf.packagename The output file will be placed under output.root\com\jackylaucf\packagename
bean.prefix.<TYPE>.X	Prefix of the bean name
bean.suffix.<TYPE>.X	Suffix of the bean name

Remarks:
(i) <TYPE> refers to the supported types (i.e. either entity or pojo or string-only-pojo)
(ii) X refers to the identifier for linking the properties of the same bean together.
    e.g. bean.package.entity.1, bean.prefix.entity.1 and bean.suffix.entity.1 refer to the configuration of the same entity bean.

Database-Bean Mapping Configuration

Properties	Description
bean.db.map.<TABLE_NAME>	One-to-One mapping of the database table name to Java Bean name. The name of the bean product will be <bean.prefix><BEAN_NAME><bean.suffix>.java
bean.db.id.<TABLE_NAME>	One-to-One mapping of the database table name to its corresponding Id field, which will be annotated with @Id in entity class according to JPA specification. Note that the value of the key-value pair should be the COLUMN_NAME in database, not the field name in entity class.

JPA Annotation Support

Annotation	Attribute(s)
@Entity	nil
@Table	name
@Id	nil
@Column	name

Default Datababase Type to Java Type Mapping

The design is based on java.sql.Types

java.sql.Types	Java data type
ARRAY	java.sql.Array
BIGINT	java.lang.Long
BINARY	byte[]
BIT	java.lang.Boolean
BLOB	java.sql.Blob
BOOLEAN	java.lang.Boolean
CHAR	java.lang.String
CLOB	java.sql.Clob
DATALINK	java.net.URL
DATE	java.time.LocalDate
DECIMAL	java.math.BigDecimal
DOUBLE	java.lang.Double
FLOAT	java.lang.Double
INTEGER	java.lang.Integer
LONGNVARCHAR	java.lang.String
LONGVARBINARY	byte[]
LONGVARCHAR	java.lang.String
NCHAR	java.lang.String
NCLOB	java.sql.NClob
NUMERIC	java.math.BigDecimal
NVARCHAR	java.lang.String
REAL	java.lang.Float
REF	java.sql.Ref
ROWID	java.sql.RowId
SMALLINT	java.lang.Short
SQLXML	java.sql.SQLXML
STRUCT	java.sql.Struct
TIME	java.time.LocalTime
TIME_WITH_TIMEZONE	java.time.OffsetTime
TIMESTAMP	java.time.LocalDateTime
TIMESTAMP_WITH_TIMEZONE	java.time.OffsetDateTime
TINYINT	java.lang.Byte
VARBINARY	byte[]
VARCHAR	java.lang.String

Import the project

The project is built with Gradle. Contributors can import the project via the Gradle option in your IDE